SoundTraxx SoundCar Users Guide - Manual (Page 27)

Tsunami SoundCar User’s Guide Page 23
Step 6: Modifying Sound Effects
One of the great features of your SoundCar DSD is the ability to adjust the
various sound effects to suit your ear and operating scenarios.
Sound Mixer Controls
The SoundCar DSD provides independent controls for setting the volume
level for each sound effect, similar to a modern sound studio mixing board. To
set the volume for a particular sound effect, set the corresponding CV to any
value from 0 (i.e., mute) to 255 (maximum volume).
For the best sound quality, we advise running the mixer as “hot” as possible
(audio jargon for maximizing the sound level). First, determine which sound
effect you would like to be the loudest (typically the airhorn/whistle) and set
its volume level to around 225. Then, adjust the volume levels for all other
sounds effects relative to the airhorn volume. Finally, use CV 128 (Master
Volume Control) to set the DSD’s overall volume to your desired level. Refer
to Table F for the CVs and default values for individual sound effects.
Note: The default value of CV 128 is 192, or 75% of full volume.
A degree of caution is recommended when adjusting mixer levels to avoid
a condition known as “clipping” or “limiting,” which occurs when the sum of
two or more signals exceeds the capacity of the associated output channel.
As the name implies, clipping causes the sound signal peaks to be lopped
off and manifests as distortion accompanied by some degree of clicking or
popping sounds.
To avoid a clipping situation, consider which sounds are likely to be played
at the same time and take care to ensure that their mixer levels are not
too high. For example, the airhorn and bell are usually heard together,
and you will likely want both to be as pronounced as possible. Rather than
simply cranking both sounds up to the maximum level, start by setting one
mixer close to, but not quite at the maximum level (this leaves a little extra
“headroom”). Then, gradually increase the setting of the second mixer
channel to your desired level. If you start to hear distortion, simply decrease
the setting of one mixer channel or the other until the distortion fades away.
The individual sound channels may also be used to disable sounds that are
not accurate to your particular car or operating scenario, or that you prefer
not to hear.
Sound Control CVs
CV 128, Master Volume Control
CVs 129‑134, Sound Mixer
Sound Programming