Great plains Audio 604 coax drivers...the best coax ever?

[morricab]

I heard a pair of these some years ago and was deeply impressed with what they can do. Also, there is a youtube video from Kenrick sound (they make properly high quality recordings...no iphone or samsung) of a pair that is frankly pretty awesome sounding. Given their pretty reasonable price (1800-2300 depending on ferrite or alnico) and then some cabinets, this is potentially a reference class (in some but not all) sounding system for pretty low money.

Given what I have heard from Dynamikks, Live Act Audio and some others, it seems that a good coax design is really a way to a high level sound. Since I already have Dynamikks Athos 10 speakers, I wanted in my own design to do somehting different but the simplicity of a big coax in a big box (or open baffle with a couple of big woofers) seems pretty darn tempting.

 

[DaveC]

IMO, no. They are excellent but not a "reference class" device.

This is the best I've heard them... from RMAF 2017 and augmented above w/ Fostex T500AMkII and below with another 15"woofer.




They also were shown with these resonators, I heard them with and without... it was very interesting!

 

[jeff1225]

I heard these speakers as well Dave, I thought they were quite good.

 

[Audiophile Bill]

IMO, no. They are excellent but not a "reference class" device.

This is the best I've heard them... from RMAF 2017 and augmented above w/ Fostex T500AMkII and below with another 15"woofer.




They also were shown with these resonators, I heard them with and without... it was very interesting!

Please can you elaborate on the with/without resonators scenarios.

 

[DaveC]

Please can you elaborate on the with/without resonators scenarios.

I was thinking about this, how to convey what I heard... and add a disclaimer that I only have experience hearing it with and without the resonators on only one track and it's possible it may not do the same for all recordings. The resonators were added and removed while the track was playing several times, and by two people, one on each speaker switching them out so it was just a second or two to add or remove them. All I can share is my one brief experience, but what I heard was very interesting.

The track that was playing was a female vocal, unfortunately I don't remember exactly what it was. What I remember most was the resonators made the vocals sound more natural and it was easier to understand the lyrics with the resonators in place. I believe what they did is extend the decay of the vocals, and this ended up sounding more "correct" to my ears psychoacoustically. Without the resonators the vocals sounded duller and less clear.

I think this is a case where a device that was conceived to modify the recording actually worked and made the music better. I also don't believe this is a subjective improvement, as there are established criteria for vocal intelligibility in PA systems. A vocal that is easier to understand to the point the lyrics were clearer and took less effort for my brain to process is an actual improvement in my book. I hesitate to say this as some may have issue with a device like this making an objective improvement, but it's only my own limited experience and is proof of nothing. However, it may be an indication that it's possible to improve on recording quality, if not in the analog realm using resonators, then in the digital realm by modifying harmonics and decay to match established psychoacoustic models (which may not exist yet either).

In any case, it was a very interesting demo and I wish I remembered exactly who made the resonators, he was a really nice guy. I'll have to look it up, it was at RMAF 2017 so shouldn't be too hard to track down.

 

[jdza]

IMO, no. They are excellent but not a "reference class" device.

This is the best I've heard them... from RMAF 2017 and augmented above w/ Fostex T500AMkII and below with another 15"woofer.




They also were shown with these resonators, I heard them with and without... it was very interesting!

Altec did the same in 1980 with the 6041-without the resonators .

 

[Audiophile Bill]

I was thinking about this, how to convey what I heard... and add a disclaimer that I only have experience hearing it with and without the resonators on only one track and it's possible it may not do the same for all recordings. The resonators were added and removed while the track was playing several times, and by two people, one on each speaker switching them out so it was just a second or two to add or remove them. All I can share is my one brief experience, but what I heard was very interesting.

The track that was playing was a female vocal, unfortunately I don't remember exactly what it was. What I remember most was the resonators made the vocals sound more natural and it was easier to understand the lyrics with the resonators in place. I believe what they did is extend the decay of the vocals, and this ended up sounding more "correct" to my ears psychoacoustically. Without the resonators the vocals sounded duller and less clear.

