Thanks for your earlier reply - which has since been edited...
I will stick to your original questions/suggestions:
1. Living/Dining hall: 25' x 18' open to a Foyer: 9' x 12' with Ceiling height 10'.
4BHK layout.jpg 775k .jpg file
Flooring is polished marble, walls are brick with cement plaster.
2. I'd be more than happy if it can deliver the performance of commercial options...
Freq. Resp: 19Hz - 120Hz
Maximum short term sine wave, SPL output averaged from 30 to 85 Hz, measured in half space at 1 meter >= 108db SPL
Maximum peak SPL output with random pink noise, measured in half space at 1 meter >= 113dB SPL
Self generated noise level in free field @ 1 m on axis ≤ 15 dB
Amplifier system distortion at nominal output THD <= 0.05%
3. You are suggesting a Ported build and dual 12"? - whereas the Genelec 7060 is achieving the above with a ported single 10" and 120W amp?
I don't know if I have the confidence yet to do a good enough ported design and do the appropriate tuning etc... unless of course someone here can tell me that the Genelec LSE design is fairly easy to implement and worth a shot.
4. Looked into Dayton Reference - but I'm leaning towards Peerless drivers - as they are locally made in India and I can try to find out if there is any cost advantage over importing, paying shipping/duties etc.
Parts Express has the - Peerless 835017 12" Aluminum Cone XXLS Subwoofer with freq. response down to 19Hz (whereas the 10" driver from the same line is rated at 22hz)
If quality of the driver is the most important - then would Peerless still be the first choice?
I know you all have recommended Dayton - but that means shipping, import duties etc and that means I probably should also consider Scanspeak (Vifa) or Seas and other makers?
5. Can you point me to some material on MiniDSP that you referred to? Apart from Behringer iNuke - any other amp males/models to compare to?
6. Since I'm in India I have some really wild choices for cabinet material - for eg... Given a drawing I could get it made in granite or marble if it turns out to have some performance advantage. So should I consider granite or marble?
The only issue is finding some good way to mount the drivers and that too can be arranged with pre-drilled holes and filled with some resin for the driver and amp. plates to be screwed on.
I know a lot more research is pending and has to be done.. my post was in the hope that I could narrow down my choices before digging further...
1. Cabinet type: Based on my research it became clear that sealed designs are easier to do and offer clean bass but the really low freq extension is harder... The matter is almost settled unless someone here has designs that are similar to LSE ported design of Genelec
2. Driver/Amp/Cabinet Material - see above...