2) Signal Present
There are individual LED's for each the Left and Right signal inputs. The LED turns green when there is audio signal
present in the VHD4.21. This signal indicator can be used to troubleshoot wiring problems.
3) Limiter
Should the rms limiting system be engaged due to overdriving of the VHD4.21, the LED will light up yellow. The
audible effect of the rms limiter is a lowering of overall output level. The rms limiter will disengage only if the input
level is turned down.
Please contact KV2 Audio or a local service representative should the system enter a thermal condition under
normal operating conditions.
4) Power On / Thermal
This LED turns green when the speaker is turned ON. The light will continue to be green during normal operation of
the speaker system. The LED will change from green to yellow under a thermal condition resulting from overheating
of the amplifier system. Under this condition, the speaker system will shut down. You can expect for the system to be
down for at least 2-3 minutes depending the ambient temperature and whether the system is being exposed to direct
sun light.
5) Cliffcon 8 pole connector socket
For connection between Active and Passive Module - cable is included with the product (part no. KVV 987 337).
6) Residual Circuit Breaker Switch
It disconnects current to prevent serious harm from an ongoing electric shock.
7) PowerCON 32 A socket
The connectors comprise of contacts for phase, neutral and protective earth (ground) conductors rated for currents up
to 32 A and for voltages up to 250V.
VHD4.21 · C
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Most source equipment is safe for driving loads no smaller than 10 times the source's output impedance. For
example, cascading an array of 10 units consisting of VHD4.21 subwoofers produces an input impedance of
2000 ohms (20kOhms divided by 10). The source equipment should have output impedance of 200 ohms or
less. This is also true when connecting VHD4.21's in parallel (loop out) with other KV2 Audio amplifiers, active
speakers and subwoofers.
If the loudspeaker produces noises such as hiss and popping, disconnect the audio cable from the loudspeaker,
if the noise stops, then most likely the problem is not with the loudspeaker. Check the audio cable, source, and
AC power for the source of the problem.
Ensure that all cabling carrying signal to multiple amplifiers and active speaker systems is wired correctly. Make
sure that the polarity has not been reversed. Reversed polarity can cause severe degradation in frequency
response and can also impact the dispersion characteristics of the speaker.
VHD4.21 · Control Panel / Inputs and Outputs
