Axiom Home Page Forums General Discussion Stereo kinda off topic -- how to wire 4 speakers stereo

hey all, figured you were nice and knowledgeable enough before when helping me decide on axioms that i would ask a totally non-axiom stereo question.

my father wants to place speakers in his house on seperate floors to give some ambient music to the place. Most likely 2 for each floor for a total of 4 speakers with each floor having its own left/right combo if that makes sense. I know of receivers with multizone capabilities but i'm thinking there may be better ways of going through this then getting a 4-500 reciever with 6.1 etc when he will only use the stereo setting. so, let me hear it. Whats the cheapest/easiest way to get this done. He's not looking for the best sound quality and will probably even use in wall speakers, so i just need advice on what receiver/amp etc i need for the job.

Thanks,
Adrian

What he needs is an impedance regulating speaker switch. Radio Shack carries them: here's one.

What you do is connect the switch box to the receiver using a pair of speaker wires, then wire each pair of speakers to a different terminal on the back of the switch. The receiver will only see the load of one pair of speakers, even if you're driving four or more at once.

Slight thread hijack....an impedance regulating speaker switch? That's something I've never heard of before. If you select more than one pair of speakers, your receiver only sees one pair? How does it work? If they're wired in parallel, the impedance lowers, right? And if they're wired in series, the impedance increases, right? So does it drive multiple pairs of speakers but have the load of one pair? I have an embarrassingly basic knowledge of electronics, but I would love a dumbed down explanation of how this things works.

Adrian, if your use of "ambient music" implies that your father wants to have both sets of speakers operating simultaneously to create an effect throughout the house, then no switching would be necessary. He could simply connect two sets of 8 ohm speakers in parallel to the outputs of a stereo receiver and have both sets playing. If he wants to run one set separately from the other, then a switch such as Peter described could be used, or possibly even better get a stereo receiver such as the HK3380(little over $200) which has output terminals and on/off switches for two sets of speakers.

I'm guessing the switch would have to know the impedance of the speakers it is connected to. When it's feeding both in parallel you're right without adding anything two 8ohm speakers would be seen as 4. But the switch could add an inline 4ohm resistor before the paralleling to bring the total back up to 8. I guess this is not a vary good solution cause of the losses. But off the top of my head I can't think of a non-active solution that inccurs no losses.

thanks for the info guys. If i wire up 4 8ohm speakers, 2 each channel, the reciever will now see a 4 ohm load correct? So i just need a reciever that wont be overloaded with 4ohm speakers and im fine right?

Adrian

JohnK -

Could he not use the "B" speaker posts on his receiver? That seems like the easiest answer to this problem. If his receiver has "A" and "B" posts, that is.

Mark

I read this differently -- your father is looking to run 4 pairs of speakers at the same time -- 2 pairs on each floor. If so, another option would be to wire them in series-parallel. You can wire 4 8-ohm speakers in series-parallel and get a resulting impedence of... 8 ohms. Pretty much any stereo receiver or amp would work fine.

Can someone else draw the diagram this time ?

Mark, yes, that's why I suggested a stereo receiver(his father may have none now)such as the HK3380, which has separate output terminals(and on/off switches)to drive two sets of speakers in parallel. Since a total of four speakers was mentioned, I interpreted this to mean two on each floor.

Adrian, yes, if the 8ohm speakers are connected in parallel the resulting net nominal impedance is 4ohms. Many receivers, including the HKs, would have no problem with this.

But... aren't the A and B terminals just wired in parallel internally ? Don't you end up with a 2 ohm load if you are running 4 ohms on A and B at the same time ?