AKG Acoustics AS 8, AS 8 TC User Manual

AS 8/AS 8 TC

Automatic Microphone Mixers

Description

While preserving the basic benefits of NOM attenuation and
minimum recirculated sound, the AS 8 adds extremely simple
setup, a seamless automatic mixing algorithm and low cost.
State of the art analog audio circuitry is digitally controlled
with a patented algorithm to provide exceptional
performance and value.

The Patented Adaptive Proportional Gain* algorithm is a
unique process that allocates the gain applied to each
channel after comparing the individual channel level with an
overall reference level. The reference level is a mix of all
active channels, so it automatically adapts to varying
background noise levels in the room. The channel with the
most signal receives the most gain. In addition to the
adaptive gain allocation, the algorithm also provides an
"intelligence" that prevents background noise and non­speech sounds from interfering with the auto mixing function.
The algorithm also keeps track of which channel has been
the most active (loudest for the longest time period) and
skews a priority toward that channel. The automatic skewing
is damped to keep it from responding to brief signal
transients. A very smooth compressor/leveler is included to
add an important finishing touch, making the AS 8 a
complete automatic level control system. The
compressor/leveler can protect amplifiers from overload and
maintains a consistent audio level with varying voice levels at
the microphones.

The AS 8 was designed to operate with any type of
microphone or line level source. DIP switches on the rear
panel adjust the preamp gain range for the input level. Front
panel controls provide a fine adjustment for an exact match
into whatever component follows the AS 8 in the signal
chain.

Simple, accurate level adjustment is assured by a single
front panel knob for each channel, which simultaneously
adjusts the input gain and the level of participation in the
gain allocation. Individual channel levels can be accurately
adjusted by ear, using nothing other than a talker's voice as a
sound source.

The AS 8 is easily configured for transparent operation in
any sound reinforcement, teleconferencing or recording
application. Multiple units can be "daisy chained" for more
than 8 channels. Connections for remote control pots or
switches are provided for individual channels and for the
overall mixed output.

An RS-232 port allows most of the functions of the AS 8 to
be controlled either by a computer or a dedicated control
system such as AMX or Crestron. The current version of the
software can also be downloaded from the Web site.

The AS 8 TC features low and high frequency shelving
controls on each inputchannel.

ÂMX

®

is a registered trademark of AMX Corp.
CrestronTMis a trademark of Crestron Electronics, Inc. USA
*US Patent Numbers: 5,414,776 and 5,402,500

Features

• Direct and mixed outputs

• Mic/line selectable inputs

• Built in Compressor/Leveler

• Expansion ports for larger systems

• Patented Adaptive Proportional
Gain mixing algorithm*

• Low and high frequency shelving
controls on each channel (AS8TC)

• RS-232 controllable - AMX

®

and

Crestron

TM

compatible

Specifications

Mic/Line Input type: Balanced and RF filtered

Impedance: >2.5K, any gain

Input Gain Settings: 0dB, +30dB, +50dB

EIN, 20-20KHz: -126dB (+50dB gain)

Maximum Input Level: +20dBu at 0dB gain

-10dBu at +30dB gain

-30dBu at +50dB gain

Remote Level Control Range: 6dB/Volt; 0 to 5V + off

Compressor/Leveller: Threshold: -40dBu to 0dBu

Maximum Gain Reduction: 25dB

Tone Controls (AS8TC): Shelving type

Turnover freq: 1 kHz
+/-10 dB at 100 Hz
+/-10 dB at 1kHz

Maximum System Gain: 75dB (input to main out)

System THD: <0.1%; +10dBu out at any gain setting

System IMD: <0.1%; +10dBu out at any gain setting

Phantom Power: +15V (selectable per channel)

Power Consumption: 10 Watts max. @ 20VAC

Weight: 3 lbs., 4 ozs.

Dimensions: 1

3

/4 x 8 x 19 inches

Microphones · Headphones · Wireless Microphones · Wireless Headphones · Headsets · Electroacoustical Components

Limited Warranty

Valid only in the United States. AKG Acoustics warrants AKG products against defects in material
or workmanship for a period of two years from the date of original purchase for use, and agrees to
repair or, at our option, replace any defective unit without charge for either parts or labor. Important:
This warranty does not cover damage resulting from accident, misuse or abuse, lack of reasonable
care, the affixing of any attachment not provided with the product, loss of parts or connecting the
product to any but the specified receptacles. This warranty is void unless service or repairs are
performed by an authorized service center. No responsibility is assumed for any special, incidental

or consequential damages. However, the limitation of any right or remedy shall not be effective
where such is prohibited or restricted by law. Simply take or ship your AKG product prepaid to our
service department. Be sure to include your sales slip as proof of purchase date. (We will not repair
transit damage under the no-charge terms of this warranty.) Note: No other warranty, written or oral
is authorized by AKG Acoustics, Inc. This warranty gives you specific legal rights, and you may also
have other rights which vary from state to state. Some states do not allow the exclusion or
limitation of incidental or consequential damages or limitation on how long an implied warranty
lasts, so the above exclusions and limitation may not apply to you.

Specifications subject to change without notice.

AKG Acoustics GmbH

Lemböckgasse 21–25, P.O.B. 158, A-1230
Vienna/AUSTRIA
Tel: [phone]*, Fax: [phone]
Internet: http://www.akg.com

AKG Acoustics; A Division of Harman Pro Germany
Bodenseestraße 228, D-81243 München/GERMANY
Tel: [phone], Fax: [phone]

Arbiter Pro Audio

Wilberforce Road, London NW9 6AX/ENGLAND
Tel: [phone], Fax: [phone]

AKG ACOUSTICS, U.S.

914 Airpark Center Drive
Nashville, TN 37217, U.S.A.
Tel: [phone], Fax: [phone]

Studer Japan Ltd.

2-43-7, Uehara, Shibuya-ku, Tokyo 151-0064/JAPAN
Tel: [phone], Fax: [phone]

Erikson Pro Audio

620 McCaffrey, St-Laurent, Quebec, H4T 1N1, CANADA
Tel: [phone], Fax: [phone]
Internet: www.jam-ind.com/eriksonpro

AKG is constantly improving and modifying its products, therefore, specifications are subject to change without notice.

The automatic microphone mixer shall incorporate an adaptive
proportional gain mixing technique and automatic skewing
between input channels to minimize comb filtering. The mixer shall
contain eight input channels. Each input shall be electronically
balanced and be capable of receiving mic or line level input
signals. Phantom power shall be provided for each input as well
as a direct output. (For Model AS 8 TC: Each input shall
incorporate both a high frequency and low frequency tone control.)
The main output shall be electronically balanced and have an
integral compressor/leveler and master level control. Expansion
ports shall provide IO access to the main and mix audio busses.

The mixer shall be controllable via an RS-232 serial port and shall
adhere to the LecNetTMcommunication protocol. The mixer shall
meet the following performance criteria. Frequency response: 20
Hz - 20 kHz. THD < 0.1% @ +10 dBu output. IMD < 0.1% @ +10
dBu output. Input Impedance: > 2.5K ohm. Maximum Input Level:
+20 dBu @ 0 dB setting; -10 dBu @ +30 dB setting; -30 dBu @
+50 dB setting. Equivalent Input Noise: -126 dB @ +50 dB gain.
Maximum Output Level: +26 dBu. Maximum Gain: 75 dB (input to
output). The mixer shall be rack mountable and occupy 1 RU. The
automatic microphone mixer shall be the AKG Acoustics
Model AS 8 (AS 8 TC).

Architects and Engineers Specifications

DS-AS 8/AS 8 TC

Graphical Data