Cheap, reasonable quality, cheap sound level meter ? - Page 1
Forum section: electronics / general

author: Boo
author_rank: Newbie
timestamp: August 22, 2024, 07:44:17 am
content: Hi,Question as title: I've put the important factors for consideration there tooJust looking for a reasonable quality, but must be cheap, sound level meter and wondered whether anyone here happens to know whether any of the many variants available on eBay etc are better than the others ? Application is hobby music use and nobody's life (or hearing) depends upon it. I have an Android "Decibel" app on my phone but obviously it's not calibrated so the numbers it gives are basically meaningless.There seem to be two types, a wall-hung disply type and a handheld type, anyone have experience of both and able to comment on the respective accuracy?Because the mfs are generic for devices at this level, it would be helpful to post pix as well as names so Ican find the equivalent type in the UK.Many thanks,

author: tszaboo
author_rank: Super Contributor
timestamp: August 22, 2024, 07:58:43 am
content: I have the UNI-T UT353.It's nice construction, reasonable quality. You can improve it by opening it, and replacing the internal IL7660 (or similar) IC to a Linear Technology one, reduces the baseline noise by 2-3 dB as I recall.I don't know how accurate it is, as it's my only meter.

author: Kean
author_rank: Unknown
timestamp: August 22, 2024, 10:27:24 am
content: Quote from: tszaboo on August 22, 2024, 07:58:43 amSameQuote from: tszaboo on August 22, 2024, 07:58:43 amAnd sameI bought the set of 3 a few years ago: UT333 (temp/RH), UT353 (sound), UT383 (lux). They get used infrequently, but are handy.I have a bunch of other temperature and light measurement devices, but nothing else for sound except an iPhone app (which now bombards me with ads).

author: EC8010
author_rank: Frequent Contributor
timestamp: August 22, 2024, 03:46:05 pm
content: Once upon a time, the go-to cheap SPL meter was the Radio Shack handheld SPL meter. I still have (and use) mine, so there may be others floating around. It's really about the sensitivity of the microphone, so you might be able to make something using a readily available microphone capsule. There was an article in Practical Electronics (Sept 2024) about calibrated measurement microphones.

author: mendip_discovery
author_rank: Super Contributor
timestamp: August 22, 2024, 05:17:24 pm
content: eBay,https://www.ebay.co.uk/itm/305736129565Tenma 72-860Pretty good. Has an inbuilt cal check. Even better, there is a jack plug on the side which you can hook up to a freq counter to get the main freq.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: August 23, 2024, 07:53:14 pm
content: Go to Alibaba and search on "sound level meter" and about a dozen will turn up starting about ten bucks. Should be something sufficient for your application. For something better look specifically at the products fromhttps://www.hzaihua.com/products_cont.html?id=106

author: Boo
author_rank: Newbie
timestamp: August 25, 2024, 07:48:20 pm
content: Thanks for all the replies, the UT353 sounds like it will work for me and is cheap enough so I will likely go with that.Thanks again,

author: F4
author_rank: Contributor
timestamp: January 06, 2025, 10:08:19 pm
content: Quote from: Kean on August 22, 2024, 10:27:24 amHow accurate are the iphone's internals for spl measurements?

author: Kean
author_rank: Unknown
timestamp: January 07, 2025, 01:07:37 am
content: Quote from: F4 on January 06, 2025, 10:08:19 pmI wouldn't expect it to be "accurate", but it has certainly been useful for the occasional quick check. Sound measurements are not something I do regularly.It will be device & model dependent, and could easily be wrong if you have had any damage to your phone. You could run some simple level tests with a white noise source.Even a dedicated SLM needs to be checked and calibrated if you want accuracy, and pretty sure that no phone app will be certified for official measurements.A few good results show up from peoples testing with a Google search on "iphone audio spl measurement" - YMMV.

author: dcarolan
author_rank: Newbie
timestamp: January 08, 2025, 08:13:09 pm
content: I use the Android app called, "Audio Tool". A calibrated mic is available on parts express specifically for it, but the phones own mic is also pretty good.As a relative measurement it is fairly accurate too.I once used it to show a sound crew that they were about to blow up an 18 inch Voice of the Theater type cabinet. They of course ignored me.Ten minutes later the cabinet caught on fire at a live venue in Atlanta.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: January 08, 2025, 11:04:29 pm
content: General Radio Company Permissible Sounds Level Meter Type 1565-Ahttps://www.sphere.bc.ca/?s=generalSphere is closing ,,,,,so there is a sale

