So far all the Hathor 1544's I've done have used the Faital 15PR400 woofer, which is definitely on the smooth side. When I designed that cab, I hadn't yet figured out how to do a cab that was voiced for bass guitar. My target response was still pretty much "puts out what you put in". Well, since then I've done some investigating into non-flat bass cabs, and the forthcoming Hathor 215 will make use of my findings. And along the way I came to appreciate the stock Kappalite 3012LF and 3015 (non-LF) a lot more, as they are good candidates for a deliberately "voiced" bass cab. In a nod to their smooth cab heritage, and to respect my original customer base, I'm including the midrange smoother switch wherever possible. Thanks, Mike and Ken! Mike's success with his Big E cabs is one of the reasons why I'm working on deliberately voiced cabs: I gotta carve myself out a somewhat different-shaped niche! Also, my priorities as far as low-end voicing have changed. We're used to thinking that the tradeoff is between box size, efficiency, and low end extension. There is actually a fourth factor that gets traded off, and that is transient response. In general, good transient response = good pitch definition. But, it's going to cost us in other areas. I'm stepping back a bit from my target of -3 dB at the first overtone of low-B. Instead, I'm going to make tradeoffs in favor of transient response, retaining good excursion-limited power handling, and expect you to crank in some EQ if you need it. The rolloff will still be gentle in the region of the first overtone of low-B, it's just that the -3 dB point will be a bit higher up. Now you guys who are already stuck with first-generation Thunderchild cabs - don't worry, you're not screwed. Plug up half of your ports, and you'll be right about where my new target is. The Hathor 1544 and Thunderchild 212 are my first cabs tuned to this new target. And I'll probably keep the original porting in my Gen 2 Thunderchild 112 cabs (both 4 and 8 ohm version), as well as the Thunderchild 115-8, but my recommendation will be to run the cab with half of the ports plugged. You see, I recently read a book on studio monitor loudspeaker design, and one of the problems recording engineers have mixing on ported console-sitting monitors (that usually try to squeeze maximum bass energy from a small box) is, pitch shift as the note decays. Say the box is tuned to 55 Hz, and we have a low-B decaying. The strongest energy is at 62 Hz, the first overtone, which is close enough to the 55 Hz tuning frequency to excite it. So as the energy decays, the energy "ridge" actually shifts south towards that 55 Hz tuning frequency, and the pitch changes!! Now we bring in a kickdrum whose fundamental is at 50 Hz, and as it decays, the pitch shifts north towards 55 Hz! This makes it very hard for the recording engineer to properly set the relative levels of bass and kick. So my solution (in a ported cab) is to tune well below the first overtone of low-B, so that we don't get significant pitch-shifting where it's likely to be audible (on the first overtones). Yes there will still be some pitch shift down around some of the fundamentals, but we'll be way down in level by then anyway so it's less likely to be audible. In a sealed cab obviously we don't have this issue, but then we've already traded off bass extension (relative to a ported cab) for transient response. Right now I have real serious competition from some excellent designers. Off the top of my head, in alphabetical order, Acme, Baer, Bergantino, Big E... and we still have twenty-four more letters to go, some of them more fRIGHTENing than others. These guys are making me revisit and revise, and up my game. That's the way it's supposed to be.