Studio Technologies 348 User Manual

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Model 348 Intercom Station

User Guide

Issue Preliminary 2, November 2019

This User Guide is applicable for serial numbers

M348-00151 and later with main ﬁrmware version 1.05 and later

and STcontroller application version 2.05.00 and later.

www.studio-tech.com

50291-1119, Issue Preliminary 2

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Revision History ........................................................... 4

Introduction ......................................................... Pending

Getting Started .............................................................. 5

Conﬁguration ................................................................ 8

Operation ..................................................................... 15

Technical Notes ............................................................ 25

Speciﬁcations ............................................................... 28

Appendix A ................................................................... 30

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Revision History

Issue Preliminary 2, November 2019:

• Added the Getting Started and Operation sections.

Issue Preliminary 1, September 2019:

• Initial preliminary release.

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Introduction

Pending

Getting Started

What’s Included

Included in the shipping carton are a Model 348 Announcer’s Console and a printed copy of this guide. As a device that can be Power-over-Ethernet (PoE) powered, no external power source is provided. This is because in most applications an Ethernet switch with PoE capability will be utilized. It’s also possible to connect an external source of 12 volts DC to power the Model 348. If this is the case then a power supply would need to be provided separately.

Connections

In this section signal interconnections will be made using the connectors located on the back of the Model 348’s enclosure. In addition, it’s possible that a gooseneck microphone will be attached via the ¼-inch jack located on the top surface of the unit.

One or two Ethernet connections will be made using either standard RJ45 patch cables or etherCON protected RJ45 plugs.

The Ethernet data connection associated with the primary RJ45 connector is compatible with Power-over-Ethernet (PoE). If desired, an Ethernet connection made to the secondary Ethernet connector can provide access to a redundant Dante network. Or it can be utilized as an active “loop through” connection associated with the primary Ethernet connection. If PoE is not going to be utilized, or a redundant source of power is desired, a source of 12 volts DC can be connected by way of a 4-conductor XLR connector.

A dual-channel or single-channel (dual- or single-ear) headset can be connected using a cable-mounted 5-pin male XLR connector. Alternately, a “computer” headset with a 3.5 mm 4-conductor TRRS plug can be used. An electret gooseneck microphone that has an integrated ¼-inch plug can be connected.

One or Two Ethernet Connections

One 1000BASE-T (“GigE”) Ethernet connec tion is required for Model 348 operation. If available and connected to the primary RJ45 connector, this connection can provide both the Ethernet data interface and power for the Model 348’s circuitry. A 10BASE-T connection is not sufﬁcient. A 100BASE-TX connection may be adequate but not optimal.

Figure 1. Model 348 Intercom Station front and back views

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A second 1000BASE-T (“GigE”) connection can be made if redundant Dante is desired. The Model 348’s network conﬁguration must be set for redundant for this functionality to be active. PoE is not supported on the secondary Ethernet connection. The secondary Ethernet port can also be used as a “loop through” port such as would be provided by an Ethernet switch. This requires that the Model 348’s network conﬁguration is set for switched. Switched mode is the default setting but using the secondary port in this mode for applications other than troubleshooting is not recommended. It will function reliably but “daisy chaining” Ethernet signals can limit ﬂexibility and present a failure point.

The Ethernet connections are made by way of two Neutrik etherCON protected RJ45 connectors that are located on the back of the Model 348’s enclosure. These allow connection by way of cable-mounted etherCON connectors or standard RJ45 plugs. The Model 348’s Ethernet interface supports auto MDI/MDI-X so that a crossover cable is not required. The Model 348’s primary Ethernet connection does not enumerate itself as a speciﬁc PoE class. As such, a PoE powersourcing-equipment (PSE) port will consider the device as a class 0 device which could use up to 12.94 watts of power.

External 12 Volts DC Input

An external source of 12 volts DC can be connected to the Model 348 by way of the 4pin male XLR connector which is located on the back panel. While the requirement for the external source is nominally 12 volts, correct operation will take place over a 10 to 18 volt range. The Model 348 requires a maximum of 600 milliamperes (0.6 amperes) at 12 volts DC for correct operation. The DC source should be terminated to a 4-pin female XLR connector with pin 1 negative (–) and pin 4 positive (+).

If an external power source is required, the PS-DC-02 power supply, available as an option from Studio Technologies, is directly compatible with the Model 348. Its AC mains input allows connection to 100-240 volts, 50/60 Hz with an output of 12 volts DC, 1.5 amperes maximum. Its DC output is terminated on a 4-pin female XLR connector.

As previously discussed in this guide, an Ethernet connection that provides powerover-Ethernet (PoE) can serve as the Model 348’s power source. Alternately, an external 12 volts DC source can be connected. For redundancy, both PoE and the external source can be connected at the same time. If both PoE and an external 12 volts DC source are connected, power will be drawn only from the PoE supply. If the PoE source becomes inoperative the 12 volts DC source will provide the Model 348’s power. No interruption in operation will occur during a power source transition.

Headset Connections

The Model 348 allows two different types of headsets to be connected. A 5-pin female XLR connector, located on the Model 348’s back panel, allows connection of a standard broadcast- or intercom-style communications headset. A 3.5 mm 4-conductor TRRS jack, also located on the back panel, allows a computer gaming headset to be directly connected. The Model 348’s two headset connectors are electrically wired in parallel. As such, only one type of headset should be connected at one time.

Headset A

The Model 348 provides a 5-pin female XLR connector that interfaces with the microphone and headphone connections of a single- or dual-ear intercom or broadcast-style headset. The connector is labeled Headset A. Refer to Figure 2 for connection details.

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Figure 2. Headset A connection pinout chart

The microphone input connections are compatible with most unbalanced dynamic or electret (low-voltage DC-powered) microphones. A balanced dynamic microphone should, in most cases, also function correctly if its signal – (low) is connected to Model 348’s mic in –/shield connection. No support is provided for microphones that require P12 or P48 phantom power.

To allow users of stereo (dual-earpiece or “double-muff”) headsets to hear a monaural version of the two headphone output channels does not require special wiring of the 5-pin male XLR mating connector. The headset’s left headphone channel should always be wired to pin 4 and the right headphone channel to pin 5. Software-based conﬁguration choices, discussed later in this guide, can be used to create the desired monaural output. It’s important not to connect together (short) pins 4 and 5 of the headset’s connector as damage to the Model 348’s output circuitry could result.

A monaural (single-earpiece or “single-muff”) headset should be wired such that its headphone is wired only to pin 4; pin 5 should be remain unused. Conﬁguration choices, discussed later in this guide, can be used to create a monaural output.

It’s possible that some Beyerdynamic head

set interconnecting cable assemblies terminate the earpiece’s left and right connections opposite from what the Model 348 and other broadcast equipment require. These cables may terminate the left earpiece to pin 5 of the 5-pin male XLR connector and the right earpiece to pin 4. If this condition is present it will require reversing or “ﬂipping” the two wires in a headset’s connector such that the left earpiece connects to pin 4 and the right earpiece to pin 5.

If a separate microphone and pair of stereo or monaural headphones need to be connected an adapter cable assembly must be fabricated. It would consist of a 5-pin male XLR connector wired to both a 3-pin female XLR connector for the microphone and a ¼-inch or 3.5 mm TRS jack for the headphones. In this scenario the microphone would, in most cases, be a dynamic type as the Model 348 provides only low-voltage DC electret power. Phantom-powered (P12 or P48) microphones would not be compatible. Most hand-held or “stick” microphones are dynamic and should function correctly.

Headset B

The Model 348 also allows direct connection of gaming headsets that are ubiquitous in the personal computer world. The 3.5 mm 4-conductor TRRS jack, labeled Headset B, is compatible with the CTIA™/AHJ conﬁguration standard which has the headphone left channel on the tip connection, the headphone right channel on the ring 1 connection, common on the ring 2 connection, and the microphone on the sleeve connection. Compatible headsets are readily available, typically described as personal computer or gaming headsets. The microphones used in these headsets are electret type which require a low-voltage DC source for operation.

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The Model 348 is able to provide this power and requires only that the appropriate setting in the STcontroller personal computer software application be selected. Refer to Figure 3 for a detailed description of the compatible TRRS plug.

Figure 3. Headset B (TRRS) connection pinout chart

Gooseneck Microphone

The Model 348 allows the connection of a broadcast-standard gooseneck microphone. A threaded combination bushing/3-conductor 1/4-inch jack is incorporated into the top panel of the unit. It’s expected that Studio Technologies will offer a compatible gooseneck microphone (a release date has not been established as of the writing of this guide). The RTS/Telex/Bosch MCP-90-series is also directly compatible and performs very well. The two main requirements for the gooseneck microphone are that it contain an electret microphone and the interconnection be in the form of a ¼-inch 3-conductor plug with integrated threads that have a pitch 7/16-20 UNF.

