Dynamo 500 woofer in Sequel II? Or, other suggestion (non-ML)?

I need a replacement woofer for one of my Sequel IIs. Having found a couple of woofers for the Dynamo 500, I was curious if the Thiel-Small parameters were similar to where I could use the Dynamo woofers for a replacement (I'd replace both . My engineering nose says the odds are that it won't work (the parameters are likely way different, since the Dynamo was designed for subwoofer usage), but if by some fluke it might, I'd appreciate the feedback.

I know the original woofers in the Sequel II weren't the best match to the panels, and since one of mine arrived dead, I am open to suggestions for other woofers (non-ML) that might work well. I searched here a bit but didn't find anything too revealing at the moment. Madisound and PartsExpress are two sources I use for drivers. I know I can probably match something to the cabinet size based on the T-S parameters, but that doesn't ever give a true indication of how the woofer responds or blends with the panel at the crossover point.

TIA!

Dynamo 500 will not work--it is a ported design, and the SII is sealed. (Aside from the fact it's a subwoofer driver.) A shame. The price was right!

Looking into some other suggested replacements.

Im going to replace the woofers in my Vistas eventually. I'm in the process of going active with some plate amps from MiniDSP (PWR-ICE250's). Unfortunately, the amps that arrived today are the (incorrect) PWR-ICE125 model.

FYI- I'm bent on making a 9" revelator work
http://www.madisoundspeakerstore.com/approx-9-subwoofers/scanspeak-revelator-23w/4557t-02-9-aluminum-cone-subwoofer-black-cone/

Sequel II uses a 10inch woofer in a sealed box, crossed over at 250Hz. Can you confirm that it uses a 4 Ohm woofer?
Will the basket of this woofer fit the counterbore (if any) of the cabinet?

http://www.madisoundspeakerstore.co...very-26w/4534g-10-aluminum-cone-woofer-4-ohm/

BTW, woofer 'blending' with the ESL is vastly improved by using an active xo and separate amp for the woofer.

Yes, the Sequel II does use a 4 ohm woofer. And that woofer you mention was recommended by others here as a good replacement.

What concerns me, though, is that the specs on this Scan-Speak woofer aren't matching that closely, although I have yet to measure the internal volume and run some T-S calculations myself. In this post, another member got ahold of the specs for the original Sequel II woofer. Which are:

SD = 330cm squared = 0.033m squared
4 ohm driver - Re = 3.77ohms
Fs 20-21Hz
Vas - 98Liter = 3.4cubic feet
Mms - 91gram
BL - 11 Newton/Amp
Sensitivity = 88.8 dB SPL at 1 meter with 2.8VAC input
Efficiency = 85.8 db /1m 1W (1W at 4 ohm is 2VAC)
Qms = 10
Qes = 0.372
Qts = 0.358

Click to expand...

Yet the Scan-Speak shows:

Fs: 23Hz
Vas: 156 Litres
Sensitivity: 90.5dB
Qms: 9.57
Qes: 0.37
Qts: 0.36

Click to expand...

The Vas being that far off is not going to be a good match for this enclosure size, despite Qms/Qes/Qts and Fs being close. (This is assuming the specs provided by ML are correct, as listed in the linked post.)

I would not even mind adapting the Sequel IIs to use an 8" woofer if the Vas spec is a lot closer (and the others comparable as well). It would improve mid-bass response, and might provide a lower extension since the enclosure would be more suitable to the smaller cone size.

Put those T/S parameters into an online box calculator to see the simulated response for both woofers, and you'll see that the difference in Vas doesn't affect things much.