Ack's DIY Subwoofer Build Idea Thread - Newbie Alert! - Page 6

First coat of Duratex down on all four subs.. This is looking like three coats...



Duratex coverage is amazing.. You put it on heavy in the center and then use your roller to spread it out on the box... I like the look of the smooth roller within minimal texture. Will be putting on the second coat tonight then need to paint the bottom with a coupe coats tomorrow...

Two coats done on all the sides and top. The second coat made a big difference but I need to do a little sanding where there is too much texture and a little streaking. So I am thinking most likely will give these four coats on the sides and top. I got the first coat down on the bottom, and will give it a second coat in about 4-5 hours. I am going with two coats on the bottom since you will never see it anyway.

I am definitely a fan of the Duratex.

Here are some more action pics of the Duratex after three coats with a smooth 4" foam roller. Apologize for the crappy cellphone pics, my good digital SLR is kaput.. They look much better in person...

I have a really busy week, but would love to have them ready for a movie on Friday night. It will most likely be Saturday as I am not going to have much time to work on them the next couple of days and two of the subs need one more coat of Duratex. I also plan on soldering the wires to the terminals, and I have never soldered in my life

I have been saving the Dark Knight Rises for these bad boys so hopefully will be doing that on Saturday night.

Thanks, me too

I did not. I can. I have plenty of scrap wood left and it would be easy to brace it now. If you think it is necessary, I can do it. With the driver in the cab, these things are pretty heavy, I thought it might be enough.

Man, those pics turned out really grainy.. Not sure what is up with my iPhone, it usually takes much better pics. Will try to hunt down our old digital camera.

I actually cut up a bunch of 3/4 scrap plywood so it should be no problem adding the additional bracing. Now is the time

4th coat is done on just the tops (there were two subs that needed the 4th coat and I went ahead and did 4 coats on all of them, why not)?

I unpacked two of the Dayton DVC 385-88 drivers and wired two of them together and played around with my new multimeter and the multimeter was jumping all over the place when trying to measure ohms... It was late. I was tired. I may have done something wrong, so will test this again tonight. Tonight I would like to get all the front to back braces cut so I can get those glued down tomorrow night or Sat AM. Goal is to have all four up and running for Saturday night movie night. I am off Monday will have some time to tweak, but until my Minidsp USB mic arrives (backordered until end of the month) I can only guess.

Man, I wish there was more time in the day and that my three kids were more self sufficient My wife has had exercise classes three nights this week so I am flying solo with three kids 7 and under.. Maybe I can put them to work on the subs...

Test wiring run completed. Wired up all four subs per the above diagram and am getting 4ohms total on load on the multimeter. Big thanks to nograveconcern for walking me through this, I definitely learned a lot about wiring in parallel and in series.

Got my old digital camera out and took some pics. Hopefully these are better than the iPhone pics:

Yep, no rubber boots which is fine with me. I am kicking myself for not doing any sine wave testing... But I am uber excited to get these things fired up tomorrow and watch some movies. I wiill definitely be testing some of my favorite bass heavy scenes.. Can't wait...

Well.. The verdict is in.. The Hsu VTF-15 will be sold I got everything hooked up this afternoon. The iNuke software is pretty straightforward and bridging the amp was cake. I am also a fan of Speakon connectors now, I really like them. After getting everything hooked up, I did some A/B comparisons with the VTF-15H, and I measured an easy 6-7db more gain at the LP with the four Ack subs. The Ack subs really have lots more steam under 20hz. I ran the VTF in full output (both ports open) and full extension (one port closed) and there was just no contest. The Ack subs were moving my pant legs at the LP and they sound extremely tight, and with four of the Ack subs in the room, the bass response is just very smooth. It is really hard to describe, but I absolutely see the value in having multiple good performing subwoofers spread out in the room. I did limited testing pre and post Audyssey MultiEQ, and liked what I heard with MultiEQ, but REW will confirm.

I watched the Dark Knight Rises (I have been waiting to watch this since I decided on this project) and I still have a huge smile on my face. I am just so happy with how everything sounds and I have to say that the project met my expectations. I have more output and more extension and I did it for $1K, which is about what I paid for the VTF-15H shipped to my door. Four DIY Ack subs for $1K (that cost includes everything) easily gives me the performance of 2 VTF-15H subs, and it would really take 3 Hsu VTF-15H subs to equal or best the 4 Ack subs, and that would be over $3K shipped.

I still need to dial everything in and once I get my Minidsp mic and fire up REW (I used an SPL meter, and some test tone CD's today, along with some bass heavy scenes) I suspect I will really fine tune everything and find some sweet spots in terms of placement.

Oh, and I won't lie. I am already thinking I can sell the 15H and build a couple more of these same subs

And I will definitely be doing the fan mod on the iNuke3K DSP. Even though I sit pretty far from the amp and don't really notice it during movies/TV, it is still louder than I was expecting. But the workaround seems easy, so I will be pursue the fan mod.

Attached are some shots from today. I will get some better pics soon and hope to get a better camera. You will see some shots of the Ack subs pre driver, an Ack sub next to a PA-150 (15" ported sub), and an Ack sub next to the Hsu VTF-15H. I won't lie, I really like the Hsu sub. It really is a beast, but I am sold on DIY and what you can do with the money.

Thanks again to all that helped and a special shout out to nograveconcern who really assisted with all my noob questions.

More to come!

Holy polyfill batman!


Ack vs PA-150





Ack vs VTF-15H