First DIY sub: The Low End (table)

[sensibull]

Just finished my first DIY sub and figured I'd share a little about the experience/results with my Ascend brethren.

After the Soundbridge disaster (I ended up returning mine for a refund) I decided to go ahead and build my own sub, figuring I could get the most bang for my buck that way and maybe have a little fun in the process. I set my spending limit at $250-$300. Any more and I might as well get a HSU or a PB10. Anyway, a little research quickly led me to the popular 15" Dayton Quatro driver and 240W Plate Amp combo, a sweet deal made even sweeter by the fact that both went on sale recently and PE's free holiday shipping. Total cost for driver and amp was $185.

My main design goal was to achieve a balance between musicality and extension, tightness and output, while not getting too crazy with the size. Young batchelors like Steve Callas and certified home theater nuts can maybe get away with big hulking subs, but I have limited space in my living room and a wife who thinks the Dayton 10" I had been using was plenty big enough. So in the end, though the Quatro models out at much deeper extension and more output in a ported design, I decided to go sealed, and make a 20 x 20 x 20 box with a double baffle, an amp enclosure, and plenty of bracing, which worked out to approx. 3 cubic feet.

I'll spare everyone the blow-by-blow. There are a lot of write-ups out there by people way more knowledgeable than me. Suffice it to say that it took a little longer than I thought (maybe 15-20 hours), and that I hope I've seen my last cloud of MDF dust for a while (I actually have bronchitis at the moment and can't be sure it wasn't caused by that nasty stuff). I had a brief scare when I first test-ran it and it sounded like utter rubbish, only to discover (with the help of a kindly PE tech) that my driver had a detached spider. PE replaced the driver for me, paying shipping both ways. The new driver arrived today and I installed it tonight. Long story short, I am quite happy. I still have a lot of calibration, testing, and equalizing to do but right off the bat the bass is WAY tighter and more musical than my Dayton 10" and blends with my 340s so well I am finally have difficulty localizing my bass.

Here are some pics for anyone who might be curious (the last one shows it next to the Dayton 10"). For the sake of WAF, I added a tabletop of stained birch plywood, hence the sub's name: The Low End. The rest is wrapped in beech vinyl laminate, to match our living room furniture. In the end, total cost was about $275.

[Lou-the-dog]

Way to go 'bull. I am a do-it-yourselfer and really appreciate your efforts. You're work is inspirational and I hope to try this myself someday. Thanks for sharing!

Randy

[rajacat]

Nice job! Good work with the veneer.

I want to build a sub too, but a sealed one, maybe using the 12" Rythmik servo driver and amp. http://www.rythmikaudio.com/index.htm. After the Soundbridge fiasco, I wanted to go after a tight sound therefore a musical sub. I see that you didn't use double layers of MDF but used a lot of bracing instead. 1 1/2" inches of MDF would incredibly heavy and perhaps overkill. The bracing is much more efficient.

Did you return the Soundbridge sub to Woot or to Soundbridge? I'd like to get rid of mine also but I wonder if I have waited to long. The 340SE's are excellent without the support of a sub but I still want one for the little extra extension and ambiance.

Roy

[sensibull]

I see that you didn't use double layers of MDF but used a lot of bracing instead. 1 1/2" inches of MDF would incredibly heavy and perhaps overkill. The bracing is much more efficient.

Yeah, I effectively have 1.5" on front and top, but all the way around would probably have resulted in a 200+ lb. sub and I wanted to be practical on that front. It's still pretty heavy as it is.

Did you return the Soundbridge sub to Woot or to Soundbridge? I'd like to get rid of mine also but I wonder if I have waited to long.

I returned it to Woot. Basically stated the differences between advertised and actual specs, and specifically requested they pay for return shipping. Might be too late at this point though...

[sensibull]

Just a little follow-up, for anyone also considering a sealed Quatro design. Unless you regularly listen at reference levels and above, I don't think you'll have anything to worry about regarding extension or output. I just tested mine and it hit 20hz fairly easily. With a little EQ, I was flat from 20-80Hz (crossover). Perhaps I'm getting a lot of room gain, but my room is 21 x 16 and open at both ends so I doubt it. Now if I can only figure out why my 340s aren't measuring as flat as they used to...

[rajacat]

Excellent! A nice flat response with equalization. Do they sound tight with a nice quick attack? Do you have 340SE's?

It's amazing what you can do with $300, some wood working skills and 25 hours of time. I can see no reason to buy a commercial sub. I like the end table concept. I live near an exotic wood dealer who has some very beautiful solid wood cuts that I might use for the top, laid over the MDF of course.

Roy

[curtis]

that looks great! What did you use to EQ?

[sensibull]

Do they sound tight with a nice quick attack? Do you have 340SE's?

Well, as with everything else, it's all relative. The Quatro is giving me the tightest bass I've had from a sub, but I only have the Dayton 10" to compare it to. Point is, I'm happy with it! And no, I have the 340 classics.

It's amazing what you can do with $300, some wood working skills and 25 hours of time.

It's also amazing how addictive the DIY concept can be. Despite the fact that I have absolutely zero complaints with my 340s, and no plans of building anything else anytime soon, I still find myself scanning the PE Tech Board, trying to soak up as much DIY Speaker info as possible....

that at looks great! What did you use to EQ?

Thanks. I used a BFD (the old model, though I've yet to determine the differences between it and the 1124] and Room EQ Wizard.

[curtis]

Thanks. I used a BFD (the old model, though I've yet to determine the differences between it and the 1124] and Room EQ Wizard.

Do you have the BFD connected to the soundcard for the automated EQ function of Room EQ Wizard? Which soundcard and microphone are you using? I keep toying with trying to get the automated portion together, I just have to get off my lazy butt and do it.

[sensibull]

Do you have the BFD connected to the soundcard for the automated EQ function of Room EQ Wizard? Which soundcard and microphone are you using? I keep toying with trying to get the automated portion together, I just have to get off my lazy butt and do it.

No, I haven't really investigated what that entails yet (lots of posts on the REW thread over on AVS to catch up with). I use the cheap but adequate Chaintech AV-710 soundcard and the cheap but adequate analog RS SPL meter (with my HK 635 as the middle man). What really interests me is the ability to do room correction across the entire spectrum. Apparently REW can now create a correction curve that you can then plug into some playback software. 99% of my music is delivered losslessly over optical by my home theater pc anyway, so why not take advantage of digital PEQ?