The 3-conductor ¼-inch jack associated with the Model 348’s bushing has a tip connection that is used for both microphone audio as well as for supplying the low-voltage DC needed for powering the electret microphone. The ring connection is used for the microphone low signal and the sleeve connection is chassis ground. Within the Model 348’s circuitry the ring and sleeve connections are connected together as well as being “tied” (connected) to the chassis.

The Model 348’s gooseneck bushing includes a hex head socket set screw with a thread pitch of 4-40. This allows the gooseneck microphone to be secured into the bushing by simply tightening the set screw against the microphone using a 5/64 hex driver. In many cases, especially in applications where the Model 348 will be moved from venue-tovenue, it will not be optimal for the hex screw to be utilized. This is because the gooseneck microphone may need to be removed and stored for transit. In this case the set screw should be removed and stored.

Conﬁguration

The STcontroller software application is used to conﬁgure the way in which the Model 348 functions. No DIP switch settings or other local actions are used to conﬁgure the unit. This makes it imperative that STcontroller be available for convenient use on a personal computer that’s connected to the related LAN.

Installing STcontroller

STcontroller is available free of charge on the Studio Technologies’ website (www.studiotech.com/stcontroller-application/) and is compatible with personal computers running Windows operating systems that are version 7 and later. STcontroller versions 2.05.00 and later are required to fully support the Model

348. If required, download and install STcontroller onto a designated personal computer. This personal computer must be on the same local area network (LAN) and subnet as the Model 348 units that are to be conﬁgured. Immediately after starting STcontroller the application will locate all the Studio Technologies’ devices that it can control. The one or more Model 348 units to be conﬁgured will appear in the device list. Use the Identify command to allow easy recognition of a speciﬁc Model 348 unit. Double-clicking on a device name

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will cause the associated conﬁguration menu to appear. Review the current conﬁguration and make any changes that are desired.

Parameters

The conﬁgurable functions include:

General menu page:

• Microphone Input – Headset Mic Power

• Microphone Input – Headset Mic Gain

• Microphone Input – Gooseneck Mic Gain

• Headset – Sidetone Level

• Headset – Dim

• Speaker – Source

• Speaker – Dim

• Dante Monitor Outputs – Mode

• Dante Monitor Outputs – Dim

• System – Level Control Position Display

• System – Signal Present Display

• System – LED Intensity

• System – Headset and Monitor Outputs Follow Mic Source

• System – Hot Mic

• System – Monitor A Call Tone Level

• System – Monitor B Call Tone Level

Channel Speciﬁc menu page (independent conﬁguration settings for channels 1-8):

• Button Mode

• Button Function

• IFB Program Dim

• Headset Routing

• Monitor Routing

• Call Indication

Changes made using STcontroller will be immediately reﬂected in the unit’s operation; no Model 348 reboot is required. Each time a change is made the eight buttons on the Model 348’s front panel will ﬂash orange in a distinctive pattern to indicate that a command from STcontroller has been received.

General Menu Page

The following conﬁguration selections are available in the General menu selections tab:

Microphone Input – Headset Mic Power

Choices are Enabled and Not Enabled (box checked or not).

A headset can be connected by way of a 5-pin female XLR connector, labeled Headset A, or a 3.5 mm 4-conductor TRRS jack, labeled Headset B. Enable the headset microphone power check box if the connected headset has an electret microphone which requires a source of low-voltage DC for operation. In virtually all cases gaming or computer headsets that use a 3.5 mm TRRS plug will require microphone power. Most broadcast headsets that terminate on a 5-pin male XLR connector will incorporate a dynamic (non-powered) microphone. In this case do not enable headset microphone power. The on/off status of the headset microphone power is displayed by way of an LED, red in color, that is located on the Model 348’s back panel below the Headset A connector.

Note that the Model 348 cannot supply P12 or P48 phantom power that may be required by balanced condenser (capacitor) microphones. This should not pose an issue as phantom-powered microphones are essentially never associated with communicationsor intercom-style headsets that would be used for Model 348 applications.

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Microphone Input – Headset Mic Gain

Choices are 26 dB, 32 dB, 38 dB, 44 dB, and 50 dB.

To match the requirements of a microphone associated with a headset, the gain of the microphone preampliﬁer can be selected from among ﬁve choices. The selected gain is applied no matter if the headset is connected using the Headset A or the Headset B connector. The compressor active LED, located below the Headset A connector, can act as a guide when setting the microphone preampliﬁer gain. When a voice signal at a normal level is present on the connected headset’s microphone the compressor active LED should light intermittently. If, for example, it rarely lights and the gain is set to 38 dB, it might be a good idea to change the setting to 44 dB. If the compressor LED is lit fully during normal talking and the gain is set for 44 dB or 50 dB, a change to one of the lower values might be warranted. There’s no “hard and fast” rule as to which gain setting is appropriate. But unless otherwise indicated, 38 dB is typically a good initial choice for a headset that uses a dynamic microphone while 32 dB would be appropriate for a headset that includes an electret microphone.

Microphone Input – Gooseneck Mic Gain

Choices are 12 dB, 18 dB, 24 dB, 30 dB, and 36 dB.

When the gooseneck microphone is selected as the Model 348’s active microphone input source the gain of the microphone preampliﬁer will operate from among ﬁve conﬁgurable choices. The compressor active LED, located adjacent to the Headset A connector, can act as a guide when setting the gooseneck preamp gain. When a voice signal at a normal level is presented to the gooseneck microphone the compressor active LED should light intermittently. If, for example,

the LED rarely lights and the gain is set to 18 dB, it might be a good idea to change the setting to 24 dB or 30 dB. If the compressor LED is lit fully during normal talking and the gain is set for 30 or 36 dB, a change to one of the lower values might be warranted.

Headset – Sidetone Level

Choices are Off, Low, Medium Low, Medium, Medium High, and High.

As a user conﬁdence signal, audio from the selected microphone source can be routed to the left and right headphone channels of the headset interface. Sidetone audio can be present whenever an applicable button function is active on any or all of the unit’s eight channels. An applicable function is one that uses either the headset or the gooseneck microphone. These include Talk, Talk with 18 kHz Tone, and IFB. There is no deﬁnitive sidetone level setting. One that provides the user with a sufﬁcient amount of their own talk audio such that they are comfortable should be sufﬁcient.

Headset – Dim

Choices are 0 dB, 6 dB, 12 dB, and 18 dB.

This headset dim function allows the output of the two headset output channels to be “dimmed” (attenuated or reduced in level) in certain circumstances. The function is provided for special applications where the headset’s left and right headphone outputs are connected to an external ampliﬁer or set of ampliﬁed speakers. Normally when a talk function is active on one or a combination of the eight channels the level of the headset’s headphone output channels would not change. As such, the default dim value has been selected to be 0 dB. But if an adapter cable was fabricated and the headset’s headphone output channels were connected to audio playback devices that presented

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audio energy in the same physical vicinity as the active microphone then acoustic feedback is possible. To prevent this from happening selecting a dim conﬁguration of 6, 12, or 18 dB might be desirable.

Speaker – Source

Choices are Off, Monitor A, and Monitor B.

The Model 348 includes an internal loudspeaker of which an audio source can be selected from the two audio “mix” buses that are named Monitor A or Monitor B. These buses contain audio content that is speciﬁed in the individual conﬁguration choices for the eight audio input channels. The speaker can be designated to monitor either of these buses or to not be active.

Speaker – Dim

Choices are 0 dB, 6 dB, 12 dB, and 18 dB.

The output level of the Model 348’s internal loudspeaker will be automatically “dimmed” (attenuated or reduced) whenever a talk or IFB function is active on any of the eight channels. This will help prevent audio from the loudspeaker from interfering with the operation of the selected microphone. Interference could be in the form of unwanted audio content or even acoustical feedback. It’s typical for a user who listens at a higher output level to select a dim value that provides more reduction. In almost all cases a selection of other than 0 dB (no dim) would be appropriate.

Dante Monitor Outputs – Mode

Choices are Off, Pre-Fader, and Post-Fader.

The Model 348 provides two Dante transmitter (output) channels, Monitor A and Monitor B, that are intended for use by other pieces of equipment such as ampliﬁed speakers, audio consoles, and matrix intercom systems.

