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Chained speakers signal connected in series

I have two pairs of the same model speakers (Tannoy SGM 10B) connected in series to two monoblock amplifiers. The left channel amp drives two speaker cabinets on a left (speakers L1 and L2) and the right channel amp drives two speaker cabinets on a right (speakers R1 and R2).
The positive speaker output of the left amp is connected to a positive post of the first speaker L1(+). Then the negative post of the same first speaker L1(-) is connected to positive post of the second speaker L2(+) with the its negative post L2(-) connected to the amplifier's negative speaker output.

AMP(+) > L1(+)
L1(-) > L2(+)
L2(-) > AMP(-)

Both left channel speakers have a cross-overs build in. Does the audio signal that the first speaker L1 receives from amplifier is any different from a signal the second speaker L2 receives from speaker L1? Does the crossover of the first speaker L1 modify the output signal that goes to a second speaker L2?
esputnix
russ69's avatar
russ69
3,520 posts
 
I didn't confirm your hook-up but it will work fine. The next question is your amps. Cannot they take the lower impedance of a parallel hookup? If they can that is better and more power. 
oldhvymec
5,101 posts
 
As long as the cable is LARGE enough and a good quality cable it should be the same. BUT you're doubling the ohms and 1/2 the output of the amp. In turn low distortion and much higher dampening. Probably sounds BETTER in series for sure.. Second it will surly help the amps run cooler.

Just something to think about.. 
imhififan's avatar
imhififan
2,205 posts
 
You can connect two speakers in series and it won’t harm the amplifier.
BUT because of two sets of crossover connected in series the sound it produce will be totally different from just one speaker connect to the amplifier! Both woofer in each speaker will get much lower crossover point and the tweeter will get a band-pass filter instead of high pass.
audiokinesis
2,746 posts
 
Unless the two loudspeakers are identical, there will be some modification of the frequency response of BOTH speakers. It does not matter which is first and which is second in the series.

The difference may or may not be small, it depends on the specifics. Try it and see what you think.

I disagree with imhififan’s opinion that the crossover points will change. In my experience, they do not. But each speaker’s frequency response will be modified by the other speaker’s impedance curve being in its signal path. If the two impedance curves are identical, then so is each speaker’s sensitivity to the other’s impedance curve, and the net frequency response of each is unchanged. But if their impedance curves are different, then there will be changes in the frequency response of both speakers.

(For geeks only: It is tempting to think of each speaker as a resistor in series with the other, thus ruining the amplifier damping factor for both and effectively doubling the woofers’ Qes, but this is also incorrect, because each speaker also has its own motor strength.  Assuming generally similar speakers the DC resistance is approximately doubled but so is the total motor strength, therefore woofer Qes is not degraded. This is a different situation from adding an equivalent series resistance, in which case only the DC resistance would be doubled [with total motor strength remaining the same], in which case the effective driver Qes would also be doubled, as predicted by the calculated degradation in effective amplifier damping factor.)

Duke 
speaker designer
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