SPL ATMOS 2, 2600 User manual

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Manual

Atmos® Surround Miking System

Atmos Surround Miking System, Model 2600 Manual

Version 1.0 E – 12/2006

R&D: Wolfgang Neumann

This manual contains a description of the product. It in no way represents a guarantee of particular characteristics or results of use. The information in this document has been carefully compiled and veried and, unless otherwise stated or agreed upon, correctly describes the product at the time of packaging with this document.

Sound Performance Lab (SPL) continuously strives to improve its products and reserves the right to modify the product described in this manual at any time without prior notice. This document is the property of SPL and may not be copied or repro-

duced in any manner, in part or fully, without prior authorization by SPL.

Sound Performance Lab

Sohlweg 80, 41372 Niederkruechten, Germany

Fon +49 (0) 21 63-9 83 40

Fax +49 (0) 21 63-98 34 20

Internet: www.spl.info

Contact

Mail: info@spl.info

The construction of the Atmos, Model 2600, is in compliance with the standards and regulations of the European Cummunity

Atmos – the complete surround miking preamp ............................................. 4

Installation ................................................................................................... 5

Control Elements .......................................................................................... 6

Specications .............................................................................................. 7

Content

Introduction

Dear customer,

thanks for using the Atmos system. We wish you have as much fun working with it as we had during the development of this extraordinary recording equipment.

The complete Atmos system includes the Atmos preamp, the external power supply and the power connection.

The Atmos system allows to record the original event and all of its authentic spatial content with highest precision. It demonstrates the signicant difference between discrete surround recordings and articial surround mixes with breathtaking results.

Due to its analog structure, the audio signals are compatible with any common surround format—DVD-A, DVD-V, SACD, AC3, DTS, MLP... you name it, Atmos can deliver it.

Together with a main microphone array this unique system offers an unparalleled combination of uncompromising audio quality and ultimate exibility.

Most importantly, the Atmos system is a breeze to use and can be set up in minutes, arming you for the most convincing 5.1 recordings you‘ve ever experienced.

Atmos – the complete surround miking preamp

The Atmos is a fully-featured stand-alone surround miking preamp for surround productions in any known format. The Atmos system operates fully analog to ensure independence from any storage or transmission format.

Atmos controller

The Atmos is equipped with ve matched high precision microphone preamps featuring SPL‘s triple gain stages to capture the superb sound of Brauner‘s mic array microphone in the most transparent, noiseless and uncoloured way.

The microphone preamps also feature SPL‘s ServoDrive-Technology which detects voltage differences (DC-offset) between the positive and negative paths of the amplifying stages. Any offset increases noise and distortion and therefore compromises the signal quality. ServoDrive minimizes DC-offsets to values between 0mV and 2mV. The recorded signal contains less noise and distortion and improved tonal transparency.

Further features include Lundahl input transformers, pads, phase reverse, phantom power, low cut lters, a switchable insert and tape send/returns. All switches are luminated. High quality switches and relays with gold plated contacts are used throughout.

5-layer gain control

An important feature of the Atmos is the high-precision ve-layer gain control. While changing the preamplication the relative loudness relationships between all ve microphones are maintained.

A Master Gain switch enables motorized control over all ve microphones preampliers by just turning one control. This is especially important when re-adjustment of the preamplication becomes necessary during recording to avoid negative effects on the spatial coherence and phase stability.

The Atmos unit should not be installed near units which produce strong magnetic elds or extreme heat. Do not install the units directly above or below power ampliers.

A main mic array has to be placed the way that the LCR heads of the microphone (those closer to the microphone center/90° angle) are facing the sound source. Be sure to place the microphone as high as necessary to avoid ground reections and comb ltering effects. Usually the best position for the mic array is right on the crossing between the direct sound eld and the diffuse sound eld.

BEFORE switching on the preamp, you have to connect the mic array via the multicore lead to the Atmos unit. Pay attention to t the bayonet joints properly. Check that the voltage details quoted on the back panel correspond to your local mains electricity supply. Use a minus (-) screwdriver to set the voltage selector to the required voltage. By the way ... the Atmos uses two 1,6 A slow fuses.

Now switch on the Atmos preamp. Set the mic gain control to the 12 o’clock position. Now the VU meters indicate modulation.

Chassis ground and AC ground can be disconnected with the Ground Lift switch (GND LIFT) on the back panel. This can help to eliminate hum.

An AC power cord is included to feed the IEC-spec, 3-prong connector.

Inputs: The microphone inputs are equipped with phantom power supply.

Installation

Control Elements

5-Channel Preamplier Control

The central, 5-layer gain control allows for adjusting preamplication values between 18 and 72 dB. It controls all channels simultaneously.

Switches: HP and PAD

The PAD switch reduces input level by -25 dBu. The HP switch activates a high pass lter at 70 Hz, e.g. to eliminate subsonic frequencies.

Outputs

For recordings of the preamplied signals recording devices like a multitrack recorder can be connected either to the XLR or DB 25 outputs.

LFE Level control

The LFE signal is composed from all channels automatically. Frequency is xed at 80 Hz, you can simply set the level with the LFE level control (-32 to 0 dB).

PPM Meters

The PPM meters display the levels at the output of each bus. Values range between

-48 dBu und +9 dBu and are displayed in steps of 3 dB.

A short example: How to use the Atmos

One can describe the work with the Atmos very good with the example of an orchestral recording.

The main mic array is placed in a central position in front of the orchestra. We choose a position of 1 to 2 meters behind and at least 4 meters above the conductor.

As a starting point we recommend to adjust all mic heads in their 0° position (if the mic capsules can be moved) and to select a hypercardioid polar pattern. Moving the mic capsules allows for ne adjustments, for example smaller L/R angles result in larger sound stages of small orchestras.

In general, the same rules apply as with standard miking techniques. So every user can and should develop his own working practice for individual optimization.

Frequency range

Mic Out @ 18 dB Gain: 10 Hz-180 kHz (+/-3 dB, Phase –2°)

CMRR 100 Hz 1 kHz 10 kHz 18 dB Gain: -79 dB -79 dB -60 dB 34 dB Gain: -66 dB -66 dB -52 dB 60 dB Gain: -45 dB -45 dB -32 dB w. Pad -16 dB @ 18 dB Gain: -90 dB -90 dB -79 dB

THD & N 1 kHz 10 kHz 60 dB Gain: 0,22 % 0,24 % 50 dB Gain: 0,07 % 0,07 % 40 dB Gain: 0,022 % 0,023 % 30 dB Gain: 0,007 % 0,007 % 18 dB Gain: 0,002 % 0,0023 %

S/N ratio (A-weighted) 150 Ohm generator, 22 Hz-22 kHz  lter, 60 dB Gain@150 Ohm Mic Out: -66,8 dB 50 dB Gain@all: -77,2 dB 40 dB Gain@all: -85,8 dB 30 dB Gain@all: -93,6 dB 18 dB Gain@all: -96,4 dB w. PAD -16 dB @ 18 dB Gain: -97,5 dB

Overload resistance +22 dB

Speci cations