These two channels can be conﬁgured as a group to function from among three choices.

Off: In this mode the two Dante monitor output channels, Monitor A and Monitor B, will not have audio present on them. The Dante Controller software application will still indicate that the channels are present but no audio will be routed to them from the Model 348’s circuitry.

Pre-Fader: In this mode the audio level and on/off status of Dante monitor output channels will not be impacted by the Model 348’s monitor output rotary encoder. To clarify, neither level adjustment or on/off control will occur. This mode is appropriate when the monitor output channels are going to be utilized by devices that incorporate, if required, level control and/or signal muting capability.

Post-Fader: In this mode the audio level and on/off status of Dante output channels Monitor A and Monitor B will follow the action of the Model 348’s monitor output rotary encoder. This mode is applicable if the device or devices utilizing the Dante monitor outputs require that the level of the source signals be adjusted and/or muted using the Model 348’s resources.

Dante Monitor Outputs – Dim

Choices are 0 dB, 6 dB, 12 dB, and 18 dB.

When a talk or IFB function is active the Model 348 will invoke a dim (attenuation) function. This is designed to help achieve maximum intelligibility and minimize the chance of acoustic feedback when loudspeakers are associated with either or both Dante monitor outputs Monitor A or Monitor B. A dim setting of 0 dB means that the signal level on the Dante monitor outputs will remain unchanged. (The signal will be attenuated by 0 dB which is no attenuation!)

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System – Level Control Position Display

Choices are Off and On.

For user assistance the orange LEDs contained within the eight pushbutton switches can be utilized in a “bar graph” format to give a general indication of the settings of the ten rotary encoders. If enabled, whenever the setting of a rotary encoder is changed the LEDs eight buttons will momentarily light. In most cases it would be advantageous to enable this function.

System – Signal Present Display

Choices are Off and On.

The top surface of the ten rotary encoders can light as an indication of the level of the audio associated with a speciﬁc encoder and related function. This is accomplished by the incorporation of red, green, and blue LEDs located within each encoder. The knob will light green when signal levels are in the normal range, yellow when the signal level is greater than normal, and red when the signal level is at risk of degrading audio performance. Note that even if the Signal Present Display function is disabled (Off) the rotary encoders will still display their normal and muted state using LED illumination.

System – LED Intensity

Choices are Low and High.

The eight pushbutton switches, ten rotary encoders, and mic source selection function have LED indicators associated with them. The LED intensity conﬁguration choice allows the overall intensity of theses LEDs to be selected. Typically, deciding which choice, low or high, is optimal will depend on the amount of ambient light present where the Model 348 is located.

System – Headset and Monitor Outputs Follow Mic Source

Choices are Off and On.

This function allows the muted/unmuted state of the headset’s headphone outputs, the Dante monitor outputs (when conﬁgured for post-fader), and the speaker output to automatically be determined by the user’s choice of which microphone is active. This is a sophisticated function that can prove useful for users who are frequently switching between the headset microphone and the gooseneck microphone. When the function is enabled, whenever the microphone source selection changes from gooseneck to headset the Dante monitor output channels (only when conﬁgured for post-fader) and the speaker will mute. And whenever the microphone source selection changes from headset to gooseneck the headset’s headphone outputs will mute. This helps to ensure that unwanted audio isn’t present as a speciﬁc microphone source is selected.

System – Hot Mic

Choices are Off and On.

A Dante transmitter (output) channel is available which provides a hot mic (always active) function. This can be very useful but has the potential for abuse. This conﬁguration choice ensures that a hot mic signal is only available when an application warrants it.

Note that even if the hot mic output is disabled the channel will appear in the Dante Controller. But in this case no signal would be present on the channel.

System – Monitor A Call Tone Level

Choices are Off, Low, Medium, and High.

The Model 348 is capable of generating an audible alerting signal when a call signal is detected on a channel that is assigned to

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the Monitor A audio bus. This signal consists of repeating sequences of three short bursts of sine wave audio that are output by way of the speaker. The level range can be selected from among three choices as well as being selected for off (muted).

System – Monitor B Call Tone Level

Choices are Off, Low, Medium, and High.

The Model 348 is capable of generating an audible alerting signal when a call signal is detected on a channel that is assigned to the Monitor B audio bus. This signal consists of repeating sequences of three short bursts of sine wave audio that are output by way of the speaker. The level range can be selected from among three choices as well as being selected for off (muted).

Channel Speciﬁc Menu Page

The following conﬁguration selections apply individually to Channels 1-8. They are available in each Channel Speciﬁc menu tab:

Button Mode

Choices are Momentary, Latching, and Hybrid.

The manner in which a button functions can be conﬁgured from among three choices.

Momentary: If this mode is selected a button’s function will normally be inactive and the LEDs associated with the button will not be lit. Whenever a button is pressed the associated function will become active and its green LED will light.

Latching: If this mode is selected the button’s function will alternate between its active and inactive states whenever the button is pressed. The button’s green LED will be lit whenever the associated function is active. Upon Model 348 power up the button will be in its inactive state and its LEDs will not be lit.

Hybrid: This mode is a combination of the Momentary and Latching modes. It’s similar to the way in which pushbutton switches often function on user stations associated with broadcast or production intercom systems. If the button is pressed and held the associated function will be active. It will stay active until the button is released. If the button is momentarily “tapped” the status of the function will change, either from inactive-toactive or from active-to-inactive. The button’s green LED will be lit whenever the function is active. Upon Model 348 power up the button will be in its inactive state and its LEDs will not be lit.

Button Function

Choices are Talk, Talk with 18 kHz Tone, All Talk, Call, IFB, All IFB, 18 kHz Tone, 20 kHz Tone, and Disabled.

Talk: In this mode whenever the function is active microphone audio will be sent out the associated Dante audio output (transmitter) channel. This mode will typically be used as part of an intercom or stage announce (SA) implementation. The sidetone function will be active whenever the talk function is active.

Talk with 18 kHz Tone: This mode is similar to the Talk mode except that an 18 kHz sine wave tone is added (summed) with the microphone audio. It is intended for use in REMI/At-Home applications where a “pilot tone” needs to be sent along with talk audio. This is speciﬁcally provided for use with the tone-activated (“TOX”) IFB function in the Studio Technologies’ Model 5422 Dante Intercom Audio Engine product. The sidetone function will be active whenever the Talk with 18 kHz Tone function is active

All Talk: In this mode the associated button will activate all Model 348 channels that are conﬁgured for Talk or Talk with 18 kHz Tone.

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Call: In this mode pressing the associated button will cause a 20 kHz sine wave call tone to be sent out any Model 348 channels that are both conﬁgured for the Talk or the Talk with 18 kHz Tone modes and are currently active.

IFB: In this mode the Model 348 channel will be used to create a broadcast-type interrupted foldback (IFB) or talent cue source. When the function is not active audio from the corresponding Dante IFB program audio input channel will be routed to the corresponding Dante output channel. When the function is active the microphone (interrupt) audio will be combined with the IFB program audio source. The IFB program audio source will be attenuated, fully muted, or not changed, following the IFB Program Dim Level conﬁguration. The sidetone function will be active whenever the IFB function is active

Disabled: In this mode the button will not perform a function. Pressing it will cause the button’s red LED to ﬂash, indicating that it has been disabled.

IFB Program Dim

Choices are 0 dB, 5 dB, 10 dB, 15 dB, 20 dB, and Full Mute.

This value determines the amount of attenuation that will be applied to the Dante program audio input (receive) source when the IFB function is active for this channel. 0 dB will conﬁgure the channel to have no change in program audio level. The talk audio will simply be added (summed) with the program audio. When Full Mute is selected the IFB program audio source level will fully attenuate and be replaced by the talk (interrupt) audio. In most broadcast applications the default value of 15 dB will be appropriate.

All IFB: In this mode pressing the associated button will cause all the channels conﬁgured for IFB to become active. Note that an audio source routed to the associated IFB program input will be continually routed to the channel’s associated audio output. This would typically be the non-interrupt audio source. This is provided such that a timing match can be made between the IFB and non-interrupt output channels.

18 kHz Tone: In this mode an 18 kHz sine wave tone will be sent out the associated Dante output (transmitter) channel. This function can be useful for triggering other functions associated with devices such as the Model 5422 Dante Intercom Audio Engine.

20 kHz Tone: In this mode a 20 kHz sine wave tone will be sent out the associated Dante output (transmitter) channel. This function can be useful for triggering other functions associated with devices such as the Model 5422 Dante Intercom Audio Engine.

