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Kirkham Motorsports

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  #1 (permalink)  
Old 07-12-2010, 07:22 PM
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Default What is a good DB sound level?

How loud is the typical cobra pipe? What about open pipes? Is 5 db's a noticeable difference?
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Old 07-12-2010, 09:23 PM
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Every 3 db is double the volume or if 3 db less then half the volume.
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Old 07-13-2010, 04:12 AM
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I like about 15 db's
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Old 07-13-2010, 05:14 AM
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Quote:
Far spread is still the
theory of psycho-acoustic pioneer Stanley Smith Stevens, indicating that the doubling or halving the
sensation of loudness corresponds to a level difference of 10 dB
That being said, my car at 30 feet at idle, was measured at 104 DB
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Old 07-13-2010, 05:51 AM
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What???????????????????????????
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Old 07-13-2010, 06:19 AM
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http://www.sengpielaudio.com/calculator-levelchange.htm

I guess I was wrong. I was thinking in speakers and electronics. Twice the watts will make your speakers 3 db louder. It looks like if +/- 3 db it is double or half the energy.

http://ntrack.com/wiki/index.php/How_LOUD_will_it_be%3F
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Old 07-13-2010, 06:30 AM
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I believe db levels are measured on a logarithmic scale ... which means things aren`t linear . Therefore as , as Greg , said , a small db change means a fairly significant in sound level .
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Old 07-13-2010, 06:34 AM
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Quote:
Originally Posted by Roscoe View Post
What???????????????????????????
Huh? You will have to say it in my right ear please.
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Old 07-13-2010, 07:52 AM
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when i was drag raceing they measured the db level at 50 feet.....
if you where over 96db at the start line at wide open throttle....
no raceing for you.....to loud and you went on the trailer....
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Old 07-13-2010, 09:39 AM
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Yep, for example, going from 96db to 104dB makes that 104dB pressure level 12 times higher/louder than the 96dB pressure level.
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Old 07-13-2010, 10:49 AM
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I just kept raising the decibel level till my wife stopped trying to talk over them.

Just right now!
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Old 07-13-2010, 11:50 AM
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You're getting old Dean. You don't want to choke your engine do you?
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Old 07-13-2010, 01:04 PM
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I cut off the standard mufflers and put on the Classic Chambered. Less restriction and less noise.....until you really hit it.
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Old 07-13-2010, 01:35 PM
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When your ears bleed, go back to the prior setup.
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Old 07-13-2010, 04:56 PM
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80 db and you need, by law, hearing protection.

I think a lot of states require a car to be 80 db or less.


In the gun world, I hear that a 2 db reduction in sound, you heard half as much noise.

Dwight
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Old 07-13-2010, 07:43 PM
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Jet engine = about 135+ db
AC/DC concert from 10th row = about 110 db
Cobra with straight pipes = ?
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Old 07-13-2010, 07:54 PM
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Here is the story behind the question. I didn't communicate clearly with the fabricator at Hurricane and as a favor to me he was willing to cut out the standard baffle and weld in the Classic Chamber system before it was all ceramic coated. He was half right. I have a beautiful set of ceramic coated side pipes with a 3.5 inch straight tube through the muffler. Yeah, thats right, wide a$$ open! I know it will be loud but how loud? It is only about 10.7 to 1 compression but still, wide open?
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Old 07-14-2010, 05:31 AM
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I had Howe racing mufflers on my Cobra....which were basically straight through, big ID mufflers. They were 98dB mufflers. You couldn't talk to the passenger easily while cruising.
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Old 07-14-2010, 05:48 AM
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Quote:
You couldn't talk to the passenger easily while cruising.
That means you weren't going fast enough, the sound was still beside you, GO FASTER, put the sound behind you.
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Old 07-14-2010, 07:52 AM
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Dean, it will basically be the same as the Howe muffler I would guess. Very loud. I had them on my CR and folks would put their hands over their ears when I passed them.

Best example is John Ross. You can hear him coming for miles...and you can hear him leaving for days!
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