Bridging amp vs. dual voice coil subwoofer

[teal'c]

and also to @teal'c who replied before you. .

True, but I'm getting added to ignore lists for my opinion, so be careful.

 

[imral3]

 

[fill35u]

This goes contrary to how most dual-woofer Infinity (and many other brands) speakers are wired, and also to @teal'c who replied before you. In fact I'd venture to guess that a large number of dual-woofer center speakers made over the last 25 or so years have their woofers wired in series.

Of the Infinity dual-woofer schematics I've seen, the woofers aren't in series. The RS-I has its bank of six woofers arranged series-parallel, presumably to achieve reasonable total impedance with typical driver impedances?
I'd be curious for examples of series-wired woofers that share the same cabinet volume.

Now, by "matched" I assume you mean the woofers have actually been measured to have their specs as close as possible, not that they are the same model. But either way, many people on AK have replaced a single woofer in a dual-woofer speaker (with another of the same type) with no reported adverse effects.

How many of those woofers were wired in series? How many of those shared a cabinet volume? How many of those were *tested* in use to verify they shared the load?

I suppose if nobody has ever noticed adverse effects, then it's not a problem.

The current through two series-connected woofers will obviously be the same. But the voltage won't necessarily be the same across them. If one sees a different acoustic load or has slightly different parameters, its back-EMF and impedance will be different, and then it won't share the power with the other.

Maybe this is a concern mainly for high-excursion subwoofers?

 

[swechsler]

Of the Infinity dual-woofer schematics I've seen, the woofers aren't in series. The RS-I has its bank of six woofers arranged series-parallel, presumably to achieve reasonable total impedance with typical driver impedances?
I'd be curious for examples of series-wired woofers that share the same cabinet volume.

Well obviously you're not going to have six woofers in series (the Bose 901 and 802 are the only speakers I can think of off the top of my head that have more than two drivers in a straight series arrangement), but the RS III-A/B and RS IV-A/B both have dual woofers connected in series in a shared cavity. The Kappa 9, too, if I'm not mistaken. On the other hand, the RS II has each woofer in a separate cavity.

 

[fill35u]

Thanks, I overlooked the RS-IIIA/B, the "plain ol' " RS-III had the ubiquitous helper woofer.
The Kappa 9's are so famous, it's hard to believe that all problems haven't already been found.
Good examples!