Pics of my DIY "High WAF" subwoofer

[vi edit]

After 25 hours about about $270 in parts it's finally complete.

It's a Dayton RS-HF 12" subwoofer in a 4.4 c/f cabinet.
Parts costs are as follows:

Sub - $120
Precision port - $18
Amp - free salvage
Birch MDF - $50
Pine plywood for double baffle - $10
Trim - $25
Stain - $6
Glue - $3
Marble top - $12
T-nuts and bolts - $10
Silicone - $3
Foam tape - $3
Legs: $8
---------------------------------------------

This was the first time I ever attacked anything remotely close to this woodworking wise. I had never used a table saw or even a plunge router a whole lot before attempting this project. I also have zero experience doing audio work.

Here's my build pics:
Cabinet build:
http://pics.bbzzdd.com/users/viedit/sub4.JPG
http://pics.bbzzdd.com/users/viedit/sub3.JPG
http://pics.bbzzdd.com/users/viedit/sub2.JPG

Internal bracing (MDF is a bitch to hole cut BTW)
http://pics.bbzzdd.com/users/viedit/sub1.JPG

The goods:
http://pics.bbzzdd.com/users/viedit/sub5.JPG

Getting really close to done:
http://pics.bbzzdd.com/users/viedit/sub6.JPG

Showing off the brains:
http://pics.bbzzdd.com/users/viedit/sub7.JPG

Now the brawn:
http://pics.bbzzdd.com/users/viedit/sub8.JPG

Almost done...
http://pics.bbzzdd.com/users/viedit/sub6.JPG

Complete!
http://pics.bbzzdd.com/users/viedit/sub9.JPG

Accessorized:
http://pics.bbzzdd.com/users/viedit/sub10.JPG

In the wild:
http://pics.bbzzdd.com/users/viedit/sub11.JPG

Given my absolute n00bness...I think it looks pretty damn good. I have two regrets though having completed it. I wish I would have done a 15" sealed and instead of doing the marble right over the top, I would have taken the time to drop it inside of the top trim using the trim as a border. I didn't have tile cutter available though, and 22" is an odd size to work with.

As far as impressions go, I wasn't sure what to expect sound wise. I've never worked with a high caliber sub driver so I didn't know what "clean" bass sounds like. It's pretty cool...you don't really know it's there until you turn it off. This is a very low distortion driver so all you hear is what you are supposed to hear. Hard to explain if all you've worked with is $100-$200 Best Buy caliber bottom end subs as I had.

I think I'm a little handicapped by the dirt cheap plate amp that I salvaged from my old sub. I'm tuned to 19 hz but I don't even know if the plate can play that low. Plus it's spec'd at 200watts but I'm guessing it's more like a 200w peak with 50w more likely being the normal amount. Plus I have no real adjustments on the amp itself to help dial in room EQ. I'll probably bump up to a 500w Oaudio amp that has a subsonic filter that I can turn on to protect the driver and dial in my room response a little better with the EQ. Plus a lot more, clean power.

But for $270 it does sound pretty good and IMHO looks great
I went downfiring for the driver and port because I'll have a toddler roaming the basement soon enough. A big shiney driver and a port is just asking for somebody to mess with or drop toys in.

Oh...and my back is still letting me know that it didn't like moving this pig.

 

[olds]

Dude! Nice job!

 

[Slick5150]

150 pounds? Yeesh. And I thought the SVS subs were heavy!

 

[vi edit]

25 pound driver (freaking beastly for a 12")
10 pounds for amp
70 pound cabinet & bracing (MDF weighs a TON)
The marble tiles are about 8 pounds each
Misc stuff makes up another 10 pounds

If you rap on it with your fingers it sounds like you are tapping on concrete. I built this thing SOLID.

Luckily I carried it into the basement before putting the marble & trim on. It's going to take 2 people to ever get it out.

