kudzurunner
3962 posts
Mar 05, 2013
7:14 AM
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I'd like to purchase a hand-held decibel meter--nothing too expensive, hopefully under $75. I'd really just like it to satisfy my own curiosity about how loud my half-dozen amps actually are, and about how sound pressure levels vary, if they do, in various spaces.
Recommendations? I don't have a smart phone, so a smartphone app isn't what I'm looking for.
Also, is there a standard way of measuring SPL's radiating from amps? If you were going to make this sort of comparison, where would you set your meter? I'm imagining three different distances--an inch or two away from a speaker; 5 or 10 feet; and 15 feet or so. The close measurement strikes me as potentially erroneous if one is testing am amp with multiple speakers. Surely a more accurate SPL measurement with such an amp would be taken at least five feet away, so that the sound wave created by multiple speakers has had a chance to consolidate.
I know we've got some experts in this area on the forum and my own knowledge here is pitifully inadequate--except that I know that in order to increase the SPL by 3 decibels you've got to double the power. Or something like that.
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orphan
260 posts
Mar 05, 2013
7:29 AM
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Adam, This is the lowest price I've seen. I do not have it. I'm thinking about trying it and am waiting until I have other things to order from them.
Has anybody tried this for $19.00?
http://www.parts-express.com/pe/showdetl.cfm?partnumber=390-722
EDIT: After reading Greg's post on amp size and dbs, as well as other reviews, I have decided to get the Radio Shack digital 2055 for $49.00.
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Last Edited by orphan on Mar 05, 2013 6:44 PM
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orphan
261 posts
Mar 05, 2013
7:12 PM
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I just tried out the Radio Shack 2055. I set it 1 yard(approx 1 meter) from each amp and dialed in the volume to the same level. Then I moved around the room to see how it affected the db level of each amp. Like you, I was curious about my amps output. The meter works well and is easy to use. I am going to take it to rehearsal and check our levels. Should be interesting.
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Greg Heumann
2043 posts
Mar 05, 2013
10:55 PM
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For me what matters is hearing myself on stage. Any sound guy can make sure I'm heard out front. I need a much less competent guy to do that than the guy who will stay on top of my monitor mix. Adam - I suggest you simply measure the volume where your head is where you play.
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/Greg
Last Edited by Greg Heumann on Mar 05, 2013 10:57 PM
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garry
368 posts
Mar 06, 2013
3:08 AM
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@STME58: i'd be interested, if you could find some links.
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STME58
375 posts
Mar 07, 2013
10:53 PM
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Finding a clear spec on measuring and amp did not turn out to be a easy as I had hoped. I found specs for measuring office equipment, hearing aids, machinery noise levels. I found a paper on lowering sound levels in a live music club though the use of sound shields and wall treatments, papers on using acoustics to control the esophageal sphincter, but nothing on measuring a music amplifier or speaker.
I sure it is out there, it may not be in the databases I have access to or I may be using the wrong search terms.
I looked again and found an international standard on Amplifiers from the IEC (International Electrotechnical Commission). But it does not seem to include sound pressure level testing specs. The keyword that found this was "Loudspeaker"
http://webstore.iec.ch/preview/info_iec60268-3%7Bed3.0%7Den.pdf
This one looks to have more info on determining locations to listen from. I can't tell if it has SPL measurement methods without buying the spec.
http://www.aes.org/tmpFiles/aessc/20130308/aes20-1996-r2007-i.pdf
Last Edited by STME58 on Mar 07, 2013 11:16 PM
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kudzurunner
3969 posts
Mar 08, 2013
3:50 AM
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Found some interesting links.
OSHA daily exposure limits in db
That link came off this thread in the Gearslutz forum:
talking REALLY loud amps
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Willspear
316 posts
Mar 08, 2013
5:11 AM
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Radio shack has one that can't cost more than. 20 or 30 bucks
I find it interesting walking around with the meter and seeing how the level of certain gear changes in a room when people don't use a pa.
Pretty much head level where you stand is what data matters. So an easy way to check it might be to rig the meter to the mic stand assuming you have one for the gig. Then you can play and just watch it. I know some meters and the apps which you can't get track it I think my app does a peak db and avg.
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HarpNinja
3239 posts
Mar 08, 2013
6:37 AM
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Besides fighting misconcpetions, etc. with guitar players, the real solution to the volume battles needs to be waged at the percussion level.
That is the trickiest issue to handle. I'd LOVE to just go in-ears with full bands, but that is TOUGH.
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Mantra Customized Harmonicas
My Website
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Kingley
2384 posts
Mar 08, 2013
7:14 AM
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"Besides fighting misconcpetions, etc. with guitar players, the real solution to the volume battles needs to be waged at the percussion level."
I find that more often than not the blame gets put on the drummer, when in reality it's more likely the bass player that is to blame. Most bass players use way too much volume on stage. The drummer then responds to the bass volume by playing louder and then the guitars bring themselves into the fight. A stand up bass usually cannot meet the volume levels of a fully electric bass. This is why generally speaking you find that bands with stand up bass players are more often less ear straining than their fully electric cousins.
Last Edited by Kingley on Mar 08, 2013 7:15 AM
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easyreeder
356 posts
Mar 08, 2013
7:26 AM
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Loudspeaker sensitivity is typically measured at one meter from the speaker, but it's a fairly complex calculation. Since you're just interested in comparing the SPL of your different amps it's more important to make sure the test signal being applied is the same level for each amp, and the same relative position of meter to amp. It would probably be informative to measure at several distances including 1 meter, and also moving the meter off-axis. Multiple speakers in a cabinet interact with each you may significant differences in off-axis volume between the amps. It would be a good idea to use a recorded clip of your own playing for the test, rather than playing live, and taking care to make sure the recorded signal is applied to each amp at the same level. So if you used a looper to record yourself, keep the playback output of the looper set at the same exact level for each amp, and adjust the amp's volume to see what it can do.
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JD Hoskins
582 posts
Mar 08, 2013
7:38 AM
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After a cop showed up with his meter and shut us down at an outdoor pig roast a couple of years ago I considered buying one. But what I've read led me to the conclusion that unless you spend a few hundred on a meter you aren't really getting anything more than a rough guess. Sound engineers say those phone apps are worthless and the rat shack meters not much better.
Last Edited by JD Hoskins on Mar 08, 2013 7:38 AM
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Greg Heumann
2052 posts
Mar 08, 2013
9:47 AM
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@JD - I've used the SPL app for my iPhone and a Radio Shack meter - and compared them to the one the sound guy I know has - which is an expensive one. They tracked within a dB or 2.
We're not graphing frequency response curves here - we just want to know how loud it is on stage where we're standing, how loud one amp is vs. another. You do NOT need a fancy meter for this. ANY one will do. If it reads low or high by a dB or two that's pretty negligible and because it will be consistent it will still give you the difference between amps with good accuracy.
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/Greg
Last Edited by Greg Heumann on Mar 08, 2013 9:48 AM
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JD Hoskins
584 posts
Mar 08, 2013
9:59 AM
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Perhaps they've improved, at the time I looked in to it the RS meter tested was reported to be off by up to 5 decibels. It was the RS 2050. And I confess, I'm more than a little obsessive about accuracy.
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Rick Davis
1419 posts
Mar 08, 2013
3:47 PM
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Here's what I use lately. Sound Meter Pro. The app costs a buck at Google Play:
(This is me listening to Commander Cody and the Lost Planet Airmen playing Hot Rod Lincoln)
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-Rick Davis
The Blues Harp Amps Blog
The Mile High Blues Society
Tip Jar
Last Edited by Rick Davis on Mar 08, 2013 3:53 PM
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