Rvpiano 6-1-2017
After much difficulty I finally got to set up my used 2Wq sub only to find that the left channel doesn’t work. I followed the directions in the manual exactly in setting up the wx-2 variable crossover, matching it to my amp. I checked all the connections several times for tightness and correctness.
I even reversed the connectors to to the amp and the left channel still was out!
You indicated earlier that you are using modified NuForce amplifiers. Like some other class D amps some or many of the NuForce models have their + and - output terminals offset from ground by 24 volts, or some other comparably high voltage. Depending on the internal grounding configuration and other characteristics of the design of the particular sub, connecting a powered sub to that kind of amplifier output can cause either improper operation, or no signal to be heard, or damage to the amp or the sub.
For example, from
this manual for one of the NuForce amps:
WARNING: Do not connect NuForce speaker-level outputs to the line-level inputs of active devices such as active subwoofers or semi-active speakers with powered woofers. If you use semi-active speakers where the woofer is powered, or a subwoofer that accepts speaker-level signal from the NuForce, or sums the left and right input signals from the speaker outputs of two NuForce mono amplifiers, please consult NuForce or your dealer before proceeding....
Floating Speaker Output – The speaker output terminals are floating, with a 24VDC offset (DC across the speaker terminals is still 0V). Please consult NuForce Support (support@nuforce.com) if your setup requires any of the following configurations:
1. Multiple amplifiers to drive a single speaker driver (Never do this!).
2. Subwoofer that accepts and sums left and right input signals from two NuForce amplifiers’ speaker terminals.
3. Grounding other audio signal grounds to any of the speaker terminals on the NuForce amplifier.
4.Using two amplifiers to drive a bi-amp, series-crossover speaker (uncommon setup).
The fact that you "even reversed the connectors to the amp and the left channel still was out" would seem to confirm that the problem is related to the amp/sub/speaker interface, not to the crossover. But the fact that "both channels work fine without the wx-2 and sub attached" presumably means that the amp has not been damaged, at least not yet.
So depending on your specific NuForce model it might not be possible to use it with any powered sub that only provides speaker-level inputs.
Good luck. Regards,
-- Al
