User manual BBE SOUND MAXCOM

[. . . ] OWNERS MANUAL SAFETY RELATED SYMBOLS protective grounding wire or disconnect the wiring of protective grounding terminal. · Operatng Condtons The symbol is used to indicate that some hazardous live terminals are involved within this apparatus, even under the normal operating conditions. The symbol is used in the service documentation to indicate that a specific component shall be only replaced by the component specified in that documentation for safety reasons. OFF: Denotes the apparatus is turned off, because it uses the single pole switch, be sure to unplug the AC power to prevent any electric shock before you proceed with your service. [. . . ] Loudspeakers tend to be less efficient in their extreme treble and bass ranges. Most sound-reproducing systems include a circuit for boosting high and low frequencies, showing an accepted awareness of the loudspeaker¹s efficiency problem. The BBE system, however, provides a dynamic, program-driven augmentation which combines with the phase compensation feature to restore the brilliance and clarity of the original live sound. The result is, as one professional journal phrased it, "The most hearable advance in audio technology since high fidelity itself!". COMPRESSION EFFECT At the beginning of this chapter, we dealt briefly with the basic functions of a compressor/limiter. Now we will discuss this point in more detail, with reference to the threshold setting, input level and compression: consider an input signal which is applied to the inputs of two compressors. The threshold of the second compressor is set 10 dB higher than the threshold of the first compressor. Since a compressor only affects signals that exceed the threshold level, it is fairly obvious that the signal of the first unit, will be compressed more because as the threshold is lower, it is exceeded to a greater exceeded before. Furthermore, it is interesting to note that by comparing the input and output waveforms for the compressed mode, the quietest sections of the input signal have been effectively raised in level, whereas the loudest sections have been effectively decreased in level. The overall effect is that both ends of the dynamics range have been pushed towards the middle. The squashing effect of compression is important to remember and highlights the major difference between compressing and limiting. Compressing and limiting differ in one more aspect: the dynamic setting for attack and release times. For compression purposes, a preferably longer attack and release time is generally the best in order to keep the overall output signal within a specified dynamic range. For limiting applications, considerably shorter times are necessary to control transient signals or to increase headroom. To achieve inaudible compression, it is imperative to work with program dependent attack and release times and a Soft Knee response. The advantage of program dependent compression is most apparent when processing musical material that is varied. The MAXCOM is suitable for all applications because of its various time settings and the AUTO processor. With the AUTO switch engaged, the unit uses program dependent attack and release times. Please note, while the AUTO switch is depressed the MAXCOM does not provide a limiter function even if the RATIO control is turned fully clockwise because signal peaks are NOT radically cut off above the threshold point. If you want to use the MAXCOM as an ultimate means of protection against overload, it is recommended to study the following chapter. THE LIMITING EFFECT The attack time is defined as the time taken for a compressor to respond to program levels which have exceed the threshold point. Because of the physical relationship between frequency and slew rate, the resulting factor is that for relatively low frequencies a longer attack time was required than for higher frequencies: any unpleasant dynamic distortion would be avoided. [. . . ] Additional delay beyond this "zero" attack time will produce a special sound effect, similar to the dynamic envelope inversion you may already be familiar with from reverse tape playback. 8 SERVICE/WARRANTY/MAINTENANCE SERvICE We recommend that if at all possible, a BBE MAXCOM which requires service be sent to our facility in Huntington Beach, California. We request that a "RETURN AUTHORIZATION" be issued by the dealer from whom you purchased the unit. directly at (714) 897-6766, extension 116 to obtain a "RETURN AUTHORIZATION". Include a copy of the bill of sale with the unit when it is shipped to BBE Sound, Inc. [. . . ]