Headset Routing

Choices are Off, Left, Right, and Left and Right.

The Dante input (receiver) audio associated with a Model 348 channel can be monitored using the headset’s headphone outputs. The destination channel(s) can be conﬁgured as desired.

Off: In this mode the input audio will not be sent to either the left or right headphone output channels.

Left: In this mode the input audio will be sent to only the left headphone output channel.

Right: In this mode the input audio will be sent to only the right headphone output channel.

Left and Right: In this mode the input audio will be sent to both the left and right headphone output channels.

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Monitor Routing

Choices are Off, Monitor A, Monitor B, and Monitor A and B.

The Dante input (receiver) audio associated with a Model 348 channel can be monitored using the Dante monitor output channels. The destination channel(s) can be conﬁgured as desired.

Off: In this mode the input audio will not be sent to either of the monitor output channels.

Monitor A: In this mode the input audio will be sent only to the Monitor A output channel.

Monitor B: In this mode the input audio will be sent only to the Monitor B output channel.

Monitor A and B: In this mode the input audio will be sent to both the Monitor A and the Monitor B output channels.

Call Indication

Choices are Off, Visual Only, and Visual and Audible.

In addition, sequences of audio tones will be output by the monitor loudspeaker. The audio tones will also be sent to the Monitor A and/or Monitor B Dante output if the channel’s audio input has been so conﬁgured.

Operation

At this point all connections and conﬁguration steps should have been completed and everything should be ready for Model 348 operation to commence. In most cases an Ethernet connection with Power-over-Ethernet (PoE) capability will have been made to the primary Ethernet connector. Alternately, a source of 12 volts DC may have been connected to provide power for the Model 348. A stereo or monaural headset will typically be interfaced using either the Headset A or Headset B connector. A gooseneck microphone may have been installed into the bushing/connector assembly on the top of the Model 348’s enclosure.

A visual and audible indication can be provided whenever a call signal has been detected on a Model 348 channel. The visual indication is provided by way of the pushbutton’s LED indicators. The audible indication is provided by way of the Model 348’s internal loudspeaker and, if conﬁgured appropriately, Dante monitor outputs.

Off: In this mode no visual or audible indication in response to a call signal will be generated.

Visual Only: In this mode when a call signal is detected the orange LED in the associated pushbutton will ﬂash on and off.

Visual and Audible: In this mode when a call signal is detected the orange LED in the associated pushbutton will ﬂash on and off.

Using the Studio Technologies’ STcontroller software application the Model 348’s operating conﬁguration should have been selected to meet the needs of the speciﬁc application. An extensive range of conﬁgurable parameters are available, making the way in which a speciﬁc Model 348 operates be quite unique.

Using the Dante Controller software application the Model 348’s network interface and audio channel conﬁguration should have been made. In this way, the operational characteristics of the unit’s two Ethernet interfaces will have been selected. In addition, some or all of the eleven Dante audio output channels (Dante transmitter channels) and sixteen Dante audio input channels (Dante receiver channels) will have been routed, by way of Dante “subscriptions,” to the receiver and transmitter channels on associated Danteenabled equipment.

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Eight of the Dante audio output channels are associated with the functioning of the eight pushbutton switches. Two additional Dante audio output channels are speciﬁed as monitor outputs. And the ﬁnal Dante output channel provides a Hot Mic output function. Eight of the Dante audio input channels are assigned to the monitor section. Each of these inputs has an associated rotary encoder to adjust its signal level. Eight more of the Dante audio input channels serve as IFB program inputs. These are used in conjunction with the eight pushbutton switches when they are conﬁgured for IFB operation.

Initial Operation

The Model 348 will start to function as soon as a Power-over-Ethernet (PoE) or a 12 volts DC power source is connected. However, it may take up to 30 or 40 seconds for full operation to commence. Upon initial power up the various status LEDs, located on the back panel, and the mic source, rotary encoder, and pushbutton LEDs on front panel will light as the internal processors, Ethernet network, and Dante connections begin to function. The various LEDs will then become operational, displaying the status of their associated functions.

Power Status LEDs

An LED labeled PoE is located below the pri mary Ethernet connector on the Model 348’s back panel. It will light green if an Ethernet signal that is providing PoE power is connected. An LED labeled DC is located below the 4-pin XLR connector that is provided for connection to a DC power source. It will light green if a source of 10 to 18 volts DC is connected. If both the PoE and DC LEDs are lit then the PoE Ethernet connection will be providing power to operate the Model 348. The DC power supply will be ready as a “hot standby” should the PoE source fail.

Ethernet Status LEDs

A total of four Ethernet status LEDs are locat

ed below the two etherCON RJ45 connectors on the Model 348’s back panel. A LINK ACT LED will light green whenever an active connection to an Ethernet network has been established. It will ﬂash in response to Ethernet data packet activity on that interface. A GbE LED will light orange when a gigabit Ethernet connection is present on that interface.

Dante Status LEDs

The SYS and SYNC LEDs, also located on the back panel, display the operating status of the Dante interface and its associated network activity. After lighting red and green as part of the power-up sequence the SYS LED will light red to indicate that the Dante interface is not ready. After a short interval it will light green to indicate that it is ready to pass data with another Dante device. The SYNC LED will also be part of the power-up sequence and will light red when the Model 348 is not synchronized with a Dante network. It will light solid green when the Model 348 is synchronized with a Dante network and an external clock source (timing reference) is being received. It will slowly ﬂash green when this speciﬁc Model 348 is part of a Dante network and is serving as the clock master. It’s possible that up to 30 or 40 seconds may be

required for the SYNC LED to reach its ﬁnal state.

How to Identify a Speciﬁc Model 348

Functions within the Dante Controller and STcontroller software applications allow speciﬁc Model 348 units to be identiﬁed. Each application provides an “eyeball” icon that when clicked will activate the Identify function. When Identify is selected it will send a command to a speciﬁc Model 348 unit. On that unit the red LEDs associated with the

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eight pushbutton switches will “ﬂash” in a unique sequence four times; the actual on/off status of the buttons will not change. In addition, the LINK ACT and GbE status LEDs, located directly below the two RJ45 connectors on the back panel, will slowly ﬂash. After a few seconds the LED identiﬁcation patterns will cease and normal Model 348 pushbutton LED, and Ethernet status LED operation will resume.

Headset Microphone Power Status LED

An LED indicator is located on the back panel adjacent to the Headset A connector. It is labeled MIC PWR and will light red whenever the headset’s microphone electret power source is active and providing low-voltage DC power to the microphone connections on the Headset A and Headset B connectors.

Compressor Active LED and Mic Preamp Gain

An LED indicator, orange in color, is located on the back panel adjacent to the Headset A connector. It is labeled COMP and displays the status of the microphone audio compressor function. This function controls the dynamic range of the audio signal associated with the selected microphone input source. (This will be either the headset’s microphone or the gooseneck microphone.) The compressor LED will light whenever the input level from the active microphone, along with the conﬁgured microphone preampliﬁer gain, is such that the dynamic range of the signal is being actively controlled. It’s perfectly acceptable for this LED to light intermittently whenever a user is talking at a normal voice level into an associated microphone. But if the COMP LED lights solid while a user is talking at a normal voice level this will typically indicate that the microphone preampliﬁer

gain setting should be reduced. Conversely, if the COMP LED almost never lights when normal talking is taking place it’s possible that changing the gain to a higher value would be beneﬁcial. Note that due to the design of the circuitry the compressor active LED will function whether or not the main or talkback functions are active.

LED Intensity

On the Model 348’s front panel there are LED indicators associated with the eight channel pushbutton switches, the mic source status display, and the ten rotary encoders. Using the STcontroller application the intensity of these LEDs, as a group, can be conﬁgured from among two choices, low or high. If during operation the LED intensity isn’t perceived to be optimal the conﬁguration choice in STcontroller should be checked and revised if necessary. In most cases the default intensity, high, will be applicable. However, the low LED intensity conﬁguration choice may be superior in applications where the ambient light in the Model 348’s location is also low.

Mic Source Selection

A small, round pushbutton switch located on the upper-left side of the front panel is used to select which microphone source is active. This audio source will be used as needed by the Model 348’s talk, sidetone, and IFB functions. The mic source choices are Headset and Gooseneck. Two green LEDs, adjacent to the pushbutton switch, indicate which microphone source is currently active. A Model 348 power-down/power-up cycle will return the microphone source to its last selection.

