Its time to enlist the help and wisdom of HTF. I am upgrading my sub from the one that comes with the Kenwood HTB-504 package and have been doing a lot reading about my options. The budget is $150-$250 and I would like to keep it towards the lower end I know that I should save up some more and get an SVS/Rava/HSU and that will make me amazingly happy. There are a couple of reasons I've decided against this - - I am in an apt. The bass that the Kenwwod put out, while quite boomy, was still loud enough to be heard across the hallway. I really do believe that a monster sub will be overkill - feel free to convince me otherwise! - Budget. I could get a passive SVS for ~400 but the only amplification I have is an old AIWA receiver which will barely do the job. Also, I don't have the extra space. These are the options I've come up with and some questions I have :- 1. Sony SAWM40 with the polyfill mod - undisputed king of budget subs. $170. How low does this sub actually go? The specs say 20hz but that's hard to believe. 2. AudioSource SW15 - same as above but harder to find and more expensive, will probably go a bit lower though. 3. DIY - this is the big one. I've read several posts saying you can build a DIY sub for $250 or so but I fail to see how. I've been pricing out parts - Shiva or Daytona drivers, a PE 250W plate amp, enclosure etc - it all adds up to $300 or more. Living in an apt, I can't build it myself - I don't have access to tools or the skills to use them. I emailed Kyle at Acoustic Visions and he basically said that at this price point there's nothing he can do. 4. Used - maybe I should start a thread in the FS and DIY sections asking if anyone is willing to build a sub for me - I've read that many of you guys go on to bigger and better DIY projects and sell off the old ones at cost. What do you think?