i have a high pitched muffler... sometimes the best perfomance mufflers make the highest pitched sound due to lack of restriction(no sound to bounce and cancel out)... so yea...my N1 sounds ricey after about 4.5K which i don't go to much
For my HKS Hi-power muffler, I match it with a custom 2.25" exchauts. The sound is pretty cool and deep. The only thing is when I downshift, the sound will be louder than usual much more!!