Pure Audio Project upgrades and tweaks

Starting this thread to discuss Pure Audio Project open baffle speakers, upgrades and tweaks. @Kingrex - if you have had both the horns and Coax10, I would be interested in hearing how they compare. And I copied your earlier post below.

What cables upgrades did you use? And can you share a picture of where you located the crossover? Is it attached to something else, or sitting on the floor? I was wondering about the height of the midrange/tweeter and if I should rake the front up. My system will be the Trio15 Coax10, Playback Designs MPS-8 source and Pass Int-25 amp. I'm still waiting for my walnut baffles to ship from RJ Millworkers.

You have to get the updated speaker cables. Its critical.

And , you have to separate the crossover from the frame. Again critical.

If the crossover is touching the frame, the music is very smeared from the intense physical vibration.

If you use stock, instead of upgraded cables, you loose life, air and bass. Less coherent.

The speaker is very good with these tweeks. You don't need to futz with any caps or reaistors with the Coax crossover.

You need to be patient. They take 500 hours like any speaker to break in. 2000 or a year to really be there. I actually put my coax in the basement connected to a class D amp and laptop for week and let it rip sitting on the floor. I would go dowm 3 or 4 times a day to switxh the album and volume.

Also, mine sit on a 9 inch tall very heavy block of wood that sits on fiberglass insulation. A rug would also work. Massive improvement in bass. Just shocking. And, it raises the center of the coax much closer to ear height. Otherwise its too low and like sitting in a balcony.

The fabric over the top keeps the sun from striking the driver. That is all its for.

 

If they are willing I would ask for the baffles too, to add rigidity to the frame.

I've also noticed what looks like a new thicker bottom plate for the frame. I wonder if I should reach out and see if they will sell me that.

 

I lined the inside of the metal supports of my Trio 15s with Second Skin vibration control sheet. Seems to do a nice job of cutting down the vibration.

I did have a question for the group about the inductor, mine came with Mundorf .27 Ohm, 6.8 mH, was looking for a little more bass and check out the Solen link, but could not find a match. Would it be better to go lower Ohms or just a bit more for the bump. Excuse my electrical engineering ignorance with this question as well.

Has anyone tried an Purtian PSM 156 with these speakers? I have heard it may clean up some transformer buzz , but may bring a bright lean presentation to the sound... although those who own these seem to say the sound is cleaned up from all the mud on the mains line that is why the bass seems more lean...

 

I don't think changing the inductor will give more bass, value for value.

I don't know about the Purtian unit. Changing PCs, interconnect and speaker cables can have a significant impact on the final sound.

 

Great thread!
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I’ve done some mods to my PAP Quintets 1.6 Voxativ

I have them sitting on 3” butcher block. I have Wave Kinetics 2NS isolators Eden Sound brass footers go into the 2NS.

I used Isodamp along the frame where the baffle attaches to the baffle. I also added washers to the bolts so I could tighten the baffle to the frame tighter. The bolts were sinking into the wood so the oversized washer fixed that issue. I added washers and lock washers on the back.
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This increased the resolution significantly. Everything was more clear and precise while still maintaining the rich enveloping sound.

I had Jonny from Snake River Audio make me custom cables and jumpers for the wiring.

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I rebuild the crossover using an air-core inductor. I needed to go to a 10 AWG wire to keep the resistance as close to possible as the stock inductor. I also added Dave Slagle’s Speakerformer to attenuate the Voxativ driver. I’m just about to solder it in and mount it.

Adding No-Rez to the metal frame on the inside added a nice step up in overall resolution as well. Mids and highs are so clear while the bass is full and tight.
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I'm thinking I'm going to cut a piece of wood to cover the hole where the crossover used to fit.

My goal with my system is to sit down and get lost in the music. I have achieved this. Have the clarity to hear all the subtle detail and nuance. The bass to lay down a good foundation. Finally the holographic presentation that has gotten to the hallucinogenic level. Some days it’s like being in a lucid dream.

My dad was telling me about an intimate concert he went to. There was one musician playing the sitar in the center of the audience encircling him. He said after a few minutes he closed his eyes, a few minutes later he was getting visions in his mind that played off of the music. This is the hallucination or psychedelic experience I’m experiencing.

