Series vs parallel (again!)

[sreten]

Hi,

The issue and loudspeaker design has nothing to do with F&M curves.

Dependent on the bass/ mid c/o frequency it has everything to with
the ~ 6dB baffle step, the two drivers could be wired as 0.5 way
for a passive crossover to give full baffle step, or just in parallel
with the usual overlarge inductor for baffle step.

Due to baffle step midrange senstivity is 4dB to 6dB lower than
the nominal bass sentistivity into half space, the reason is that
that bass is into full space lowering senstivity by 6dB.

rgds, sreten.

[Legis]

Sorry for resurrecting an old thread, just wanted to share my experience.

I have usually tried to maximize the parallel connections in my line arrays. Then yesterday I connected one of the midwoofer arrays fully in series. Ten 8ohm woofers in series, so the nominal impedance was 80 ohms. I liked the sound! Even with somewhat current limited amplifier I could generate huge SPLs with everything the amp could swing. The way that the quality of the bass stayed the same regardless of the volume, was unheard of. The control and the attack, which were very good, were nearly identical regardless of the volume.

I was speculating that maybe the back emf behaves slightly differently with series connection. I think normally the generated back emf goes first to the output of the amplifier and from there it can go back to the driver and damp it. The smaller the output impedance that the amplifier has, the less the back emf is dissipated at the amp, and the more it can damp the driver (the basics of the "damping factor").

With series connection the back emf travels through the voice coils of the speakers to the amp, when it travels there for the first time. Most of it might be dissipated at the woofers before it even reaches the amplifier. Maybe the generated back emf damps the series connected drivers more efficiently... If so, wouldn't it also mean that the amplifier's negative feedback loop does not get affected by the back emf so much, because the emf is almost dissipated before it reaches the amp? Just speculating.