I think this is a case where a device that was conceived to modify the recording actually worked and made the music better. I also don't believe this is a subjective improvement, as there are established criteria for vocal intelligibility in PA systems. A vocal that is easier to understand to the point the lyrics were clearer and took less effort for my brain to process is an actual improvement in my book. I hesitate to say this as some may have issue with a device like this making an objective improvement, but it's only my own limited experience and is proof of nothing. However, it may be an indication that it's possible to improve on recording quality, if not in the analog realm using resonators, then in the digital realm by modifying harmonics and decay to match established psychoacoustic models (which may not exist yet either).

In any case, it was a very interesting demo and I wish I remembered exactly who made the resonators, he was a really nice guy. I'll have to look it up, it was at RMAF 2017 so shouldn't be too hard to track down.

Thanks for this feedback, Dave. I actually do subscribe to this philosophy rather than being a detractor. I have being experimenting with resonance in my speaker designs a lot recently.

Best.

 

[morricab]

Thanks for this feedback, Dave. I actually do subscribe to this philosophy rather than being a detractor. I have being experimenting with resonance in my speaker designs a lot recently.

Best.

In my own experiments with this new, plastic elliptical horn from 18 sound, it seems to have very low coloration, perhaps the advanced design and very low diffraction gives far fewer resonances? I will still experiment with putting bitumen or panel damping materials on the outside of horn to further control residual resonance.

 

[morricab]

In my own experiments with this new, plastic elliptical horn from 18 sound, it seems to have very low coloration, perhaps the advanced design and very low diffraction gives far fewer resonances? I will still experiment with putting bitumen or panel damping materials on the outside of horn to further control residual resonance.

That said, the solid wood horns for my Odeons are really low coloration.

 

[morricab]

IMO, no. They are excellent but not a "reference class" device.

This is the best I've heard them... from RMAF 2017 and augmented above w/ Fostex T500AMkII and below with another 15"woofer.




They also were shown with these resonators, I heard them with and without... it was very interesting!

Heard these in Munich and didn’t like them so much...came across as quite colored. Live Act Audio Coax systems were better at the show at least.

 

[bonzo75]

I heard a pair of these some years ago and was deeply impressed with what they can do. Also, there is a youtube video from Kenrick sound (they make properly high quality recordings...no iphone or samsung) of a pair that is frankly pretty awesome sounding. Given their pretty reasonable price (1800-2300 depending on ferrite or alnico) and then some cabinets, this is potentially a reference class (in some but not all) sounding system for pretty low money.

Given what I have heard from Dynamikks, Live Act Audio and some others, it seems that a good coax design is really a way to a high level sound. Since I already have Dynamikks Athos 10 speakers, I wanted in my own design to do somehting different but the simplicity of a big coax in a big box (or open baffle with a couple of big woofers) seems pretty darn tempting.

Dynamikks 8.12 with silvercore TB3/1000 amps - system belongs to user fbs on the forum. Nice tone and flow. A bit of a break to the lower driver noticeable only on the piano, that needs adjusting to. Didn't notice it with anything else. Easy to drive with the 25w SETs. A bit of the they are here feel compared to you are there.

 

[morricab]

Dynamikks 10.8 with silvercore TB3/1000 amps - system belongs to user fbs on the forum. Nice tone and flow. A bit of a break to the lower driver noticeable only on the piano, that needs adjusting to. Didn't notice it with anything else. Easy to drive with the 25w SETs. A bit of the they are here feel compared to you are there.

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Nice. That speaker is the Monitor 8.12 mkii, which is the second smallest speaker (there is the now slightly smaller Athos 10, which we have and is 8 inch coax with 10 inch woofer). It has 8inch coax with 12 inch woofer. There will be a new model of 8.12 coming though and a new Monitor 10.15 as well (middle model). We also have the Monitor 12.18, which is 12 inch coax and 18 inch woofer.