I have an AU XR6
viewtopic.php?f=53&t=95556

Was making hinkey crackly noises from the exhaust so I had a feel and put 5 fingers in through the rust holes in the back section. Took it to the exhaust guy and he said the center section (cat onwards) had a crack in the muffler on that and it also needed replacement.
Now I liked the sound of the original though it was quite loud in the cabin but I was putting that down to the hole. Anyway what I was after was an exhaust that was quiet to about 3000RPM or so (IE highway) and then it can get as loud as it wants (IE hooning).

He put in a redback system with resonator and its really rather quiet, which I must say crushed my inner hoon somewhat, missus said the car sounded more refined (but has now admitted it also makes the car feel much less done up ) I could live with it but the thing is at 2100 or so RPM as soon as there is any load on the engine it makes a decent drone its not deafening or anything but its louder in the cabin than most of the rest of the noises it makes, drop it down to 4th same hill and the drone goes away with the engine at 3000 RPM.

Anyway what am I to do, this was put in for $380 or so 2 weeks ago.

my mate in his dunnydore had the same problem, was really loud around 2.5k to 3.5k and then it feathered off to nothing. He had a lukey exhaust but the guy put in a rear resonator and that fixed it all, evened out the noise nicely. I see you have done this with a redback exhaust so not sure what you could. Just buy hurricane - thats what i got and sounds awesome, only gets better as the revs climb

I was mostly happy with it without the resonator and the lukey, sounded pretty cool ;->
But the guy had redbacks in stock and I said i wanted it quieter around 2k rpm.
There is just a peak in drone noise from 1800 to 2500 or so.
About the only place I don't want it lol.

when you pile on the revs getting up around 4000 or so it sounds ok, though I think I might still prefer it without the resonator, If i'm ever up that high its because I want the loud pedal to be loud lol ;->

also because its a new system it will take a little while to carbon up and sound better, Mine was still changing 6 weeks after it was installed. Just chop out the resonator and let it carbon up, then put it back in if you still dont like it.