I hope someone here can answer or provide insight. I have the Klipsch Promedia 5.1 speakers hooked up to my computer. Recently the center channel stopped outputting a signal, so I figured instead of shipping the heavy subwoofer/amp combo cross country for out of warranty repair, I'd just buy the Panasonic SA-XR70 receiver and use the optical digital out on my soundcard to the receiver.
The 5 speakers work fine. What I did(and have done in the past with an old Analog Pioneer receiver with success) was hook up the subwoofer out from the receiver to the subwoofer's minijack in using an RCA/composite cable with a stereo minijack connector on the end connected to the subwoofer. All I get from the subwoofer is a consistent buzzing and no audio signal.
What did I do wrong? How do I fix it? Thanks for your help in advance.
Does the sub buzz when nothing is plugged in except power? ->check another outlet, bad sub
Does the sub buzz when the cable is plugged into the sub but not into the reciever? ->bad cable, possibly bad input on the sub
You might also want to check the sub output on the reciever (make sure the sub is turned on, make sure it works with another sub/speaker, etc).
Just to clarify, when you say minijack, exactly how big is that? Usually layman's term for 8MM is minijack, and that's the wrong plug. It should be the same type of end as a standard RCA stereo or video cable. When you plug the cable into the sub it should have a pin that fills in the inside and a metal part that fits snug around the outside of the jack as well.
The sub will only buzz when plugged in to the receiver. I had actually already tried the other options in hopes of discovering the problem.
Minijack refers to a stereo 1/8"(3.5mm) plug. It is the usual analog connection out from a sound card.
Interestingly enough, should anyone try this in the future with these Promedia's, is that I got it to work. Not in a way I had expected though.
On the back of the subwoofer are 3 minijack(3.5mm) inputs where you would normally plug in the 3 corresponding analog outputs from your sound card. The inputs are Center/Subwoofer, R/L Front Speakers, R/L Rear Speakers. I had assumed that when plugging in the subwoofer pre-out from the receiver, it would naturally connect to the Subwoofer/Center channel. This, however, produced the buzzing noise with no signal. Connecting the subwoofer preout to the R/L Front Speakers input on the subwoofer, amazingly, works correctly.
There is a very low hum that is more felt than heard when doing this method, however, I was able to alleviate it by lowering the subwoofer power/volume via its own control tower and boosting the subwoofer signal coming out from the receiver.
Ah, I completely missed that you were using a computer setup! Good that it works though. Computer subs typically don't have the dynamic range of a Home Theater sub, so I'd replace that eventually. Incidently, the reason you're still getting a small hum is that input (on the sub) is looking for a powered input and it's getting line-level from the reciever.
Eventually when money is no object(alas), I would like to get a nice home theater system. The Klipsch Promedia subwoofer isn't bad though, dual 8" drivers, and it's in a small room right now, so serves my purposes.
The subwoofer itself is bundled with an amplifier that drove the speakers and the sub. So, the subwoofer itself is powered (I turn it on and off via it's control tower), and the receiver pre-out shouldn't be sending any power to the subwoofer (minus what is needed to send the signal.) Unless I misunderstood what you wrote, the subwoofer should only be looking for a powered input if it is passive, correct?
This was happening because your sub is powered. It needs power because it has a built in amp. When you plug it in to a pre amp out on the receiver, you were overdriving the output and getting an impedence mismatch.