Behringer MDX4400 manual Special Applications, Multicom PRO as a protective device

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MULTICOM PRO MDX4400

6. SPECIAL APPLICATIONS

6.1 Using The MULTICOM PRO For Recording And Cassette Duplication

In the recording and duplication field the goal should always be to achieve an optimum recording level onto the recording media. Too low or too high recording levels lead to side effects such as noise, distortion etc. In mastering and multitrack recording, as well as in duplication, one should always take care to utilize the full dynamic range of the tape recorder, DAT recorder etc. Principally, it is possible to control the recording level by “riding” faders, which means with low level signals, the gain is increased, whereas the amplitude of high level signal is reduced. It is obvious that this method is insufficient because, especially in live recordings, the expected signal levels cannot be anticipated correctly. Especially with multitrack recordings, which are run under hectic circumstances, the signal level of all channels cannot be monitored and controlled at the same time. Generally, with manual control, it is not possible to achieve satisfying recording results.

An automatic gain control system achieves better and more constant results. Use the MULTICOM PRO by starting with the initial settings, and use its dynamic control functions in order to be able to drive an analogue, as well as a digital recording, up to the limit of its maximum dynamic range while remaining noise- and distortion-free.

6.1.1 The MULTICOM PRO In Digital Recording And Sampling

In an analogue recording, too low recording levels lead to an increased noise level, whereas too high levels will cause a compressed and “squashed” sound. In extreme cases, it will cause distortion due to tape saturation. In contrast to analogue, side effects in the digital field always become extremely audible: with decreasing level, a tape previously recorded with insufficient level loses resolution: the recording sounds “hard“ and loses “atmosphere”. With excessive level, the recording sounds harsh and heavily distorted. In order to avoid these effects, the Peak Limiter section of the MULTICOM PRO should be placed before for example a sampler. As a result of this process, a digital recording or a sampling event can be optimally set in level without any problem.

6.1.2 The MULTICOM PRO In Mastering

The mastering process is one of the most critical processing steps in recording. In this production step, it is the goal to achieve a “maximum level” copy of the recording, without any noise or distortion. In many applications it is further required to produce a high average volume. In the field of commercial media for exam- ple, this is apparent especially with records and cassettes which are processed with high average volumes. Quite often in these cases, dynamics suffer drastically, because the program material has been compressed and limited too heavily. Using the compressor and the Peak Limiter section of the MULTICOM PRO allows you to drastically increase the overall volume, without audibly affecting the dynamics.

Proceed as follows:

1.Limit the dynamics of the program material by 6 dB using the Peak Limiter section. By softly clipping just the transients, the real audio signal will not be limited, resulting in a higher headroom. The overall gain can now be increased by 6 dB, which leads to a higher volume. More than 6 dB should not be limited, otherwise side effects could become audible.

2.Therefore, in addition, you should also use compression. It is recommended that the compression is limited to the “first” 6 dB of the dynamic range only. A high threshold level in addition to the auto mode will give good results.

This effect is particularly noticeable with DAT recorders, whose level indicators achieve a response time of less than 1 ms. Set the DAT recorder at unity and now reduce the LEVEL control of the peak limiter until the LIM LED starts to illuminate. The “cut” signal peaks cause a reduced recording level of about 6 dB, which is visible on the level indicators of the DAT recorder. Now increase the recording level of the recorder back to unity. The result is a clearly louder recording without any loss of sound.

6.2 The MULTICOM PRO as a protective device

Sound system distortion is usually a result of amplifiers and loudspeakers being driven beyond their limitations by signals clipping. The signal limitations that occur lead to unpleasant distortion that is dangerous to the speakers.

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6. SPECIAL APPLICATIONS

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Contents MDX4400 Safety Instructions Detailed Safety InstructionsForeword Multicom PRO Table of Content Introduction Technical Background Dynamic range capabilities of various devices Multicom PRO MDX4400 Inputs And Outputs Design ConceptHigh Quality Components And Design Installation Rack MountingMains Voltage Audio ConnectionsSelecting The Operating Level Balanced use of stereo 1/4 jack plugsControls Front Panel Control ElementsMulticom PRO MDX4400 Rear Panel Control Elements Of The Multicom PRO Control elements of the rear panelApplications Compression/Leveling/Limiting/ClippingIKA characteristic of the compressor section Compressor SectionTab .1 Initial settings for the compressor section Tab .3 Initial settings for the peak limiter section Peak Limiter SectionSpecial Applications Multicom PRO as a protective deviceProtection Of a System With a Passive Crossover Multicom PRO In Broadcast Specifications Audio InputIndicators Gain Reduction Warranty § 1 Warranty CARD/ONLINE Registration