Blameshift 2 Report post Posted January 31, 2018 Alright so I have the Inivida N1 exhaust (only catback) fitted to my otherwise engine-wise stock GT86. I know this is a loud exhaust and people have said that it does drone but it is literally dronecity x100 when you reach 2500rpm to 4200 rpm. What can I do except for taking the exhaust off? Any tips/tricks? Share this post Link to post Share on other sites
Deacon 1357 Report post Posted January 31, 2018 11 minutes ago, Blameshift said: Alright so I have the Inivida N1 exhaust (only catback) fitted to my otherwise engine-wise stock GT86. I know this is a loud exhaust and people have said that it does drone but it is literally dronecity x100 when you reach 2500rpm to 4200 rpm. What can I do except for taking the exhaust off? Any tips/tricks? Apart from taking it off about the only thing you could do is have a large resonator or silencer fitted into the system. Share this post Link to post Share on other sites
Varelco 211 Report post Posted January 31, 2018 +1 to what Dean said. Sound deadening will make little difference due to the low frequency it's resonating at. Share this post Link to post Share on other sites
Lauren 2259 Report post Posted January 31, 2018 Sounds like you've bought an exhaust that is too loud. Either get a silencer welded in or change it. Not much else you can do. Share this post Link to post Share on other sites
Blameshift 2 Report post Posted January 31, 2018 1 hour ago, Lauren said: Sounds like you've bought an exhaust that is too loud. Either get a silencer welded in or change it. Not much else you can do. With a silencer it will get more quiet though... I like the noise but not the drone that makes my entire brain vibrate and go into stasis. Share this post Link to post Share on other sites
nerdstrike 186 Report post Posted January 31, 2018 Drones are resonant frequencies. There are several ways to get there, but one of them could be a crack or poor fitment which changes the acoustics. Otherwise, a helmholtz resonator is your primary option, to damp only those frequencies, but leave everything else at full volume. I have seen a chap fashion his own by computing the appropriate dimensions from an analysis of the exhaust noise and some good guesses of the gas temperature, but it's a technical bit of work. No idea if your typical exhaust shop is able to do that sort of thing, as opposed to just bunging a standard silencer on. Share this post Link to post Share on other sites
Blameshift 2 Report post Posted February 1, 2018 2 hours ago, nerdstrike said: Drones are resonant frequencies. There are several ways to get there, but one of them could be a crack or poor fitment which changes the acoustics. Otherwise, a helmholtz resonator is your primary option, to damp only those frequencies, but leave everything else at full volume. I have seen a chap fashion his own by computing the appropriate dimensions from an analysis of the exhaust noise and some good guesses of the gas temperature, but it's a technical bit of work. No idea if your typical exhaust shop is able to do that sort of thing, as opposed to just bunging a standard silencer on. What is a helmholtz resonator? Can you hand a link so I can check it out? Can't seem to find much but then again I don't know what I'm looking for...it sounds interesting! Share this post Link to post Share on other sites
Nimz 70 Report post Posted February 1, 2018 7 minutes ago, Blameshift said: What is a helmholtz resonator? Can you hand a link so I can check it out? Can't seem to find much but then again I don't know what I'm looking for...it sounds interesting! Check out this thread for more info mate 1 nerdstrike reacted to this Share this post Link to post Share on other sites
nerdstrike 186 Report post Posted February 1, 2018 Yes, exactly like Nimz says. Loosely, a helmholtz resonator is akin to an acoustic guitar body, and the shape of the body dictates what frequencies it resonates with. Unlike a guitar, you can use them to quieten noise instead of amplifying. Share this post Link to post Share on other sites
Mr Slow 4 Report post Posted February 1, 2018 google 1/4 wave resonator it's the same concept as sound cancelling headphones, but not dynamically adjusting and tuned for only a single frequency. Share this post Link to post Share on other sites
