Flowmaster drone solved.

it seams like stuff is all over the place some get drone some don't I'm all about sound and tone NO drone not extremely loud (I've had my fill of too loud with my harley) my setup will be I'm putting in a 360 auto TTI shorty headers 2 1/2" all the way back tips and lost on mufflers Flowmaster Delta flow 40's, dynomax ultra flow or super turbo (heard a couple people say super turbo's drone bad) or pypes street pro
You have mentioned all three of the common muffler types, chamber type, straight thru, and triple pass. (Chambered have a rep for droning). My suggestion is to find a car with the sound you like, cause all three sound different, and use what you like. My answer for a good flowing, quiet system, is get the right size pipe, and the biggest,longest muffler you can fit under the car!