 

[alfa147x]

that looks like a beast, i think we will be building one soon around the same budget

 

[Aharami]

awesome job. We just got a townhouse with an unfinished basement. Im getting all giddy thinking about how I'll turn it into a family/HT room!

where do you get birch MDF from? I like how it looks after stained

and is bottom firing a better design for home theater subs than side firing?

 

[pennylane]

That looks really awesome. Any worries about that lamp staying in one place?

 

[vi edit]

If you have an unfinished basement, definitely give some thought to an infinite baffle array. I could have done it with mine. The whole wall behind the sub backs up to another 700sq/ft of unfinished area. But I already have enough holes and patches in that wall, plus some braces that I would have to work around. If I was going fresh in an unfinished area, a IB array of 18's being driven by a rack amp would be my first choice. They are out of the way and offer unrivaled performance for the costs.

The birch MDF came from Menards - it's a midwest Lowes/HD equivalent except a bit cheaper. The stain came out a lot lighter than I thought it would. You can get an Oak MDF that will have much more of a coarse grain and deeper colour to it.

But the birch is a very smooth finish and I hit it with a very fine grit finish sanding paper and it is smooth as my baby's bottom.

As for the configuration - I went bottom firing to protect the goods from the impending doom my daughter will likely try to impart on it. That port is 4" and is plenty big enough to shove a couple barbies or stuffed animals into it. And the speaker just screams "PUSH ME!!!!"

I'm taking a little bit of a risk of driver sag setting it up this way. It's not perfectly set up for a down firing by specs, but I run pretty modest levels and only a few times a week so it won't get abused that bad.

 

[Aharami]

where did you do all your research for sourcing/building this? I've built my own enclosure for my car sub (JL Audio 10w7) so I have a little experience with building enclosures but I wanna make sure I do things right when I build my HT

edit: IB would be preferable, but unlikely with our basement. Since it's a townhouse, basement isnt too big. Im looking at maybe 500-600 sq ft total for the basement (if that). So not a lot of extra room

 

[vi edit]

Originally posted by: fanerman91
That looks really awesome. Any worries about that lamp staying in one place?

It's very well dampened. When it's firing at high volumes I can hear stuff upstairs vibrating, but the cabinet itself is pretty motion dead. I've never heard any glasses or remotes rattling around on it amazingly. The sheer mass of the thing plus a quart of wood glue and ample bracing certainly helps.

 

[vi edit]

As far as resources go I used the following:

AVS DIY
http://www.avsforum.com/avs-vb/forumdisplay.php?f=155

HT Shack DIY
http://www.hometheatershack.com/forums/diy-subwoofers/

Win ISD for modeling
http://www.linearteam.dk/

Boxnotes for more tuning info and cutouts
http://www.subwoofer-builder.com/freesoft.htm

My cabinet is a little bigger than what the driver really wants. 4.3CF is more of the ideal amount, but I wanted easy cutouts because of the miter cuts on the edges. Trying to calculate out different lengths and messing with the fence on the table saw would have been a major PITA.

I'm positive that there are much more ideal driver/cabinet layouts that will yield better performance, but just how much better is hard to guage.

 

[Aharami]

sweet. thanks! :thumbsup:

 

[Excelsior]

Nice build. Good choice of driver. Love the Dayton Reference series.

 

[jamautosound]

Wow, that came out very nice! Good job!

I had an idea to do that to some existing end-tables my friend had in his front room. Strong, sturdy old wood that could have accomodated a 15" each. I should have just done it. He ended up buying some $3,500 speakers that have blown out four times since he purchased them a couple of years ago.

 

[vi edit]

Yeh, for the price that I paid for the precision port, I could have just gone with a 15" version of the driver I bought.

But, if I went the sealed route, there was no way my current amp was going to power that thing sufficiently. With a vented design you can eek a bit more out of a driver with less power. Going sealed I would have been dropping another $250 in an amp.

Plus I could have fudged the dimensions a lot more and went with a 3 c/f build and dropped the proportions down a few inches each direction. It's a bit deeper and wider than I really wanted, but I had to accomidate for the port somehow.

 

[Aharami]

doesnt a ported/vented enclosure yield less accurate bass response?

