Thing One and Thing Two (Dayton HF 15's 500w Oaudio)

While my wife and kids were away on summer vacation I had the house to myself. I took the occasion to create these two monsters I like to call "Thing One" and "Thing Two". I call them monsters foremost because they produce monstrously powerful bass, but also because they were a beast to build, and are not nearly as pretty as projects some other craftsmen here have put together.

2 Dayton HF 15's 4 ohm
2 Oaudio 500w plate amps
The enclosures are 5.2 cubic feet sealed in 3/4" birch.

Other HT audio setup from pictures:

Onkyo TX-SR805 7.1 receiver
Atlantic Technology System 350 THX 7.1 speakers
Panasonic BD 60 bluray player
Panasonic 54" 1080p plasma

room is 18.x' by 14.x'
TV is on the longer wall. Sorry the room is such a mess in the pictures.

Here is a speaker







Here is a plate amp:







Thing One coming together, lucky the wife's not home!:







Notice Thing Two has 2 brass screws (gold teeth as I sometimes call them) and the top piece is way out of alignment. These are remnants two of the many mini disasters I ran into on this build that almost derailed the entire project. I'll spare you the details, but I can tell you the cabinets are 100% sealed as birch can be and they are strong.

I will say Thing Two was where I put all the worst cuts, to give Thing One a better chance of making it. In the end i was able to save both patients LOL But they bear the scars.







Here's Thing One, he was my "good" cabinet until he met the wall. Notice the corner ding with bare wood.







Here is a shot of the TV and LCR.






I think this project officially ends my speaker building career

I did lift the name from "The Cat in the Hat"

They sound really good to me. There is no fill and no extra bracing. There is also no flex or give on any wall. 3/4" birch is pretty strong stuff and a sealed cube is a physically strong design (compared to slot vented enclosures). I would have liked to brace just to say I did, but I cannot

I'm no professional, anyone in the Dallas area is welcome to give them a listen and provide honest criticism of any kind

Thank you.

I have no measurement equipment, I would guess the f3 to be about 24hz, it modeled at 22hz.

Not at all, they are very well sealed with what looks like hot glue. Also they each had a note that came with it or it was a sticker on the inside that said they had passed a QA check for leaks. They also have a full gasket around the perimeter.

Oh yes, and to answer an earlier question, I defeated all the Oaudio eq (by setting it to zero db) and I'm only using Audyssey.
I did set the subsonic to 20hz which effectively creates a slight boost at 23hz.

The only thing I could do is manipulate (lower) the subsonic filter to get boost that low. It would provide a little boost though. Your right i do need measuring equipment to really know if it's working. That' why I chose a relativity high boost range (subsonic filter setting that provides a little boost). The parametric eq on the oaudio only lets you cut to tame room modes. I figure that if I don't know by measurement that low end boost is actually doing anything, best to keep the lower stuff out.

I do not anticipate buying measuring equipment anytime, can someone recommend a movie track or song that I could say would provide 20hz on the dot content. Then another for say 18hz. If I had those two I could go a long way towards getting a feel for my real low end extension. If I can hear such and such in scene x of movie y, I'm getting 20hz for sure.

I can tell you that the scene three sequence in the Blu-ray Serenity where the ship enters the atmosphere is crazy. Not sure how deep it goes but the subs are 11ft away and it shakes my but cheeks through the couch LOL

Items in my room make unpleasant sounds long before anything distorts and I just don't seem to have the gonads to turn it up to it's limit yet. The plate amps are less than 1/4 up and Ayddyssey trims to to -6. Sometimes I manually set the trim up to about -3 and I don't think I'd reach the Oaudio amps limit with the receiver volume knob.

The loudest I've had them was today on Iron Man 2 bd. I had the Onkyo turned up to 62/100, i kept -6 trim and the amps still at 1/4 gain (I never really touch that anyway). after the last fight scene which was "pretty darn loud" I felt the Oaudio amps and they were just a little warm to the touch, barely breathing; like it was no effort for them to do what they just did.



Thank you! I hope I don't hear from the book publisher!

It will be using an analog input, but who cares! I'm going to try it! I hope I get good news out of it I'd hate to hear only the upper 20's, I don't want to make anymore sawdust

Well I tried Audacity and got good news out of it. Of course I do not have an spl meter so I cannot say where the -3db point is, but to the ear, the model was spot on -2db 26.x hz f3 23.x hz, again to the ear. I was surprised to hear lots of usable output down to 15hz, where I decided to stop in case of over excursion. There appeared to be a slight impedance rise (less power) around 20hz where at first I though the sub was done below that level. I was pleasantly surprised that it quickly recovered and was giving lots of output below 19hz down to 15hz. I suppose that does make for uneven output, but with a driver at this price point I'll take it especially given how low in the spectrum this slight anomaly occurs. With a ported design to target the impedance point say 9 cubes tuned to 17hz, I suspect the output would be a lot more even, but then again, I'm no expert so I could be wrong; or it could really introduce excursion issues even if it works.