A system conﬁguration choice in STcontroller allows the microphone source selection to impact the on/off status of the headset’s headphone outputs and the monitor output channels. Named Follow Mic Source, this selection is provided to assist users who frequently

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change between using the headset’s microphone and the gooseneck microphone. The default conﬁguration is for this feature to be disabled (Off). When this conﬁguration choice is enabled (On) and Gooseneck is selected as the microphone source the headset’s headphone outputs will mute. When the headset’s microphone is selected as the source the monitor outputs and associated loudspeaker will also mute. In both cases the mute state that was automatically enabled can be overridden by pressing the knob on the applicable rotary encoder.

Each microphone source, headset and gooseneck, has an independent preampliﬁer gain conﬁguration parameter which is accessible by way of the STcontroller software application. If switching between the two microphone sources results in a greatly different overall microphone audio levels then the conﬁguration choice for the microphone preampliﬁer gains should be reviewed and revised as appropriate.

Hot Mic Output

A Dante output channel has been designated as a hot mic output. This output can be enabled or disabled using the STcontroller software application. The default setting is Disabled. When enabled the selected microphone source, headset or gooseneck, will be permanently connected to the Hot Mic Dante output channel. No pushbutton or encoder operation is required for the audio associated with the selected microphone source to be active on the Hot Mic Dante output. This can be a useful feature but it’s important that user be made aware that there is no means of turning off (“muting”) this output. They must assume that other personnel will be continually monitoring audio associated with their selected microphone.

Button Action

The action of each of the eight pushbutton switches can be individually conﬁgured using STcontroller. There are three button action choices available and a description of them follows:

Momentary

If this mode is selected the pushbutton’s as

sociated function will become active whenever the button is pressed and held. When the function is active the pushbutton’s green LEDs will be lit.

Latching

If this mode is selected the function associated with the button will alternate between its active and inactive states whenever the pushbutton is momentarily pressed (“tapped”). The pushbutton’s green LEDs will be lit whenever the function is active. Upon Model 348 power up the button’s associated function will be in its inactive state.

Hybrid

This mode is a combination of the momentary and latching actions. If the pushbutton is pressed and held the associated function will become active until the pushbutton is released. If the pushbutton is momentarily pressed (“tapped”) the function will change state. The pushbutton’s green LEDs will be lit whenever the function is active. Upon Model 348 power up the pushbutton’s associated function will be in its inactive state.

Button Function

The button function conﬁguration is used to select the overall manner in which a speciﬁc pushbutton channel operates. Each pushbutton can be independently conﬁgured from among nine choices. A careful study of how each of these choice’s function will highlight the variety of applications a Model 348 can support. While the product’s title includes the

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text “Intercom Station,” that far from covers all the applications in which the unit can provide value.

Talk

When a button function has been conﬁgured for Talk and the pushbutton is pressed or the function is active then audio from the selected microphone source will be connected to the associated Dante output channel. The LED in the pushbutton switch will light green whenever the function is active. When the pushbutton is not pressed nor currently active no audio will be present on the associated Dante output channel. The associated Dante IFB program input channel will not be utilized.

Talk with 18 kHz Tone

When a button function has been conﬁgured for Talk with 18 kHz Tone and the pushbut

ton is pressed or the function is active then audio from the selected microphone source, mixed with an 18 kHz sine wave tone at a level of –20 dBFS, will be connected to the associated Dante output channel. The LED in the pushbutton switch will light green whenever the function is active. When the pushbutton is not pressed nor the function is active no audio (voice or tone) will be present on the associated Dante output channel. The associated Dante IFB program input channel will not be utilized.

All Talk

When a button function has been conﬁgured for All Talk and the pushbutton is pressed or the function is active then all other buttons that are conﬁgured for Talk or Talk with 18 kHz will become active. The LED in the pushbuttons conﬁgured for All Talk will light green whenever the function is active. The associated Dante output channel will not be utilized, nor will the associated Dante IFB program input channel.

Call

When a button function has been conﬁgured for Call and the pushbutton is pressed or the function is active then all other pushbuttons that are both conﬁgured for Talk or Talk with 18 kHz and are active will have a 20 kHz sine wave tone at a level of –20 dBFS added to their associated Dante output channels. The LED in the pushbutton conﬁgured for Call will light orange whenever the function is active. The buttons that are conﬁgured for Talk or Talk with 18 kHz that are active will ﬂash orange. The associated Dante output channel will not be utilized, nor will the associated Dante IFB program input channel.

IFB

When a button function has been conﬁgured for IFB a broadcast-type interrupted foldback (IFB), also referred to an interruptible foldback or a talent cue signal, will be created. When the pushbutton is not pressed or active the associated Dante IFB program input source will be connected to the associated Dante output channel. The Dante IFB program input source is connected to the Dante output channel at unity level (no gain or attenuation will be applied to the signal). When the pushbutton is pressed or the function is active then two things will occur. The ﬁrst is that the Dante IFB program input source will be acted on following the conﬁguration for the IFB program dim value. This will result in the signal level either staying the same, dropping in level (being attenuated) by one of four values, or completely muting. The second action is that the selected microphone source will be added (summed) with the Dante IFB program input source and then routed to the associated Dante output channel. The pushbutton will light green when the function is active.

The IFB function creates a talent cueing signal that is sometimes referred to as Interrupt, Program with Interrupt, or Program + Interrupt.

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The selected microphone source (headset or gooseneck) serves as the interrupt source. The Dante IFB program input signal is considered to be the program audio source. Note that there is no means provided within the Model 348 to adjust the level of the IFB program input source. This should not be considered an operational limitation as typically an audio console will provide the program audio source at a nominal line level. As such, any needed adjustment of the signal level can be performed on the console.

All IFB

When a button function has been conﬁgured for All IFB and the pushbutton is pressed or the function is active then all of the other but tons conﬁgured for IFB will become active. The LED in the pushbutton will light green whenever the function is active. The Dante IFB program audio input will continuously be connected to the associated Dante output channel. This is provided as a Program or Program Only audio signal for use in a dualchannel IFB implementation. Typically, the ﬁrst channel of a dual-channel IFB signal or “feed” is referred to as Interrupt or Program with Interrupt while the second channel is referred to as Program or Program Only. Using this Dante input-to-output loop-through arrangement can be valuable as any latency (time delay) that occurs within the Model 348’s IFB function will be matched in the All IFB signal path. In this way, the Model 348’s audio latency will essentially be matched in the program with interrupt and program-only audio paths.

18 kHz Tone

When a button function has been conﬁg

ured for 18 kHz Tone the channel’s operation is very simple. When the pushbutton is pressed or the function is active an 18 kHz sine wave tone at –20 dBFS is connected

to the associated Dante output channel. No voice or IFB program audio is connected to the associated Dante output channel.

20 kHz Tone

When a button function has been conﬁgured for 20 kHz Tone the operation is very simple. When the pushbutton is pressed or the function is active a 20 kHz sine wave tone at –20 dBFS is connected to the associated Dante output channel. No voice or IFB program audio is connected to the Dante output channel.

Disabled

When a button function has been conﬁgured for Disabled no audio action will take place.

If the pushbutton is pressed it will ﬂash red to indicate that this speciﬁc button is disabled. No voice, tone, or IFB program audio is connected to the Dante output channel.

Using the Rotary Encoders

On the front panel of the Model 348 there are ten rotary encoders. Eight of the rotary encoders are located above the channel pushbutton switches. They are associated with the Dante audio input channels. A single rotary encoder is associated with the level of the headset’s headphone outputs. And ﬁnally, a rotary encoder is associated with the monitor section, impacting the internal loudspeaker and, if conﬁgured for post-fader, the two Dante monitor output channels. Each encoder has 24 steps (“clicks” or “detents”) for each 360 degrees of rotation. Turning an encoder knob clockwise by 1 and 1/3 rotations (32 steps or 480 degrees) is required to change from audio minimum to audio maximum. (As expected, the same action occurs in reverse: when rotating an encoder counterclockwise by 32 steps the audio level will change from maximum to minimum.) Pressing on the top of an encoder’s knob will activate a momentary switch function that is used to mute the associate audio signal(s).

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The top surface of each encoder’s knob is translucent and RGB (red-green-blue) LEDs within each encoder can display a wide range of colors. An encoder knob that is dimly lit with a dark blue color indicates that its associated function is active. This provides a physical identiﬁcation of each encoder’s location when a Model 348 is being used in an environment where the ambient light is very low or nonexistent. An encoder knob that’s lit dark blue could be considered as being in its default state. It’s important to note that there could be a signal present on the associated Dante audio input but unless the Signal Present Display conﬁguration has been enabled the encoder’s knob will remain dark blue.

