GregW said:
Hi John,
... and others (myself included) put Dynamat Extreme down. Be warned, Dynamat ain’t particularly cheat.
Not to resurrect a dead thread, but for a less expensive alternative to Dynamat try B-Quiet Ultimate:
https://www.b-quiet.com/ultimate.html
$129.00 for 50 sq. ft. ($2.58/sq. ft) vs $270.00 (list) for 36 sq. ft. of Dynamat Xtreme ($7.50 sq. ft.).
The specs are virtually identical.
B-Quiet Ultimate:
Acoustic Loss Factor ASTM E756 @ 200 Hz:
0.23 @ +0C (+32F)
0.26 @ +10C (+50F)
0.39 @ +20C (+68F)
0.32 @ +30C (+86F)
0.24 @ +40C (+104F)
Dynamat Xtreme:
Acoustic Loss Factor @ Temperature
(Using ASTM method E756 @ 200 Hz):
0.081 @ +14°F (-10°C)
0.240 @ +32°F (+0°C)
0.257 @ +50°F (+10°C)
0.417 @ +68°F (+20°C)
0.259 @ +86°F (+30°C)
0.194 @ +104°F (+40°C)
0.140 @ +122°F (+50°C)
0.094 @ +140°F (+60°C)
Dynamat is slightly better at lower temps and B-Quiet is slightly better at higher temps, at least in terms of the Acoustic Loss Factor. For all I know, It's just a statistical error and they both source from the same factory!
Installation wise, if "Dynamat" wasn't emblazoned all over their products, you'd never know the difference. I've used both, but only used the Dynamat because I ran out of B-Quiet and could get the Dynamat 4 sq. ft. Wedge Pack for the princely sum of $40.00 ($10.00/sq. ft.!!!) from the local Best Buy.
Paul