My Dayton Reference 12" Subwoofer

[owdi]

I've wanted a musical sub for my HT for a long time now, and have finally built something I am proud of.

I chose the the Dayton Reference 12" RSS315HF-4 for the following reasons:

1) Distortion measurements from zaphaudio.com and mfk-projects.com showed this driver could produce bass that is not overwhelmed by harmonics.

2) It must be capable of 105db in-room down to 20hz. This is based on my typical listening volume of 75db a-weighted. When I get a little crazy I listen at 85db, and I wanted 20db of headroom. The Dayton RSS315HF can do this at about half of xmax.

3. I wanted a sub that could be crossed over high, at least 120hz. This one could definitely do it.

A teaser pic:



The box is built from 3/4" mdf, and braced with 3/4" 13-ply baltic birch. I figured the baltic birch is stiffer than mdf, so would make a good bracing material. The front and back baffles are also baltic birch. The magnet of the driver is wedged against a 4" wide brace.

The enclosure is 2.4 cu ft sealed, with no stuffing (a la LW thor).

I plan on taking distortion measurements and more pics later this weekend. More coming soon.....

Dan

[Thawach]

you may get the the 105 dynamic headroom.but at the time it may be high of x max(peak). the xo you can use 120 hz but you don't try to be higher than this.

[evad]

I'm looking forward to your impressions when your build is complete. This driver is in my future, so I want to learn as much as possible about the do's and don't's. Zaph uses approx. 2.1 cuft. net volume. I was thinking about 2.6 to 2.8 sealed, similar to yours. Please tell me how you arrived at 2.4?
Regards, evad

[badman]

nice work mate. I built a sub with a tempest with a very very similar box design, I think you'll find it to be exceedingly solid.

[owdi]

Thawach - At 100 watts this sub should be good for 94db @ 20hz, w/ 10mm excursion. After room gain I should be in 105db territory, but I will not know for sure until I take measurements. The upper limit will be determined by distortion measurements. If it's high enough, one day I hope to try a stereo pair with a reduced BSC speaker.

evad - I arrived at 2.4 cu ft by balancing foot print, baffle size, and performance with one or two drivers. I considered distortion, power requirements, internal reflections and structural strength. The design process was on and off for about 4 months.

badman - so far it sounds great, except it shakes the condo too much, limiting how loud I can play it. I need to find a way to decouple it from the floor, or get a second driver and go push-push. The box is designed for push-push, I just need to make the cutout.

Some more pics. I still need to route the back baffle with my flush trim bit.







Dan

[evad]

owdi Nice pix, I like your bracing scheme. Please tell me if you have considered making it a down firing sub? Also I'm interested in your spkr stands. The base looks very similar to sketches I'm working on. Glad your happy with the sq.

[owdi]

Originally posted by evad
owdi Nice pix, I like your bracing scheme. Please tell me if you have considered making it a down firing sub? Also I'm interested in your spkr stands. The base looks very similar to sketches I'm working on. Glad your happy with the sq.

I have considered down firing, but I live in a condo with someone below me. The floors are not very solid, so I would be more limited in how loud I can listen.

The speaker stands are nothing special, just the Sanus 30" stands from partsexpress. They are just the right height for my zaphaudio L18's.

Dan

[buggsson]

I have this driver on my short list. However, last time I looked, a couple of days ago, I could not find it, neither at Dayton or at PartsExpress, is it discontinued?

[owdi]

Originally posted by buggsson
I have this driver on my short list. However, last time I looked, a couple of days ago, I could not find it, neither at Dayton or at PartsExpress, is it discontinued?

It is not discontinued. In fact, it's on sale right now for $20 less than usual.

Dan

[owdi]

Finally took a nearfield FR measurement... and found I really need a new receiver. The LP crossover in my Pioneer VSX-517 just does not cut it. It's set to 100hz right now, but the -3db is around 130hz. The -12db is around 300hz... that is bad.



I need either an amplifier with a built in 24db/octave LP and a parametric equalizer, or a Behringer Feedback Destroyer Pro.

I suspect the dip peak at 280hz is an enclosure resonance. The box is not stuffed right now, so there is nothing to dampen the primary pipe resonance. My enclosure is 24in deep, which happens to be the half wavelength of 281hz.

Dan