Subwoofer question.....

[777php]

I finally put together my home audio system with a Pioneer VSX-D811s receiver and 4 Wharfedale Vivendi Modus satellites with a WH-2 Center channel and a Powercube 8 subwoofer.

My question is regarding the inputs on the back of my subwoofer. I have both a L and R input/outputs but on my receiver I only have one subwoofer output. I thought that all subwoofers were mono so why the left and right inputs? I attached a single output cable to the sub on R channel however whenever I turn on my sub I get this loud hum eminating from it. This happens when I switch from Right to Left also, is this normal?

I am a total home audio newbie so bear with me. Can someone explain to me how to properly attach a sub? Is there a special sub wire that goes from one to two outputs?Also, I have a crossover frequency knob, what the heck does that do?
Thanks guys.

 

[Colt45]

im assuming the sub out is mono or center channel.

therefore... if you can ghetto rig it like car audio, you can hookit like this:

(+)out from amp ---> Left(+) on the sub
(-)out from amp ---> Right(-) on sub

might not work though.. i only deal with car subs and sh|t, and that works. so don't quote me on it

as far as the crossover, that just sets what frequency range the sub responds to.. most likely just a low pass thing.. 0-80hz, 0-120hz, allhz.

 

[cavdraco]

are there outputs as well as inputs on the sub if so the crossover is to tell the sub what frequencies to use and which to send to the satelites
i dont know much about that sub so i can only guess but you might want to use speaker outs from the reciever into the sub some subs dont use the mono in off the pioneer

hope this helps
cav

also try going into the menu on the reciever and see if the sub out is on

 

[sohcrates]

all you need is a y-adapter available at radio shack

rca male to dual rca female, then run a normal RCA cable to sub...

 

[vi edit]

When I was in that situation, I ran the sub off of the second set of speaker outputs. My Yamah receiver had an "a" and a "b" set of speaker outputs and I could run both simultaneously. I had my mains running of of the "a's" and the sub running off of the "b's".

 

[Flashram]

Subwoofers are mono. Therefore, you only need to run a cable to one of the RCA jacks. If you want to buy a y-adapter you can, but you're not going to get any extra output from it.

 

[777php]

Originally posted by: Flashram
Subwoofers are mono. Therefore, you only need to run a cable to one of the RCA jacks. If you want to buy a y-adapter you can, but you're not going to get any extra output from it.

Thats how I have it setup right now but there is this constant annoying hum coming from it. Is that normal?

 

[davestar]

Thats how I have it setup right now but there is this constant annoying hum coming from it. Is that normal?

I had a similar problem with my sub, and the problem was due to the sub and reciever not having a common ground. I simply run a wire from the metal casing on the reciever to the metal casing on my sub, and the hum is no more.

And don't bother with the Y-adapter - there's no benefit from using it.

 

[sohcrates]

also check where your power strip is plugged in for your stereo / sub...sounds like you might be getting a hum from a bad ground...

 

[Flashram]

Regarding the hum (which is not normal to answer your question), go to radio shack (or Lowe's, Home Depot, Wherever) and pick up a cheater plug. Shouldn't be more than a dollar or so. You just plug the sub power cord into the cheater plug and then the plug into the wall.

 

[777php]

Originally posted by: Flashram
Regarding the hum (which is not normal to answer your question), go to radio shack (or Lowe's, Home Depot, Wherever) and pick up a cheater plug. Shouldn't be more than a dollar or so. You just plug the sub power cord into the cheater plug and then the plug into the wall.

I've tried plugging the sub into another wall outlet but I still get the hum so I just might go and get the plug that you're talking about. Hopefully that will solve the problem. Thanks guy, I'll let you guys know.

Until then I'll be open to even more suggestions.

 

[Flashram]

Definitely try the plug. It worked for me. And for a dollar you can't lose.

 

[davestar]

The "cheater plug" simply floats (i.e. doesn't affix voltages at which the device operates relative to a ground) the device to which it is connected. So if you use the cheater plug, the sub should operate about the ground of the receiver.

However, you're prolly more interested in getting the hum fixed than in getting an explanation. If you connect a wire between your sub and reciever casings (as I mentioned before), you can find out if your problem is due to differing grounds. If the wire stops the hum, then you can either use the wire as a permanent solution, or get a cheater plug and make your setup a bit prettier. If the wire doesn't stop the hum, you've saved yourself a trip to Home Depot.

 

[777php]

Originally posted by: davestar
The "cheater plug" simply floats (i.e. doesn't affix voltages at which the device operates relative to a ground) the device to which it is connected. So if you use the cheater plug, the sub should operate about the ground of the receiver.

However, you're prolly more interested in getting the hum fixed than in getting an explanation. If you connect a wire between your sub and reciever casings (as I mentioned before), you can find out if your problem is due to differing grounds. If the wire stops the hum, then you can either use the wire as a permanent solution, or get a cheater plug and make your setup a bit prettier. If the wire doesn't stop the hum, you've saved yourself a trip to Home Depot.

Do I affix just another speaker wire to the metal casing of my receiver and attach the other end to the sub? Where do I attach the other wire on the sub?

 

[777php]

BTW can anyone recommend some good websites to buy some speaker wires and also name some good brands?

 

[davestar]

My reciever has an extra screw type connection labelled "signal ground" that I attach one end of the wire to (any screw on the metal back-plate should do though). On the sub end, I simply back out a screw that holds the amp on the enclosure, wrap the wire around the screw a couple times, and put the screw back in place.

 

[777php]

Originally posted by: davestar
My reciever has an extra screw type connection labelled "signal ground" that I attach one end of the wire to (any screw on the metal back-plate should do though). On the sub end, I simply back out a screw that holds the amp on the enclosure, wrap the wire around the screw a couple times, and put the screw back in place.

Cool...I'll give that a try. Thanks.