As usual, the first thing I do with a woofer is break it in, or “exercise” it. In this case, I used a 10Hz signal to maximize excursion and allow the suspension to soften up a bit if it was going to. With enough power applied to get about half an inch of cone movement, I let the woofer run for about 10 hours. Then I removed the signal, and allowed the woofer to cool and the temps to normalize overnight. Normally you don’t need to do this when buying a new woofer, because it will break in as you listen to it for the first couple of weeks. But because I don’t have the luxury of taking 2 weeks to review a product, I have to accelerate the process as described above. The manual does not specify a particular enclosure recommendation, but a quick call to Bob Ahuja at American Bass got me the info I was looking for. Bob suggested a vented enclosure between 1.5 and 1.75 cubic feet, with a low tuning frequency, between 35 and 40Hz. From what I had seen of this woofer, those suggestions sounded spot on, so
I pulled out a sheet of ¾-inch MDF and constructed a 1.75 cubic foot box, and tuned it to 38Hz.
After I got the woofer in the enclosure, I connected it to my reference system, and used a 1,000 watt amplifier to drive the woofer, with the coils in parallel for a 2 ohm load. With the amplifiers crossover set at 80Hz, and the subsonic filter at about 30Hz, I sat down and played a bunch of different music through the XFL1244.
This American Bass woofer plays low, and loud! Power handling was never an issue, and I never saw any indication of reaching the woofers limits even when playing at very high levels. The sonic performance of the woofer was good too, the output was warm sounding, with decent definition, and not a lot of “overhang” on the transients. Fast plucked bass notes such as in Thom Rotellas’ “Friends” sounded strong and powerful, and you could easily hear the resonances and echo in the recording. The bass and drums in The Blues Brothers version of “Sweet Home Chicago” sounded very natural, and like I’ve noted with other paper cone woofers, had that really pleasing “round” and warm timbre that I particularly find natural and realistic.
Pushed hard on bass heavy tracks from Nine Inch Nails, Nelly, and 50Cent, the American Bass XFL1244 simply pounded out the bass with nary
a whimper or protest. In terms of output, the woofer is right there with most of the other very high power handling woofers I’ve tested. They have a bit lower overall efficiency, but the tradeoff is the extreme power handling and the amount of abuse they’ll take, where a more efficient woofer would simply self destruct. No worries here, this American Bass subwoofer can certainly handle all the power it’s rated for.
With my listening complete, I let the woofer cool back down overnight and moved it to my bench and measured the Thiele-Small parameters. I was a bit surprised to find them significantly different than the published specs, so I took the time to start over, and completely re-measure them, but my results were the same. This happens from time to time, as products evolve and improve over time, and isn’t all that unusual. If you are designing subwoofer enclosures with Thiele-Small parameters, it’s always a good idea to double check them with a call to the manufacturer, just to be sure you have the “latest and greatest” information. The American Bass XFL1244 measured pretty much exactly as I suspected it would after examining it and listening to it. It has a fairly high Fs, and extremely low compliance, which makes it very well suited to vented box applications. I would agree with American Bass’ recommendations, this is definitely a vented box woofer only.
The very reasonably priced American Bass XFL Series of subwoofers are a great choice for anyone looking for high power handling and better than average sonic performance in a vented system. They excel at higher than normal SPL levels, and are realistically rated when it comes to power handling. And while there are lots of more expensive 1,000 watt woofers out there, the American Bass XFL1244 certainly proved to me that you don’t need to spend a fortune to get a good quality, hard-hitting, high performance subwoofer.