author: EE-digger
author_rank: Frequent Contributor
timestamp: February 20, 2025, 04:34:55 pm
content: A bit late to the party but this may help others.TheNIOSH Sound Level meter appis considered accurate to +/- 2dB. It is available only on iOS devices because they are a fairly stable entity (compared to Android) in terms of hardware and build, with regard to sound qualities. But it isNOT OFFICIALLY ACCEPTED FOR COMPLIANCE TESTING.I've been thru 5 Android apps and they are all over the place, BUT ... in a controlled setup with 1kHz test source, 3 of them were fairly close. Your presence, room acoustics and all reflective sources ALL affect your readings.For reference, Class 1 and 2 accuracies:At the reference frequency of 1kHz, the tolerance limits for Class 1 are +/- 1.1dB and for Class 2 the tolerance is +/- 1.4dBThe sound level meter calibrators generally use a tiny speaker / driver but have a carefully controlled mounting and damping.Class A weighting, considered the international standard for compliance testing, fails miserably at replicating response of the ear and brain but was legally pushed into a standard so we're stuck with it.If you test with white noise (or any noise) vs a 1kHz tone, keep in mind that you will be looking at any differences in the weighting along with the basic measurement accuracy. In general, the weighting may be analog or DSP based and probably a non issue, except for the very different response of your acoustic setup vs frequency.I started out wanting to compare cooling fan noise levels but I think (unproven) that you will need Class C weighting or a meter with no weighting. Possibly you're better off with a spectrum plot with your "favorite" fan, then the others for comparison.Lastly and keeping with the OP's question, I picked up a "Risepro" sound level meter two weeks ago for $18 on Amazon. Cheap unit but solid feel, buttons behave well. No cal adjustment but out of the box, was within 0.1dB at 114dB and 0.8dB at 94dB, against a quality calibrator. Only has Class A weighting if that matters to you. Has nice display backlight (switched) and a tripod mount. Don't know if it's factory calibrated or not but the test speaks for itself.

author: trobbins
author_rank: Frequent Contributor
timestamp: February 21, 2025, 02:36:56 am
content: There are often many, many 2nd hand meters on ebay and similar, with analog meters or digital readouts. You aren't needing any form of calibration, or even an old calibrator, as that still doesn't achieve cal-level confidence, so no real need to have a meter with say 1/2" end to suit a calibrator - which means an app on a mobile is likely a reasonable starting point imho.

author: jonpaul
author_rank: Super Contributor
timestamp: February 21, 2025, 01:30:03 pm
content: What is "cheap" ..$10? 50? 100?free: many Apps for iOS and Android.$20: Chinese knockoffs of Radio Shack 1980s analog$35..100 Vintage Genrad sound level metersOur lab: GenRad 1565-A, 1982 with GenRad calibrators 1562-ARadio Shack 33-2050See GenRad Hand book on s noise measurment for mics, weighting curves, loudness (Fletcher Mundsen) etc.https://www.worldradiohistory.com/BOOKSHELF-ARH/Technology/Technology-Radio/Handbook-of-Noise-Management-Peterson-9th-1980.pdfEnjoy!Jon

author: EE-digger
author_rank: Frequent Contributor
timestamp: February 21, 2025, 03:43:16 pm
content: My definition of cheap is $15 or less. My definition of expensive is that which comes close to dissolving our marriage.Those vintage units are built like bricks and will last another 50 years. And, ZERO chance of firmware or software errors.

author: Overspeed
author_rank: Frequent Contributor
timestamp: February 22, 2025, 07:06:36 am
content: HelloA UNI-T UT353 cost less than 30 Euro that works for most basic purpose , in case of failure , straight in the trash bin and purchase another.Old sound meters can perhaps work ( if calibration is still ok ) but electronic have made a lot of progress , just compare what was needed in the 80's to built a good amplifier and the cost of a precision op amp in 2025 ...RegardsOS

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: February 22, 2025, 01:45:40 pm
content: As a GR fanboy I like several GR meters but watch out for two things. Some of them use unobtainium batteries. I've bought a couple just for the ceramic mics and tossed the rest. You can usually buy a unit with a mic for far less than people sell the mics for. The standard 1" GR ceramic mic is wide band and decently flat, but they sometimes don't age well. The sensitivity can be down and I've seen a few that were stored in bad conditions and have corrosion. But, when it all works it can give excellent results.

author: benseno
author_rank: Regular Contributor
timestamp: February 22, 2025, 02:43:46 pm
content: Your android app correction coefficients can be figured out If spl meter can be lend for a short time. No need to buy it.Or Iphone app (mentioned by EE-digger) installed on your friends phone can be used for the same purpose .

author: Emo
author_rank: Regular Contributor
timestamp: February 22, 2025, 03:20:35 pm
content: There is a number of USB microphones that are delivered with full calibration. So using an app (PC or mobile) is easy.examples are;DAYTON AUDIO IMM-6C Measurement Microphone approx 70 eurUmik-1 approx 90 eur