spintechs are awesome sounding mufflers. I have pro streets and a prochamber. I think that below 2k they almost sound like flows...but after that a sound all their own. I have only driven my car like 150 miles since I have put them on and I have had more complimants and the what exhaust do you have comments already. When you crack into them, its like heaven is coming out of your tailpipes......it will scare people but the sound is so clean. They are completely quiet at idle and have very little to no drone. But at soon as you give it the foot, they bark. I highly recommend them to anyone. I noticed a difference when I put the muffs on more so then my prochamber.