Pure Audio Project Open Baffle kits?

[drivas]

Has anyone heard any of the Pure Audio Project open baffle systems? I know that these aren't DIY designs and perhaps a bit overpriced, but in terms of actual performance would they approach the SOTA?

They typically use pairs of upgraded Eminence Alpha 15 woofers per side and either Tang Band, Voxativ or Heil AMT HF/MF drivers.
http://www.pureaudioproject.com/product ... -speakers/

http://www.pureaudioproject.com/product ... -speakers/

http://www.pureaudioproject.com/product ... -speakers/

They are ~95db and their chief rep Ze’ev said that bass is down to 30Hz is achieved at only 20" from the rear wall.

Ze’ev said that his Bottlehead 2.5 watt 2A3 amp driving his pair sounds best to his ears.
Not surprisingly, he did add that it doesn't sound very dynamic, but claimed that the quality
of the highs and mids well made up for it.

He also claims that they chose the modded Alpha 15 woofers-over the otherwise excellent Acoustic Elegance woofers-because they cross high with the driver above, and because you
get full range response at low listening levels. When asked about active crossovers, Ze’ev
didn’t recommend them, saying that better performance is attained by swapping in better
caps, via the solderless crossover boards.

If I don’t go with one of these OBs, my other choice is very different: A pair of restored
Quad 57s, raised 15 to 20" with a pair of Rythmik 12" sealed servo subs. Ct0517 did this
and is very happy with the results. https://forum.audiogon.com/discussions/review-quad-57
https://photos.google.com/share/AF1QipP ... o3cER2WE9n

Clearly, this is not an easy choice. I might be lucky enough to hear the Quads locally next month. Would anyone in the New York area care to play their PAP OBs for me? Or has anyone heard both speakers?

Aside from bass response, how do they compare on sound stage size in all dimensions beyond the speakers, imaging, detail, tonality, midrange, midbass?

[Scottmoose]

Has anyone heard any of the Pure Audio Project open baffle systems? I know that these aren't DIY designs and perhaps a bit overpriced, but in terms of actual performance would they approach the SOTA?

Not to my mind, but that does depend how you define state of the art; I would be rather more inclined to describe Siegfried Linkwiz's and John K's designs under that heading -YMMV as always though.

They typically use pairs of upgraded Eminence Alpha 15 woofers per side and either Tang Band, Voxativ or Heil AMT HF/MF drivers.
http://www.pureaudioproject.com/product ... -speakers/
http://www.pureaudioproject.com/product ... -speakers/
http://www.pureaudioproject.com/product ... -speakers/

They are ~95db and their chief rep Ze’ev said that bass is down to 30Hz is achieved at only 20" from the rear wall.

While a very good cheap woofer, the Alpha 15 is not exactly a state of the art basis for the LF drive unit either in terms of its motor, suspension or cone design. Granted, that's the base model & they've got a custom variation from Eminence with a neo. motor on it, which is probably a step forward in terms of the basic motor linearity, but on a very quick skim read, I don't see anything mentioned about cone or suspension.

You may get 30Hz from it, but if that's only 20in from the front wall it's presumably using room modes to help prop the LF up. Which is fine, providing you weren't hoping to reduce room influence by going down the dipole route of course.

Ze’ev said that his Bottlehead 2.5 watt 2A3 amp driving his pair sounds best to his ears. Not surprisingly, he did add that it doesn't sound very dynamic, but claimed that the quality of the highs and mids well made up for it.

Fair enough; we all like different things and compromise on areas that are less important to us in order to obtain xyz advantages elsewhere.

He also claims that they chose the modded Alpha 15 woofers-over the otherwise excellent Acoustic Elegance woofers-because they cross high with the driver above, and because you get full range response at low listening levels.

The XO frequency is stated to be 450Hz for the TB variation, which doesn't seem especially high. Cascaded 2.5 way (in essence) for the Heil version (250Hz & ~950Hz) which again doesn't seem especially high. Not stated for the Voxativ model, with the option of an 'adjustable' filter, so again, YMMV as far as that part goes.

When asked about active crossovers, Ze’ev didn’t recommend them, saying that better performance is attained by swapping in better
caps, via the solderless crossover boards.

'Better performance' than what, and in exactly what way? How are the 'better caps' defined? I don't care for active filters much myself, but that is purely personal preference on my part; they are perfectly valid and have some advantages that passive filters do not have (and visa versa). They require more amplifiers of course. Reducing the comparison between active and passive filters to capacitors alone doesn't make much sense to me though; there are too many factors involved to simply pick one & set aside all the others.

If I don’t go with one of these OBs, my other choice is very different: A pair of restored Quad 57s, raised 15 to 20" with a pair of Rythmik 12" sealed servo subs. Ct0517 did this and is very happy with the results. https://forum.audiogon.com/discussions/review-quad-57
https://photos.google.com/share/AF1QipP ... o3cER2WE9n

Clearly, this is not an easy choice. I might be lucky enough to hear the Quads locally next month. Would anyone in the New York area care to play their PAP OBs for me? Or has anyone heard both speakers?

Aside from bass response, how do they compare on sound stage size in all dimensions beyond the speakers, imaging, detail, tonality, midrange, midbass?

Given that all these points are entirely subjective and depend both on personal opinion / experiences and the specific implmentation (i.e. system-wide: source, amplifier[s] and above all the room), I doubt you'll get many comments that will necessarily be applicable to your own situation. About the best that I would suggest is that in both cases there is a solid basis with decent speakers / drive units and the implementation in a broad sense seems sound. Unmodified the Quads tend to be quite (OK, 'very') directional in the HF -whether that will apply to the restored versions or not I don't know. Likewise, the MC driver based baffles look to be using solid components as their basis; the TB, Voxativ & Heil units are all good examples of their particular types, same for the [modified] Eminence.