PAudio Coax on an OB

[abmoggy]

Hello,

I just got my hands on a Pair of PAudio 8" coax (BM-8CXA) drivers. General Specs:

Dia: 204 mm 8"
SPL: 95dB
FS: 53Hz
Re: 6.5 ohm
Qes: 0.22
Qms: 4.6
Qts: 0.21
Vas: 26.45L
Xmax: 3mm

http://www.paacoustic.com/Product_Detail.asp?CatalogID=0108&ProductID=BM-8CXA

They weigh a ton and the build quality is superb. I'm burning them in now. I was thinking of putting them on an open baffle but still don't know what size the ob should be. Also what about cross over since they are two way with 1" compression driver. Or would I be better off putting them in a BR.

I can also test out PAudio 15" and 18" coax with 2" comp driver. I'm interested in trying out the 18" coax on an OB. I've seen 15" coax like Altec 604 on an ob but not 18". Any difference? What about using the 18" with a flea powered tube amp?

General spec for 18CX38
Dia: 460 mm 18"
SPL: 100dB
FS: 34Hz
Re: 7 ohm
Qes: 0.33
Qms: 6.64
Qts: 0.31
Vas: 432.96L
Xmax: 4.5mm


http://www.paacoustic.com/Product_Detail.asp?CatalogID=0108&ProductID=BM-18CX38


Thanks for any suggestions.

ABMOGGY

 

[G]

I am by no means an expert on speakers but I think the QTS is a bit low for open baffle. I wonder how a BIB would sound with these(8" model)? Perhaps one of the more learned members will comment.

 

[tburman]

Try this thread: http://www.diyaudio.com/forums/showthread.php?s=&threadid=94520&highlight=

There's an MLTL design in there, if OB is not suitable, as G suggests.

 

[abmoggy]

Hello tburman,

I saw in your thread that you own a pair of 8CXA. How do you like them. Did you build the MLTL? What type of crossover design did you use?

Anyone else out there that have experience with PAudio coax, especially the 8CXA, I like to get your opinion about them.

Best

ABMOGGY

 

[tburman]

No abmoggy, I don't own those drivers, but considered buying them since they are easily available where I live. If they are cheap enough, I still might, though.

 

[Cameron Glendin]

Ive tried the 15" BM-15CXA in a bass reflex design, I like it, only it was a bit peaky at 3.5k, probably in my x over though. They are now used by a traveling outdoor cinema, the owner loves them. Ive used the 2" driver seperately with a largish flare x overed at 800hz and was very impressed for its price, quite smooth.

I am keen to try the 8" sometime, whats your ears first impression?

 

[abmoggy]

When I first got them, I just x-over the highs with 8mfd oil cap. I hooked them up to my SE EL34 amp. NO BOX, NO OB, nada. First impression was how "bright" the highs were. I guess I need to use L-Pad to tame the highs. The mids were pretty good. I don't know if adding 1.5 mH coil will help. I guess this is called adding a notch filter?
I'm planning on putting the drivers on a OB just to see what it sounds like and maybe in a box to see if it helps with the bass.

ABMOGGY

 

[Cameron Glendin]

I tried simulating the response of the 8" on bass box pro, umm it said the ideal box was 3 litres? -3db@120hz