DENOISER SNR2000 SAFETY INSTRUCTIONS CAUTION: To reduce the risk of electrical shock, do not remove the cover (or back). No user serviceable parts inside; refer servicing to qualified personnel. WARNING: To reduce the risk of fire or electrical shock, do not expose this appliance to rain or moisture.
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Relay-controlled hard bypass with auto-bypass function during power failure (failsafe relay) s Cut-in delay to avoid switch-on thumps s Ultra low-noise audio operational amplifiers offer outstanding sound performance s High-quality detented potentiometers and Illuminated switches s High-performance output transformer BEHRINGER OT-1 retrofitable s Manufactured under ISO9000 certified management system...
DENOISER SNR2000 TABLE OF CONTENTS 1. INTRODUCTION ........................6 1.1 The design concept ......................... 6 1.2 Before you begin ..........................7 1.3 Control elements ..........................7 1.3.1 Front panel ........................... 8 1.3.2 Rear panel ..........................8 2. OPERATION ..........................9 2.1 Operation of the filter section ......................9 2.1.1 The masking effect ........................
The need for both a professional and all-purpose noise reduction system was the basis for the development of the BEHRINGER DENOISER. Many years of experience in the field of noise reduction technology enabled us to design a system particularly suited to the highest demands.
DENOISER SNR2000 1.3.1 Front panel Fig. 1.2: Front panel control elements The IN/OUT switch activates the relay and, consequently, the corresponding channel. The unit is bypassed when the switch is not depressed. By depressing the COUPLE switch you will tie channel 1 and 2 together for stereo tracking.
2.1 Operation of the filter section 2.1.1 The masking effect The function of the BEHRINGER DENOISER is based on the masking effect: noise will be masked and thus becomes inaudible, as soon as considerably louder sound signals are added. One of the basic components of BEHRINGER circuitry is a dynamically controlled low-pass filter which allows low frequencies to pass but filters the high-frequency information, depending on the music material.
2. However, if the control times are too fast, flutter may occur, i.e. intermodulation distortion could be produced. The new BEHRINGER TAC (Transient Attack Control) filter circuit gurantees extremely fast control times without producing audible intermodulation distortion. In contrast to conventional units based on so-called RMS rectifiers, the TAC circuitry uses a peak detector.
DENOISER SNR2000 Fig. 2.2: Comparing the BEHRINGER TAC filter circuitry and the conventional RMS characteristic curve 2.2.1 SENSITIVITY control This control determines the sensitivity of the filter. If the input level exceeds the value adjusted with the SENSITIVITY control, the dynamic filter begins to open. If the adjusted value is, for example, -30 dBu, high- frequency signals with a level above -30 dBu cause the filter to open.
DENOISER SNR2000 2.2.4 AUTO switch The AUTO switch allows to automatically control release time and cut off frequency of the TAC filter. Thus, by depressing the AUTO switch, the RELEASE and CUT OFF controls are deactivated. Release time and cut off frequency of the filter are now automatically derived from the input signal.
DENOISER SNR2000 Fig. 2.3: The function of an expander 2.4 The IRC expander of the DENOISER The response characteristics of conventional expanders tend to cut the signal abruptly and the result is generally unacceptable, since the effect is clearly audible. Inaudible expansion, however, requires a gentle Soft Knee...
12 dB, which is indicated by the 10 dB LED. Although the VCA of the BEHRINGER DENOISER provides a control range of 80 dB, it is not very useful to display the entire range, since such drastic control processes are performed very rarely in practice. The displayed range of the GAIN REDUCTION indicators is 40 dB.
DENOISER SNR2000 2.5 The COUPLE function The couple switch links channel 1 and channel 2. This includes each channels expander detection and filter detection circuits. Although this allows the two channels to track each other for stereo applications, it should be pointed out that this is not a master/slave setup, but rather a link and for true stereo tracking it is necessary to set both channels controls identically.
Fig. 3.1: Noise reduction during playback 1. Set up your equipment as usual, while bypassing your DENOISER. 2. Turn on the BEHRINGER DENOISER and adjust the controls as desired (if necessary, read chapter 1.3 Control elements once again). 3. Check your settings by making A/B comparisons using each channels IN/OUT switch.
1. If your mixer features subgroup inserts, you can reduce noise in subgroups separately. 2. You can also connect monitor or effects buses (aux sends) to the BEHRINGER DENOISER and route the signal back to a channel input. For this purpose, the respective signals have to be taken pre fader, while the respective channels must be muted.
Particularly old and noisy tapes can be new lease of live with the DENOISER. If adjusted properly, it will produce copies that sound better than the original. Simply insert the BEHRINGER DENOISER between the line outputs of the master machine and the inputs of the recorder.
Fig. 3.6: Noise reduction on keyboards Please note that low level signal sources such as guitars must be pre-amplified beforehand, as the BEHRINGER DENOISER only processes line level signals (-10 dBV to +10 dBu). 3.2.7 Reducing noise in P.A. systems The noise produced by P.A.
DENOISER SNR2000 Fig. 3.8: Noise reduction in Hi-Fi systems The BEHRINGER DENOISER can be used for: s disc and tape recordings s video and audio cassette playback purposes s TV reception s radio reception 4. TECHNICAL BACKGROUND 4.1 What are audio dynamics? A remarkable feature of the human ear is that it can detect the widest range of amplitude changesfrom...
DENOISER SNR2000 The usable dynamic range of electro-acoustic equipment is limited to both the low end and the high end. The thermal noise of the electrons in the components results in an audible basic noise floor and thus represents the bottom limit of the transmission range.
DENOISER SNR2000 The noise gate is the simplest form of an expander: in contrast to the expander, which continuously attenuates a signal below the threshold, the noise gate cuts off the signal abruptly. In most applications this method is not very useful, since the on/off transition is too drastic.
5. INSTALLATION 5.1 Rack mounting The BEHRINGER DENOISER fits into one standard 19" rack unit (1 3/4"). Please allow at least an additional 4" depth for the connectors on the back panel. Be sure that there is enough space around the unit for cooling and please do not place the DENOISER on high temperature devices such as power amplifiers etc.
DENOISER SNR2000 Fig. 5.1: Different plug types 6. SPECIFICATIONS Analog inputs Connectors XLR and 1/4" TRS Type RF filtered, servo balanced input Impedance 80 kOhms balanced Nominal operating level -10 dBV to +4 dBu (switchable) Max. input level +20 dBu balanced and unbalanced...
4.2 kg BEHRINGER is constantly striving to maintain the highest professional standards. As a result of these efforts, modifications may be made from time to time to existing products without prior notice. Specifications and appearance may differ from those listed or illustrated.