Does 120db seem right?

[2wheeler 10+ year member]

Just got a new sound meter for work (verifying sound levels of fire alarm systems) and of course I went right to my truck and turned it up! Basic system, 1 pair of comps in the front doors on a 100x2 amp and 1 ported IDQ10 on a 400 watt amp. Meter peaked at ~120db, C scale.

This is nothing important BTW, just interesting. The biggest thing to me is how loud competion systems must be at 140+. The difference from 100 to 120 is huge, so the next 20db to the 140s must be painful....

Do my #s seem plausible?

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[mazdakid 5,000+ posts]

ive seen a stock system hit 120's on the old termlab. what kind is it that you have and how high does it go?

 

[JimJ 5,000+ posts]

Using music, I assume?

 

[Wkbdkid 10+ year member]

Ive seen meters like this before and thought bout my truck but the highiest the meter goes is bout 120. I would think 1 ported 10 would get louder than 120.

 

[2wheeler 10+ year member]

Using music, I assume?

Yes, music off the sirius sat. Its just a $90 sound level meter, +- 1.5 db accuracy, up to 130db range. I was nowhere near clipping the amps so it would probably go a bit higher.

 

[theCybe 5,000+ posts]

Meter peaked at ~120db, C scale

http://en.wikipedia.org/wiki/Frequency_weighting

* where was jim on this one? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[theCybe 5,000+ posts]

The filters used for dBA and dBC

• The most widely used sound level filter is the A scale, which roughly corresponds to the inverse of the 40 dB (at 1 kHz) equal-loudness curve. Using this filter, the sound level meter is thus less sensitive to very high and very low frequencies. Measurements made on this scale are expressed as dBA. The C scale is practically linear over several octaves and is thus suitable for subjective measurements only for very high sound levels. Measurements made on this scale are expressed as dBC. There is also a (rarely used) B weighting scale, intermediate between A and C. The figure below shows the response of the A filter (left) and C filter, with gains in dB given with respect to 1 kHz. (For an introduction to filters, see RC filters, integrators and differentiators.)

 

[theCybe 5,000+ posts]

edit, dunno why the ****ed image won't display. probably because of the & in the link.

 

[2wheeler 10+ year member]

So is C the most accurate scale? The manual for the meter said something similar and as I was playing with the meter, the A weighting was totally missing output from my sub. Plus C weighting gave me the highest #s, woohooo!!! Turn it up to 11!!! 11 is one higher than 10 after all....