 

[TastesLikeChicken]

Nice work.

:thumbsup:

Does the lamp rattle when you crank it up? Sitting on the marble, seems as if it would.

 

[vi edit]

Originally posted by: Aharami
doesnt a ported/vented enclosure yield less accurate bass response?

That's a bit of an exaggeration. There are some very significant pro's and cons to ported systems.

Pro's:
1) Require a fraction of the power of a sealed box
2) Very high output at the bottom end of their tuning
3) Easier to tune to lower frequencies than a sealed driver of similar dimensions

Con's:
1) They require much larger enclosures
2) Cabinet building and tuning is imperative...wrong size box and tuning can kill your response
3) Can be too bottom heavy for some listeners
4) Feeding them a frequency below tuning can destroy the driver if you don't have a subsonic filter in place

Building a small sealed cube is a much, much easier affair than building a proper tuned, vented box. They are much smaller, and require far less planning. But as a trade off, that smaller size and lack of vent loses you some serious ouput at the bottom end of the frequency range. It's hard to find a sealed 12" that will play under 25hz with significant volume without some very fancy passive radiators or throwing an insane amount of power at it. Example is the 1000+ watt setups from JL (Fathom)

But many ported 12" drivers have no problems dipping under 20hz with only 250-350watts on tap.

Since it's easy to get deep bass so cheap out of ported, you see a lot sloppy designs and cost cutting in drivers going into ported systems. Just simply - bad builds - that propagate the "sloppy bass" myth of vented boxes.

And then you simply have the intended use of the sub. If it's for music only (or mainly) there really isn't much available under 30hz, so the extra digg of a ported box isn't needed as much. A ported system loses much of it's value. But for movies, a vented system typically provides more value and "punch" where you want it over a similar sized & powered sealed box. There is a lot of stuff in the low 20's and high "teen" hz ranges there. A sealed box simply isn't going to be able to dig that low at similar volumes unless you go high displacement drivers with lots of power thrown at them.

 

[Oyeve]

That is freaking sweet! Nice job!

 

[kalrith]

Originally posted by: fanerman91
Any worries about that lamp staying in one piece?

fixed

Edit: nice job btw

 

[vi edit]

Originally posted by: kalrith

Originally posted by: fanerman91
Any worries about that lamp staying in one piece?

fixed

Edit: nice job btw

Maybe it's because I'm going downfiring and all of that mechanical energy of the speaker is being driven vertically vs. horizontally doesn't cause things to rattle off. I don't know. But it hasn't been an issue in a week worth of movies. And I even tested things with the "Sandstorm/Crash" scene in Flight of the Phoenix...which is regaurded as one of the most intense LFE chapters out there.

Seriously. I could put something on one corner and bang on the opposite corner with a baseball bat and not make it shake.

My lateral stability is a lot worse due to how the legs are attached. I've just got a 5/16" t-nut epoxied into the bottom face of the sub. From there I have about 1/2" of threadding of the legs going in there. It weighs so much that I have to lift it completely off the ground and then flip it without putting any pressure on the legs. They'll snap right off if I put any sort of leverage against them.

 

[iRONic]

pics.bbzzdd.com DOESN'T FUCKING WORK!!

It hasn't for six months...

 

[Muadib]

Damn fine job!! Now you need some test tones & a sound meter.

 

[Dman877]

Originally posted by: iRONic
pics.bbzzdd.com DOESN'T FUCKING WORK!!

It hasn't for six months...

It works for me. Nice job dude.

 

[vi edit]

Ok...so I have to rescend the comment about it not shaking the lamp.



My AVR was set to "LFE/L+R" for the LFE channel. Because of this I was turning down the gain too much to balance out to the main speakers (sub overpowered everything).

I set it to only send LFE signals and now I could really bring up the gain on the sub without it sounding out of whack with everything else.

Holy crap.



I watched Cloverfield and the footsteps of the monster made the couch bounce....and I'm on a concrete slab. It did shake the lamp a little bit in those scenes. Heh.