I know JD's isn't stock & mine is, so this may not be entirely applicable, however when I removed my resonator there was no resonance or 'boominess' in the cabin at all. It just sounded a wee little bit louder than stock inside - so little in fact that if you didn't compare them back to back you'd swear it was a stock system.
Outside the car it's a similar story, except that when you give it a good throttling the car has this really nice crackling note to it that the stocker never did, and is a little louder as well.
Still, at no rpm do you get any 'boom'. Instead you hear what sounds like every individual piston firing - like an infinite series of little far away explosions each one discrete from the other.
I love it as it is now (as you can probably tell
) but I recognise that what 'does it' for me may sound like complete rubbish to someone else. As in everything it's horses for courses.
I should add that I replaced my resonator with a fabricated x-pipe, not 2 bits of straight through piping, though I don't know how much difference that makes.