GS,
Would you kindly indicate the thickness of Isodamp you used in between the baffle and frame and whether or not you removed the grommet that came with the kit? I’m also ordering the No-Res for the frame. It may do well under the XO?

 

I also added 3 braces per frame which did not eliminate, but seemed to diminish the magnitude of said vibrations, most severe in the 45-90 hz area.

 

@Retk9doc I'm not exactly sure. My guess is 1/8th inch for the Isodamp. I ran a strip along the entire area that the baffle will touch. I forced the bolt through to punch a hole in the Isodamp. I removed the tan squishy washer.

Putting NoRez on the base seems worth while. One of these days I'll get around to putting some on the base.

The bracing is an interesting idea.

 

@Retk9doc I'm not exactly sure. My guess is 1/8th inch for the Isodamp. I ran a strip along the entire area that the baffle will touch. I forced the bolt through to punch a hole in the Isodamp. I removed the tan squishy washer.

Putting NoRez on the base seems worth while. One of these days I'll get around to putting some on the base.

The bracing is an interesting idea.

Also interesting as to the difference between attempting to isolating 4 points on the baffle vs spreading out the contact area as you have done. Tightened all, screws, that maintenance tip I missed, good one. Lastly, I have the xo wires attached to the vibrating frame which I will now mount on the NoRes. At the time of purchase, upgraded xo wires were from Espirit(Kappas). Thanks for the reply.

 

I did a cable change to my Coax 2 days ago. OMG. Magnitudes of improvement. I have not tried bracing or damping my frame.

 

This speaker platform starts out good. A few tweaks and modifications and they really can come alive and provide an fantastic stereophonic sound spectacular.

Adding Isodamp along the frame where it comes in contact with the baffle is the best improvement per dollar I experienced. It was less than $150 for the sheet of Isodamp and I still have left overs.

Cables is another good improvement. The results can be remarkable as Kingrex mentioned.

NoRez is another high performance per dollar improvement.

 

I forgot to mention. I had the manufacturer of my amp (Scott) over. I was not happy with what I was hearing. We made a few changes. One was removing the horn and putting the coax in. We both agrees the coax is a much better configuration.

Scott still feels I have a ways to go. He wants me to get a 6.8mh air core choke.

 

This speaker platform starts out good. A few tweaks and modifications and they really can come alive and provide an fantastic stereophonic sound spectacular.

Adding Isodamp along the frame where it comes in contact with the baffle is the best improvement per dollar I experienced. It was less than $150 for the sheet of Isodamp and I still have left overs.

Cables is another good improvement. The results can be remarkable as Kingrex mentioned.

NoRez is another high performance per dollar improvement.

What isodamp do you use. Does it have adhesive or do you need your own.
I asked Ze'ev about a heay frame. Like Daisis has. He experimented with a thick aluminum one. Said it was more clean, but gave up some life.

 

Granite Audio Bass test CD 102 is worth a consideration to easily feel, explore individual frequencies from 20-100 Hz. Fwiw, can easily find any object in the room that’s being excited. The frame behavior is easily felt.

 

@Kingrex Sorry I missed this. I got a 12x24" sheet with adhesive from Eden Sound.

When I first got the speakers Ze'ev did send me a horn1 to demo. I put a lot of time and effort to get it to sound as good as I could. Ultimately I ended sending it back. Everything sounded more cohesive with the Voxativ.

 

I don't see any

@Kingrex Sorry I missed this. I got a 12x24" sheet with adhesive from Eden Sound.

When I first got the speakers Ze'ev did send me a horn1 to demo. I put a lot of time and effort to get it to sound as good as I could. Ultimately I ended sending it back. Everything sounded more cohesive with the Voxativ.

I don't see anything there. When I look up the material, it is priced from about $2000 to $5000.
I have wondered about other dampening sheets. But I don't want to end up with a flat sound and not be able to remove it. I though about getting a second frame????

I did talk to Ze'ev about this a couple times. He seemed to say they have experimented to get the best sound. Whatever that means to them. We all have what we believe is the best sound. Anyhow, he liked the coupling of vibration of driver to frame.

