Pure Audio Project Trio15TB Home Build

jonbuilds · « **on:** 1 Sep 2019, 11:50 pm »

Earlier this year, with personal input and OB-A15Neo 15" drivers from Pure Audio Project (thank you, Ze'ev!), terminals and TB1808 from Parts Express, and about 10 Home Depot runs, I finished building a slight variant of the PAP Trio15TB speakers. This version matches most of the original performance intent: Open baffles using the OB-A15Neo 15" woofers and Tang Band 1808 full range drivers, with baffle face dimensions and driver spacing based on the PAP layout. If you ever get a chance to hear the Pure Audio Project versions (or mine, I suppose) please do so! PAP got their driver selection right.

With almost every other parameter, there are slight variations - some budget driven, others based on aspirations for improved performance. In the end, I have a pair of actively crossed speakers (no savings there, let me tell you) that regularly amaze me, for a total $$ investment of about $1,700 plus active crossover and another amp. If I considered my time valuable, these speakers probably cost me the same as, or more than, a new set from PAP...

I will add to this as my first ever build thread, as I sort through the pics I took during the process. I was not terribly disciplined about documenting it, but will gladly answer any questions based on what I did/learned.

Cappy · « **Reply #1 on:** 2 Sep 2019, 03:09 am »

Beautiful speakers you've got there.

I'm curious about details on your crossover. Cheers.

musicdre · « **Reply #2 on:** 2 Sep 2019, 11:02 am »

really cool! nice work. thanks for the share.

jonbuilds · « **Reply #3 on:** 2 Sep 2019, 05:29 pm »

Quote from: Cappy on 2 Sep 2019, 03:09 am

Beautiful speakers you've got there.

I'm curious about details on your crossover. Cheers.

Thanks. I made an early decision run these actively crossed, since I'm a long-time poly-amp kinda listener. While I was building and finishing, I hadn't made a decision on how I would do that, so for the short term I pulled an old AudioControl 24XS out of a 90s-era box in the garage, bought a battery, and hooked it up (you can see some of that going in the pic). Sounded pretty dang good. Those AudioControl pieces were always great, and reliable. Current crossover is K231 by Sublime Acoustic, which has proven to be quite good, even better in light of its price point.

Tyson · « **Reply #4 on:** 2 Sep 2019, 05:31 pm »

How do they sound?

jonbuilds · « **Reply #5 on:** 2 Sep 2019, 05:56 pm »

Initial practice with a router to make speaker holes in the baffles. Borrowed tools, it's been a long time since I did any woodworking so I was moving slowly. Material is red oak plywood from Home Depot. Not great in terms of voids or finish ply thickness, but its what I could afford and I like the way it looks.

First routing test:

Have to see if it fits! With the TB1808

First full baffle view with my super custom router jig:

Here's a closer look at that incredibly cost-efficient router circle cutting setup:

First pair of baffle pieces standing together, not yet laminated:

Raw baffle pieces side by side:

All the baffle pieces are cut, standing together.

FullRangeMan · « **Reply #6 on:** 2 Sep 2019, 06:09 pm »

Why toe-in and close to walls?
Do you tested soundstage with no toe-in?

jonbuilds · « **Reply #7 on:** 2 Sep 2019, 06:11 pm »

Quote from: Tyson on 2 Sep 2019, 05:31 pm

How do they sound?

Man, that's a loaded question in this room - I don't have broad experience in a variety of home equipment compared to most folks in here. That said, to me they sound big & open, wonderfully dynamic especially with a lot of the jazz and fusion I listen to. Tight, clear, alive. Main thing I notice whenever I hear other equipment is that I really prefer open baffle (or planar, or electrostatic, etc) over box speakers. The "beaming" quality of most box designs distracts me since they tend to sound so much better in the optimum listening position, particularly those within $50k of my price range...

jonbuilds · « **Reply #8 on:** 2 Sep 2019, 06:16 pm »

Quote from: FullRangeMan on 2 Sep 2019, 06:09 pm

Why toe-in and close to walls?
Do you tested soundstage with no toe-in?

Oh yes. That's an old pic, set up mostly to get a good view of both speakers at that time. My current alignment has them about 4' off the back wall facing a completely different direction than the one shown, with a slight toe-in. That's as far out as I can get them and still use the space effectively for the rest of life. Frankly, I'd like a bigger room! My poor living room has undergone multiple layout transformations over many months to test various positions, alignments. That's part of what we do, right?

FullRangeMan · « **Reply #9 on:** 2 Sep 2019, 06:23 pm »

Thanks Jon

Congratulations its a beautiful speakers.
What plywood you consider best for baffles?
There is a level grade?

