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Topic: Need advice on hooking 2 speakers to 1 output |
Wayne Carver
From:
Martinez, Georgia, USA
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Posted 28 Apr 2004 7:33 am |
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| I have two 8 ohm speakers that i want to hook up to a Mono pa amp. Should I wire them in parallel to the 8 ohm tap or wire them in series to the 4 ohm tap? I have them wired in parallel to the 8 ohm and it sounds ok. The amp is powerful enough and the speakers are small so I could only turn the volume up about halfway as it is. Just wondered what the advantages of either hookup would be. |
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C Dixon
From:
Duluth, GA USA
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Posted 28 Apr 2004 10:12 am
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Wire the speakers in parallel. This will match perfectly your PA's 4 ohm output and the transfer of power will be maximum.
As far as a listening test, few (if any) would ever know the difference. A missmatch causes a fall off in power directly proportional to the amount of missmatch in either direction. But remember, the human ear cannot detect a power increase or decrease by a factor of 2 until the power has changed by a factor of 10!
Thus, missmatches rarely are noticed, unless one compares in an A/B test. Also, unless the amp is running full power, it makes little difference anyway, because a slight adjustment of the gain control will make up for any loss in power. Noticable fidelity changes is rarely ever a factor in missmatches.
carl
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Roger Kelly
From:
Bristol,Tennessee
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Posted 28 Apr 2004 10:14 am
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I believe I would hook the two 8 ohm speakers in parallel to the 4 ohm tap.
Have you tried that? The Amp should "See" a 4 ohm load that way. |
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Wayne Carver
From:
Martinez, Georgia, USA
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Posted 28 Apr 2004 10:46 am
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Thanks for the tips. I never can remember the formula. So: two 8ohm speakers(parallel)equals 4ohms
two 8ohm speakers(series)equals 16ohms
Any advantage to wiring them in series to the 16ohm? I guess it would be better on the amp wiring them in parallel to the 4ohm taps?
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Roger Kelly
From:
Bristol,Tennessee
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Posted 28 Apr 2004 12:44 pm
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| If you have a 16 Ohm Tap, you can hook two 8 Ohm Speakers wired in series to it and the Amp will like it.....but you said you only had a 8 Ohm and a 4 Ohm Tap. If you hook a 16 Ohm load to an 8 Ohm Tap, it will cut your power down to about half, but otherwise shouldn't cause any problems to the Amp. |
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C Dixon
From:
Duluth, GA USA
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Posted 28 Apr 2004 1:09 pm
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Wayne, here is the formula:
If the two speakers are not equal, use...
"product over the sum".
Example: a 16 ohm speaker in parallel with an 8 ohm speaker, is (16 times  divided by (16 plus ; or 5.34 ohms.
If the speakers are equal, simply divide one of them by two if parallel; or add them together if in series. Thus two 8 ohms in parallel is 4 ohms. In series it is 16 ohms.
carl |
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jeff reynolds
From:
Jackson, Ms.
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Posted 4 May 2004 7:57 am
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| does any of the different wiring i see hear change the tone? |
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C Dixon
From:
Duluth, GA USA
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Posted 4 May 2004 8:12 am
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For all practical purposes no.
Of course if you changed it on a given person's guitar, and they knew it, in all likelyhood, "the tone has changed". If they did not know it, few (if any) would ever detect a power or tone change at all.
I must add the following story I have told before on this forum. I was at a dear friend's house one time and was talking about cabinet drop. Whereupon he said, "my guitar does not have it". I said, "may I try it?" He said, "sure, go ahead"
So when I put a tuner on it and pressed the A pedal, the 6th string dropped. When I showed him the tuner, he said,
"well, it never did that before you messed with it!"
He was NOT kidding. 
carl |
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