PAP Trio 15 and DIY - Discussion

Yeah thats what I was thinking. I might snap a pic later to show in better detail how it looks now. It might also help give ideas to people that may build these in the future.

 

FWIW, I tried the Heil and it was a big downgrade from the TBs to my ears

 

lve become more intrigued by full range drivers in the last few months. In the future I could see myself experimenting with the TB and other drivers. I’d have to buy or clone the Leonidas Xover for that though.

 

Regarding PAP's washers, i tried rubber, steel and nylon. I could not hear or feel any difference so i kept the nylon washers as they were the last experiment. I have not tried without washers as i used steel channel for my frames and thought some isolation might help, something!
I also wonder if the baffle gap to frame is per design, similar to the gap between the baffles?

 

I could be wrong, but I would imagine the baffle gap to the frame was probably more a matter of convenience than calculations.

 

...and to clarify, one of the nice things about the rubber washers provided with production Trios is that they are tight around the bolt. This makes it easy to remove the baffles with the bolts and washers intact for easy swapping once the fastening nuts are removed.

 

I had a chunk of heavy glue lam beam left over from my home build. I laid it on its side and its 7 inches tall. I cut it down and placed it under my PAP Trio 15 horn as a stand. They weigh about 50 lbs each. It raises the mid/high driver up much closer to ear level. Huge improvement. Not only is it more in line with ear height, it also seems to reduce the early reflection off the floor. The bass jumped out at me.

My crossovers are also on remote stands behind the frame. The frame vibrates way to much for a crossover to be on them. There is a profound sense of calm that comes over the speaker once the crossover is remote. It will get rid of any fatigue.

Lastly, lace the crossover to the drivers with quality cable. I got a mix of the Verastarr copper gold to the woofers on one leg only, and a quality copper to the other leg. The horn is wired with a quality Teflon coated pure CU copper. The cables make a big difference. Don't use Dueland or other cloth coated wire. Don't use Mill spec silver coated copper wire. They don't work well.

I also have the trio 10 with Voxative. I would sell them as I prefer the 15 horn, but I want to keep the voxative AC1.5 and use it in a transmition line speaker. That voxative is a good drive. It is a lot better than other drivers I tried for kicks and giggles.

 

Hi,

I have been enjoying this thread for a while. I have the trio15TB with neo woofers.

It is currently setup via a minidsp 2x4HD with a Harsch cross at 235 hz in w w FR configuration, with the fullrange panel tilted back 10 degrees as the (only) method of equalization, aside from a notch at about 2,400 hz (that I likely can remove).

the entire fullrange baffle is covered with two layers of wool felt.

Ive tried many many configurations. Kinda reached the conclusion that any of them can work quite well. IMO the Harsch beats a 24db LR marginally.

I am contemplating a number of changes to extend bass and reduce distortions. IMO one big problem to solve is frame and baffle resonance.

 

What thickness felt did you use and is it on both the front and back of the baffles?

 

the felt I used was two layers of 3/16” separated by 1/8 air gap.

since I did further experiments I am convinced the air gap is not as good as two layers tight, and I’m changing that today.

I did not put felt on back of baffle. I did put two layers of felt on all frame me,bets behind the fullrange, and also one layer on the inside ribs of the TB driver...to reduce early reflections. More work is needed on frame. I might dump the frame entirely.

 

One interesting observation about felt. I tried listening through layers of felt while I scanned the tangband. Each layer added reduced the frequency response starting about 3khz by 2db at 10 kHz, and it did that with only a tiny impact on phase, and that impact was on,y with the first layer.

felt appears to be a good high frequency acoustic resistor. It can potentially equalize hf drivers!

 

This really surprises me. I would have guesssed the opposite.

 

your post on this is bang on in my experience (I have the trio15 Tb with twin neo woofers).

I’ll just add a couple of items that made a big difference for me...

1] Achieving a tangband baffle tilt of 10 -12 degrees pretty much flattens the on axis listener response, and avoid need to filter it. It results in about +/-10 degrees off axis horizontal response before beaming effects dominate. That’s OK for my constricted listening env’t but might be something more critical to others.


2] High end choppiness in response due to diffraction is helped by covering that baffle with felt.

I currently don’t equalize the tangband, with its tilt.

 

I just found the schematic I sketched of the crossover that came with the trio...it’s a biamp cross, not the Leonids.

pretty simple topology. Woofers driven through a 3.9mh 0.22 ohm choke, with a zobel at 100uF and 2.7 ohm, 25w

Tangband (inverted polarity) gets a 33uF cap and then a 3.3mh, 3.3 ohm choke to return. There is a pin strappable resistor in series with the driver, which is shunted with 33 ohm, 25W resistor. The selectable resistors are zero, 2.2 , 2.7 and 3.3 ohms.

the independent filters can operate together using pin strap option to support a single amp at the front end.

I believe this crossover is tuned to the 21” wide baffle loss (-3db at 210 hz) and will only work properly in WFrW configuration because the tangband loses low end when mounted atop (only 12” high) instead of middle position. Because of the tangband’s questionable low end (without boost), the woofers cross gently to support it.

BTW, using DSP, I have found tangband amp channel best at -2,1 dB.

And 4’ from wall seems necessary.

 

You might be interested in what I am doing with the Trios next.

I met a gent at diyaudio who has been building homemade Open Baffles for many years. He suggested this.

I believe fullrange open baffle drivers are best NOT attached to a baffle via the front-of-basket screws. Better is to attach the driver by its magnet to a rigid support, such that the driver inserts into a (separately mounted baffle) hole a bit bigger than its outside diameter, with foam seals in the gap.

mounted this way, there is no possibility of the baffle acting as a membrane in response to the driving force of the cone. There is also no more potential for the driver/baffle system to resonate. Result is (much) cleaner sound, according to the gent I talked to.

In about a week I should have some results. I’m expecting big improvement, but time will tell.

The Trio also has a general problem with bass drivers exciting the frame. It can get very severe when you equalize the trios to get bass down to 40 hz and play anything exciting. So after fullrangers, I will look at how best to tackle that. I expect I will simply abandon the frame entirely and build something inherently more mechanically sound.

 

I did it yesterday, took a while to figure out an easy way, but this works...

I used two pieces of 1x2. One screws to a single driver bottom mount hole extending 6” backwards. A short piece glued on it rises to support magnet, and has a hole in it so a band of zip ties clamps the magnet, through a piece of felt, onto its support. It’s very solid. A pair of thumbscrews through the 6” piece will allow fine adjust of front back position for timing alignment.

Because the 1x2 is aligned with and same size as one of the tangband basket ribs, the mount doesn’t interfere at all with air movement around driver.

This driver isn’t vented, but what I’ve described doesn’t interfere with the rear of the magnet at all, soI may well do the same thing with the woofers. For now, The TB is the job.

Now I need figure out baffle size and shape...that’s a performance defining choice, so I think I will at first try some sort of flexible sheeting that permits experiments with curved baffles.

 

One other way that I considered was to but a set of super strong puck magnets, glue them to a mount pole and just “stick” the driver on that. I might use that method when I investigate crossing the TB to a real tweeter.

one problem is many ideas, not enough time to try em all

 

Hi, it seems PAP no longer sells the 15" driver for diy. I was hoping to build the trio TB with the 8" tangbang driver which is easily accessible.

what alternative 15" driver is best? thank you