Follow up questions regarding my NAD C375BEE

A number of good comments and suggestions have been provided above. I'll add one further thought while awaiting feedback on what has been suggested:

Are you certain that the two speakers are connected with the same phase, i.e., that + and - are not interchanged in the connections to ONE speaker?

If the two speakers are not connected in phase with each other, some of the results would be vague and diffuse imaging, and weak bass. I'm thinking that in some circumstances a result might also be the channel imbalance you have perceived, and also a perceived reduction in volume (which would be further compounded in one channel by the balance control offset). If so, to achieve reasonable volume and bass perhaps you are turning the volume control up high enough to overload the amp, with the clipping distortion that would normally result from doing that perhaps being prevented by the amp's soft clipping feature and/or by the amp's unusually large dynamic headroom.

Also, as Pgawan2b suggested, verify that the bridged mode switch on the rear panel is set to off/stereo. If the speakers are connected as a normal stereo pair but that switch is set to bridged mode, it would cause similar effects to those I described above for an out of phase speaker connection.

Regards,
-- Al

One more thought: Make sure that the black wire from the REL is connected to one of the negative (probably black) speaker terminals on the amp, and not to one of the positive (probably red) speaker terminals. If the black wire is interchanged with either the red or the yellow wire from the REL, and is connected to a positive speaker terminal on the amp, I believe that could account for all of the symptoms you have described here and in the other thread that was referenced above, and (consistent with what you have reported) could result in the amp shutting down even if the sub is turned off.

Regards,
-- Al

"Are you certain that the two speakers are connected with the same phase, i.e., that + and - are not interchanged in the connections to ONE speaker?

If the two speakers are not connected in phase with each other, some of the results would be vague and diffuse imaging, and weak bass. I'm thinking that in some circumstances a result might also be the channel imbalance you have perceived, and also a perceived reduction in volume (which would be further compounded in one channel by the balance control offset)."

That could be the problem. If you play a recording that normally has a solid center vocal image, wiring the speakers out of phase with each other will make the vocals sound like they are coming from one of the side walls, and not the center. Its very easy to hear. You can't miss it.

Another cause for the channel imbalance could be your room. If you have something like the right speaker near a corner and the left near a free space, one speaker will have to work harder to match the volume of the other one.

Also, if you bought your speakers used, go over all the screws and make sure they are tight. They can loosen up over time.

ZD, thanks for the good elaboration on the point I raised.

Joseph54, regarding my other point, even if you have verified that the black wire from the REL is connected to a negative output terminal on the amp, I would not rule out the possibility that the cable itself is miswired. In other words the black wire could conceivably be connected to a pin on the Neutrik connector which should be connected to either the yellow or the red wire, and vice versa.

Again, the possibility that the sub's ground (which should be the black wire in the cable) is connected to a positive output terminal of the amp seems very consistent with the symptoms you have reported in all of your threads, here and elsewhere.

Regards,
-- Al