Subwoofer auto-off

[Actran]

I recently realized that my subwoofer is not turning off automatically. It works great in every other respect. I had the same issue with another sub on the same Denon 1912 receiver. I have ensured it's switched to "auto" rather than "on". Since my receiver only provides a single RCA sub output and this sub requires two inputs, I use a Y splitter for the RCA connection. Could that be causing the problem?

 

[mike c]

1) you don't need a y splitter from your receiver to your sub

2) how do you know it's not turning off automatically? did it used to change color on it's LED at the back and now it doesn't?

 

[Actran]

It has a color LED on back that indicates off or on. Additionally, there is a low hum when the sub is on, but the receiver is off. If I don't need the Y splitter, how should I hook it up?

 

[mike c]

It has a color LED on back that indicates off or on. Additionally, there is a low hum when the sub is on, but the receiver is off. If I don't need the Y splitter, how should I hook it up?

if it has a hum, i'm guessing that's what's keeping your sub from going to sleep.

check your cables and cords.

one just needs one cable from the AV receiver's LFE/subwoofer output to the sub's LEFT or RIGHT input (just one will do). you also need to recalibrate when you remove the y splitter.

 

[Grador]

If your subwoofer is well designed you do not need that Y-splitter, however not all subwoofer are. I found that my subpar sub was far less subpar when I added one.

As for the issue at hand, check out this thread http://forums.audioholics.com/forums/beginners-audiophytes/5667-ground-loops-eliminating-system-hum-buzz.html

Somewhere along the line you are picking up that hum, which is likely what is keeping your subwoofer on as Mike said.

 

[theJman]

Y adapters are fine to use, and their function doesn't indicate any engineering deficiencies. All it does is increase the input sensitivity, and the only tangible result is you'll need to turn the gain down on the subwoofer because it's a bit louder. For a subwoofer that is reluctant to come out of standby mode the use of a Y adapter is often the only viable solution.

In your case, however, it seems you have the opposite problem. The link above pertaining to ground loop issues would be a good place to start, because the hum you're experiencing may very well be that. If so, that could be why it's not going into standby.

 

[Actran]

Thanks for the link. It sounds like I have a few potential ground issues to address. The new dimmer switch may be one of them. I'll do some troubleshooting and post what I find.

 

[theJman]

Thanks for the link. It sounds like I have a few potential ground issues to address. The new dimmer switch may be one of them. I'll do some troubleshooting and post what I find.

I had a ground loop problem myself, so if that turns out to be your issue consider getting one of these. It did the trick for me.

 

[Destreyf]

Thank you theJman for the link. It helped me out with another issue i was having.

 

[theJman]

Thank you theJman for the link. It helped me out with another issue i was having.

I'm glad it worked out, but now I'm curious; what other issue did a ground loop isolator solve for you?

 

[Actran]

Sorry for the delayed response. The other problem was that when I ran my dishwasher, my TV got all fuzzy. However, my excitement was premature. Bot the sub hum and dishwasher static still exist even with the isolators installed. I'm going to try removing the light dimmer next.

 

[ImcLoud]

My subs still get warm when in standby mode so I grabbed one of these and it solved the problem,
when you plug a master device {such as your avr} into the outlet marked master, it completely shuts down all the devices you have plugged into the other outlets.. Works good, mounts in your rack and show voltage... For under $50 its a good unit...
Also has a couple plugs that are unswitched... plus a ground lug..

 

[Actran]

For those interested, I was able to resolve my issue with some high quality cabling to my sub. Guess I should have started there. Thanks all for the advice and help. I now have a "humless" sub.

@imloud - it may be because I'm on my phone, but I couldn't see your link. What is the device you use?

 

[ImcLoud]

For those interested, I was able to resolve my issue with some high quality cabling to my sub. Guess I should have started there. Thanks all for the advice and help. I now have a "humless" sub.

@imloud - it may be because I'm on my phone, but I couldn't see your link. What is the device you use?

Rocketfish RF-HTS120 $45

 

[flarkitah]

For those interested, I was able to resolve my issue with some high quality cabling to my sub. Guess I should have started there. Thanks all for the advice and help. I now have a "humless" sub.

@imloud - it may be because I'm on my phone, but I couldn't see your link. What is the device you use?

I have a sub with a low hum which is also not powering off automatically. So I intend to dedicate a vacation day or 2 on resolving this.

Actran, could you perhaps clarify which cabling you used to sort your sub out, please?

 

[Actran]

I ended up ditching the Y-adapter and buying a shielded rocket fish Audio coaxial cable that was six feet long. Previously I was using a very basic RCA AV cable that was about 20 feet long and the y-adapter.

When I say coax, I'm not talking about the screw on type for you cable box. The terminations looked exactly like my previous RCA cable, but I'm guessing the internal construction was different.

I wish I knew more and could give you the techie answer, but a trip to wal-mart and $9 dollars later my problems were gone.

 

[flarkitah]

I ended up ditching the Y-adapter and buying a shielded rocket fish Audio coaxial cable that was six feet long. Previously I was using a very basic RCA AV cable that was about 20 feet long and the y-adapter.

When I say coax, I'm not talking about the screw on type for you cable box. The terminations looked exactly like my previous RCA cable, but I'm guessing the internal construction was different.

I wish I knew more and could give you the techie answer, but a trip to wal-mart and $9 dollars later my problems were gone.

That's excellent, thanks so much

This gives me a start, which I can grab with ease, before I start hunting for isolators and such, which are less easy to source