An encoder knob that is lit with a purple color indicates that its associated function has been muted. To mute or unmute a function simply requires that the associated encoder knob be pressed and released (“tapped”).

For user assistance, the LEDs associated with the eight channel pushbutton switches can be conﬁgured to indicate the approximate position of each of the rotary encoders. For this to be active the Level Control Position Display conﬁguration within STcontroller must be On (it is by default). There are two means of observing the level setting associated with each rotary encoder. One is to press and hold an encoder’s knob. One or more of the eight pushbutton switches will light orange. If a function is muted (minimum level) then pushbutton 1 will ﬂash orange. If a function is at full (maximum) level then pushbuttons 1 through 7 will light orange and pushbutton 8 will ﬂash orange. The display of the level will continue until the encoder’s knob is no longer pressed. The second method of displaying an encoder’s level setting is to rotate an encoder knob at least one step in the clockwise or counterclockwise

direction. The pushbutton switches will light orange to display the approximate level and then hold for approximately one second past when the last encoder change is made.

As previously mentioned, 32 encoder steps (1 and 1/3 full rotations) are required to move between the minimum and maximum levels. Each pushbutton switch will light orange in response to an encoder being within a group of four steps. So pushbutton 1 will light when an encoder has been set to steps 1-4, pushbutton 2 will light when an encoder has been set to steps 5-8, etc. Step 1 is considered to be mute and causes pushbutton switch 1 to ﬂash orange. Step 32 is the maximum level and causes pushbuttons 1 through 7 to light orange and pushbutton 8 to ﬂash orange.

The RGB (red-green-blue) LEDs within the encoders can shine through the end of the associated knobs and provide a visual indication of the level of signal associated with the encoders’ functions. For the signal level to be displayed on the knob ends requires that the Signal Present Display conﬁguration in STcontroller be selected for On. This is the default condition and is appropriate for most applications.

The encoder knobs labeled 1 through 8 will light in response to the level of signals connected to the associated Dante inputs. As such they are pre-encoder (also known as “pre-fader”) which means that the LEDs will respond to input signal levels prior to any gain or loss that may be selected by adjusting the associated encoder. An encoder’s knob will light green to indicate that a signal is present on the associated Dante input with a level of –40 dBFS to –16 dBFS. The knob will light yellow when the signal has a level of –15 dBFS to –5 dBFS. And the knob will light red when the signal has a level that meets or exceeds –5 dBFS.

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The encoder knob associated with the headset’s headphone output and the encoder knob associated with the monitor function will also light at the same level thresholds as the eight Dante inputs. But there’s a major difference as their function’s will be post-encoder (also known as “post-fader”). In this way, the level indication on these two encoder knobs will reﬂect the setting of their associated encoder. This will prove useful when adjusting the encoders to achieve the desired level settings.

If an encoder is placed in its mute state by pressing the encoder’s knob then the knob cap will light purple and the level display will not occur. Also, when mute is active any changes to an encoder’s position will not be recognized. To clarify, if an encoder knob is lit purple then any rotations of the knob will not be recognized.

Headset Operation

A headset with either a 5-pin XLR plug (male) or a 4-pin 3.5 mm TRRS plug can be connected with one of the headset connectors on the Model 348’s back panel. The connectors are labeled Headset A and Headset B.

Headset Microphone

On Headset A and Headset B the electri cal connections for the microphone input and two headphone output channels are internally wired together (“multed” or connected in parallel). As such, only one headset should be connected at a time. If power for an electret microphone that’s part of the connected headset is required it should have been selected in the STcontroller application. The red LED, label MIC PWR and located adjacent to the 5-pin XLR connector, will be lit to indicate that low-voltage DC has been applied to the microphone connections on both headset connectors A and B.

Headset Headphone Outputs

Settings within STcontroller select which of the eight Dante input channels are routed, by way of rotary encoders 1 through 8, to the headset’s headphone left and right output channels. The rotary encoder labeled HEADSET on the front panel adjusts the level of both headphone output channels. As previously discussed, the headset’s headphone output can be muted by pressing the headset encoder knob. The knob will light purple to indicate that both headphone output channels are muted. If the signal present function is enabled in STcontroller the encoder’s knob, when it is not muted, will light green, yellow, or red to indicate the overall headset headphone output channel level. (It will follow a monoaural version of the left and right headset headphone outputs.) It’s acceptable that the knob lights yellow on occasion but lighting red would indicate that either or both headphone output channels are at risk for signal clipping (distortion due to insufﬁcient audio headroom to handle the signal level). This would indicate that distortion may be present due to insufﬁcient audio headroom.

Sidetone

A sidetone function is available for assist

ing headset users in hearing audio from the currently active microphone. The sidetone function will be active whenever one or more buttons conﬁgured for Talk, Talk with 18 kHz, or IFB functions are active. Using STcontroller the sidetone level is conﬁgured from among ﬁve values as well as mute. By default, sidetone is enabled at a conﬁgured level of medium. Once conﬁgured in STcontroller the sidetone level is ﬁxed and cannot be changed by the user. This is implemented in this manner such that a user will always be provided with a reference level as to how much microphone audio signal is being sent out the Dante output channels.

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Headset Headphone Output Dim

Following an STcontroller conﬁguration set

ting the headset’s headphone output level can reduce in level (“dim” or be attenuated) when one or more of the eight button functions are active. Enabling the headphone dim conﬁguration is provided for the rare situation where the headset’s headphone output channels are being used as line-level analog outputs. This could be useful, for example, when connecting to the analog inputs on ampliﬁed loudspeakers. If a headset is being used and the headset dim function is enabled then it’s probably incorrectly conﬁgured and needs to be revised in STcontroller.

Headset Headphone Output Automatic Mute

As previously discussed in this guide a setting in STcontroller allows the headset’s headphone output channels to automatically mute when the microphone source is selected for Gooseneck. (By default, this function is not enabled.) This can be useful for users who frequently change from using a headset and associated microphone to using a gooseneck. The unneeded output, either the headset’s headphone outputs or internal speaker/post-fader monitor output channels, will automatically mute as the microphone source is switched. It’s simple to observe this action by noting that the headset encoder’s knob will turn purple when the gooseneck microphone is selected as the source. (Conversely, the monitor encoder knob will turn purple when the microphone source is selected for Headset.) The muting of the headset’s headphone outputs can be temporarily overridden by simply pressing the headset encoder knob.

Monitor Output

The Model 348’s monitor section consists of a rotary encoder, two Dante audio output

channels, and an internal loudspeaker. These resources allow a wide range of listening scenarios to be implemented.

Monitor Sources and Rotary Encoders

Settings within STcontroller select which of the eight Dante input channels are routed, by way of the eight rotary encoders, to the two monitor output channels. Mixing (summing) of the selected sources creates the two monitor audio signal buses. The rotary encoder, labeled Monitor, on the right side of the front panel, adjusts the level of both the internal loudspeaker and, if conﬁgured for post-fader (level following the setting of the encoder), the Dante monitor output channels.

As previously discussed, the loudspeaker and post-fader monitor output channels can be muted by pressing the monitor encoder’s knob. The knob will light purple to indicate that mute is active. If the signal present function is enabled in STcontroller the encoder’s knob, when it is not muted, will light green, yellow, or red to indicate the overall monitor output level. (It will respond to a monoaural version of the two monitor channels.) During normal operation it’s acceptable that the knob lights yellow on occasion. But frequently lighting red would indicate that the level of either or both monitor output channels is too high and presents a risk that signal clipping will occur.

Dante Monitor Output Channels

As previously discussed, two Dante audio output channels are associated with the Model 348’s monitor section. Several conﬁguration settings in STcontroller impact the way in which the monitor output channels function. Eight independent conﬁguration choices select which of the eight Dante audio inputs are routed to either or both of the monitor output channels. Another conﬁguration setting determines if the level of the

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monitor output channels will be impacted by the monitor rotary encoder. The Dante monitor outputs can be conﬁgured for post-fader making their signal level respond to the setting of the Model 348’s monitor level encoder. If conﬁgured for pre-fader the level of the monitor output channels will not be impacted by the action of the rotary encoder. This is provided for applications where the monitor output channels will be routed to devices that include level control capability. Such devices would include audio consoles, matrix intercom systems, and ampliﬁed loudspeakers that contain integrated level controls.

Another STcontroller conﬁguration setting allows the monitor output channels to be automatically dimmed (attenuated) when any of the functions associated with the eight pushbutton switches are active. This can help to ensure that audio signals being reproduced by externally connected ampliﬁed speakers don’t interfere with audio that’s being picked up by selected microphone.

