I've had this sub for 2 months from a buddy who moved and needed me to hold it for him. For the money, sounds very good. I have a Sunfire True Sub MKII, and I can tell you that there is no comparision. The Sunfire is louder (but not by much) but gets much lower. Side by side comparisons, everyone agress. The 15TL does not go to 20hz. The sunfire does. For the money it is great, but if you can get the Sunfire for $1000 (as I did) it is worth the $300 more, plus it is much smaller.

My system: H/K FL8300 CD player, Theta Cobalt DAC, Audio Alchemy DLC preamp, Acurus A80 amp, NHT SuperOne speakers, Definitive Technology PF15TL sub, wired with Kimber PBJ (interconnect) and 4VS (speaker).
I'll start off with just one comment on the other reviews for factual purposes: the PF15TL will do 20 Hz bass in an average room. How do I know? Frequency sweeps with an SPL meter. I suspect the claim is based on the fact that its response is down at that point against the rest of the response band, although -6 dB may not be all that severe in your judgment. It's not in mine. I'll note that I haven't heard the Sunfire Mk. II, and it may well be down LESS at that point, especially at peak output (I don't think the PF15TL's peak output is uniform that far down).

There is no question in my mind that this sub kills its competition and competes with everything better. I auditioned it against a mostly pitiful lineup of Energy, Klipsch, Cerwin-Vega and JBL, and nothing they sell at these prices will match it for pitch accuracy or peak output. However, a better benchmark in this price range is the NHT SW2Pi, which certainly does the pitch accuracy bit as well, but simply can't match the output levels. That's not a knock, the PF15TL simply wins the laws of physics wars -- 15" vs. 10" driver, 325 vs. 120 watt amp.

The PF15TL is admirable on its own merits objectively, though, not just by comparison to the garbage at its price. It's clean, hits notes on pitch, is certainly no more distorted than any other non-servo-corrected sub (and subjectively I'd have to say it's better than most in that regard), it has uniform frequency response at all crossover settings, and its extension certainly is down to 20 Hz, if not the 15 Definitive claims (without specifying a dB figure). Dismissing 15 Hz response as marketing hype, what the PF15TL offers you is the best possible set of trade-offs between bass extension, accuracy, peak output level and distortion below $1000. And to improve in all of those areas, not just in one or two, requires you to spend at least double the $700 that Definitive is asking.

If performance were the whole story, it would still be the best you could get in its range. But it's the most flexible I've seen at the price, too. The crossover is full-active, unlike the low-pass-only of comparable M&Ks or the passive-only of most mass-market junk. Not only that, but it's continuously variable and the slopes (24 dB/octave low; 12 dB/octave high) allow you to get electrically flat response with the help of the phase control. That's simply unheard of in the mass market; between the powerful musicality and the audiophile-grade control capability, the PF15TL has to be compared to the best single-driver subs out there, and you may well find that for the audiophile who has to ask the price, it doesn't get any better.

I feel this sub is among the best under $1000. Bass notes are resolved with good speed and definition. It goes deep (but not down to 17 hertz as claimed) and have good power level. It is full equiped and easy to be merge with main speakers, and it looks not bad too.
Very good overall performance for the price. I give 4 stars for the performance and and extra star for the nice price.

I narrowed the field down to either the Paradigm PW-2200 or the Definitive Tech PF15TL. Both were incredible, but the Def. Tech. was $100 less...what a bargain.

I haven't listened to this sub yet because our dealer hasn't yet given it for home-listening. But, I'm not too impressed about www.hometheatermag.com measurement curve from this sub. It looks more like bookshelf speakers bass output not subwoofer. Anyone else noticed this?

Like most of you out there, I just finished the audition dance. There are some great subbies (Velodyne, Sunfire, Energy, Paradigm, Mirage, Bag End, M&K, Atlantic Tech, Hsu) out there!! However, this is one category where I was looking for the most BANG for my bucks. The Def Techs were the clear winners (325 watts, 15 inch driver, $600). This is Home Theater Magazines highest rated subwoofer. And, they absolutely ROCK on music and home theater. I was so impressed with the first one that I bought a second one two weeks later. Any doubters out there should hook up a pair of these bad boys to their HT set up,fasten their seat belts, and watch LOST IN SPACE on DVD. Game over!! The best $1200 I ever spent on A/V equipment. A BIG P.S. TO JAN FROM FINLAND IN THE PREVIOUS REVIEWS: Please don't waste any more of our time or yours by posting reviews at this site on equipment you have not heard. I guess common sense isn't very common these days. ALLAH AKBAR!

I can only say that this sub is incredible! I have owned 6 different subs prior to this one and have never found the satisfaction I get from the Def Tech. My last sub was the Sunfire MKII, what a disappointment after 2 years of dreaming of owning it, I could only live with it for a week before I had to take it back and bought the PF15TL for half the price. The Sunfire may extend lower, but is VERY boomy with virtually no output above 40hz, at least in my listening room. The PF15Tl on the other hand has excellent tight response across the entire bass spectrum. My interests are mainly musical, but this sub will rock your house with movies as well. Try watching the Desperado DVD, you will feel the gunshots hitting your chest. On music, especially jazz with acoustic bass, you will need to turn the sub down a bit to get an even natural sound, but it blends easily with all the controls at your disposal. I keep mine set at about the 10 o'clock position for music and turn it to about 11 for movies. This sub will play incredibly loud if that's what you want, but i like my bass to blend naturally. Also, room placement isn't anywhere near as critical as it is with the Sunfire. I also suffered severe high and low sound pressure zones within the room with the Sunfire. With the PF15TL, I have smoothe even response throughout the room. Overall, an amazing subwoofer, regardless of the price, which is pretty incredible by itself. There may be better subs available, but I haven't found one under 2000 dollars. You would be cheating yourself if you don't audition one of these in your home before spending 2 or 3 times as much. I'll never mistake high cost for high end again.

The definitive TL is by far one of the best subs i have heard regardless of price. The sunfire mk II which i read about in a lot of these reviews is LOUD! But unfortunatley thats it! To me it has no real musical output that's comparable to M&K, velodyne, paradigm,....let alone the PF-15TL. It's reproduction of movies on the other hand is quite impressive especially on Jurasic Park. But again if you use your sub for movies as well as music you can't go wrong with the 15TL, this sub actually has a 425 watt amplifier! Just look on the back of your sub (those of you who own one),..and a continuous of 325 watts, more than enough power unless you live in the terrordome!!!! Again for the money this has to be the best out there and for the sound.

Picked up one of these for $350 used. Figured I'd play around with it and see if it's worth keeping. Well, it may be staying for a while. This thing has some serious output. I have full range towers, but didn't have a sub before this. Wow, what a difference. Did the hookup last night, and did a quick demo. This think was literally shaking my apartment building. This is going to cause some serious problems between me and my neighbors. I didn't try it for music yet, and really need to upgrade my electronics to get better integration, but so far, it's just what I was looking for.
I'll post more when I get the setup more complete

I have owned this sub for a year and a half after owning an equivilant Infinity, Cerwin Vega, as well as some hi fi car audio. This sub has enough output to kill a small animal! Coupled up with my DVD player, this sub can make my windows shake while the T-rex is bashing in the windows on the camper in Jurrasic park 2! For those of you who give this sub a poor rating, what is your damage?