# SPL — Professional Sound Level Meter

> Professional digital sound level meter (decibel meter) for iOS devices. (iPhone/iPad app by Andrew Smith.)

- Source: https://appshunter.io/ios/app/spl/id293573990 (this page in markdown: same URL + `.md`)
- Developer: [Andrew Smith](https://appshunter.io/developer/291822462)
- Category: Music, Utilities
- Price: $8.99
- Rating: 3.00/5 from 4 App Store ratings · 34 written reviews indexed
- Age rating: 4+
- Requires: iOS 13.0 · 25 MB
- Languages: American English, French (France), German (Germany), Japanese, Polish, Chinese (Simplified, China), European Spanish, Swedish
- Released: 2008-12-03
- Data updated: 2026-09-09
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/spl/id293573990/reviews.md

## What is SPL?

SPL is a professional-grade digital sound level meter (decibel meter) for your iPad,  iPhone or iPod touch. It includes all of the modes, filters, and features that you would expect from a professional ANSI or IEC Sound Level Meter. All filters and averaging modes meet or exceed the criteria for ANSI Type 1 standards or better. SPL is created from the same team who brought you the Audio Toolbox and ATB Plus.  

Store Results -- Uses the same powerful Save / Recall engine as our premier app, AudioTools. Allows storing GPS and time-stamped results, and exporting them to your computer.

You can also use SPL with our calibrated iPhone measurement mic, iTestMic, or iAudioInterface. 

The screen flips if you turn the phone upside down, so that you can point the built-in iPhone mic directly at the sound source.

*** Modes: Slow, Fast, Impulse, Peak, and Leq.

*** Filters: A and C weighting, and 10 octave band filters.

*** Includes a resettable Max field to track the highest reading.

*** Includes a reference field (except in Leq mode) so that you can set a reference level and do seat-to-seat comparisons.

The SPL meter can be fully calibrated. It comes preset with the calibration for a typical iPad, iPhone, and iPod Touch. Most iOS devices will be within a few dB of this reading. If you have access, even temporarily, to a calibrated sound level meter, just use the calibration field on the settings scree to match the meter, and you will be accurately calibrated.

Also, see our other professional-grade audio apps: AudioTools, our premier suite of professional-caliber audio and acoustics test apps, Speaker Pop, to test speaker polarity, and RTA, a real-time analyzer for the iPhone.

And, we have a group of calibrated, accurate measurement microphones, including iTestMic,iTestMic2, and iAudioInterface2, that allows full professional results for Type 1 or Type 2 measurements. 

This will allow measuring a range from approximately 30 dB SPL to 130 dB SPL. Each mic will include a calibration factor that you will enter into the SPL app for calibrated measurements. This mic will also work with Speaker Pop, our speaker polarity tester, FFT, RTA, ETC, and other acoustical measurement apps in our AudioTools app that is available now.

Also, see our iAudioInterface2 system, which supports any pro test and measurement mic. 

Now includes an iPhone internal mic compensation filter, to cancel out the low-frequency roll-off present in the iPhone and other iOS devices.

See our other audio apps, including AudioTools.

## Key features

- Professional-grade digital sound level meter
- ANSI/IEC Type 1 standards compliant filters and modes
- Store, recall, and export GPS/time-stamped results
- Supports external calibrated microphones
- Adjustable calibration for accuracy
- Internal mic compensation filter

## Recent user reviews (10 of 34)

All indexed reviews: https://appshunter.io/ios/app/spl/id293573990/reviews.md

### 1/5 — Apps color scheme is unreadable

*2025-12-06*

The color scheme/UI is gray all over even after resetting all settings and relaunching the app.  There is no control in settings to change this.  The app does not look like the screenshots.

### 5/5 — Accurate and Easy to use

*2018-04-12*

Once calibrated correctly this SPL meter is easy to use and accurate, worth every dollar!

### 1/5 — Amazing

*2017-10-08*

Oh no!  A disastrous update!!!

They finally took the horrible, battery-draining background operation so-call "feature" out of RTA, but they put it into SPL.  Now, when you exit this app in the conventional way, it keeps running and draining your battery!!!  

Why they think this is a good idea or should be the default operation is just beyond me.  Please, please, make this behavior optional and default it to operate in the way that most iPhone apps do, to exit the app when you press the home button.  

------ original review -------

I have recently had the opportunity to compare with a very calibrated instrument and was very favorably impressed.  This thing works very well. 

I also checked my Radio Shack meter at the same time and it's good right around 1KHz which is where -- if you read its instructions -- it is calibrated.  The Radio Shack SPL meter, by the way, while a bargain for the price and quite good for what it is, is not a good tool for tuning subwoofers at all.  This iPhone ap, while better, still isn't the best for subs either with the built-in mic, but worked much better with an external.  

Also, this ap's A-weight filter is better than Radio Shack's.

In conclusion, this ap is a bargain for the price and so handy to have with you.

A+.

My one suggested improvement:  a logging mode which logs SPL at selectable intervals -- minutes and seconds -- and then can e-mail the log out in csv format with time and SPL reading.

### 5/5 — Excellent

*2016-11-14, version 4.9*

I tried a few similar apps before trying this one, and found it the best so far. Many options, and accurate settings.