Tyson · « **Reply #10 on:** 2 Sep 2019, 09:39 pm »

Quote from: jonbuilds on 2 Sep 2019, 06:11 pm

Man, that's a loaded question in this room - I don't have broad experience in a variety of home equipment compared to most folks in here. That said, to me they sound big & open, wonderfully dynamic especially with a lot of the jazz and fusion I listen to. Tight, clear, alive. Main thing I notice whenever I hear other equipment is that I really prefer open baffle (or planar, or electrostatic, etc) over box speakers. The "beaming" quality of most box designs distracts me since they tend to sound so much better in the optimum listening position, particularly those within $50k of my price range...

I went to an OB speaker setup about 8 years ago, after having box speakers for the first 15 years of my audio hobby. I've never looked back. Well done OB speakers just do things that box speakers can't. Congrats on a great looking build. Seems like it sounds as good as it looks

jonbuilds · « **Reply #11 on:** 2 Sep 2019, 10:12 pm »

Quote from: FullRangeMan on 2 Sep 2019, 06:23 pm

What plywood you consider best for baffles?
There is a level grade?

There are definitely a wide variety of plywood types and quality. I'd recommend asking a more accomplished speaker builder than I am about which is "best," but I personally considered density, strength/hardness, appearance, and cost when I chose this sheet of plywood. Given some pricier alternatives, I would have preferred more plys and fewer voids, and more consistency at each ply. PAP uses ply-boo among others, which is very nice looking and made from a rapidly renewable resource. I could very well have used some type of fiberboard in 1-1/2" stock, and done some kind of paint job, but finishing was already going to be a laborious process since I was working entirely by brush and hand, and paint is touchy. Having the wood grain be the finish feature was important for this build, instead of me looking at "mostly perfect" paint in my living room, since there is no chance I would get it perfect first try!

Here's an edge shot of a baffle with both sheets of 3/4" red oak plywood laminated together, and edge filling/sanding underway. You can see the variations in the interior ply grains. This was a tedious process, but I really like how it came out after finishing:

FullRangeMan · « **Reply #12 on:** 2 Sep 2019, 11:48 pm »

That is a nice job Jon, I appreciated your valuable insight

jonbuilds · « **Reply #13 on:** 3 Sep 2019, 01:33 pm »

I spent the most time figuring out how to finish the baffles, probably over 50% of the work building these was on finishing. They're still not perfect, but I learned a lot and if I ever get bored (ha!) I will work on the finish some more, adding layers of clear, then sanding and polishing.

3/4" baffle front/back pieces laminated together:

Test stains, and test clear. I ended up using only clear finish.

Baffle filling and sanding well underway:

First coat clear:

Three coats clear:

three coats, 45 degree edge routing detail showing need for sanding. That was an adventure getting it right:

sanded that router detail, looking better:

Learning to sand and polish the clear:

Three coats of sanding & polishing:

FullRangeMan · « **Reply #14 on:** 3 Sep 2019, 01:43 pm »

Great photos Jon, thanks for posting

PDR · « **Reply #15 on:** 3 Sep 2019, 02:24 pm »

Nice build....congrats!

I also went the DIY route with the Trio TB.

FullRangeMan · « **Reply #16 on:** 3 Sep 2019, 05:14 pm »

Jon if you could manage to test an upright or vertical baffle position, it certainly can increase the soundstage, you can see this position below>

Brad · « **Reply #17 on:** 3 Sep 2019, 07:15 pm »

Quote from: PDR on 3 Sep 2019, 02:24 pm

Nice build....congrats!

I also went the DIY route with the Trio TB.

I'm using that same Tang-Band driver in OB. Love it, driven by a Korneff 45 SET.

Russell Dawkins · « **Reply #18 on:** 3 Sep 2019, 07:48 pm »

I'm curious how the 1808 compares with the 1772
https://www.parts-express.com/tang-band-w8-1772-8-neodymium-full-range-driver--264-893

On the surface they look similar, but the 1808 has more excursion and is 1 dB less sensitive.

jonbuilds · « **Reply #19 on:** 4 Sep 2019, 01:04 am »

Quote from: FullRangeMan on 3 Sep 2019, 05:14 pm

Jon if you could manage to test an upright or vertical baffle position, it certainly can increase the soundstage, you can see this position below>

Thank you for the suggestion - I have twiddled endlessly (and still am) with most every placement and orientation parameter imaginable over the past months. As you'll see when I get around to posting the hardware install that supports the baffles, the approach angle facing the room is quite adjustable. I'll measure their current angle of attack post with the final pic. They are still angled up slightly, which works best in my current layout. This is also consistent with Pure Audio Project's base design, which is typically slightly angled as well. I really should note - Ze'ev and his team at PAP really seem to have thought through their approach; that guy is extremely thoughtful, and based on my conversations with him, has well trained ears and a terrific ability to explain what he's hearing!