Exhaust sound question

Does anyone else's exhaust tone change from day to day? There are times when my Bassani pipes have this beautiful throaty deep rumble cruising around, makes me absolutely love them, and other times its just kinda boring and/or raspy. Its got a few different tones, hard to describe.

Does everyone have this problem? I'm guessing its weather related, but I'm not 100% sure on that. Is it possibly a Bassani thing, or maybe poor installation?

Setup, as it says in my sig, is Bassani from the headers to the tips, with cats.

The best sound I get is on cold dry nights, but that's not to say it doesn't get quite when its cold, or doesn't get loud when it's hot. It seems almost random.

And yeah, it's a different sound. One is much more defined, and loud. The other is raspy, airy... hard to describe... and not as loud. Just doesn't stand out as much as the louder one. And the most recent mod, the headers, were put on like 10k miles ago, so its well broken in.

I'd really like to get it to sound right all the time, cuz when it does... damn, it sounds good. Almost hoping its an install problem, so I can fix it. Otherwise it means I'll be unhappy with my exhaust 60% of the time.