Comparison

Valiance Backbone for CW vs Sound Level & Spectrogram

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

Head to head
About

Valiance Backbone for CW

Decode Morse code signals in real-time using your device's microphone. This app employs advanced FFT technology to accurately distinguish transceiver signals from noise, offering a high success rate for radio communications. It features a range of tools for signal analysis and log management.

Highlights
  • Real-time Morse code decoding via microphone
  • Advanced FFT technology for signal detection
  • Minimizes false decodes from noise
  • Morse Sound Recorder & Player
  • Export text logs and audio data
  • Predictive decoding for difficult codes
  • Tone and sound pressure measurement
Features
Read full description

Morse Decoder: Valiance Backbone for CW (VBC) VBC is the No. 1 Morse code decoder in the Japanese market, encompassing both paid and free categories. This app allows you to decode Morse code using the built-in microphone of your iPhone or iPod touch. VBC utilizes the world's fastest FFT (Fast Fourier Transform) technology to detect and decode carriers. It is specifically designed to minimize false decodes from atmospheric noise, voices, or beep sounds (square or trapezoidal waves). While it will not decode vocalized "dit-dah" sounds, it offers an extremely high success rate for decoding actual transceiver signals. (Please check our videos of real DX station communications). We believe its decoding capability surpasses that of many expensive dedicated hardware units and PC software. The carrier detection mode is highly effective, making it a truly practical tool for active hunting and pouncing in real-world radio operations. The default settings are optimized for the best performance balance. We recommend testing it with an actual radio (800Hz tone) at a short distance using the default configuration. Key Features: Morse Sound Recorder & Player Export text logs, audio data, and history via email Timestamp and cancel stamp insertion in logs Predictive decoding for difficult or connected Morse codes Zero-in Tone Indicator / Shift-in Indicator Tone frequency measurement (±5Hz) Sound pressure measurement (dB) Audio frequency response measurement & automatic correction Peak search / Manual frequency setting (double-tap screen) Automatic speed tracking / Manual speed setting (double-tap screen) Auto Level / Auto Threshold / Manual Threshold (double-tap screen) Noise reduction & waveform shaping via carrier detection Japanese (Wabun) Morse support Signal level adjustment Input Level Over-Range Indicator When the input level exceeds the range (Over-Range), the waveform becomes distorted, leading to poor decoding accuracy. If this happens, please move your device further away from the radio. (Avoid placing the device directly on a vibrating radio; maintain a sufficient distance. The app is designed to decode accurately even from a significant distance.)Supports decoding speeds from 5 to 40 WPM For more information and to see the app in action, please visit our YouTube channel for Real-DX videos and more: http://goo.gl/ALXAqH http://goo.gl/yEu3d1 http://goo.gl/7gp4yw Note: Due to scrolling issues on the decode screen since iOS 8, we utilize the following library for text display. Our sincere thanks to the developer: SECoreTextView Created by kishikawa katsumi on 2015/03/25. Copyright (c) 2013-2015 kishikawa katsumi. All rights reserved.

About

Sound Level & Spectrogram

Measure sound levels in decibels and visualize sound frequencies with a real-time spectrogram. Understand your environment's noise and protect your health. Offers advanced settings for accurate acoustic analysis.

Highlights
  • Sound level measurement (dB)
  • Real-time spectrogram analysis
  • Frequency weighting correction (A, C, Z)
  • Time weighting characteristics (Fast, Slow)
  • Time course graph
  • Environmental noise measurement
Read full description

