Essex502
03-29-2004, 07:35 AM
We did some informal testing of exhaust noise this past weekend in Havasu and here are the results:
496 HO MAG with above waterline exhaust equipped with hardin Marine Silencers - 89 dB-A (this boat was significantly louder before the mufflers we added but we didn't test it at that time).
HP525 above waterline exhaust equipped with no silencers - 100 dB-A
502 MAG with below waterline exhaust with no silencers - 84 dB-A
The first two boats had molded - Euro style - swimsteps which undoubtedly magnify the sound.
The above tests were conducted in accordance the SAE J2005 test standard in use in many states. A Radio Shack Digital meter was used and is advertised as accurate to +/- 2 dB.
We conducted the test early in the day in Steamboat Cove so background noise and echos from a dock or other structures with minimized.
Hope this helps any of you on choosing whether or not to muffler you rides. We'll be doing more testing during the season and I'll post the results of each test.
496 HO MAG with above waterline exhaust equipped with hardin Marine Silencers - 89 dB-A (this boat was significantly louder before the mufflers we added but we didn't test it at that time).
HP525 above waterline exhaust equipped with no silencers - 100 dB-A
502 MAG with below waterline exhaust with no silencers - 84 dB-A
The first two boats had molded - Euro style - swimsteps which undoubtedly magnify the sound.
The above tests were conducted in accordance the SAE J2005 test standard in use in many states. A Radio Shack Digital meter was used and is advertised as accurate to +/- 2 dB.
We conducted the test early in the day in Steamboat Cove so background noise and echos from a dock or other structures with minimized.
Hope this helps any of you on choosing whether or not to muffler you rides. We'll be doing more testing during the season and I'll post the results of each test.