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.

 

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.

Congrats on your new speakers!

Is this your first venture into open baffle?

 

Yep, I'm a true open baffle virgin. I've never even heard an open baffle speaker, but Steve Guttenberg sold me with his passionate review. I have been looking for high efficiency speakers for a couple years, and this seems to tick all the boxes. I decided I needed to hear them in my home so placed the order.

 

Yep, I'm a true open baffle virgin. I've never even heard an open baffle speaker, but Steve Guttenberg sold me with his passionate review. I have been looking for high efficiency speakers for a couple years, and this seems to tick all the boxes. I decided I needed to hear them in my home so placed the order.

I recommend you to attend Audio show to compare between different speakers.

Axpona and Munich shows are the prime ones.

But there are many local audio shows around US or Asian countries like Korea, Japan, Hong Kong, Taiwan and Singapore.

It will give you chance to experience two or more open baffle speakers.

 

My crossover is screwed to a wood post set mid height behind my speaker. I want all my cables the same length.
My cables are a mix of Veristar from our friend OCD Mike Meltdown Powell and Graditech. A Graditech dealer tore apart a set to see what was inside and sold me the guts.

I know of another PAP owner that uses Iconoclast.
PAP premium cables are going to be good. Ze'ev knows what he is doing. Ask if they can be made the same length for a stand mount crossover.

PAP has their cables designed to place the crossover on the floor. This bugs me as the woofer cables are significantly different in lengrh. Just seems wrong.

Use Deoxit G100 on every wire tip and screw terminal. I mean every. At all the caps and resistors across the crossover and on the drivers. Slightly loosen them all, deoxit, then torq tight. And torq dies not mean manhandle. I grip the plastic shield to keep from stressing the solder toncircuit board and snug them. I have 30 years doing as such so its hard to know if you have any idea what my idea of snug is.

The horn is very good at highlighting violin and brass. But it was burying details for me. Such as harpsicord in large orchestra. The coax is far more even where the harpsicord will come out and be heard. But its still alive and natural.

Bass is going to be your biggest enemy. While these speakers are very forgiving to set and listen in the midbass up, rhe low frequency may challenge you. What do I mean. You don't have to puts it to a fraction of an inch to get the mids and highs to sound great. But. I went to the Pink Martini concert a couple days ago. Yesterday I was cranking the 45 rpm Edna Vazquez collaboration with them. I have a horrible bass suck out where the bottom is fat and bloated, then as it rises just disapears. As in no bass. Its all placement. I have been fairly absent at my stereo listening with all the work I have and trying to close on a piece of land to build our new home. So, my speakers are sort of shoved into place in the living room. Too close to the back wall. Just be aware. They have good bass. You will have to work at it. try 40 inches to the face from the back wall, then move them around.

And give them time to braeak in. I got mine with the horn from a guy who only played them maybe 100 hours and was all over the place with crap cable. He got very dissatisfied and dumped them. It took me a few months to dial them in and break them in.

 

I also find theae speakers realky excell with a tube. Lower power. Like say, 9 watts to 60 watts. I actually am waiting on funds to clear, then my Dartzeel is sold. I have the Found Music Blade on order.

https://foundmusic.info/?page_id=180

I have very much liked any amp I threw at then. Thomas with PAP likes very high power SS to control the woofers. I was completely blown away when Scott with Found Music brought his blade to my house. Jazdoc has one of the best systems I have heard. I thought it was the Daedalus speakers. It was the amp. When I heard the Blade in my system, I had just finished the Pacific North West Audio Show. My speaket with that amp was better than any system I heard at that show. Some have better bass. But I feel a swarm will reaolve that delta.

If you get it set up properly and feed it a good signal and power it will return in spades.

 

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.

I'm thinking about trying the Butcher Block speaker stands with the iso-band footers. This would raise the height of the speaker and hopefully decouple vibrations in the speakers from the floor. I am still waiting on the parts, but I already received the cross-over with stock cables.

@Kingrex - you mentioned that Ze'ev is working on premium cables - do you know anything more about that? Or are you referring to the Silversmith Fidelium cables he used at the Pacific Audio Fest?

 

His premium cable is on the website. And it should be what he uses at shows.

Just make sure the footer slides. Your going to want to move them till you find the rifht spot.

 

His premium cable is on the website. And it should be what he uses at shows.

Just make sure the footer slides. Your going to want to move them till you find the rifht spot.

Thanks - I did not see the wiring upgrade option when I placed the order, but it looks like it is something I can add later. The internal wiring upgrade for the Trio15-Coax10 is $1850, and I think it used the Fidelium cables, with another option to also add Fidelium speaker cables.

 

They are going to come as a long set, medium for coax and short for bottom woofer. You can put the crossover on the floor. That is easiest. Just make sure they know your doing that. It may impact the length. Or you need a stand to put the crossover at the correct height.