I had the guy who made my amps over again last night. This guy is a serious engineer. He gets it. Anyhow I have a nice 12 inch single of Thriller. We cranked it up. When the initial organs and other instruments start, the impact is less than I wanted. But, we had just been discussing how thick the paper is on the 15 inch woofers. He says that is a massive amount of weight to move. You need a iron fist to control it. That does not mean it can't be a musical speakers. It just takes work. He still wants me to ditch the 6.8 mh iron choke for air core. I found a few for about $67 each. 1.4mm wire. I may try that. I think ultimatly, he is circling the idea of ditching the current woofers for a better 15 inch that is more lightweight and easier to control. I don't know I want to do that. It just seems a can of worms. Something will be a little off and it will be chasing my tail forever. As it is, I have some of the best sound I have heard from my stereo to date. Is it perfect, no. But its really good.

Those wires from the crossover to the speaker really have a dramatic impact. So does the amp.

 

@Kingrex I emailed Dan directly and he added it to my order. I bought a few brass weights and footers from him.

I could peel the Isodamp off if I wanted too no problem.

Using the NoRez I had the following experience. I covered the inside if the frames from top to bottom on the inside. I wasn't happy with the sound. I ended up removing the NoRez from the wall side of each and enjoyed the sound much more. I moved and finally got a treated dedicated room. One day, actually might have been this thread inspired to to revisit. Took the cut sheets of NoRez that I saved and put them back on. I found it was a drastic improvement. Clarity, punch, soundstage and subtle details all increased.

I find the bass on the speakers insanely fast. The impact, texture and nuance are all insane. The tons of diaphragmatic treatment helps with this I'm sure. Point being, I wouldn't point the finger to the drivers. I'm running a 20 watt PP tube amp.

I don't know how the XO is different between the Coax and Voxativ. When I added the massive aircore inductors, I heard a improvements in the bass and midrange. To match the DCR I needed 10 AWG which is heavy.

The Bass isn't the deepest, most chest pounding or OH @#%^!. It does have a lot nuance and it can hit hard and fast.

 

He still wants me to ditch the 6.8 mh iron choke for air core. I found a few for about $67 each. 1.4mm wire.

Is this for the woofers? 1.4mm seems really thin for woofers. I guess if the DCR is close on both worth a shot.

 

I don't disagree about bass. I'm surprised how real the music sounds. How natural a stand up is. How well a Timpani strikes. Even Piano is quiet good. I still get some perceived shortcomings at times. But in all, its darn good. I have 40 watts of PP KT88. 83 lb each monoblocks. All Monolith iron.

I want to try damping. But even Groovey has had it fall short. Then its good. I wonder if your opinion will change again.

The chokes are for the woofers. Its supposed to add air when you get rid of the iron. There are negative affects to the circuit. I don't remember the details. I have tried them in the past. I ended up taking them out and giving them away. PAP has done a good job of making a very good out of the box speaker. I have tried messing with it and end up back to stock. So I am not very excited to open the can again.

The wires though are critical. Very sonically apparent. PAP does have a new wire. I think its $1400. If I bought a set of speakers, I would say its critical to get the updated wire. More important than most anything else.

 

I added the NoRes only to the inside of the inner frame wall to much effect. Lower midrange more evident. Not convinced to was an overall improvement. Then experimented with additional toe-in, less than an inch and the image improved to what I perceived as a negative result of the no res. Now speaker axis crosses over 2-3 feet behind seat. Curious as to the effect of removing the damping just at the level of the coax. The dedicated treated room symmetry makes the adjustments easy to discern.

 

The wires though are critical. Very sonically apparent. PAP does have a new wire. I think its $1400. If I bought a set of speakers, I would say its critical to get the updated wire. More important than most anything else.

Is that the Fidelium wires? They are $1850 now.

 

Is that the Fidelium wires? They are $1850 now.

I have not heard the PAP upgrade wires. I have some of the Verstar that were the first upgrade wires. But I thought I was getting wires for the whole system and only got wire for the horn. And someone had modified them. Cut them in half to get more wire. Threw away the ends.
I am saying the stock wire is not that good. You will hear a better wire. I am assuming what Ze'ev offers as an upgrade wire, whatever it is, is going to work well.
I know another PAP fan who uses Iconoclast. I think he spent close to what the speaker cost to wire the drivers.