Eminence Kappalite 3015 as open baffle bass?

[EC8010]

I'm considering using the Eminence Kappalite 3015 on a 600 x 750mm open baffle for bass up to a few hundred Hertz. Claimed efficiency is high (100dB/W) so even the equalisation needed to overcome baffle loss doesn't bring the required amplifier power beyond 100W for 100dB peaks at 3m. The driver is overdamped, so a little feedback on the amplifier will be needed to raise its output resistance to bring the driver Q up to the 0.5-0.7 region. I don't know if a switching amplifier will tolerate this sort of monkeying, but I'm not prepared to contemplate thermionic watts at this level.

Other points:

Crossover will be active.
Mid-range is to be Jordan JX92S, tweeter ESg1 ribbon.
Jordan and ribbon will be driven from valves.

Does anyone have any comments regarding suitability of the proposed bass driver (before I order them)? Note that I am not considering the 3015LF version with its increased Xmax. because I don't like the look of those nasty midrange peaks and the reduced sensitivity.

Link to the driver data sheet:

http://www.eminence.com/proaudio_sp...nk=KAPPALITE3015&speaker_size=15&SUB_CAT_ID=3

 

[Pano]

I can't speak to the regular 3015, but a buddy of mine who does a lot of big driver OB work had this to say about his Kappalite 3015LF (the one you don't like)

Beat the crap out of it, 200 watts free air at resonance. Couldn't get it to bottom out. Ran out of clean power. Put it on a baffle board with simple crossover and the venerable SS 8200 as a mid-tweeter and it sounded very good. Some lead slap on the back of the cone at very high excursion. A little bit of chuffing through the pole vent. On my 24" wide test baffle with 10" wings it would easily put out 100+ db at 35 hz at 10' distance. This thing can move some air and at 95 + db it is surprisingly efficient given the total 11 mm peak of usable xmax.

FWIW.

 

[EC8010]

Thanks for that - I may have to rethink my prejudices.

 

[freddi]

I'd like to know how 3015Lf sounds run high (~1K6) compared to Delta-type Eminence 15"

 

[EC8010]

Download the data sheets and you will see that the Delta could be equalised to run up to 3kHz and cross over there, whereas the Kappalite LF would need to be crossed over well below 500Hz to avoid that nasty behaviour between 1kHz and 2kHz, and the Kappalite (not LF version) might be tolerable up to 1kHz.