 

I own the trio 15's with the coax and have always wondered how the horns sound in comparison. I run Fidelium cables to my Trio's including the bi-wire option. That little jumper never gave me much confidence. I run a mix of cables from the crossover. When i first got the speakers I felt they lacked a bit of high frequency energy so I tried some solid silver and silver plated copper. Ended up with the later. More recently I have found that the mids were too prominent and forward for me. This prompted me to model the crossover in XSIM. I have been able to make meaningful improvements to the mids by swapping out resistors in the mid portion of the crossover. The 4th order crossover for the coaxial is fairly complicated hence the XSIM model. Happy to share with other members but out of respect to Zev and PAP I wont post them. PM me if you are interested. If you have never used XSIM its a free crossover modeling software. Once you plug everything in it gives you a projected frequency response curve. You can swap out component values and see clearly how they will effect the sound of the speaker. I have my crossovers mounted to a very thick sheet of bamboo on the floor behind the speaker with some simple damping techniques. Cant say it helps much but it couldn't hurt. I run my Trios with a Melody 845 monoblock amps which put out 22watts. More than enough power.

 

Great thread!

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.



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.



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.

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.

 

GroovySauce
Great post. We have very similar goals in what we are attempting to achieve with our listening sessions. Where might I ask did you get that 10ga inductor? I'm guessing that is custom wound. For the coaxial crossover with 4 woofers the inductor in the bass section is 6.8mh / .28 ohm. The only commercially available air core inductor I can find to match this would be a Mundorf MCoil VL300 at $500 a pop. I didnt bother to research foil inductors. I always wondered what a Jantzen C-Coil inductor might do in this position. However even the lowest 17ga coil at 6.8mH gives a DC resistance of .17ohms. Not sure how If running bass through such low guage wire would be a net gain.

On a side note I have been looking for a formula to make the mids more lush on my coaxials. I always felt them to be a bit dry. I have been playing with interstage capacitors on my amps. Been switching between VCap Copper and Miflex Copper for a year now. Last night I popped in a pair of Jupiter coppers not expecting much and the whole presentation in the midrange lit up with a warm glow and the bass became more pronounced to a not subtle degree. These are far from neutral capacitors but for me I very much like what I am hearing out of the gate in my room with my setup. The will need to break in before making any kind of final judgement of course.

 

It’s a Solen inductor. 0.41 ohm while the supplied inductor is 0.35 ohm so close. I bought them two+ years ago, both with shipping around $500.

https://solen.ca/en/products/solen-perfect-lay-air-core-inductors-s1010_0-10mh-10awg-inductor

I haven’t heard the Coax driver PAP offers. Are. the bolts holding the baffles on loose? I would check those as I needed to tighten mine—before the mods—every month or so.

I also found my PAP quintets lacked the upper frequencies when I first set them up. I found big band music dull and dark, it should be lively with all the brass! Tightening everything up made a big difference here. It also brought richness.

Have you done anything to dampen vibrations from the frame or baffle? I highly suggest getting some Isodamp and adding it along the frame touching the baffle and tightening it down.

I find with the Voxativ driver the speakers to be responsive to the rest of the components. If a component makes it dry and harsh they will play dry and harsh. If something makes them syrupy and overly sweet they will play syrupy and sweet. Find the right stuff and it becomes lusty.

As I was reading about your cap changes before I got to the Jupiter caps that was what I was going to suggest. I haven’t heard Vcaps in my system so I don’t know about them. I have heard from some people they are very clean and don’t have any sexy midbass sashay.

@Sandston I see you have a 845 amp, what other components are you running?

 

I honestly have not played much with the tightness of the screws holding the baffles to the frame. I have instinctively always felt you wanted them tight enough to hold them in place but loose enough to limit vibrations in the panel from transferring to the frame and vice versa. I know that's a lot to ask from the little rubber washers that come with the speakers! I will try tightening them down and see if I notice a change.

I find it interesting that you heard a change in the upper frequencies with tighter panels. Seems counterintuitive but I am nonetheless going to give it a try. Curious as to your theories on why the highs were improved?

Good call on the Solen Inductors. $334 for a pair of 6.8mh / .34ohm Air Coils. Pretty dam close versus .28ohm stock. Curious if felt these coils made a worthwhile difference. The size of these guys would involve some planning. The coax crossover is quite a bit more complex than the Voxativ. I've thought about moving it to a new board and going point to point and soldering all the connections. Someday perhaps if I find I am done tweaking the crossover.

I agree the VCaps Cu are a bit clinical but have a lot that is tight and right about them. I was vey surprised at the difference between the Miflex and the Jupiter. The Miflex Cu lay somewhere in between the two but much closer to the VCaps then I would imagine.

