posted
you mean the response right? i honestly don't know but i would guess no. this is due to the fact that the dB scale is logarithmic in nature......someone else may know for sure tho. i like educated guesses to see if i'm right
------------------ Team "Under Pressure"--now in Minnesota for the summer with the stroke of a cone, i can make you moan wall w/two shocker15's and a cadence a7hc, soon to be 2 class D's
posted
I think the logarithmic calcs are when converting power levels from pressure levels or so. But if the mic has a linear response in relation to pressure sound levels, a simple volt meter can be configured to output db numbers when doing home measurements. How much does one of those mics cost, the one used in competitions?
Linear X and B&K's upwards of a couple thousand dollars
------------------ Team "Under Pressure"--now in Minnesota for the summer with the stroke of a cone, i can make you moan wall w/two shocker15's and a cadence a7hc, soon to be 2 class D's
posted
Interesting topic gl7! I ever try to build my proper dB meter with different way ...with Spectral Lab software on a laptop and the sound card input. I bought a drum mic (seneizer Md 504 -160dB) and compensated the curve with the software with another mic (B&K ). The mic output was too high and i needed to build a gain controler with op amplifier. After many test i decided to to give up this idea because the mic was too directionnal and many other problem... For your question, I know that mic have sensivity noted in mV per Pascal. A Pascal is equal to 94dB. Each time you add 20dB, you multiply by ten the output voltage, i am pretty sure of that.
The biggest problem is that to found a mic linear and able to support High SPL at low price is not easy... Personnally i often try to found it and i never got better then 800$ for 170dB.. I know many place like Krisst industries or something like that who sell these mic.. Now i work with used and recalibrated Audiocontrol RTA and SPL meter sa-3055 with SPL upgrade and i think thats the better solution.
------------------ Show me the bass !
Posts: 643 | From: Quebec city | Registered: Mar 2000
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posted
I agree, a used RTA would be best, especially when I searched the mics and found out they are around $300 and up. If there is a direct relationship between pascals and db, maybe a pressure transducer (different type of mic I guess) would suit my needs. I've come accross many industrial grade db testers, I haven't found the difference between them and an audio grade db meter yet, dba & dbl or something. I have been doing many op amp projects, modifying rates of rise and stuff, so if I can make a meter for $50 or so, it seems like a fun project. I just need a mic.....
Thanks for all the replies....
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[This message has been edited by gl7 (edited 07-08-2001).]
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