### 5/5 — Enthusiastically recommended

*2014-11-09*

After accidentally losing the calibration of my subwoofer, I discovered that my trusty Radio Shack SPL meter was no longer accurate with sub-100-Hz test tones. I bought SPL and found it agreed stably within 1 dB of my main channel measurements using the old hardware and wideband pink noise. This is more than enough to validate it as a replacement for the RS meter, while it is a lot more cost-effective -- I spent the same amount today on a 9-V battery for the meter as the app cost!

### 4/5 — Inaccurate after iOS 8 update

*2014-09-27, version 3.9*

Spl does not read correctly after updating to iOS 8

### 1/5 — UI elements do not scale correctly on iPad

*2014-03-28*

I've found that UI elements do not scale correctly on iPad such as "74.5" would show up as "74..." for the peak dB value. This makes it unusable on iPad.

**Developer response:** Hi
Please update to the latest version to correct this issue. --Andrew

### 2/5 — Horrible color scheme

*2013-11-24*

I have loved this app previously. In fact, I would have always given this app five stars until this version. I have been using this app for years now and I have always used the 'dark metal' color scheme. Now the only option is white. The white color option is TERRIBLE!!!!! 

As a foh guy, I use this app a lot. But I think I will be looking for another app because the white color scheme adds extra light to foh and the white is extremely harsh on the eyes. 

If you have not updated to the newest version, don't. It's not worth it.

### 2/5 — SPL

*2013-05-04*

Big battery drain

### 5/5 — Crash at 66.6db

*2012-12-27*

Like the title says this app apparently likes heavy metal or satan or both. It has crashed several times frozen on 66.6db. \m/

## Frequently asked questions about SPL

### What does the SPL app do?

SPL is a professional-grade digital sound level meter for iOS devices. It measures decibels (dB) using various modes and filters that meet or exceed ANSI Type 1 standards. The app allows you to store, recall, and export your measurements, and can be calibrated for maximum accuracy.

### What are the key features of SPL?

Key features include professional-grade measurement capabilities, compliance with ANSI/IEC Type 1 standards for modes (Slow, Fast, Impulse, Peak, Leq) and filters (A, C weighting, 10 octave bands). It also offers GPS and time-stamped result storage, export functionality, and the ability to calibrate the meter using external devices or by matching to a calibrated sound level meter.

### How much does SPL cost?

Based on the provided information, the app is a paid application. There are no mentions of free versions, subscriptions, or in-app purchases for core functionality.

### What devices is SPL compatible with?

The app is designed for iPad, iPhone, and iPod touch devices. It utilizes the built-in microphone and can also be used with external calibrated microphones like iTestMic, iTestMic2, and iAudioInterface2 for professional results.

### What are common use cases for SPL?

Common use cases include measuring ambient noise levels in various environments, conducting acoustic analysis, testing speaker polarity (when used with compatible hardware), and performing seat-to-seat comparisons by setting reference levels. It's suitable for professionals in audio engineering, construction, and environmental monitoring.

## Version history (last 5 releases)

### 7.9 — 2025-12-22

-Bug fixes and stability improvements

### 7.8 — 2025-12-01

-Fixed SPL not running after storing data

### 7.7 — 2025-11-24

-Updated for new iOS devices
-Bug fixes and stability improvements

### 7.6 — 2024-11-24

-Updated for latest iOS devices and calibrations
-Bug fixes and operational improvements

### 7.5 — 2024-10-18

-Added taking a photo as a screen background to document what is being tested
-Added screen recording to save a video of the sound levels with the photo as the background if desired
-Added more device support

## Apps similar to SPL

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [AudioTools, dB, Sound & Audio](https://appshunter.io/ios/app/audiotools-db-sound-and-audio/id325307477) | 4.8 (5,060) | $19.99 | Music |
| [Decibel meter for personal use](https://appshunter.io/ios/app/decibel-meter-for-personal-use/id6448749318) | 4.5 (28) | Free | Music |
| [Sound Decibel Meter-NIOSH,OSHA](https://appshunter.io/ios/app/sound-decibel-meter-nioshosha/id1571075296) | 4.5 (335) | Free | Music |
| [Spectrum Analyzer: Spectrogram](https://appshunter.io/ios/app/spectrum-analyzer-spectrogram/id981810895) | 4.2 (195) | Free | Music |
| [SPL Meter](https://appshunter.io/ios/app/spl-meter/id309206756) | 4.1 (27) | $0.99 | Music |
| [Bass Tester & Booster Pro](https://appshunter.io/ios/app/bass-tester-and-booster-pro/id941024213) | 3.9 (225) | Free | Music |

## More apps by Andrew Smith

- [Speaker Polarity](https://appshunter.io/ios/app/speaker-polarity/id293263027)
- [RTA](https://appshunter.io/ios/app/rta/id298839433)
- [FFT](https://appshunter.io/ios/app/fft/id298840058)
- [RT60](https://appshunter.io/ios/app/rt60/id298840320)
- [Generator](https://appshunter.io/ios/app/generator/id298840802)

All apps by Andrew Smith: https://appshunter.io/developer/291822462

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-09.*