Comparison

Decibel X vs Audio Frequency Analyzer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Decibel X

This tool transforms your device into a professional sound level meter, offering precise measurements of ambient noise. It features advanced calibration, frequency analysis, and data management for various applications, from personal curiosity to professional use.

Highlights
  • Pre-calibrated sound pressure level (SPL) measurements
  • Frequency weighting filters (dBA, dBC, ITU-R 468)
  • Apple Watch and Health App integration
  • History data management with export options
  • Dosimeter with NIOSH, OSHA standards
  • FFT and BAR graphs for real-time frequency analysis
  • InstaDecibel for sharing dB reports on photos
Features
Read full description

"Decibel X" is one of very few noise meter apps on the market that has highly reliable, pre-calibrated measurements and supports dBA, dBC. It turns your iOS device into a professional sound level meter, precisely measures the sound pressure level (SPL) all around you. This extremely useful and beautiful tool will not only be a great tool for many uses but also bring you a lot of fun. Have you wondered how quiet is your room or how loud is a rock concert or sport event? "Decibel X" will help you answer all of those. WHAT MAKE IT GREAT AND STAND OUT FROM OTHER APPS: - Trusted accuracy: the app is tested and pre calibrated for all Apple devices. The precision is matching with real SPL devices - Apple Watch support: see noise level right from your wrist - Health App integration: export noise levels directly into Health app - Frequency weighting filters: ITU-R 468, A, B, C, Z - Powerful, smart history data management: + Recording data can be saved into a list of history records for future access and analysis + Each record can be exported as hi-res PNG graph or CSV text via sharing services + iCloud support which synchronize all history records across your Apple devices + Fullscreen mode to give overview the whole history of an record - Dosimeter with NIOSH, OSHA standards - Powerful calibration: Linear, Octave 1/1, 1/3, Load/save profile - FFT and BAR graphs to display real time FFT. Those are very useful for frequency analysis and musical tests. Real time predominant frequency is also displayed. - InstaDecibel to capture your dB report overlaid on photos and easily shared via popular social networks (Facebook, Instagram, Messages, etc.). - Support Live Activity, Dynamic Island - Support both Portrait and Landscape layouts - Beautiful, intuitive and carefully crafted UI design. Themes: LIGHT, DARK and CLASSIC OTHER GREAT FEATURES: - Standard time weightings (Response Time): SLOW (500 milliseconds), FAST (200 milliseconds) AND IMPULSE (50 milliseconds) - MIC Gain Offset from -50 dB to 50 dB - Standard measurement range from 30 dBA up to 130 dBA - HISTO graph for plotted history of the recorded values - WAVE graph with 2 display modes: Rolling & Buffer - SPECTROGRAPH - Real time scale level chart - Display Current, Average/Leq, and Max values with both nice and clear digital and analog layouts - Quick reference text to help you compare with real-life examples NOTES: - Please do not expect a quiet room reading will be 0 dBA. The range 30-130 dBA is the standard usable range and an average quiet room will be about 30 dBA. - Although all devices are pre-calibrated, custom calibration is suggested for serious purposes requiring higher precision and accuracy. You will need a real external device or calibrated sound meter as a reference, then adjust the trimming calibration until the reading matches with the reference. * Privacy Policy: http://www.skypaw.com/decibelx/privacy_policy.html * EULA: http://www.skypaw.com/decibelx/terms.html

About

Audio Frequency Analyzer

This real-time audio analyzer measures and evaluates sound environments with 1/3 octave band frequency response and FFT analysis. It supports calibration for high accuracy and is suitable for various audio testing and tuning applications.

Highlights
  • Real-time frequency spectrum response measurement (1/3 octave, 30 bands)
  • FFT Analyzer
  • Observation frequency range: 20 - 23000 Hz
  • Calibration function for high accuracy
  • Supports built-in and external microphones
  • Snapshot and averaging functions
Read full description

