Buyout PR Subwoofer Project...

[tomzarbo]

I'm running them off of a Dayton APA150 amp for now. My Onkyo amp must have a weak output, it's not using all the excursion it seems.... though I am using a 1 to 2 RCA splitter... but that amp should be able to murder the 5" TB sub...

I'll try it on another amp to see. The bass with two of these is low enough to be really convincing that it's a big sub. I think I'll end up gifting these as the subs in a set of 2.1 speakers to a few co-workers paired up with a set of Bantams with curved sides. I really like these, though. That veneer is the most convincing "man-made" grain pattern I've seen yet.

Anyway, another project wrapped up... and a bit more learned on the 'finishing' side of things. Still a way to go on that front, though! Thanks Kevin K for the tips, I admire your perfect finish work even more now that I've given it a good try.

TomZ

[tomzarbo]

I finally wrapped these up. Here are the results:



This is Striped Ebony veneer. I used boiled linseed oil first, sealer, then several applications of grain filler, then some more sealer... finally, a whole bunch of coats of clear lacquer.
The base is 2 layers of 1/2" MDF with black Rustoleum textured paint, followed by black lacquer.

It's not perfect, but my best attempt yet spraying a finish. Seems like the closer to perfect it gets, the more you see the flaws.

...more pics...

[KEtheredge87]

Lookin good sir! I think the angled binding posts adds a lot of style points! Also nice to see some good bases being made for those. I feel like that could become a Tom Zarbo design trademark.

[tomzarbo]

Dos Post

[tomzarbo]

More progress...

made these bases out of two pieces of 1/2" MDF. 45 degree bevel on the top, rounded corners to match the radius of the enclosure (I used a compass to transfer the curve to the base and just cut the curve on the band saw.)

There is a 6" x 6" 1/2" thick piece of MDF as a spacer between the base and cabinet. The base will be texture painted, then gloss black applied.

I'm using some binding post pairs to get power to the driver. I didn't want to ruin the back of the box by drilling a hole in it, so I decided to go through the base. I found a 45 degree "V" router bit that I was able to use to make an inside cut that matched the outside 45 degree bevel on the base. This will allow the binding post screw terminal to fasten flush and tightly. Between that and some bulk removal drilling with a fostner bit and some careful work with a chisel, she's got a path for the electrons to flow.

Probably hard to see, but I doused the routed areas in the base with wood glue in an effort to stiffen up the MDF fibers. I'm hoping if it absorbs into the MDF some it may add just a touch of strength to it since it's fairly thin and could be broken if it were whacked into with something, maybe a vacuum cleaner or something like that. I also dropped several drops of super glue in all the wood screw holes for the drivers. I've found that doing so helps keep the hole from busting open when there isn't much meat on the opening side.

Some boiled linseed oil on the stripped ebony veneer and some BIN primer on the bases.

TomZ

[tomzarbo]

Thanks, Kenny.

I few more pics of the top which gives a decent look at the finished product.
Warning: They're a bit dusty.




I have to do a bit more sanding still. This is reconstituted veneer and I've found that stuff to be slightly uneven thickness-wise. A little block sanding with 220 grit seems to take it down to flat again.

The sides are one continuous piece of veneer with the seam on the solid back side. I used that piece of romex copper wire under the veneer near the seam to add just enough material so it fit together just perfect -- can't even see it. Since the veneer shrinks a tiny bit as it is ironed, and as it dries, cutting through both thicknesses without adding a bit of extra material will cause a small gap to form. I don't mind getting out the tub-o-wood putty, gosh knows it never has a chance to get a coating of dust on it... but it's nice to not need it for a change!

I think I'll be making bases for these like I've done in the past. Nothing too fancy, just a 1" thick slightly rounded over base with a textured black finish for durability. I think these need something to bring the pizazz level up just a bit since I'm going fancy with the veneer.

TomZ

[kenny_k]

Inspiring!

[tomzarbo]

Those look very nice!
How do they compare to the Voxel?

