doubling up speakers?

[soundhound]

i was looking at an amp on ebay, and the guy told me one reason he was selling it is because it's only 2 channel, and he has 3 sets of speakers. he said he doubled up two sets of speakers on one channel. he said he's had it and (presumably) has been running it that way for about 6 or 7 months. i was wondering, can that stress the amp at all, or maybe damage it?

 

[zildjian]

can that stress the amp at all, or maybe damage it?

Sure it can stress the amp, but how much depends on several factors: the amp and it's low ohm stability, the impedance of the speakers, and HOW the two speakers were wired together (either in series or parallel). I don't know why one would want to do this anyhow, then you have two speakers playing the same exact thing, and at a different level than the other channel... odd set up.

 

[soundhound]

thanks. i asked him, and he said he used some kind of "separate multi-speaker unit/box" that ensures nothing gets fried. it sounds like a weird setup to me, too, but he seems to know what he's doing with this multi-speaker thing, so i think it's probably okay.

 

[MikeSp]

I don't know why one would want to do this anyhow, then you have two speakers playing the same exact thing, and at a different level than the other channel... odd set up.

I use a 6.1 surround setup and doubled up the two rear surround speakers on one amplifier channel in order to provide a wider soundfield for the rear surround information (there is little source material with true 7.1 anyway) -- but used the 4 ohm connections on that amp channel instead of the 8 ohm speaker connection on the other channel on the same amp that is used to drive the front center speaker and used the 8 ohm connections for the other speakers on the other two amps.

MikeSp

 

[jcPanny]

Impedence matching

thanks. i asked him, and he said he used some kind of "separate multi-speaker unit/box" that ensures nothing gets fried. it sounds like a weird setup to me, too, but he seems to know what he's doing with this multi-speaker thing, so i think it's probably okay.

Impedence matching volume controls or speaker selectors are common in whole house audio systems. When installed properly, they ensure that the amp sees a 6-8 ohm impedence regaurdless of how many speakers are connected. With 2 pairs of speakers, for example, a 100 Watt receiver will deliver 50 Watts to each pair.