Do I need an amp?

[Louis Rizzo]

Hi all,

I just got my used KEF psw 2150 subwoofer, and when I use rca cables to connect to my denon receiver, it emits little to no sound during the calibration test, and the reciever doesn't recognize the sub. This may be entering dumb question territory, but do I need an amp for the sub? It's already powered so I didn't think I did, but that would be the obvious answer.

 

[tyhjaarpa]

You should be fine as long as the amp in sub is still alive.. Have you checked the controls in your sub that they are not set to minimum etc?

 

[Louis Rizzo]

You should be fine as long as the amp in sub is still alive.. Have you checked the controls in your sub that they are not set to minimum etc?

Yea I turned it all the way up and am at least getting something out of it, but it's very muffled and scratchy. Like I'll get the basic bass tone but it's not a clear pitch it's a hum. I think the driver might be blown, although that's a guess, because I know nothing about it.

 

[mtrycrafts]

I would go into your receiver's manual and setup menue to make sure you have properly set it for a sub.
The sub is powered. RCA is proper but it needs to be from the LFE out on the receiver. Check your speaker setup on the receiver.
What yopu are hearing probably is crosstalk between channels but not actual activation of the LFE.
Turn down the subs controls or it will wake you up for sure.

 

[markw]

You specify the sub is used. Try this to see if the sub works.

Plug in a CD player (even a portable) into the sub and play some bass heavy music.

If it makes sound, it probably works. It'll naturally be all bass but at least you'll know that the sub works. ...or doesn't.

You might be interested in this: http://www.avsforum.com/forum/155-diy-speakers-subs/1364560-aftermarket-amp-kef-psw2150.html

 

[agarwalro]

Plug in a CD player (even a portable) into the sub and play some bass heavy music.

Or even a phone headphone out and a cable with RCA - headphone pin.

OP - Keep the volume 1/3 on the sub and no more than 50% on the phone, so you don't blow the sub in testing it.