Thanks! They perform very similar really. I think the F3 is close to the Voxel's at around 35 Hz. In my mind at least this sub seems to have a bit more 'visceral' impact, possibly because of the PR's being used and the fact that they are so close to the floor... but that's unsubstantiated opinion!

TomZ

[RexDog]

A few more pics to illustrate the size.
Triumph on left 9.5" cube..... Buyout PR sub on right, 10.5" cube. Coffee can on left, tape measure on right.






Closeup of flush-mounted Passive. If I didn't recess it, it would have looked as goofy as all getout.





Yeah, this setup sure does dig pretty deep. I played a few test tones on youtube and the volume didn't seem like it was beginning to fade until around 28 Hz or so... just by ear of course.

Only lacking in Overall SPL I'd say. Those PR's are pretty nice, I really wish PE had more of them.

TomZ

Those look very nice!
How do they compare to the Voxel?

[tomzarbo]

Well, sometimes things take longer than you think they will.





I finally am getting around to finishing up the last two of four of these subwoofers with some nice Striped Ebony veneer. I tell you it's a great feeling for a speaker hoarder to finish up some projects that have been sitting around for too long.

These boxes have had time to expand/contract and stabilize pretty well over the past year-and-a-half. I gave them a thorough final sanding to get the seams and surfaces 100% smooth and have applied the veneer to all sides in one session yesterday, and the top this morning. I'll trim them tomorrow hopefully.

I really like the Striped Ebony veneer... it's a man-made (reconstituted) product, but looks very nice, and I can't detect any repeatability or patterns in the veneer... looks totally random, which is a bonus.

I had planned on using the PE 25 watt plate amp with these, but I'm thinking that I may just put a binding post on them, or make a small bass and put a binding post on that, and use one of Dayton's APA150s to power these with, along with a small set of two-ways... or maybe even my pair of Wolf's N.E.H.D. speakers, depending on how low they go. It's been awhile since I've heard them, I can't remember what the low end sounded like on those.

Anyway, I've always wanted to do a dual-subwoofer setup, not necessarily stereo, which I guess this would be, but just two subs... this may be the one to try that on, since they're so small.

Thanks for looking at this 'blast from the past!'
TomZ

[tomzarbo]

Interesting. Thanks Tom

No Problem Sir.
Here's a link to the NLA buyout PR: http://www.parts-express.com/6-1-2-h...iator--299-018

A 15 Hz Fs is LOW for a 6.5" PR! The Dayton Fs is 30 Hz.

Tomz

[cooper]

Interesting. Thanks Tom

[tomzarbo]

Anyone know if the buyout PR is the same (or specs the same) as the 6 1/2" Dayton currently offered by PE?

The specs are pretty different from one another. The buyout PR has a lot more mass for one thing.
Here is a screen shot of the two PR's for comparison:



The red line is the Dayton 6.5' PR with the maximum recommended weight added (existing mass plus 60%) and in the same size box the F3 is about 44 Hz as opposed to the buyout PR with it's F3 of 35 Hz. The built in mass of the buyout PR is 88 grams, the Dayton 37.5 grams... to which only 60% can safely be added, bringing the total weight to 60 grams.

The curves look very similar when I brought the weight to 80-90 grams of weight on each PR, but apparently it can't handle that much weight safely per MattP (in the question area on the PR web product page.

Apparently the buyout PR's are fairly beefy.

TomZ

[cooper]

Anyone know if the buyout PR is the same (or specs the same) as the 6 1/2" Dayton currently offered by PE?

[tomzarbo]

Gracias, fellas.

I LOVE that 25 watt plate amp. I've used over 10 of them over the years. Cute little bugger that gets the job done.
Yeah, it's small, and you should see the mounting screws they give you with it... they're tiny!

I had to dig in there pretty well with a brush to get the sawdust out of the screw holes, it's kind of 'sticky' in there. I hope Dad likes it.

TomZ