Monitor Output Automatic Mute

As previously discussed twice in this guide, a conﬁguration setting in STcontroller allows the loudspeaker and post-fader monitor output channels to automatically mute when the microphone source is selected for Headset (by default, this function is not enabled). This can be useful for user’s who frequently change from using a headset and associated microphone to using a gooseneck microphone and internal loudspeaker and/or monitor output channels. The unneeded output, either the headset’s headphone outputs or the internal loudspeaker/post-fader monitor output channels, will automatically mute as the microphone source is switched. It’s simple to observe this action by noting that the monitor encoder’s knob will light purple when the microphone source is selected for Headset. The muting of the loudspeaker speaker and post-fader monitor output channels can be temporarily overridden by pressing the monitor encoder knob.

Loudspeaker Output

The Model 348 contains a small loudspeaker which is located on the right side of the front panel. A conﬁguration setting in STcontroller selects the audio source or sources that are to be sent to the loudspeaker. The choices are Monitor A or Monitor B. Another conﬁguration selection allows the loudspeaker level to automatically be dimmed (attenuated) when any of the functions associated with the eight pushbutton switches are active. This can help to ensure that audio signals being reproduced by the loudspeaker don’t interfere with audio being picked up by the selected microphone. Use the monitor rotary encoder knob to adjust the level of the loudspeaker. Push the rotary encoder’s knob to mute or unmute the loudspeaker (and postfader monitor outputs) as desired.

Call Indication

The Model 348 can be conﬁgured to respond to call signals that are present in any of the eight Dante input channels. A 20 kHz tone that’s in-band (part of the audio content in a channel) will be detected as a call signal. Any channel that is conﬁgured for Talk or Talk with 18 kHz Tone will respond to a call signal using either a visual-only indication or by way of both a visual and an audible (audio tone) indication. The visual indication is displayed by ﬂashing the associated pushbutton switch’s orange LED. The audible indication is created by sending a continuous 3-burst sequence of 524 Hz sine wave tone to both the Dante monitor output channels and the internal loudspeaker. Using STcontroller there are individual conﬁguration choices that allow the overall level of the call tones to be independently selected for Monitor A and Monitor B.

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Technical Notes

IP Address Assignment

By default, each of the Model 348’s Ethernet interfaces will attempt to automatically obtain an IP address and associated settings using DHCP (Dynamic Host Conﬁguration Protocol). If a DHCP server is not detected an IP address will automatically be assigned using the link-local protocol. This protocol is known in the Microsoft® world as Automatic Private IP Addressing (APIPA). It is also sometimes referred to as auto-IP (PIPPA). Link-local will randomly assign a unique IP address in the IPv4 range of 169.254.0.1 to 169.254.255.254. In this way, multiple Dante-enabled devices can be connected together and automatically function, whether or not a DHCP server is active on the LAN. Even two Dante-enabled devices that are directly interconnected using an RJ45 patch cord should correctly acquire IP addresses and be able to communicate with each other.

The Model 348’s IP address(es) and related network parameters can be manually set for a ﬁxed (static) conﬁguration using the Dante Controller software application. While this is a more involved process than simply letting DHCP or link-local “do their thing,” if ﬁxed addressing is necessary then this capability is available. But in this case, it’s highly recommended that every unit be physically marked, e.g., directly using a permanent marker or “console tape,” with its speciﬁc static IP addresses. If knowledge of a Model 348’s IP addresses has been misplaced there is no reset button or other method to easily restore the unit to a default IP setting.

In the unfortunate event that a speciﬁc Model 348’s IP address is “lost,” the Address Resolution Protocol (ARP) networking command can be used to “probe” devices on a network for this information. For example, in

Windows OS the arp –a command can be used to display a list of LAN information that includes MAC addresses and corresponding IP addresses. The simplest means of identifying an unknown IP address is to create a “mini” LAN with a small PoE-enabled Ethernet switch connecting a personal computer to the Model 348. Then by using the appropriate ARP command the required “clues” can be obtained.

Optimizing Network Performance

For best Dante audio-over-Ethernet performance a network that supports VoIP QoS (voice-over-internet-protocol quality of service) capability is recommended. This can typically be implemented on virtually all contemporary managed Ethernet switches. There are even specialized switches that are optimized for entertainment-associated applications. Refer to the Audinate website (www.audinate.com) for details on how to optimize a network for Dante applications.

Application Firmware Version Display

The STcontroller software application is used to display the version numbers of the Model 348’s three ﬁrmware (embedded software) components. These are the main ﬁrmware, the secondary ﬁrmware, and the FPGA ﬁrmware. The main ﬁrmware is used by the main microcontroller integrated circuit to implement most of the Model 348’s general operating actions. The secondary ﬁrmware is used by a second, less-sophisticated microcontroller integrated circuit that controls and reports on the actions of the rotary encoders, the pushbutton switches, and the LEDs associated with them. The FPGA ﬁrmware is used by the ﬁeld-programmable-gate-array integrated circuit in which all audio processing is performed.

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To observe the ﬁrmware version numbers, begin by connecting the Model 348 unit to a network. Connect an external source of 12 volts DC if a PoE Ethernet connection has not been made. The unit will power up and begin to function. Start STcontroller, review the list of identiﬁed devices, and select the speciﬁc Model 348 from which you want to determine its application ﬁrmware versions. Then select Version under the Device tab. A dialog will then display that will provide a host of useful information. This will include the ﬁrmware versions as well as details on the Dante interface ﬁrmware.

Application Firmware Update Procedure

It’s possible that updated versions of the three ﬁrmware (embedded software) ﬁles that are utilized by the Model 348’s two microcontroller and one FPGA (ﬁeld-programmablegate-array) integrated circuit will be released to add features or correct issues. Refer to the Studio Technologies’ website for the latest ﬁrmware ﬁles. The unit has the ability to load revised ﬁles into non-volatile memory by way of a standard USB ﬂash drive. The Model 348 implements a USB host function and provides access by way of a type A receptacle located on the back panel. The Model 348 updates its ﬁrmware using ﬁles named M348.bin for the main ﬁrmware, M348sec.bin for the secondary ﬁrmware, and BWY.bit for the FPGA ﬁrmware.

The update process begins by preparing a USB ﬂash drive. The ﬂash drive doesn’t have to be empty (blank) but must be in the personal-computer-standard FAT32 format. One, two, or all three of the ﬁrmware ﬁles can be automatically loaded at the same time. In the root directory, save the desired new ﬁrmware ﬁle(s), ensuring that the required name or names are speciﬁed. For the main ﬁrmware

the ﬁle name must be M348.bin. For the secondary ﬁrmware the ﬁle name must be M348sec.bin. And for the FPGA ﬁrmware the ﬁle name must be BWY.bit. Studio Tech- nologies will supply each ﬁrmware ﬁle inside a .zip archive ﬁle. While the ﬁrmware ﬁle inside of the zip ﬁle will adhere to the naming convention required by the Model 348, the name of the zip ﬁle itself will include the ﬁle’s version number. For example, a ﬁle named M348v1r05MCU.zip would indicate that version 1.05 of the main MCU ﬁrmware (M348.bin) is contained within this zip ﬁle.

Once the USB ﬂash drive is inserted into the USB interface, located on the back panel, the unit must be powered off and again powered on. At this point the ﬁle(s) will automatically load. The precise steps required will be highlighted in the next paragraphs of this guide.

To install one, two, or all three ﬁrmware ﬁles follow these steps:

1. Remove power from the Model 348. This will entail either removing the Ethernet connection from the RJ45 jack labeled Primary-PoE or removing the external source of 12 volts DC. (Both must be disconnected if for some reason dual-power has been implemented.)

2. Locate the USB connector on the Model 348’s back panel, labeled Firmware Update. Directly below the USB connector is a small hole that provides visual access to a green LED indicator.

3. Insert the prepared USB ﬂash drive into the USB connector.

4. Apply power to the Model 348. Power can be provided by Power-over-Ethernet (PoE) associated with an Ethernet signal connected to Primary-PoE or from an external 12 volts DC source.

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5. After a few seconds the Model 348 will run a “boot loader” program that will automatically load and save the new ﬁrmware ﬁle(s) that are present on the USB ﬂash drive. The update process can range from approximately 15 seconds to approximately 45 seconds, depending on which combination of the three ﬁles are going to be updated. While the ﬁles are being loaded the green LED, located below the USB connector, will ﬂash slowly. It’s also possible that the ten knobs associated with the rotary encoders will light red to indicate that normal activity is not taking place. Once the entire loading process has completed the Model 348 will restart using the newly saved main ﬁrmware.

