Getting The Sound You Want
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G
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While the DSPX can help you obtain the sound that you want we must always take into account the limitations
presented to us by the transmission channel. The biggest problem we have is the maximum peak level that can
be handled by that transmission channel. For FM broadcast this is +/- 75 KHz for 100% modulation and for dig-
ital services, 0dBfs.
The trade off in any audio processor is loudness vs. quality. The mark of how good a processor is is how loud
the processor can go while maintaining sufficient quality. It is up to you where this loudness / quality trade off
point is set. This point is also usually market and format dependent.
In the effort to squeeze as much bass and high frequency energy into the peak limited channel we must make
compromises. Bass takes up a lot of room in the waveform and pursuit of a 'mega bass' type sound will leave
you less room for high frequencies. When processing aggressively we usually will have to accept a certain level
of bass distortion in making room for high frequencies or we will have to accept a certain level of high frequency
distortion if our desire is lots of clean loud bass.
If your aim is a cleaner sound and a slight loss of loudness is not important then it is easier to get the tonal char-
acteristic you're after without distortion. Lower clipper drives will provide you with clean bass and crystal clear
razor sharp high frequencies. The choice is yours.
More LOUDNESS
Loudness can be increased in several ways.
Multi-band AGC:
Increase the drives to the bands.
Speed up the release times, making them faster.
Decrease the bands ‘RATIO’ control so less control is performed and the waveform is allowed to pass to the
following peak limiter.
Reduce the band and channel coupling ratios.
While it is possible to create a strange response in the multi-band AGC, it is hard to produce distortion
because whatever gets through the AGC is dealt with by the following peak limiters
Multi-band Limiters:
Slow down the peak attack times, letting more through to the clippers.
Speed up the release times of the average release time constants.
Slow down the average attack time so that the peak time constants dominate the control signal providing
faster control.
Reduce the HOLD level or turn the HOLD level off.
Reduce the DELAY control to lower numbers.
Increase the limiter thresholds, letting more through to the clippers.
Reduce the band and channel coupling ratios.
Extra loudness can be obtained by working on only a single or a couple of the above suggestions. You are
likely to run into trouble if you 'crank up' all of the above settings. You are likely to generate excessive distor-
tion in the final clippers and generate a fatiguing sound if you're not careful. Less can be more. Make small
changes and compare against the settings of the factory presets if you find you have lost your way some
where.
Final clippers: (FM USE)
Increase the multi-band clipper drive.
Possibly switch the bass clipper to hard mode.
Raise the bass, mid and HF clip levels.
Increase the final clipper drive.
Look-ahead limiter: (DR USE)
Increase the look-ahead limiter drive
Increase the attack time constants, sl.owing down the attack of the secondary time constant circuits.
Decrease the decay time constants, speeding up the decay of the secondary time constant circuit.
Adjust the shelf control to obtain the most suitable HF/loudness balance.
WE SUGGEST ONLY SMALL MODIFICATIONS FROM FACTORY PRESET SETTINGS IF YOU ARE
MODYFYING LOTS OF THE PARAMETERS. IF YOU ARE ADJUSTING ONLY A COUPLE FROM THE
