I'm building a pair of ripole subwoofers with 2x 12" speakers and I'm getting to the point where I have to make a decision on whether to wire them in series or parallel. They are Peerless/Tymphany 830669 speakers rated for 8 ohms so the amp is going to see either 4 or 16.
The amp is an XTZ AP100 which is rated 2x110 W @ 8ohm, 2x180W @ 4ohm. I don't really care much about SPL, as the maximum level I'll be listening will be below 85dB and they'll be supplementing 2 Quad ESL57's running on a Quad 303 amp and I expect to cross at about 70 Hz.
Is there any advantage in wiring the speakers in series vs wiring them parallel?
The amp is an XTZ AP100 which is rated 2x110 W @ 8ohm, 2x180W @ 4ohm. I don't really care much about SPL, as the maximum level I'll be listening will be below 85dB and they'll be supplementing 2 Quad ESL57's running on a Quad 303 amp and I expect to cross at about 70 Hz.
Is there any advantage in wiring the speakers in series vs wiring them parallel?
If your amp is ok with 4 ohm loads, use a parallel connection.
The 4 ohm connection can use more power from the amp than the 16 ohm connection can.
And the parallel driver impedance will be less variable than the series.
The 4 ohm connection can use more power from the amp than the 16 ohm connection can.
And the parallel driver impedance will be less variable than the series.
The advantage to series wiring for subwoofers would be raising the impedance to an acceptable level for the amplifier, like two 2 ohm in series for a four ohm capable amp. Series wiring also makes cable losses less and raises damping factor, neither being a factor in relatively short cable runs using adequate wire gauge. Neither of those advantages are applicable to your application.
In much of the ripole's range below 70 Hz impedance will be much higher than "8 ohms", doubling 70+ to 140+ ohms the amp will only have a few watts output, probably not enough to reach a useful driver excursion before clipping.
At any rate, series wiring will needlessly reduce your available amp headroom by around 6dB.
In much of the ripole's range below 70 Hz impedance will be much higher than "8 ohms", doubling 70+ to 140+ ohms the amp will only have a few watts output, probably not enough to reach a useful driver excursion before clipping.
At any rate, series wiring will needlessly reduce your available amp headroom by around 6dB.
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In other words, your amp would only have half the power into 16 ohms, compared to into 8 ohms.
And only 1/4 the power into 16 ohms compared to into 4 ohms. (If the speakers were ideal resistors.)
And only 1/4 the power into 16 ohms compared to into 4 ohms. (If the speakers were ideal resistors.)
I was more or less assuming I was going to wire them in parallel but I couldn't come up with the reasoning behind it. Thanks, this does give me some validity.
Also apparently the amp can be bridged over 4 ohms so I don't expect it to have any problems with a 4 ohms rating when it is not bridged.
Also apparently the amp can be bridged over 4 ohms so I don't expect it to have any problems with a 4 ohms rating when it is not bridged.
