The ASG-1 is one of the best universals I've tried to block out ambient noise. I think it's partly because it covers a good portion of the concha and sits close to the skin. So figure attenuated plus a bunch of decibels for the music and it probably won't be much louder than being on stage without them. Disclaimer: it is probably a lot more complicated than this.
His point is that the bass frequencies are most affected by ambient noise so it would be useful if a performer needed to hear the bass. Though I agree in that I have no idea how much decibels relative to ambient noise you would need to hear the bass well enough.
I hope so.
I look forward to hearing what the mad scientist has done.
I think this comment might be just as helpful as your entire, very awesome, review for those that are in the "Should I upgrade?" camp.
Edited by vwinter - 6/14/13 at 5:05pm