6. At this time the Model 348 is functioning with the newly loaded ﬁrmware and the USB ﬂash drive can be removed. But to be conservative, remove the power source ﬁrst and then remove the USB ﬂash drive.

7. Conﬁrm that the desired ﬁrmware has been loaded and that the Model 348’s three ﬁrmware ﬁles are as you desire. This is accomplished using the STcontroller software application. (Use the

Version selection under the Device tab.)

Broadway Firmware Update

As previously discussed in this guide, the Model 348 implements Dante connectivity using the Broadway integrated circuit from Audinate. The Dante Controller software application can be used to determine the version of the ﬁrmware (embedded software) that resides in Broadway. The STcontroller software application can also be used to identify the ﬁrmware version. (Use the Version selection under the Device tab.) The Dante Firmware Update Manager (FUM) application program has traditionally been used to update the Broadway ﬁrmware. The Dante Controller software application also includes an automated method of updating Broadway ﬁrmware. Both applications are available, free of charge, on the Audinate website (www. audiante.com).

Restoring Factory Defaults

A command in the STcontroller software application allows the Model 348’s default conﬁguration selections to be reset to the factory values. From STcontroller select the Model 348 for which you want to restore its defaults. Select the Device tab and then select the

Factory Defaults feature. Then click on the OK box. Refer to Appendix A for a list of the

Model 348’s factory default values.

Note that upon power being applied to the Model 348 if the USB ﬂash drive doesn’t have the correct ﬁle(s) in its root folder no harm will occur. Upon power up the green LED, located below the USB connector, will ﬂash on and off rapidly for a few seconds to indicate that a valid ﬁle has not been found and then normal operation using the unit’s existing application ﬁrmware will begin.

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Speciﬁcations

Applications: Dante-based intercom, IFB (interrupted

foldback) master station, audio monitor mixer, specialized tone generator

Overall Number of Channels: 8

Power Sources: Power-over-Ethernet (PoE): class 0 (classiﬁcation

unimplemented, ≤12.94 watts) per IEEE® 802.3af External: 10 to 18 volts DC, 0.65 A maximum at 10

volts DC (can be powered by optional PS-DC-02)

Network Audio Technology: Type: Dante audio-over-Ethernet AES67-2013 Support: yes, selectable on/off Dante Domain Manager (DDM) Support: yes Ethernet Interface Conﬁguration:

Redundant

Bit Depth: up to 24 Sample Rate: 48 kHz Dante Receiver (Input) Channels: 16 Dante Transmitter (Output) Channels: 11 Dante Audio Flows: 32; 16 transmitter, 16 receiver Internal Digital Audio Processing: 32-bit, ﬁxed Input-to-Output Audio Processing Latency:

<200 uSec

Nominal Input and Output Level: –20 dBFS

Network Interfaces: 2, Primary-PoE and Secondary Type: 1000BASE-T (Gigabit Ethernet (“GigE”))

per IEEE 802.3ab (10 and 100 Mb/s not supported) Power-over-Ethernet (PoE): per IEEE 802.3af

(applicable to Primary-PoE network only)

Microphone Input – Headset: Compatibility – Headset A: single- or dual-ear broad-

cast-style with dynamic or electret (low-voltage DCpowered) microphone: pin 1 mic common; pin 2 mic; pin 3 phones common; pin 4 phones left; pin 5 phones right

Compatibility – Headset B: CTIA™/AHJ conﬁguration (typically uses electret powered mic): tip phones left; ring 1 phones right; ring 2 common; sleeve mic

unbalanced

Type: Impedance: 1 k ohms, nominal, microphone power off;

690 ohms, nominal, microphone power on

Gain: 26, 32, 38, 44, 50 dB, selectable Frequency Response: –4 dB at 30 Hz, –2.6 dB at

40 Hz, –1.8 dB at 50 Hz, –2.4 dB at 10 kHz, –3.8 dB at 20 kHz

Switched or

Distortion (THD+N): <0.09%, measured at –20 dBFS, 22 Hz to 22 kHz bandwidth, 38 dB of gain

Dynamic Range: >93 dB, A-weighted, 26 dB gain

Microphone Input – Gooseneck: Microphone Power: 5 volts DC via 4.99 k resistor Impedance: 3.3 k ohms, nominal Gain: 12, 18, 24, 30, 36 dB, selectable Frequency Response: –3.0 dB at 40 Hz, –2.0 dB

at 50 Hz, –2.0 dB at 16 kHz, –3.0 dB at 20 kHz Distortion (THD+N): <0.04%, measured at –20 dBFS,

22 Hz to 22 kHz bandwidth, 36 dB of gain

Dynamic Range: >97 dB, A-weighted, 12 dB gain

Compressor: Application: applies to headset and gooseneck

microphone audio Threshold: 1 dB above nominal Dante output level

(–19 dBFS)

Slope: 2:1 Status LED: compressor active

Headset Headphone Output: Type: 2-channel (stereo) Compatibility: intended for connection to stereo

(dual-channel) or monaural (single-channel) headsets with a nominal impedance of 50 ohms or greater

Maximum Output Voltage: 3.0 Vrms, 1 kHz, 150 ohm load

Frequency Response: 20 Hz to 20 kHz, +0/–1 dB Distortion (THD+N): <0.02% Dynamic Range: >93 dB

Speaker Monitor Output: Type: single-channel (monaural) Speaker: 1.3-inch (32 mm) diameter Maximum Power: 4 watts RMS, nominal Frequency Response: 150 Hz to 20 kHz, ±3 dB

18 kHz and 20 kHz Tone Outputs: Type: sine wave Level: –20 dBFS Frequency Accuracy: Distortion: <0.0001%

Call Function: Receive Frequency: 20 kHz, ±800 Hz, within audio

channel

Receive Level: –27 dBFS minimum Send Frequency: 20 kHz Send Level: –20 dBFS Audible Alert:

selectable level range

3-burst sequence, 524 Hz, sine wave,

<10 ppm

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INTERCOM STATION

Connectors: Headset A: 5-pin female XLR Headset B: 3.5 mm 4-conductor TRRS jack, per

Japanese standard JEITA/EIAJ RC-5325A Gooseneck Microphone: ¼-inch 3-conductor with

7/16-20 UNF threaded bushing Ethernet: Neutrik NE8FBH etherCON RJ45

receptacles External DC: 4-pin male XLR (pin 1 negative, pin 4

positive) USB: type A receptacle (used only for updating

ﬁrmware)

Conﬁguration: requires Studio Technologies’ STcontroller software application, version 2.05.00 and later

Environmental: Operating Temperature: 0 to 50 degrees C (32 to

122 degrees F)

Storage Temperature:

–40 to 70 degrees C (–40 to

158 degrees F)

Humidity: 0 to 95%, non-condensing Altitude: not characterized

Spare Connector Location: 1

Allows a Studio Technologies’ cable assembly or option module to be installed. Also compatible with Neutrik NC*D-L-1 connectors (*=3F, 3M, 5M, 6F, 6FS, etc.).

Dimensions (Overall):

6.5 inches wide (16.5 cm)

2.9 inches high (7.4 cm)

4.9 inches deep (12.5 cm)

Deployment: intended for tabletop applications

Weight:

2.1 pounds (0.95 kg)

Speciﬁcations and information contained in this User Guide subject to change without notice.

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Appendix A

STcontroller default Model 348 conﬁguration values:

General Menu Page:

Microphone Input – Headset Mic Power: Off

Microphone Input – Headset Mic Gain: 38 dB

Microphone Input – Gooseneck Mic Gain: 24 dB

Headset – Sidetone Level: Medium

Headset – Dim: 0 dB

Speaker – Source: Monitor A

Speaker – Dim: 6 dB

Dante Monitor Outputs – Mode: Off

Dante Monitor Outputs – Dim: 0 dB

System – Level Control Position Display: On

System – Signal Presence Display: On

System – LED Intensity: High

System – Headset and Monitor Outputs Follow Mic Source: Off

System – Hot Mic: Off

System – Monitor A Call Tone Level: Off

System – Monitor B Call Tone Level: Off

Channel Speciﬁc Menu Page (all data identical for Channels 1-8):

Button Mode: Hybrid

Button Function: Talk

IFB Program Dim: 15 dB

Headset Routing: Left and Right

Monitor Routing: Monitor A

Call Indication: Visual Only

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Studio Technologies 348 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

Revision History

Introduction

Getting Started

Operation

Technical Notes

Appendix A