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HomeTheaterUser
01-20-2004, 11:18 AM
Recently, I re-connected my home theater and I am having a problem with my subwoofer and AV Receiver. The receiver is a Denon AVR-5700 and the Subwoofer is Paradigm Reference Servo. The problem is that when the receiver changes inputs the subwoofer spikes. It make a loud boom (one time only, no hissing or other sounds). This also happens if the receive goes from one sound mode to another (Pro Logic to DTS).

The subwoofer works fine after the initial boom. The boom does not happen simply by turning on the subwoofer. There is something going on between the receiver and the sub. I unplugged the connection from Sub to receiver and plugged it back in and it stil has not fixed the problem. I have also tried using different outlets and it is still there.

At first I thought it was that the connecto was plugged in too much on the back of the receiver and the problem happened because the receiver was using it as a ground since it made a connection with the receiver metal box but I determined this was not the case. I am using an Audioquest wire between the sub and the receiver. I can't remember the exact type but it was pretty expensive.

Let me know if you have any ideas on what I should do to debug or fix the problem. Thanks in advance,
Charlie

HomeTheaterUser
01-20-2004, 04:05 PM
Thanks for your quick reply to my problem. If I turn the sub off in the receiver menu and then change inputs, it does not pop or make a sound. Whether the sub is on or auto-on, it makes the noise. I also told the receiver that the signal is digital instead of audio and the problem was still there. I have had this receiver for a number of years and I can't believe that now that I have finally completed my home theater with a Samsung HLN567W DLP, I have this annoying problem. Ever since the problem started, I have kept the sub off and turn it on after the input and sound mode is set. Then I avoid the popping. Not the best solution but the noise doesn't sound good at all and I want to make sure nothing happens to the speakers. The receiver only sends the bad signal to the subwoofer. It doesn't seem like it is the wire from the receiver to subwoofer, Right? When I go through the on screen menus for the receiver, there is a lot of popping each time I move from one screen to another. Not sure if I am going to live with this or if I am going to have Denon look at the receiver.

F1
01-21-2004, 07:53 AM
It looks like relay switching problem. Receiver should mute the sound for a fraction of a second when switching from one mode to another to avoid spikes. Is there any way to reset everything on the receiver (check your manual), who knows it solves the problem. Or you may try to connect the subwoofer from the front pre outs and see if the problem persists. Otherwise, call Denon. Good luck.

HomeTheaterUser
01-22-2004, 05:27 AM
Late last night after I read your message, I reset the receiver. The spike problem was eliminated after the reset. I went to the speaker configuration and made sure that the receiver knew that I have 5 speakers plus the subwoofer and the spike problem still did not happen. Next, I went back to the setup and changed the settings for each of the digital sound inputs letting the receiver know whether the signal is coming in via coax or optical. The default configuration had everything set and there was no problem. Once I assigned the correct digital inputs, the spike problem re-appeared. Isn't that strange? I didn't have enough time to thoroughly debug the situation but I plan on doing that this evening after work. Maybe one of the inputs is causing a problem? I am only using 2 of the 5 optical inputs so maybe if I change the configuration and use different ports, the problem may not re-appear or I could make it that I use the default and change the input accordingly. This speculation rests on the discovery of the problem being the digital input sources which doesn't make much sense but that is when the problem re-appeared. Anyway your resetting idea was excellent and I think it may lead me to the problem.

HomeTheaterUser
01-22-2004, 12:10 PM
Performed all of the checks and found that the problem does not occur if the receiver is set to analog on every mode. Once I set one of the modes to digital or configure the digital inputs, the problem appears. I called Denon in NJ today and spoke to a technician. They said that it sounds like a muting transitor that is bad. I am going to drop it off tomorrow for repair. Thanks for your help.