I don't do much sound work, other than the occasional "surround sound" system for a clients home.

Current client is a a small doctors office which has existing 8-ohm (unamplified) speakers in the ceiling and a volume control in each exam room. Wiring has been cut-up/out over the years.

What is the best method to wire these? Parallel, series or combination? How do I wire in the individual volume controls?

We're not talking "hi-fidelity" here, just background music for a medical office.

:shrug:

Rip it out and use 70 volt speakers with an 70V volume control, and of course an amplifier with a 70-V output.

Two of the best sites for products, solutions and information:

• Valcom
• Bogen

I agree, this is the only way to go for single channel commercial audio. Paging speakers and amps are even quite economical.

70V lets you run one 16 ga. pair from the amp out to all the volume controls, they just all connect in parallel. Parallel any speakers if you need more than one in each zone and then drop to the appropriate volume control. Remember to keep the wattage below the maximum allowed on each volume control, 20W is common I think.
Check with your local codes for cable type required and if speaker and volume control back boxes are necessary.
Oh and with a real amp you can give them...paging with their music. From the phone system even.

CUF

Russound uses Cat5e and distributed amplification at the volume control.

No high power through the wires, no wattage loss on long runs, plug-n-play.

No. Client does not want new equipment, they wish to utilize what they have. Haven't you heard? Doctor's are broke!

Now, can anyone refer to my original question and advise the best way to wire these existing speakers & volume controls?

I don't believe the existing volume controls are rated for Cat5. They are the old-looking plastic knobs numbered with 1 ~ 8 on the wallplate.

How many speakers are we talking about? Do you have the music source they were originally using with these speakers? Are you adding anything, or just rewiring what was there already?

To specifically answer the question, when dealing with 8 ohm you need to carefully plan out the location and wiring for each speaker and physically connect in series or parallel (as appropriate) to put no more than an 8ohm load on the amplifier. For example, two 8 ohm speakers in parallel equals 4 ohms - you'd need to wire those two speakers together in SERIES with another two speakers wired in parallel to balance back to 8 ohms.

THIS is why 70 volt exists! So that you can add a speaker or two or three without carefully tracking the wiring and keeping it all in balance.

A simpler answer may be to rewire just as it is now. If it used to work, it should continue to work.
Mike

Don't use a series/parallel setup or one volume control will effect all the other rooms. You need to put a regulated output amp 25 or 70 volt will work. Just add transformers to the existing speakers. To add a volume control you can use a 5K pot on the primary side of transformer or a 50 ohm between Transformer and speaker.

Control wiring
feed and load common to one side of pot (left side if looking face on)
feed hot to other side of pot
load hot to center of pot

There's approximately 8 speakers. Not adding anything, just trying to resurrect what's there. No music source. Was thinking something basic (e.g. Radio Shack).

Can't/won't be adding amps, transformers or flashing LED disco lights. Volume controls are already present in each room. This worked years ago, it should work again. Just need to know how to connect what's already there, thank you.

As Mike points out, you may need a combination of speakers that are in parallel and series to keep the load around 8ohms. In parallel the resistance is the inverse of the sum of the inverse of each resistor. In series they just add. If you end up with a 2ohm load on your music source, you may burn up the output. Maybe they had something in there before with 8 outputs? As Merritt points out, the volume control will affect the overall circuit, so that needs to be taken into account as well. A volume control that is in series with a speaker, and they are both in parallel with another speaker/volume control, and that whole mess is in parallel with the same again, that should give you 4 speakers on one output. How well the music source deals with that depends on the quality of the music source.

Disclaimer: I don't deal with audio ever...just digging back to my electronics education from 1996, so I may be completely wrong here.

You home run from the volume control to the source of the background music. Wire from the volume control to the speaker or speakers if it happens to be a stereo volume control or two channel as some call it.

After home running you need something like this:

https://www.amazon.com/Niles-VCSHUB...p;ie=UTF8&qid=1302816939&sr=1-37

a speaker wiring distribution hub.

It works really well. The input goes to the music source/amp (can be 8 ohm or 70 volt) and the output to the volume controls.

If customer doesn't want to spend a couple hundred bucks on this you will just end up with a mess of wire nuts somewhere...you can't punch down stranded speaker wire on a 66 block, it just will not work.

You need to determine the wiring, and whether or not its usable. At that point come back here and give us a rundown of whats going on and they'll be much better help. 8 speakers is nothing and should relatively easy to get going right with minimal tweaking.

Can't/won't be adding amps, transformers or flashing LED disco lights. Volume controls are already present in each room. This worked years ago, it should work again. Just need to know how to connect what's already there, thank you.

Just sitting here shaking my head.

You want us to tell you how do do something and you have no clue what's there. There ARE impedance matching volume controls that allow multiple 8 ohm speakers to be hung off an 8 ohm amp output. Niles, Russound and many other manufacturers of residential systems make them. Are you competant enough to determine WHAT kind of volume controls are "already there"?

If this is a hack job and the proper equipment was not used, wire it up any way you want to any POS Rat Shack amp. It should work "just the way it did years ago" and there is a reason it's not working today. Just collect your money before you leave.

-Hal

So glad you're back, Hal.

Glad to be of service.

-Hal

It's not working today because the previous client moved from the office and the source wires were cut at the ceiling during a re-model.

Nonetheless, project is finished, music sounds fine and client is happy.

Thanks, all!

You got to love Hal. Jeez I missed him. Lets talk about electricians doing cabling and then lets talk about CAT 5 being punch down on 66 blocks for voice just to welcome him back.

Just kidding Hal. The place has been boring without you.

Jim

Hal was always a voice of reason in this world gone crazy, welcome back hal

Nonetheless, project is finished, music sounds fine and client is happy.

See what a little positive encouragement can do?

-Hal

Great to see you back Hal!

All Respects for the knowledge.. NOT the Crass.

Danny,

I had to read a couple replies past your original source to see if a music source and amp were mentioned. Did you have any kind of frank discussion with the client to see if they could provide a little more of a budget for the music/amp source?

If you ever go new someday, go valcom. I did and it turned out great. All speakers at least based on what I remember, were wired in parallel to the valcom unit.

LMFAO....

Having been in this exact similar situation, I have used the Phoenix Gold ISM Speaker Selector. I don't see it on their web site but my distributor still has it in their newest catalog. It appears to be like Derrick's suggestion so there are some limited work- arounds. I would have chimed in earlier but somehow missed this discussion. I'm adding my 2 cents just for future reference.