[jaycalgary]

Diy of course but is there any good reason this would not sound good? Too little bass maybe?

 

[NamelessPFG]

Let me get this straight: you're going to make a Sigma with SR-Gamma Pro drivers?
 
You certainly can't use an actual Sigma housing, given that their drivers are in the same oval shape as the Lambda line. That leaves a custom housing designed to use the round Gamma Pro drivers in a similar front-firing fashion to the Sigma line.

 

[jaycalgary]

Yes that is the idea but would like to know if there would be any reason the gamma pro drivers would not sound good like this?

 

[NamelessPFG]

I can't think of a reason they wouldn't sound good splayed out in front of the ears, but it's said that the Sigma housing was pretty carefully designed, down to the mineral wool padding the interior of each earcup.
 
You'll have your work cut out for you in designing an acoustically-ideal frame for the drivers, though I'm sure it's possible.

 

[jaycalgary]

Well I didn't win the auction to buy the drivers. Went a little higher than they are worth for a broken old pair I think. I read that they changed how much mineral wool they used over the years in the Sigmas and am in doubts how scientific the Sigmas housings really where. When I saw the pics of a pair of Gamma pro's opened it looked like a daunting task to make this happen but wasn't long till I figured out a way I would make it work. A new idea came out of this and would like to try it with a older Lambda series. Not sure which one yet. The best way I could mount the gamma pro to the 1/4in aluminum baffle is cut the hole larger than the circumference of the gamma driver and mount it centered or even angled in there with marine epoxy. This would have the driver diaphragm rock solid to the baffle and I would say every little bit of solidarity is audible. Here is a past project that the housing works well in my opinion.
http://www.head-fi.org/t/541076/stax-sigma-wood-mesh-housing/75

 

[edstrelow]

I wouldn't think these drivers would be an advance on the various Lambda pro drivers tht would fit better.  Their diaphragms would be smaller thus giving more intermodulation and thicker so a poorer attack and decay.  But I could be wrong.
 
Wat you really need is 007 or 009 drivers in a Sigma type enclosure but the drivers alone would cost a bundle.