# Using Pro-Amp with home speakers...



## michael1892 (Oct 12, 2011)

Hey everyone,

So this is a pretty beginner-level question I'm sure...
I would like to start using a pro amp such as the crown xti 2000/4000 with my home speaker system.

I have 14 100-watt speakers throughout the house, all in-celing/in-wall, and would really like to crank them up to full power. 

My question is, how much amp power would i need, and what kind of receiver will i need to send the signal to the amps?

-Thanks


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## tonyvdb (Sep 5, 2007)

Before you try to do this do you have impedance matching volume controls for each speaker in your house? Running 14 speakers without this will overload/overheat any amp and cause damage.


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## michael1892 (Oct 12, 2011)

tonyvdb said:


> Before you try to do this do you have impedance matching volume controls for each speaker in your house? Running 14 speakers without this will overload/overheat any amp and cause damage.


There are volume control knobs for 8 of the speakers (4 knobs, 2 speakers each), I do want to add 2 speakers each to 2 of the knobs, so it would be 2 with 4 speakers and 2 with 2 speakers. not sure if thats what your referring to though...


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## tonyvdb (Sep 5, 2007)

The problem is that every time you add a speaker this puts more and more of a load on the amp. Anything below 4 Ohms is not good for an amp of any size. It sounds like you already have a 4ohm load at present, adding more would bring it far to low.


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## michael1892 (Oct 12, 2011)

interesting... so what do you suggest i do in order to run these speakers properly? i assumed that using pro-amps would solve the problem because consumer-grade receivers just aren't doing it... i know its an unusual set-up...

also, I'm pretty sure they are all 8ohm speakers.


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## tonyvdb (Sep 5, 2007)

Your really only option is to have a small amp/receiver in each room to power your speakers. You would run a line level signal from a zone 2 or 3 off your main receiver.
yes, if the speakers are 8ohm then each time you add another speaker to the line you reduce the ohms by half so two 8ohm speakers gives you 4ohms. There is another option but that means that you would need to rewaire everything you have installed and make sure that all the speakers are in series so the negative of the one speaker connected to the positive of the next and so on....so positive out from the receiver to the +- speaker +- speaker +- speaker +- back to the receivers negative post, do you follow?

More info here


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## Guest (Oct 12, 2011)

I think your looking for something like this.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-815


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## WooferHound (Dec 8, 2010)

If you put four 8 ohm speakers on the output of an amplifier you will end up with an impedance of 2 ohms which is almost a short circuit and of course it will blow an amp if you short the speaker outputs.

What you want to learn about is a 70v Distributed Sound System which is also called a Constant Voltage System. This involves getting a bunch of Impedance Matching Transformers. A large transformer goes onto each output of the amp, and a smaller transformer goes onto each individual speaker in the system. This will present the amp with a proper 8Ω load on it's outputs and lets you use inexpensive volume controls in the rooms that you want to control. This is very much cheaper than using a 12 channel amplifier system

Here is some more information about these systems . . .
http://http://en.wikipedia.org/wiki/Constant_voltage_speaker_system
http://http://www.jblpro.com/catalog/support/getfile.aspx?docid=215&doctype=3
http://www.ticcorp.com/25v_70v_100v_systems.htm
http://www.wescomponents.com/datasheets/100v_guide.htm

for a discussion about this , see this thread . . .
http://www.hometheatershack.com/for...6-whole-house-audio-help-im-held-captive.html


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