The Ultimate 8" Coax

[zerokelvin99]

Hello,

What do you guys consider to be the ultimate 8" Coax? (Compression driver HF preferably)

Money no object! I am currently searching for it, and have tested the likes of BMS, Radian and soon Beyma...

Thanks everyone!

 

[kipman725]

B&C SPEAKERS looks quite nice and is very expensive, considered it for some desktop monitors but cannot produce significant bass so would need to be part of a 3 way system.

 

[Pano]

I think there isn't any such animal. The 8" cone is too small to act as a proper horn/waveguide. They work, but the bigger coaxes work better.

 

[zerokelvin99]

Thanks Kipman, shame none of them use the DE250 CD. The neo does look interesting though.

Pano, yes unfortunately the 8" is a compromise in many respects (aren't pretty much all loudspeakers?), just looking for the best in its format. Unfortunately the form factor has already been chosen! (Not by me, I may add!)

Cheers,

 

[weltersys]

I think there isn't any such animal. The 8" cone is too small to act as a proper horn/waveguide. They work, but the bigger coaxes work better.

An 8" co-axial cone/waveguide can be extended as a shallow wide angle horn to good effect as Danley does with the SH-100, or used at the apex of a 90 x 60 degree horn as in the SM-96. In the SM-96 the cone is used in an ofset horn configuration, and the co-ax HF driver directly drives the conical horn.

Both designs avoid many of the problems the "bigger, better" co-axial speakers have.

Art

 

[Pallas]

An 8" co-axial cone/waveguide can be extended as a shallow wide angle horn to good effect as Danley does with the SH-100, or used at the apex of a 90 x 60 degree horn as in the SM-96. In the SM-96 the cone is used in an ofset horn configuration, and the co-ax HF driver directly drives the conical horn.

Both designs avoid many of the problems the "bigger, better" co-axial speakers have.

Art

Correct me if I'm wrong, but doesn't the SM-96 use the 5" BMS unit?

 

[Pano]

An 8" co-axial cone/waveguide can be extended as a shallow wide angle horn to good effect

Yes Art, I think that's a great idea.

 

[Pano]

Unfortunately the form factor has already been chosen! (Not by me, I may add!)

I understand, quite.

 

[zerokelvin99]

An externally hosted image should be here but it was not working when we last tested it.

Beyma 8CX300Nd - coming soon hopefully.

Weltersy, will this actually have much of an effect? Surely the expansion is too rapid at the edge of the cone for any loading? Perhaps would help with space loading (4pi to 2pi shift) - reducing baffle step effects.

The expansion of the tested drivers so far is irregular at best - inside the pole piece it's nice and smooth until it gets to the, often straight, cone.

 

[zerokelvin99]

And yes, does need correction to sort the reflections between the underside of the horn and cone !

 

[RockLeeEV]

I know there's a lot of emphasis on high efficiency, but if I were doing a coax build, i'd start with this (probably ~90-91db sensitivity)

Speaker Exchange | KEF 8″ Q900 Coaxial Driver

And then add in a pair of better woofers, active to compensate for sensitivity differences.

 

[zerokelvin99]

Thanks RockLeeEV.

Looks to be a phase-plugged dome rather than CD but worth looking into

 

[RockLeeEV]

Thanks RockLeeEV.

Looks to be a phase-plugged dome rather than CD but worth looking into

Yes, correct. It is however a 1.5 inch dome rather than a 1 inch dome.