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Guys, I really don't know where else to write about this, and although this forum deals with studio sound, maybe someone can help me out.

Setting up sound in a 2-floor restaurant, just not sure about what gauge cables to use, how to hook up about 14 small speakers to one amp, the issue of splitting cables so that I only come into the amp with maybe 2 rights and 2 lefts, etc, etc.

Any comments/suggestions?

Comments

moonbaby Sat, 07/21/2007 - 06:00

Your situation sounds like you need a professional contractor (no, I'm not one). The fact that you asked how to drive 14 speakers off of a single power amp (!) illustrates this. But, to answer that question, there are special amplifiers and speakers, utilizing 70-volt transformers, so that this can be done. The afore-mentioned contractor will have the proper tools and equipment to interface and install this type of gear. Trust me, it's harder than it looks, and the last thing you need to be doing is climbing up into the ceiling to correct mistakes !

anonymous Sat, 07/21/2007 - 07:30

Actually where I'm located, there aren't that many professionals that could help me out. I'm a pro music producer, and obviously quite clueless right now, but I can't see why I would really have to bring in a contractor.

How do restaurants and cafes do it? If anyone knows of any site that can be of help, PLEASE TELL ME!

I wasn't thinking of bringing 14 x 100+watt speaker cables into an amp directly. I'm guessing about 14 x 30w speakers. This is for a two floor restaurant, in an old house, playing light lounge music.

I want to look into an amp that can control 2 or more sets of speakers, meaning speakers "A" and speakers "B" (meaning 2 lefts and 2 rights.)

I'd like to have 2 cables running upstairs, and 2 running downstairs. Upstairs will probably have about 5-6 speakers, and downstairs about 8.

I want to know if it's ok to run two cables upstairs (and what gauge), then split them to connect the 6 speakers (and if splitting is not a bad idea, what gauge cables I should use), and the same for downstairs.

Again, I'm not talking about connecting 100w speakers, I'm guessing maybe 30w each. And I'm assuming insulated cables, such as Monster cables, are required.

Space Sat, 07/21/2007 - 08:48

Hey Chris,

What you are trying to do is set up a multi zone audio system and since you are willing to have a go at it yourself...do a search for "multi zone audio."

It's a good place to start to get a more clear definition of what it is you can or maybe cannot do. Even a simple setup as you have requested needs care and attention to placement of speakers, components and proper wire gauge per foot run.

I know the simple math reads like you can take an amplifier rated@ 100 watts per channel and couple it with (5) 20W speakers per channel. In practice it is a bad idea. Even if all it does is overload and shut off as newer models do, worst case scenario is you blow an amplifier and maybe worse...

http://www.home-technology-store.com/structured-wiring/NT-8ZAWH.aspx

Hope this helps,

Brien

moonbaby Sun, 07/22/2007 - 14:24

LIKE I SAID you need to look at 70-volt line distribution for lots of small background music speakers instead of your standard-issue "ohms-rated" speakers. That's what a contractor would more than likely use to prevent loading issues ("ohms"), and for background music/paging systems they can sound decent.
Since you have a problem finding a contractor in your area, try going to Parts-Express.com. This place caters to the DIY crowd and they have a lot of A/V contractor components (speakers, amps, mixers, hardware, cabling, tools, you name it), specializing in sound. They also have a good tech support network for ....novices. Check them out, I think they'll be able to assist you!

anonymous Mon, 07/23/2007 - 02:17

A very long time ago I set up music for a beach bar using borrowed consumer amps and speakers. We had 4 amps and 8 speakers; the cassette (yes it was that long ago!) and cd player were connected to the first amp which had its tape-out plugged into the aux-in of the next amp which had its tape out plugged into the aux-in of the next amp and so on. Perhaps some of the amps could have driven 4 speakers but we didn't try. It worked fine, but we never pushed the amps more than half-way and had a desk fan blowing at the amps.

However, if you want to use just one amp, as others have said, you cannot just connect all 14 speakers to the posts regardless of their declared power as you will get impedance problems. You will probably need to buy a multi-zone PA amplifier or at least a "speaker distribution hub".

Buzzgrowl

anonymous Tue, 07/24/2007 - 14:48

I just did an install at a country club where we put in 6 JBL speakers oustide on the driving range, and ran all of them off of one Crown Amplifier. We ran music from inside the country club, a cd player from the pro shop, and an announcement microphone through a Shure SCM262 mixer, to a Crown 280A Commercial Amplifier, and then out to 2 Control 28T, and 4 Control 25T. These JBLs have transformers in each speaker and switchable taps for 70W or 100W systems (ceiling models are available as well). As long as you adjust all of the taps according to the total ohm load, (and of course, don't take the amp below its rated ohmload) you should be able to run all of your speakers off of one amp. The entire install including the 300ft of low voltage, all weather wiring cost about $2000.00. Here are the links to the gear that I used in my install.

http://www.shure.com/ProAudio/Products/MixersAndDSP/us_pro_SCM262_content

http://www.crownaudio.com/ca_htm/ca-a.htm

http://www.jblpro.com/pages/install/cc_surface.htm

The problem with that system is all of the speakers are on one volume control. If you needed seperate zones, you would need a mixer with more output capabilities and/or more amplifiers as well. You could also check out the DBX Zone Pro System. Its a bit more sophisticated, and more expensive, but check it out. The site explains a lot about how a low voltage system works.

http://www.dbxpro.com/1260_1261/1260_1261.php

Also, if you can get your hands on a Crown Amplifiers catalog, they have a great signal flow diagram to demonstrate how their commercial series amplifiers work in a low voltage system