What year is your car?
Likely you're hearing diff clunk. Even if it sounds more forward its likely the diff. TIC (turnin concepts) has what you need to fix that. I'm not affiliated but they're one of the best vendors we have at our reach and they will not steer you wrong.
- Turn in Concepts
Edit: Should probably carify what diff clunk is, diff moves up and down during hard acceleration because of soft mounting. Diff mount inserts or new diff mounts are the way to mitigate the condition. My 2010 did this about 3 weeks after I bought it. Scared the crap outa me until I figured out what it was. Ordered up some bushing inserts, installed.. and not only did I get rid of the diff clunk, the whole feel of the driveline is better. Its not sloppy anymore. I've also done the cradle bushings out back and the trans mount (group N) as well.
If your car is quite a bit older or has high mileage it may not hurt to do all the mounts at once from the engine rearward. Engine and trans are most expensive, the mounts/bushings or inserts for the rear are very inexpensive. For under $80 you can do the whole rear and really improve how the car feels.