My system is all digital. I run Roon Core / Euphony on a NUC in a fanless Akasa Case. Fiber Internet -> AfterDark switch with two SFP ports -> Etherregen with AfterDark Geisman Clock -> OpticalRendu V2-> Denafrips Hermes DDC -> Denafrips Terminator 2 Dac -> Linear Tube Audio Preamp Level 2 -> Melody 845-1 Monoblock Amps; DSPeaker Antimode 2.0 Dual Core -> 2X SVS 4000 series subs. I have several linear power supplies from Uptone, Farad, AfterDark and HDPlex. All run from a Synergistic Research PoerwCell SX Conditioner.

 

Great thread!
View attachment 122879
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.
View attachment 122883
View attachment 122880

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.

View attachment 122881

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.
View attachment 122882
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.

Thank you for the excellent post! Everything matters doesn't it.

I haven't had the opportunity to listen to open baffle speakers yet but I am looking forward to it.

 

If you’re comfortable rebuilding the crossover point to point that is the way to do it.

I don’t know why tightening up the baffles brought for clarity to the highs. I'll ramble on why it might make a difference. My experience has been as the resolution of the system goes up the need for more SPL goes down. When a 75 db peak kick drum is hitting me hard and fast in the chest and I’m lost in the music the idea of turning up the volume doesn’t show up. I’ve also found that when resolution increased richness and envelopingness show up. As resolution increases harshness is reduced.

If the baffle is vibrating, it’s vibrating the driver, this is adding distortion. By lowering the unwanted vibrations on the baffle the resolution increases.

You’ve got a nice set of gear! Is revisiting speaker and listening position possible? Knowing nothing of your room (shot in the dark here) try moving the speakers together a little bit this might brings some more life to the mids and bass. I also found that an equilateral triangle is a great spot to start the listening position.

I’m having Jupiter caps put in my amp that Aric Audio is building.

 

GS
I appreciate you taking a stab at why tightening the screws might effect the speakers highs. After I sent that message i was afraid it might come off as a bit of a passive aggressive challenge. Thinking on it with the small compression driver tweeter in the coaxial I could see where external vibrations could effect the tweeters ability to render accurate highs. I hand tightened all my bolts last night and had a wonderful listening session into the wee hours. I cannot say the their was a difference as I am day two into the beguiling effect of the Jupiter interstage cap effect.

I wish I had an accelerometer sensitive enough to measure panel vibrations to test your theory. It seems analogous to the idea that decoupling your speakers from the floor with say IsoAcoustic Gaia feet is better than the traditional wisdom of coupling the speakers to the floor with spikes. I prefer the Gaia footers over spikes.

For my Coaxial Trios I found the mids to pronounced and forward and have modified the crossover to drop them back with great results. I determined my speaker placement using the Room Simulator in REW and have ended up with my speakers about 42" off the front wall and about 6' apart. I find I am a more of a midfield listener. The nearfield equilateral triangle sounds a bit too much like headphones to me. I have a modest amount of room treatment and like a little bit of bounce off the side wall that the mid field gives. Too me this creates a wider perceived soundstage and simulates the feeling of being at a concert in my preferred location. 2/3rds of the way between the soundboard and the stage. As for toe in I actually like the speakers to cross a bit behind my head which I know is not "popular". My feeling is that too much toe in and the speakers dont interact with the walls to the front of my treated first reflection point. This bit of bounce creates a wide soundstage without too much smearing.

I am intrigued that you have lifted your quintets off the floor. At what height does that put the Voxativ in the Quintet? I always felt the Trio would benefit from the coaxial being raised to ear height but the block required to do this would be pretty thick. I secretly have wished PAP made a taller frame or extension that accomplished this where you could add an additional panel below to clean things up.

 

All good, I didn’t hear it coming off as passive aggressive. How long do you estimate the burnin of the Jupiters to be? If I recall correctly it was a few hundred hours before my Decware Torii MKIV settled in with Jupiter caps.

I found I prefer decoupling speakers from the floor too. I’ve used the GAIA footers on speakers and have been happy with the result. The Wave Kinetic N2S also decouple the speakers.

My ear height 3’ 6” from the floor. The Quintets on the butcher block are 3’ 8”. My speakers are 10’ 6” center to center. My ear is 10’ 10” from the center baffle.

Speakers are 7’ 4” from the front wall 3’ 8” side walls. They are toed in crossing a little behind my head.

I spent 3-4 months tweaking the positions of the listening position and speakers. I had blue painters tape with notes all over the floor I should have taken a picture it was crazy. I have a dedicated fully treated room. I literally have over 6,000 pounds of treatment. The tweaking was to maximize the holography, 3D and envelopingness. Everywhere in the room the bass response is very similar except to the sides and guessing between the speakers.

 

I'm guessing a minimum of 100 hours burn in before a switch out the Jupiters for the Miflex to compare.

I reached out to PAP to see if I could buy just a set of quintet arms to lift my trios up to quintet ear level.