"Sound Level & Spectrogram" is a sound level meter app for iPhone to easily measure the sound level of noise and music in your living environment. Simply tap the start button to measure sound levels in decibels (dB) and view the real-time variation of the sound level. You can also use the spectrogram feature to visually check the frequency characteristics of the sound source. Furthermore, you can select between frequency weighting correction characteristics and time weighting characteristics, which are essential for standard sound level meters, enabling appropriate sound measurement. Exposure to noise can impact health, potentially causing tinnitus, sleep disorders, stress, cognitive decline and heart disease. These risks have also been highlighted by the World Health Organization (WHO). Understanding noise levels is the first step towards improving your quality of life. Use this app to protect your health and create a comfortable living environment. Features: - Sound level measurement (dB): Leq (equivalent sound level), Min (minimum value), Max (maximum value), Avg (time-averaged equivalent sound level) - Frequency weighting correction characteristics: A (general sound level measurement with auditory correction), C (sound level measurement with almost flatter correction than A correction, e.g. peak evaluation at high volume), Z (flat characteristics without auditory correction, physical sound level measurement) - Time weighting characteristics: Fast=0.125sec, Slow=1.0sec - Time course graph - Spectrogram: 1/3 octave band analysis - Measurement time: 20 sec Applications: - Environmental noise measurement - Architectural acoustics - Live sound check - Installation of audio equipment - Tuning of sound equipment - Device management Example of the noise level situation: - 130 dB: Engine sound of Airplane - 110 dB: Horn of Car - 100 dB: Noise of passing train - 90 dB: In loud factory - 80 dB: In the train, Vacuum cleaner - 70 dB: Noisy office, Noisy Street - 60 dB: Quiet Car, Normal conversation - 50 dB: Quiet office - 40 dB: In the library, Quiet residential area - 30 dB: Outskirts of midnight, Whisper - 20 dB: Sounds of rubbing leaves Note: - Spectrogram is a tool to analyze the frequency spectrum of sound, with time on the horizontal axis, frequency on the vertical axis, and the strength of the signal represented by colors, and is used for acoustic analysis, voiceprint identification, etc. - This app is adjusted the reference value for iPhone. However, the built-in microphone of your iPhone is likely to have a non-uniform gain. Therefore, exact measurements are not guaranteed. - The standard noise measurement range is 30-130 dBA, and the measured value (Leq) is about 30 dBA in a quiet room of the household. Due to the presence of background noise, noise levels are never measured at 0dBA even in very quiet environments. In a typical anechoic room, the noise level is around 5-15 dBA. - At the initial startup after installing the app, the iOS system asks for permission to access the built-in microphone. In this case, you need to enable access to the microphone. If you have not enabled this setting, this app cannot work by privacy restrictions of the iOS system. Please enable the access permission on the iOS setting, "Settings > Privacy & Security > Microphone". Please visit our iOS app support page for more information on this app.

Screenshots

Valiance Backbone for CW4 screens
Sound Level & Spectrogram4 screens

Verdict

The call

The clearest difference is price: Sound Level & Spectrogram at Free against Valiance Backbone for CW's $3.99. Sound Level & Spectrogram also leads on in-app purchases (none vs 4) and review sentiment (100% vs 73%). Valiance Backbone for CW's advantage is ads (none vs shown) and device support (3 vs 1).

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

Sound Level & Spectrogram is free to download; Valiance Backbone for CW costs $3.99 up front. Valiance Backbone for CW sells 4 one-off in-app purchases. Sound Level & Spectrogram asks for nothing beyond the download.

UpkeepUpdate frequency

Valiance Backbone for CW ships an update every 11 months, Sound Level & Spectrogram every 5 months. The most recent releases landed on October 29, 2026 and October 23, 2026 respectively.

Scorecard8 real differences · 2 level
Valiance Backbone for CW versus Sound Level & Spectrogram: the parameters behind the verdict, then further details
ParameterValiance Backbone for CWSound Level & Spectrogram
Price$3.99Free — better
Rating2.0 (1 ratings) — better—
Positive reviews72.7% of reviews100.0% of reviews — better
Number of ratings1 — better—
Update frequencyEvery 11 monthsEvery 5 months — better
AdsNo — betterYes
In-app purchasesYesNo — better
MonetizationPaidAd-supported — better
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS11.0 — better18.7
Further details — not scored
Size28 MB4 MB
Age rating4+4+
DeveloperNobTOON,LLC

Customer experience

Valiance Backbone for CW

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews11 reviews
Positive72.7%
Neutral0.0%
Negative27.3%

Sound Level & Spectrogram

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

4 purchases

Valiance Backbone for CW

One-time4
  • Tip for the Developer$0.99
  • Standard Support$4.99
  • Premium$9.99
Show 1 more
  • Ultimate Supporter$29.99
None

Sound Level & Spectrogram

No in-app purchases

Questions

Is Valiance Backbone for CW free?
Valiance Backbone for CW costs $3.99, and also offers in-app purchases.
Is Sound Level & Spectrogram free?
Sound Level & Spectrogram is free to download, with no in-app purchases.
Do Valiance Backbone for CW or Sound Level & Spectrogram have ads?
Sound Level & Spectrogram shows ads; Valiance Backbone for CW does not.
Which is updated more often, Valiance Backbone for CW or Sound Level & Spectrogram?
Valiance Backbone for CW ships an update every 11 months, and Sound Level & Spectrogram every 5 months. Most recently, Valiance Backbone for CW was updated on October 29, 2026 and Sound Level & Spectrogram on October 23, 2026.

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