The Remus did give it a great sound on the cold start. Nice rumble, not too loud.
When its warm engine its a little bit noticeable, more if you of course accelerate it hard or manual shift and bring the revs up.
I would say like 10% louder maybe. I could be wrong there.
It was for sure not at all like their you tube video of the car on the snow in the mountains. Its a little louder in the cabin not alot.
For sure it has no drone of any type in the cabin.
It is a high quality system, was just way too tame for me.
The Madness is only real loud at start up, when the engine warms up it is fine with that slight rumble on the highway and crackles nice on hard acceleration