Howdy all.. been a bit since I've browsed the boards. Did a little modification (some may say bastardization!) to my Heresys today. They're not known for their titanic bass performance, and I was looking to do something about it. My neighbor won auction on some stuff on eBay, part of it being a pair of Speakerlab 1208R woofers. For kicks, I put them in my Klipschs, to see what kind of difference they would make.
Well, the difference was stark. They're a little less efficient, but are still significantly stronger in the low frequency than the Heresy woofer. On that receiver, clicking the low frequency boost to raise the bass 3 db (my guess), the 1208s keep up well with the horns, and the bass extends a LOT farther down. Gives a whole new sound to the speakers, as if they've been transformed, or someone hid a powered subwoofer in the room somewhere. The subsonics are just THERE, and they definitely extend much farther down than the stock woofer does, thanks to a lot more excursion and a looser suspension. They don't sound muddy to me, either, the bass is clean, and a lot deeper.. very pleasing. My neighbor (who owns the speakers) gave them a blast, and mentioned that they sound like they extend down to their 21 Hz Fs. They definitely rumble. To me, they sound perfect.
Now I gotta find some of these woofers for myself! Kinda hard to find, period, much less in the near mint condition his are in. Ohhhh I'm gonna hate having to give back those things. They've got an Fs of 21 Hz, like a cabinet around 1.7-1.8 cu. ft (About 1.78 cu. ft for the Heresy cab, minus the volume consumed by the internal bracing, crossover, and mid/tweeter... probably close to 1.7 with them, my guess.), they really seemed to make my babies come alive.
Now, hopefully I won't be tied to a stake and burned for defacing their Klipschness with Speakerlab drivers!