Buyout PR Subwoofer Project...

[scottvalentin]

Will heatlock work with non-backed (raw) veneer? It notes on the website that it will, but I would worry about the absorption and the resulting wavyness/warping of the veneer. I have raw maple veneer.

Thanks for the detailed explanation though, I will check out your tips as well as save what you wrote here as it is very helpful either way. I'm hoping to cut some wood this coming week so will start a thread.

[tomzarbo]

Will heatlock work with non-backed (raw) veneer? It notes on the website that it will, but I would worry about the absorption and the resulting wavyness/warping of the veneer. I have raw maple veneer.

Thanks for the detailed explanation though, I will check out your tips as well as save what you wrote here as it is very helpful either way. I'm hoping to cut some wood this coming week so will start a thread.

Scott,

On that webpage where the glue is listed, It mentions that Heatlock is 'not suitable for crotch grain veneers' I assume because they tend to have 'openings' for want of a better term that will allow the glue to squeeze out through the 'pores' of the wood. Many non-backed veneers will allow some of the glue to move through to the surface as well. On paper-backed veneers, the paper/glue line stops the migration of glue through to the surface of the veneer... on unbacked veneers, that may not be the case. You may be alright using the iron-on method for unbacked veneers, but it's probably at least a bit more risky.

Also consider that as you apply heat to the veneer as it bonds to the substrate, it will shrink a bit. That's why when you do a seam on a box with veneer, often you need to place something under the veneer like a wire or something to allow for some 'slack' so that the veneer actually overlaps by a 16th or so.... so when you iron it on, it will shrink to a perfect fit. If unbacked veneer shrinks too much, you may have some mild splitting, potentially allowing some of the glue to make it's way to the surface, and that's a problem for finishing.

Think about it...You're applying water based glue to a very thin piece of wood for 45 minutes which will cause it to absorb some of the moisture... then you're applying it to a cabinet and pressing on it with an iron which will cause rapid drying/curing/shrinking. The paper backing prevents many potential problems.

Truthfully though, none of these issues are probably deal breakers, and wood putty and some fiddling can fix almost anything, but paper backed is just much less problematic.
The fact that you have maple, which is a very hard wood, is working in your favor. My suggestion if you have enough for 'scrap' is to try it out on a leftover piece of the same substrate you plan on making your cabinet out of. Not a tiny piece 2" x 3", but hopefully something a bit larger where you can see the shrinking in action. Maybe even b-u-t-t together two pieces of veneer, then iron them in place and see how much of a gap results after you're done.

Lots of variables also, thickness of veneer, method of cutting, moisture content of veneer and substrate, etc.

You may find that you'll make out fine in the end, and I hope you do. I'm looking forward to seeing your project!
TomZ

[tomzarbo]

One done...



It's the one in for foreground. The littler' bugger behind is Wolf's 'Triumph' subwoofer that uses the neo version of the same TB driver for comparison. \/ --- Triumph on left, Buyout PR sub on right.



I made Ben's 3/4" version, he also spec's a 1/2" version which would even be a smidge smaller. Doesn't sound like much, they're both small, but the Triumph for what it does in it's size still kind of amazes me....

Anyway... this slightly larger setup works nicely. I was just a little bit concerned about building four of these things without ever hearing the PR in motion... they looked pretty high quality, but you never know of there will be some noise from them especially considering the price... but they're dead silent. They look very high-end too.... the rubber surround rolls around and becomes the outer flange trim piece. That means they need to be recessed to look decent, but when done, they look pretty nifty.

I think I hear them digging just a bit deeper than the Triumph, but honestly, I can't be sure; they both go mighty low. It's a shame these PR's are NLA, they're pretty nice.

In the pics though it's kind of dark you may see a sheen difference between the two. The 'Triumph' was finished with gloss rub-on poly, where these buyout subs were finished with satin, both from Minwax. My local Walmart used to sell Minwax rub-on in satin and gloss for $2-3 cheaper than my Home Depot. Now Walmart doesn't sell rub-on at all, and my HD only has Satin. No biggie I guess, but I'll have to find another source, sometimes I want the shine. This has only 3-4 good coats. I spend a half hour rubbing in with several applications per session. To say one session is only one coat's thickness probably isn't correct. It builds the more you apply, so 4 coats seems like enough for satin. Clear would probably need a few more to get uniform "shininess."

I'm listening to it with a small pair of two-ways as I'm typing this and there's no lack of extension. That 25 watt Dayton amp is plenty of power for this driver. I like it. Thanks Kenny K! good idea

Three more to go!

TomZ

[Paul Carmody]

You can put something next to it for a sense of scale?

[tomzarbo]

You can put something next to it for a sense of scale?

Yup, when I get home I'll put them side by side with a ruler and a water bottle or something. I need to get a better, closer-up'er picture also.
TomZ

[tomzarbo]

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

[Derekj]

Sweet little project Tom! That plate amp sure is small too.

[Kevin K.]

They look great Tom! And you managed to get all of the dust off of the drivers and PR's.

+1 on wishing PE had more of the PR's, they are good looking.

[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

[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]

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]

Interesting. Thanks Tom

[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

[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

[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?