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View Full Version : Loud decibel meter?



DanMan
05-15-2016, 03:14 PM
Seems all the decibel meters I can find for sale only go to 130 dB (though if they're digital, the display only goes to 129).

Anyone know where to get relatively cheap meters that go higher?


Funny Story>>>

Last time I bought a meter was from Radio Shack last year. I actually had to explain what a dB meter was, he looked and said 'no we don't carry that'. I said 'dude, I checked your website and it says you have 2'. So he found it and then asked if I needed batteries. Wasn't sure I had any 9-Volt batteries so I said 'Okay'. He opens the meter and reads the manual for about 4 minutes, and finally says ...... "okay, you're gonna need nine of the V size batteries". I. Nearly. Fell. On. The. Floor. But I kept a straight face and said "okay do you have 9 of those?". He turns around to the batteries behind him and picks out a 10-pack of 9V batteries ... and proudly exclaims "you'll even have 1 left over!" My eyes kept bouncing between the tiny meter fitting in the palm of one hand, and his other hand with a foot long row of batteries ... took him a full 30 seconds and then says ... "no wait, lemme read the instructions again". I whipped out my Radio Shack Battery Club Card and insisted the 10th battery should be free, but he said he'd never seen one of those, and we finally settled on a single 9V battery.

LowPhreak
05-16-2016, 07:10 AM
:applaud:


"Good old" Rat Shack.

hsosdrum
05-16-2016, 01:36 PM
I'm almost afraid to ask what you need to measure that's over 130dB. Whatever it is, I don't think I'd want to be anywhere near it while it's making sound!

1audiohack
05-16-2016, 01:42 PM
You can exceed that in a plane wave tube at a fraction of a Watt.

You get out of the $50 mic world at 130dB SPL.

Barry.

grumpy
05-16-2016, 01:51 PM
Even most of the less expensive measurement mic's (no meter) poop out around 130dB
(the crappy ones, often with internal amps, poop out even sooner... the amps clip).

My non-toy measurement mic goes to 150, but 1) I don't plan on needing/using that
capability and 2) just the mic alone was many hundreds of $

Might try the car audio crowd :dont-know: for ideas. Drum/amp mic's come to mind,
but the readings might be distorted some (not sure of your application) and if
you needed accurate SPL readings you'd have to calibrate... at least at the frequency of interest.

DanMan
05-16-2016, 02:06 PM
Found this subwoofer locally on craigslist. It's a prototype model, 6.5' tall tri-fold subwoofer, 15" woofer. I removed the built-in amp from the box, upgraded it to a 1,000 watt plate amplifier and relocated the amp into a car subwoofer box.

Yes for sure, I have to wear ear plugs when I get near it, but it pegs the meter before I even get close to the horn opening.

It's broken many glasses and routinely knocks things off shelves!

I'm thinking it's likely putting out 140 dB near the box opening but I'd LOVE to know for sure.

71565

71566

grumpy
05-16-2016, 02:19 PM
only an estimate, as the room/walls will affect it, but you could drag the box outside and measure 4m away
with your existing meter (and add 12dB for the 1m estimate).

71567

DanMan
05-16-2016, 04:59 PM
Ha, dragging it outside would be nice. I use a handtruck to cart it around the house, must be at least 250 pounds. It does have ill effects based on its location and my house isn't the greatest at trapping bass. Surely putting it outside would be non-congruent with my neighbors wishes, they're only slightly amiss about the jam sessions now.

But I'm also really curious about the pressure levels inside the box. Seems 140 at the throat would mean 150 or more inside the box?

I'm also at a loss at finding a stereo pair of speakers to match this subwoofer. Any ideas? I see the 4670, 4675, even a 3632 on the bay (although they only have one of those).