Connecting Speakers to an Amp

seashaw

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Is it possible to connect 4 speakers to a 2 channel amp.
I presume it will work, but do I risk damaging the amp or speakers.
Anything I special I need to do or is there a better solution apart from buying a 4 channel amp.

Mark
 

cliffb

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It depends, ..... <grin> didn't you know this would be the answer!!
If it's a reasonably modern amp...i.e. one without valves... then the short answer is yes. The long answer is to match the amp's output impedance (ohms) to the impedance of the speakers. To do this you caneither connect the speakers in parallel, which will halve the total impedance on that leg of the amp, or you can connect them in series, which will double the impedance. Most modern amps are pretty insensitive to low impedances.
Oops.... I have a visitor..... so ... hope this helps and I'll get back to you if you need more advice.
 

aluijten

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Quote:
Why would it be any different to attaching a single speaker (box) which had multiple drivers in it?

This is quite a nice question.
When a box has multiple drivers there is a piece of electronics in the box called a cross-over filter. This 'assigns' the different frequency ranges to different speakers.
Impedance is another word for Resistance for Alternating Currents (AC).
Loudspeaker signals are always AC (as opposed to DC).
The annoying thing about impedance is that it varies with the frequency of the AC signal.
A good speaker/box/crossover filter design tries to compensate this as much as possible to get a constant impedance over the full frequency range

Back to the original question:
Normal domestic amplifiers have an recommended speaker impedance of 8 ohms, most car radio's have 4 ohms.
If you put two 8 ohm speakers in parallel the total load will be 4 ohm. If you put them in series it will be 16 ohm.
As a general rule the speaker load should match the amplifier. Higher values for the total speaker load are Ok but will lead to powerloss. Lower values can lead to amplifier damage.

Hope this helps,

Arno
 

seashaw

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It depends, ..... <grin> didn't you know this would be the answer!!

Was hoping it be simple, however thinking it wouldn't.
The amp has 4 ohm on each channel. So I should check the rating of the speakers and then decide how to wire them.
Next question then, is how do you wire them in parallel and how do you wire them in serial.

Thanks

Mark
 

VicMallows

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What sort of amp are you talking about? You are presumably talking about an amp on a boat, so do you just mean a regular car-radio/stereo sort of thing?

If you are talking about some really powerfull home (I hope not boat!) kit. the answers could be very different.

Vic
 

William_H

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To connect in series you take the wire coming from the amp (active or +) take it to the first speaker and connect to the (+ or red) terminal. Take a wire from the (-) terminal of that speaker to the (+) of the next speaker. The remaining terminal of the second speaker is connected to the (-) or other terminal of the amp. This pattern is repeated for the other channel speakers. so the current flows from the amp through the speakers one after the other back to the amp. Note we use the term (+) for connections of course it is not DC and these connections are not critical unless the speakers are close to one another. if you can identify (+) then you might as well wire it correctly.
Now for paralell connection the (+) of the amp connects to the (+) of the first speaker and the (+) of the second speaker and the (-) of the amp to the (-) of both speakers. So the current has a choice of which speaker to flow through. A bit like turning 2 lights on it loads the amp more and may damage the amp.
Puting two speakers in series will reduce the power capability slightly but will probably still be very adequate and will not damage anything.
If you have 8 ohm speakers and put them in paralell on a 4 ohm amp that should be fine but 2X 8 ohm speakers in paralell on a 8 ohm amp is bad.
regards olewill
 
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