User Manual

18
Crimson
Control Elements
Volume
Use the Volume potentiometer to adjust the volume of both channels of the Speakers A and
Speakers B outputs on the rear panel. The high-grade potentiometer regulates the audio
signal directly to avoid any coloration/distortion typical of VCAs and DCAs, which require
higher inter-channel tolerances and have a tendency towards higher distortion figures.
The Volume control uses a relative dB scale referenced to the input level. When set to the 0dB
mark the input level is „as is“ (the amplification factor is 1 or unity gain).
The signal can be amplified from -∞ dB to +7dB. With such signal amplification you can
control better quiet passages by monitoring them at higher volumes or, more generally spea-
king, listen better to the signal in order to check for any problems (artifacts, crackling noises,
etc.).
If the signal can still be heard when hard left, do not worry: the potentiometer is not a switch.
This was a conscious decision we made to be able to offer you an amplification possibility too.
Power off the source when you want to mute it.
Recommendation: Calibrate the whole monitoring system (read the following section) so
that the control range in use is always between eight and two o‘clock of the travel. This is
the range where the potentiometer works best, which guarantees a good and noiseless level
matching for the monitoring system.
Calibration of the Monitoring System
The input signal level of the Crimson and the input sensitivity of the power amps or active
speakers should be matched to ensure a proper overall gain. An inappropriate matching
results, for example, in an extremely high monitoring level with a fairly low volume setting
(at 9 o‘clock). Likewise, settings above two o‘clock should sound really loud, otherwise it is
indicative of a matching problem.
Important: During calibration it can get very loud, so don‘t forget to wear ear protection. For
calibration we recommend using a SPL Meter (where SPL stands for „Sound Pressure Level“).
Place the measuring microphone at the listening position and playback pink noise from
a generator calibrated to 0dBu. Each measurement should be done with one channel (and
loudspeaker) at a time. 83dB SPL at the listening position is a good and very common refe-
rence value.
Adjust the volume control until the SPL meter reaches 83dB with pink noise.
Ideally, 83dB SPL should be reached when the volume control is near the 12 o‘clock mark.
Write down the exact value for 83dB SPL at the listening position. If it only reaches 83dB SPL
above two o‘clock, increase the power amps‘ or active loudspeakers‘ input sensitivity (higher
dB value). Conversely, you should decrease the power amps‘ or active loudspeakers‘ input
sensitivity (lower dB value) when it indicates 83dB SPL before reaching the 12 o‘clock mark.