Argon or Krypton gas is really mainly beneficial for solar heat gain and loss. For sound control, air (or even better a vacuum) is preferred, so stick with the Loewen argon gas.....they've done their tests.
The 40 STC rating they achieve is pretty good and the keys to this result are the reasonably large air space (21mm compared to industry standard 12mm), and the use of laminated glass for the internal glass skin.
To REALLY control sound through glass, you would need an air/vacuum gap of 1" minimum and 2 sheets of 1/2" to 3/4" laminated glass so this is mostly impractical in residential dwellings.
The Loewen system as I mentioned, allows both sound AND solar benefits. If you wanted only the acoustic reduction, you could achieve the same results with a single skin of 3/4" LAMINATED glass (1/2"+1/4").
The 40 STC rating they achieve is pretty good and the keys to this result are the reasonably large air space (21mm compared to industry standard 12mm), and the use of laminated glass for the internal glass skin.
To REALLY control sound through glass, you would need an air/vacuum gap of 1" minimum and 2 sheets of 1/2" to 3/4" laminated glass so this is mostly impractical in residential dwellings.
The Loewen system as I mentioned, allows both sound AND solar benefits. If you wanted only the acoustic reduction, you could achieve the same results with a single skin of 3/4" LAMINATED glass (1/2"+1/4").