Affordable subwoofer for music cont'd

Blkadr, Your response reminds me of a parallel situation with cars. I love Subaru's. I drive a '97 Impreza Outback Sport. Decent car. I'd love to be driving a 2005 Impreza Sti. Too bad it costs 3x as much, and I'm still paying the '97 off. Sometimes we have to sacrifice what we want for what we can afford.
And anyway, a stereo isn't "my all" in life. I also DH/freeride mountain bike, hike/backpack, rock and mountain climb, and drive my car on gravel roads very fast for fun. These are also money-gobbling pursuits. If I only sat at home and listened to music and watched movies, I'd have nicer stuff. Fortunately (or unfortunately, depending on your outlook) I'm a very active person, and only a fraction of my play money can go to a stereo. So, I buy as high end of audio as I can afford and appreciate after a long night in a storm or after a hard mountain bike ride.
I have checked out those Dayton Audio DIY subs on ebaY. I looked them up on Parts Express, and they were out of my price range new. I'll keep an eye on ebaY for them, or maybe parts, and build an enclosure myself I am just afraid of getting the right frequency response out of a particular driver/amp/sealed box combo. I have modeling programs that you can input T/S parameters into, and get a response graph, and I could use a woofer's parameters combined with the box size to get what I desire. I would just need to make sure that the amp was up to par as well. For that I would like an on/off switch, phase adjustment, LP crossover and a single RCA input jack. I can't think of anything else I'd want for music, though it'll probably have speaker-level inputs, outputs, and RCA outputs as well.
The main problem with all of this though is that even if I get the parameters right, the box right, etc etc... it could still be a mediocre sounding sub that cost just as much as a reputable manufacturer's offering that DOES sound good. So, I'd like to try DIY, but I'm just skeptical that it will turn out as well as something "engineered." I'm not afraid, or even uneducated, just wary.
Anyway, I'm rambling on, so any more advice on the subs I have available to me would be great, and I'll check out Dayton.

Dude the Def Tech Pro Sub 80 is an excellent choice for your budget. THe Pro Sub 80 out of the Pro Sub line has the best sound it is the fastest of the line. It is musical I use it with JM Lab 906 speakers and it sounds fine. I do not see much use in paying for a more expensive sub because our ears really can not pick up on it that well. It is ported and when you get it loud and have real base heavy music it does have port noise which is to be expected. My budget was 500 and I chose this sub becasue I did not see or hear anything that would be a drastic improvement in the sound for the same price. I did like some subs better but they are out of the range you want to spend. Remember it is a sub. And one annoying thing about the def tech all of them actually and most other subs aroudn is they are signal sensing so you can not turn them off or on it just happens automaticly and even closing a door loud or playing guitar can turn it on. But over all i enjoy my Pro Sub 80.

Erik i am in the same boat you are I got all of my equipment cheap and when i go to a store esp when i was looking for a sub i wanted to spend 500 max and the audio guy was like for your speakers you need a sub that cost at least 1.5k i was like hahahahaha lets see I Mt. Bike, I Rock climb and have other expensive hobbys too. So i understand your situation. Ok its off topic what bike do you ride where do you climb and what all. peace bro Nick

Accorddude,
Thanks for the opinion. I will more seriously consider the DefTech (I think it's mostly between the DefTech and the M&K, though I was leaning toward the M&K because I don't have much music that has bass below 35Hz). I am also looking for a deal on a Dayton Titanic 10, but it'll have to be under $200 shipped as well, or I just can't afford it. They do look cool though.

I ride a custom SC Bullit around Bellingham and on the North Shore, as well as Whistler and Hemlock in the summer. I climb around Bellingham, though I get to start that up again this summer after a two year hiatus due to a broken toe, then as soon as that healed, a broken wrist. Never done much more than sport, but I enjoy that enough! I boulder a lot too because climbing partners can be hard to find.

Erik,

I stopped in my local Best Buy today and they were closing out the Celestion s20 Sub for $99. I have not heard this sub, but Celestion has a good reputation and you could always return the sub to Best Buy for a refund if you don't like it.

Enjoy,

TIC

Well, the M&K was sold out from under me, and the seller of the ProSub 80 backed out on selling once I confirmed the desire to buy, so I'm back to square one. Suck.
I'll continue to watch the auctions for Daytons Titanic MKIII's as well as the Pinnacle Baby Boomer, Aperion Audio S-8APR and anything else sealed and small. There can't be much demand for small sealed in home audio because everyone wants deep bass for movies, right? I hope not...