Impdence Question

...Do not connect speakers in series...

Point taken, but this is a "pick your poison" issue. I'd take possibly making my bass quality a bit worse off as opposed to burning out an amp.

You will recall that our original poster stated that "only a certain high-end car speakers fit the design criteria." It sounds like he has looked for other drivers and not found any. In situations like that, one is often left with choosing the lesser of two evils.

When I was fooling around with adding stereo speakers to my 57 Packard in the "good ol' days" I seem to remember that some speakers had transformers attached to them. ( Sweet ride..staight 8, used more oil than gas)

It looks like my previous answer didn't make it past the moderators. I have no idea why.

Connecting two drivers in series does not lower the amplifier's effective damping factor - instead, it raises it. Damping factor is the ratio of speaker input impedance to amplifier output impedance.

I have some experience working with series-wired drivers.

Duke
dealer/manufacturer

Audiokinesis - JBL in users manual for GT4 car subwoofer system states:

"We recommend that you avoid
connecting separate woofers in
series. The amplifier-damping
factor (the amplifier’s ability to
control the motion of the woofer
is expressed as a ratio of termin
impedance (the sum of speaker
impedance, wire resistance and
the D.C. resistance of any
crossover coil connected to the
woofer) to amplifier-output
impedance. Therefore, connectin
separate woofers in series
reduces the damping factor of
the amplifier to a value less
than 1. This will result in poor
transient response. "

and the link is here: http://manuals.harman.com/JBL/CAR/Owner's%20Manual/15515%20GT4%20Man_ENG.pdf

Of course they might be wrong.

Sorry - link got shortened in my last post - here it is again:

http://manuals.harman.com/JBL/CAR/Owner's%20Manual/15515%20GT4%20Man_ENG.pdf