What measures SPL? Can this be purchased? If so how much?! And where? Just curious, as my system gets closer, I would like to know what it can do.
Derek
Replies (5)
ttocs on 06/11/2003 12:29:37
an spl meter. You can get a cheap on at the hack shack for a few bucks but they are generally un accurate.
Most descent shops will have a real meter on hand for tuning an tweeking.. They are nice and run a few grand normally. I have heard of shops getting $5-20 for a test run...
Swez on 06/11/2003 23:07:02
Yes, Radio Shack has one that will top out at 125 dB of SPL. Is pretty cheap, but good enough to get a general feel for SQ installs that do not usually exceed 120 dB.
If you have more SPL then this meter can handle, then a shop will have to make that test for you. Try several frequencies in a slow sweep or test tone to determine maximum SPL in vehicle... which is near resonance of the vehicle. ( 55-70 Hz is normal)
Swez
dflock on 06/12/2003 08:59:20
Hmm...
I was going for SQ but...
When all's said in done, I will be measuring a Brahma 12" getting about 900-1000 watts RMS, so I would probably have to take it to a shop or maybe a show sometime.
Why the 126 Db limit? Cheapness?
xplicitblitzboi on 06/12/2003 10:14:18
yes, for the price of the meter u can get there, you arent going to get precise results or results over 125, but yeah, cheapness. lol
Blitz
Swez on 06/14/2003 10:09:54
Part of it is to keep the price down and affordable. Also, most HT and portable DJ system rarely go above 110-115 dB of SPL.
In high SPL applications like car DB Drags, SPL #'s exceeding 150 dB are common place. This level of SPL readings, require high end electronics and a calibrated mike that can handle that much input signal. The cost of these meters are much higher too.
Since you are shooting for an SQ system, balance is the key to getting quality results. An RTA and a "pink noise" generator (CD test tones and pink/white noise) reference signals, are the proper tools here.
If you want some tips on how to do this, first find a shop that has an RTA and get a test CD as noted above. They will help dial out the peaks and valleys with the RTA/pink noise tests to get the "flattest"
possible calibration settings for all frequencies. (Reference test)
Once you have these Reference points, then you can tweak the EQ and amp gains to get the sound you prefer. This will be a moving target, from one CD cut to another. But at least you will have a Reference point to return to, if things get out of hand.
Finally, SQ testing is generally done at lower SPL values. The human ear begins to naturally filter out high SPL information, once we get above ~95 dB. So, SQ testing is best done under 95 dB.
Swez
Copyright ClubKnowledge 2009 * All Rights Reserved
