Series-Parallel Or Parallel-Series

[shaan]

Hello Friends!

My current project is a pair of full-range speakers. I have two 20watt SE class-A amps which will drive them. I searched for 15-20watt full-ranges in my area but found nothing. The only available ones are of 30watt, but, are 8"! My liking is in the range of 4"-6". There are 4" drivers available, are of 8ohm impedance, but have a mere 5watt maximum power handling. My amp is happiest with a 8ohm of load impedance. So I decided to connect 4 of the drivers to each amp in Series-Parallel configuration resulting in 8ohm total impedance.

My question is that which connection technique should I choose? Which Of the following would be better?

Left or right?

........OR........

I have listened to both, but did not hear any difference in sound quality. I would like to interconnect the drivers in both channels in physically identical ways, i.e. will use any one of the two configs for both channels.
So any information about any objective advantage/disadvantage of either configuration is very much appreciated.

Thanks


.

[picowallspeaker]

With series connection of two speakers ,except the doubling of impedance and the output level (And a double efficiency)=,nothing changes .Paralleling two speakers ,it halves the impedance ,doubles sensitivity and output . With serial-parallel connection impedance remains the same , but you get 4 times output level ,which is +12dB,same rise of efficiency(+6dB-1W) ,and same change in sensitivity ,+6dB with 2,83 V.

[shaan]

Originally Posted by picowallspeaker

With series connection of two speakers ,except the doubling of impedance and the output level (And a double efficiency)=,nothing changes .Paralleling two speakers ,it halves the impedance ,doubles sensitivity and output . With serial-parallel connection impedance remains the same , but you get 4 times output level ,which is +12dB,same rise of efficiency(+6dB-1W) ,and same change in sensitivity ,+6dB with 2,83 V.

Thanks for your response. But I doubt this answers my question.

Experts please help. Thanks for your time.


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[picowallspeaker]

Apart from the fact that the pictures you've made are pretty unreadable-undetectable , I suggest you to try both configurations,ie //per pair then two pairs in series ,or series of two // pairs , and I'm not even sure that is the optimal solution , specially when you put in series two coils ,don't know what exactly happens in terms of distortions. I tried a dipole in push-pull with two drivers in series ,and the drum attack is remarkable !
Bye

[richie00boy]

The answer is that either way of wiring gives exactly the same result of impedance, Qts, Fs, efficiency, everything.

But for safety sake the best way is to wire two drivers in series, then connect the pair in parallel to another series connected pair. This way ensures that if a driver goes open circuit due to over powering the voice coil then the other paired driver gets cut off so is less likely to get damaged also.

[FullRangeMan]

Hi all,
The best sound quality connection is parallel by a mile, but you should get four 16 ohms speakers for a final impedance of 4 ohms (16ohms/4drivers=4ohms).

The second best is parallel-serie, that is not show in your drawer, the calc is (16ohms/2speaker=8ohms, plus 16ohms/2speakers=8ohms then 8+8=16ohms). For four 8ohms speakers is (8/2=4) + (8/2=4) so (4+4=8ohms)
The worse sound is the serie connection, but in Pro Sound it is used, the speaker impedance is added (4+4+4+4=16 ohms).

As I like line arrays Iam over this issue much years, for my dismay according Scottmoose and others experts in this Site, various FR will have problems of frequency anomaly(comb filter effect etc) see page four at: Initial Impressions: Alpair 12 full-range driver by Mark Fenlon
Good Luck, Gustavo
P.S.: Please, inform us about the sound results of your experiment in the future.

[richie00boy]

Originally Posted by FullRangeMan

Hi All,
The best sound quality connection is parallel by a mile, but you should get four 16 ohms speakers for a final impedance of 4 ohms (16ohms/4drivers=4ohms).

Which will then have different Qts and possibly Fs, so you cannot make a valid comparison.

[shaan]

Originally Posted by picowallspeaker

Apart from the fact that the pictures you've made are pretty unreadable-undetectable , I suggest you to try both configurations,ie //per pair then two pairs in series ,or series of two // pairs , and I'm not even sure that is the optimal solution , specially when you put in series two coils ,don't know what exactly happens in terms of distortions. I tried a dipole in push-pull with two drivers in series ,and the drum attack is remarkable !
Bye

I know what happens when one puts two coils in series, it worsens high frequencies(double the impedance). I am with full ranges here.

Making things clear(er). Red= +ve Black= -ve. But that info is already there. I'm just making things readable. The rest of the fact is unimportant.

thanks.

[FullRangeMan]

Originally Posted by richie00boy

Which will then have different Qts and possibly Fs, so you cannot make a valid comparison.

Looks you are thinking this parameters will suffers alterations. By what I know only the CMS may add If the box volume is small for the driver.

[shaan]

Originally Posted by richie00boy

The answer is that either way of wiring gives exactly the same result of impedance, Qts, Fs, efficiency, everything.

But for safety sake the best way is to wire two drivers in series, then connect the pair in parallel to another series connected pair. This way ensures that if a driver goes open circuit due to over powering the voice coil then the other paired driver gets cut off so is less likely to get damaged also.

I see. Thanks for the information.