BTSW,

Looks like I found a partner to this lonely deserted topic...

By lacking any sound knowledge of acoustics, I don't think our "Malaysian contractors" are gonna comprehend the word, "asymmetric". So it's actually pretty simple, of course it's not the right way of answering a text book thesis or dissertation paper answers in acoustic terms. You might just have to tell the contractors in pretty layman term that instead of using the same thickness glass on the outer and the inner, they'd just have to use a different one. E.g. 5-12-5, means 5 mm then separated by 12 mm air space (or vacuumed or argon-ed) then another layer of 5 mm, so instead of the conventional "symmetric" values used on the twin 5 mm, just order one at the outer as 5mm and the inner at 4 mm, that to me, completely changes the attenuation property.

There are still some fancy ideas on doing this, you could have gotten a laminated glass specially made to improve sound proofing and make use for all of them on the two different thickness double glazing. But not sure bout the costs though.

The windows installer I met that day told me he would do a vacuum central on the large air space, not sure how good he can do that though, coz I wouldn't wanna see condensation built-up in there as some mind-twisting tormented artistic displays or some mini aquariums showing up after several years of use. Nevertheless, whether vacuum or argon, they're almost as good for noise insulation, the differences in actual value using either vac or arg lie on the thermal insulation qualities, this I assume.

Conclusively, the installer told me the RM 750 is the price for standard, I assume standard means 4ft x 5ft? But of course my windows are bigger than this measurement, so he'd yet to come back to me for a real quote, and... it's been three days already... Oh and yes, asymmetric or not depends on your call on glass thickness so long as the thickness does not run out of the provided profile. And how much is yours / sqft? Not sure my contractor can go down to KL I presume just to check out or to install your unit though.