I have been sitting here waiting for my RC-F and thinking about the lack of spec on sound levels
of stock and after market exhaust systems. I wish there was a standard aftermarket spec of exhaust sound level db vs RPM that one could compare against. Today I saw the Novel video post and earlier this week I saw an listened to JoeZ's RC-F prototype exhaust system for the RC-F It got me thinking about how to compare vs stock sound when you can not hear them in person and these of course the recording are done at different distances from the car.
If folks used something like the free iPhone app (decibel 10) on their phone or tablets, we could the post samples taken at the same distance or a known distance or in the drivers seat and show the app reading as an overlay or just post the reading values. Given measurements one would have a better way to compare. Since the free db apps dont seem to support video, one could take stills of the tach to show db level per RPM from the driver's seat. Yes, not as impressive as a video of the tail pipes but maybe more useful.
Even better would be for the after market manufactures to do this as a standard measurement spec.
I will update this post when I get my RC-F and measure it. Until then, here is a db reading of my IS-F with after market dual catback with Magnaflows, 2 resonators and 2 mufflers but it sounds great. Also, I decided on road trips with windows up I wanted some sound dampening in the cabin so I added some B-Quiet to the trunk and behind the back seat.
At 4000 RPM the sound level near the bumper was up 6-8db from stock sound and was just under the 94db limit at my local track.
But right now with all 4 windows open and in the drivers seat, with iphone at the steering wheel, car at idle just after starting, i get 68db.
Same iphone location but after a 9min warm up 63db.
Same iphone location At 4000 RPM after 10min 79db.
Move to the trunk area, iphone at 3ft away looking at left exhaust tips 74db (idle)