Audio Distribution

okiepolkie

I've come across a couple of systems where speaker distribution is wanted throughout the house. This seems to be a pretty simple idea, but I have a couple of questions first.

Do I specific channel of amplification for each speaker? I understand series and parallel wiring, so how many speakers could you actually hook up to one channel of amplifcation to keep everything kosher.

I'm guessing a speaker selector works using combinations of parallel and series wiring, so would this be a viable solution.

One system asked about this morning inquired about the following setup:

Techniques 5x100 dolby digital receiver.
5.1 running of the receiver for the living room.(probably RM6005 system)

8 in-wall speakers throughout the house in different rooms.

On the B channel of the receiver, hook up a speaker selector like this or this and use two channels of amplification for the whole house audio system. He knows that only one system can be used at a time.

As you can tell, he doesn't want to spend a lot of money, so I was hoping the speaker selector would work.

I forgot to look, but I doubt he has pre-outs for the receiver.

Thanks for any help guys.

Zach

madmax

You can do as many speakers as you want but you need multiples to keep the impedence between about 6 and 10 ohms. For example, with 8 ohm speakers you can wire two in series for 16 ohms, another leg with two in series which is 16 ohms and when you parallel the two you end up with 8 ohms. So, if you were shooting for 8 ohms then your choice is 1 speaker, 4 speakers, 16 speakers or 64 speakers. I'm not sure what formula to give you for this. You will notice I said keep it between 6 and 10 ohms. This is because you can have dips depending upon frequency and as you add more and more series/parallel legs these dips become bigger so you leave a little room for that. So, if you were using 16 speakers at 8 ohms each you may dip down to 4-6 ohms at certain frequencies.
madmax

unc2701

Madmax is absolutlely correct, but
1)that would have all speakers on at once and
2)No volume controls on each speaker.

With that method you wouldn't need any speaker selector or additional gear...

Those speaker selectors will work, however, a good chuck of the amp's power gets turned into heat in the selector box instead of sound coming out of the speakers...

Impedence matching volume controls are a better option and can be had for about $30- which will cover one pair of speakers. These will keep a constant load on the amp and give you volume control on each speaker.

The best option is a big multi channel amp, but that's probably out of budget.

okiepolkie

No budget for the multi channel amp. Because of the prices, one amp would be worth as more than the rest of the whole audio system.

They don't care if all the speakers are the same volume, so volume controls are not a big deal.

So I could run 4 speakers off of each stereo channel(each set in series, then parallel to the receiver).

That would be fine for his system.

I'll make sure to test the nominal impedences before I turn anything on though.

Thanks for the help so far.

Zach

unc2701

Sounds like you've go it. If the impedence on a voltmeter is the same for what you're wiring to the amp as it is for just one speaker, you've got it right.

BTW- I'd run all the wires back to the amp, instead of doing your series connections as you go. That way, it'll be much easier to change the setup in the future.

schwarcw

Hi Zach!

I was using a speaker selector a couple of years ago. Worked pretty, well ran two pairs of bookshelf speakers. Bought it at Circut City.

okiepolkie

I might bypass the speaker selector altogether. Since the receiver does have an A and B output, I'll just run the mains off of one output and the house speakers off of the other. I'll program the remote(probably a Harmony 659) to select speaker "a" for watch tv and dvd, and select speaker "b" for listen to music.

My next question has to do with the speakers themselves. He wants them as cheap as he can get them, so I'm thinking about using these for in-walls(not in-ceiling): Dayton 6.5's. I'm thinking they will work because they are ony 2.75 inches deep. At $17/speaker, I think they would be fine.

The other option would be the actual in-wall speakers: http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=300-036

I'm thinking the cheaper ones will work just fine, so if it won't work, let me know.

He did things pretty well overall when wiring his own house(electrician by trade). The only problem we might run into would be that he only used 16-18 gauge wire. I would have pointed him towards the 14 gauge direction, but too late now. He put a closet right behind his entertainment system and ran all of the wires into that closet, which is very nice. He also labeled all of the wires and left about 18" of wire hanging out of the wall at each location.

All that has to be done is to cut out the holes, put in the speaker, and move to the next one.

I thought about going with the RM6005 set at first, but I think the R15's, when they go back on sale, will sound better for about the same cost. He already has a decent subwoofer, so all he needs are the speakers.