Denon 3805 causing Velodyne sub to rumble

[edcroteau]

Advice needed desparately.

My subwoofer is rumbling and popping, even with no signal at all.

I've got a Velodyne SPL-1000 II, a Denon 3805 AV/R, B&W speakers, and other components that seem unrelated to my problem.

I've hooked up the sub directly to the subwoofer line out on the 3805 using a Monster sub specialty RCA cable. The cable goes into the sub in the single input line in jack.

I've set the internal crossover to OFF and set the 3805 crossover frequency to 120Hz.

The speaker configuration setup is Subwoofer YES and it doesn't matter (for this problem) whether the other speakers are all set to SMALL or the fronts are set to LARGE and others to SMALL.

I've tried both the LFE and LFE+Main settings on Subwoofer setup.

I tried turning off the Denon and it still causes the rubbling (popping), only when the cable is physically removed does it stop.

Also, the kicker to the problem is that it is INTERMITTENT. It doesn't happen until things have warmed up. When I turn off the sub and try again later it may or may NOT rumble again.

When rumbling or not rumbling the sub seems to be working otherwise.

Any suggestions ?

Thanks,

Ed

[Azeke]

Plug the sub into a different outletl, different from the rest of your equipment ( use an extension cord if necessary).

Plug sub into different receiver to determine if the Denon is the issue.

Call tech support.

Just my quick thoughts,

Azeke

[David Meek]

I tried turning off the Denon and it still causes the rubbling (popping), only when the cable is physically removed does it stop.

Also, the kicker to the problem is that it is INTERMITTENT. It doesn't happen until things have warmed up. When I turn off the sub and try again later it may or may NOT rumble again.

Hi Ed, welcome to The Guide. :welcome:

I think you nailed the problem with those two lines. It "sounds" like you've got your sub plugged into an electrical circuit with something else plugged into it that intermittently comes on and causes the output. Get a good heavy extension cord and plug the sub into an outlet that isn't on that circuit. You can easily identify the plugs on the bad circuit by flipping the breaker on the problematic one and then finding a hot outlet.

Good luck!

[Snap]

A trick I have used in the Pro stuff is to use a "ground lift" Some times it is hard to find a outlet near by that is not on the same circuit. One of those orange ground lifts that takes the 3 prong plug and turns it into a 2 prong. That can some times help out with circuits that have bad grounding issues.

One other thing to check is to see if the RCA LFE input is all wrapped up with a power cord, or near a bunch of power cords. Sometimes, you can get junk to jump to the lines if the the lines are all crossed as well.

Last thing I would check is the cable itself. If the cable is messed up inside you could have that "intermittent" problem that you were talking about. Try hooking up another RCA cable to it. But the above post are in MO the most accurate.

[Clive]

We have seen this problem on occasion. What we've found is/are loose connections on the main board. If your unit is new, I'd suggest bringing it back ASAP. If not, you may need service, if after everything the above members suggested didn't work. Subs vibrate alot and if the board is not done right will cause intimitting sparking, surging or arching.

BTW, click on the Cats Cable logo at the bottom of this page for some good sub cables. I'd suggest to replace the ones you have also. :T

[edcroteau]

Thanks so much for the input guys. I left my system on for hours today trying to recreate the problem so that I could switch AC outlets, switch cables, etc. but the problem never arose ... good for today but the problem may still be lurking beneath. Someone suggested changing the sub's volume setting, which worked for him. I'll try the other stuff when the problem returns. I do think that it is a power issue at this point but it may be the output circuitry on the 3805's subwoofer line out.

I'm also going to call Velodyne tomorrow. The Denon email tech support replied after several days and said the problem was probably with the sub ... hmmmm.

Thanks again,

Ed