"Audio Frequency Analyzer" is a powerful real-time audio analyzer (RTA) app for iPhone. With its simple operation, you can easily measure and evaluate your sound environment. This app measures the frequency response in 30 split band scale of 1/3 octave in real time. It can also display the FFT analysis results. It supports calibration for 1/3-octave bands. By adjusting the characteristics to match not only the built-in microphone but also your external microphone, it achieves high measurement accuracy. "Audio Frequency Analyzer" can be used for various applications, including sound room tuning, speaker settings, audio equipment testing, stage setup measurement, sound mixing environment evaluation and noise environment investigation. Features: - Frequency spectrum response measurement of 1/3 octave unit, 30 bands. (OCT) - FFT Analyzer (FFT) - Observation frequency range: 20 - 23000 Hz - Logarithmic amplitude display. - Touch-scroll function to adjust visible amplitude ranges. - Display the measured value of 1/3 oct bands at OCT mode. (dB@OCT) - Function to change the graph slope at FFT mode. (Slope): -3dB/oct (less than 1kHz), +3dB/oct (1kHz or higher) - Peak hold function. (Hold) - Average display function. (Avg): Time linear averaging. Fast-2.56sec, Slow-12.8 sec - Display response control. (Fast/Slow) - Reset of Measurement display position. (Scroll) - Snapshot of Measurement display. (Snap) - Calibration function in OCT mode. (Calibrate): 1/3 octave band offset and total offset setting. - Supports built-in microphone, headset microphone, and external digital audio connection. Note: The first time you access your microphone and photos after installing the app, the iOS system will ask you for permission to access them. If you have not enabled this setting, the app will not be able to access them due to iOS system privacy restrictions. Please enable the access permission in the iOS setting "Settings > Privacy & Security > Photos or Microphone". Please visit our iOS app support page for more information about this app.

Screenshots

Decibel X4 screens
Audio Frequency Analyzer4 screens

Verdict

The call

The clearest difference is price: Decibel X at Free against Audio Frequency Analyzer's $9.99. Decibel X also leads on rating (4.6 vs 3.7) and ratings volume (164K vs 3). Audio Frequency Analyzer's advantage is in-app purchases (none vs 5). On review sentiment and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Decibel X is free to download; Audio Frequency Analyzer costs $9.99 up front. Decibel X sells 5 in-app purchases, starting at $1.99 per 7 days. Audio Frequency Analyzer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Decibel X holds the better App Store score, 4.6 against 3.7. That said, the two scores are not equally well evidenced: Decibel X has 164K ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 66% of Decibel X's written reviews are positive against 60% of Audio Frequency Analyzer's.

UpkeepUpdate frequency

Decibel X ships an update every 3 months, Audio Frequency Analyzer every 8 months. The most recent releases landed on November 4, 2026 and November 1, 2026 respectively.

Scorecard8 real differences · 2 level
Decibel X versus Audio Frequency Analyzer: the parameters behind the verdict, then further details
ParameterDecibel XAudio Frequency Analyzer
PriceFree — better$9.99
Rating4.6 (164K ratings) — better3.7 (3 ratings)
Positive reviews66.3% of reviews — better60.0% of reviews
Number of ratings164K — better3
Update frequencyEvery 3 months — betterEvery 8 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium — betterPaid
DevicesiPhone, iPad, Apple Watch — betteriPhone
Requires iOS17.0 — better26.2
Further details — not scored
Size90 MB0 MB
Age rating4+4+
DeveloperSkyPaw Co., LimitedTOON,LLC

Customer experience

Decibel X

All ratings163,488 ratings
Positive92.2%
Neutral3.5%
Negative4.3%
Written reviews1,925 reviews
Positive66.3%
Neutral5.5%
Negative28.2%

Audio Frequency Analyzer

All ratings3 ratings
Positive66.7%
Neutral0.0%
Negative33.3%
Written reviews10 reviews
Positive60.0%
Neutral20.0%
Negative20.0%

Bugs and requests

Decibel X

Reported bugs

3 issues
  • App crashes when deleting recordings
  • Microphone issues on certain devices
  • Saved files not accessible after updates

Requested features

5 requests
  • Add GPS coordinates to recordings
  • Improve reporting and data export
  • Provide more weighting options
  • Extend frequency range
  • Allow music playback while using the app

Audio Frequency Analyzer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

5 purchases

Decibel X

Subscriptions3
  • Weekly Membership$1.997 Days
  • Monthly Membership$5.991 Month
  • Annual Membership3 Days trial$49.991 Year
One-time2
  • ITU-R 468, A, B, C Weightings$1.99
  • Data Export$2.99
None

Audio Frequency Analyzer

No in-app purchases

Questions

Is Decibel X free?
Decibel X is free to download, with in-app purchases available.
Is Audio Frequency Analyzer free?
Audio Frequency Analyzer costs $9.99, with no in-app purchases.
Which has better reviews, Decibel X or Audio Frequency Analyzer?
Decibel X is rated higher. Decibel X averages 4.6 out of 5 from 164K ratings, while Audio Frequency Analyzer averages 3.7 from 3 ratings.
Do Decibel X or Audio Frequency Analyzer have ads?
Neither Decibel X nor Audio Frequency Analyzer shows ads.
Which is updated more often, Decibel X or Audio Frequency Analyzer?
Decibel X ships an update every 3 months, and Audio Frequency Analyzer every 8 months. Most recently, Decibel X was updated on November 4, 2026 and Audio Frequency Analyzer on November 1, 2026.

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