I have the magnaflow 12288, and it also has a drone or more like a groan at about he same RPM levels... mine kinda start at 1500RPM, and then lasts till about 2000, maybe alittle higher...
I just got flowmaster 40 series put in yesterday, and the drone got a bit louder...
It is really deep according to the guy that left the muffler shop with me, but I want to hear it from a follow vehicle to see what it sounds like from outside.
It isn't so loud that the stock stero doesn't drown it out, but it is a little annoying, especially with the stereo off if you're trying to have a conversation. Either I will get used ot it, or have to go to a different muffler.
I read a post or two earlier that talked about how the exhaust is mounted, and if they got rid of the stock rubber muffler hangar gromet deals, and used some other method of mounting, that that will contribute ot the resonance inside the car. I plan on getting a good look at what they have done, and see if there is a way to soften up the hangers or anything...
I have 2.5" downpipes (connected at the first several inches of stock exhaust ), and they go into a 12288 magnaflow, and that connects back to the stock pipes, and then out to the flowmaster 40 series mufflers.
I am curious if a set of tips can change the drone at all.
Or even if a glasspacks may help out beforr the resonator, it looks like there is plenty of room to try it... Any ideas on that? That would be 5 mufflers in there, but does a glasspack really reduce the flow? Would that negate the whole purpose? I wanted flow, without riceer sound, not really interested in trying to get s V8 sound or anything...
They have a really sweat DEEP idle though! Sounds threatening!!!