I'm on a set of Firestone Firehawks, and I swear these are the loudest things I've ever heard...it literally sounds like you are riding over those fine chatter aprons that are supposed to wake you up if you fall asleep...

What's the main factor in this? Too much or not enough air? Alignment or balance? Crappy tires?

 

Probably tread design

 

Tires are compromises. I rather have a noisy, but grippy under all conditions tire, than a quiet but mediocre eslewhere tire.

 

The tread design has the most, if not all, influence on tire noise. An aggressive tread design will sing a bit louder than a more docile design. I think tire compound would have to factor in as well because of tire hardness or softness. My old Goodyear RSA's were extremely quiet and performed/wore well. My new Toyo Proxes are a bit louder, but they have a much more aggressive tread design.