Comparison

Low Frequency Detector vs SCT Calculator 3

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

Head to head
About

Low Frequency Detector

This tool measures and analyzes low-frequency sounds that are difficult for the human ear to detect. It helps identify potential noise pollution from sources like construction or factories, providing detailed reports on frequency components and sound levels.

Highlights
  • Low-frequency power level measurement (<100Hz)
  • Audible band power level measurement (Leq)
  • 1/3 octave band analysis (OCT)
  • FFT analysis (FFT)
  • Time course graph (TIME)
  • Measurement report generation
  • Calibration function
Read full description

"Low Frequency Detector" is an acoustic measurement tool for detecting low-frequency sounds that is hard to hear in normal situation. The human ear is not sensitive enough to low-frequency sounds. If you are exposed to noise from nearby construction or factories without realizing it, you may feel discomfort or a sense of pressure. In such cases, you can use this app to check what kind of low-frequency noise is present. Generally, low-frequency sounds is a sound wave ranging from 1Hz to 100Hz. Depending on its frequency component and sound level, the degree of influence on the human body and the noise sensation is different. This app allows you to examine the frequency component of low-frequency sounds by 1/3 octave band analysis and FFT analysis. Features: - Low-frequency power level measurement less than 100Hz (LF Level): Flat characteristic, Updating indication of measurement period 1 sec. - Power level measurement in the audible band (Leq): Flat characteristic, Updating indication of measurement period 200ms. - 1/3 octave band analysis (OCT) - FFT analysis (FFT) - Time course graph (TIME) - Snapshot (Snap) on the measurement display screen. - Report function (Report): Analysis report of a peak LF Level with TIME, OCT and FFT. - Measurement time: up to 60 sec Functions: The measurement analysis is performed in the following step. Be sure to set the measurement conditions in Step-1 once before starting the sound measurement. 1) Calibration (Calibrate): The reference signal (1kHz sine wave) is output to determine the reference noise level for the low-frequency component. If the volume level of iPhone is set to about 20-50%, the calibration will automatically adjust it to the optimum volume level for the reference signal. 2) Measurement (Measure): Analyze a power level of low-frequency sounds. - LF Level (dB): Low-frequency power level less than 100Hz. - Leq (dB): Sound power level with the frequency weight characteristic Z (Flat) of the audible band. 3) Measurement display: It can select either 1/3 octave band frequency analysis, FFT analysis or Time course graph. They are updated in real time. 4) Report: Measurement result report. It is effective when measuring for 10 seconds or more. # Time course graph: TIME - Low-frequency (LF) Level (dB): Time course graph with peak level noise level judgment (RED-very noisy, YELLOW-noisy, GREEN-normal) at the peak level. - LF max (dB): maximum dB value of low frequency. # Frequency response graph: OCT, FFT - OCT Band LF max (dB): maximum dB value in 1/3 octave band at LF max observation. - Max Level Frequency (Hz): peak frequency at LF max observation. Notes: - The sound measurement of the low-frequency range is a level difference with respect to the reference signal, which indicates the relative power level. - The reference signal is output during calibration and sound level measurement. - Do not change the volume level of iPhone after the calibration. - White line in the OCT and FFT modes indicates frequency characteristics in frequency weight correction of G characteristics. - Since iPhone's built-in microphone has a lower sensitivity on the very low frequency range, it is not recommended to measure a huge volume sound near a very loud noise source. - Since it takes a while for the observation value to stabilize immediately after the start of measurement, the maximum value is calculated from about 2 seconds later. - In the case high power of 1kHz component is included in the measured noise source, the precision of measured value by this app largely decreases. - Sudden noise or impulsive sounds are not low frequency noises in general. - The previous calibration information can be maintained internally. - The analysis results may vary due to individual differences in iPhone devices. - The authorization to access built-in microphone and Photos will be confirmed by iOS system at first access. Please visit our iOS app support page for more information.

About

SCT Calculator 3

Features
Read full description

The SCT Calculator is a utility for AKC Agility Judges to easily calculate and record their Standard Course Times (SCTs) at a judging event. The app allows you to enter in distances measured either in feet or in yards (the app assumes that numbers larger than 220 are designated as feet measurements). Quickly select the class type (either Standard or Jumpers With Weaves) and the class level (either Premier, Master, Open, Novice or ISC) and press the calculate button to update the onscreen display of your SCTs. Use the Settings button to set your email address, the name of the club, and any calibration adjustments for your wheel. If you don't supply both an actual length and a measured length, the wheel calibration will not be taken into account when you enter in your measured course distances. Pressing the Email Button will automatically send the calculations to your supplied email address (using the email app on your device) for permanent record keeping. If you select the ISC class, you can also record which level (L1 thru L3) the class is for. This version of the app includes the latest rule changes announced by AKC that went into effect on July 1, 2024.

Screenshots

Low Frequency Detector4 screens
SCT Calculator 34 screens

Verdict

The call

The clearest difference is price: SCT Calculator 3 at $0.99 against Low Frequency Detector's $9.99. SCT Calculator 3 also leads on device support (3 vs 1) and iOS requirement (13.0 vs 26.2). On update cadence, ads and in-app purchases 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

Low Frequency Detector costs $9.99 and SCT Calculator 3 $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Low Frequency Detector ships an update every 9 months, SCT Calculator 3 every 8 months. The most recent releases landed on October 26, 2026 and October 25, 2026 respectively.

Scorecard3 real differences · 7 level
Low Frequency Detector versus SCT Calculator 3: the parameters behind the verdict, then further details
ParameterLow Frequency DetectorSCT Calculator 3
Price$9.99$0.99 — better
Rating2.8 (6 ratings) — better—
Positive reviews50.0% of reviews—
Number of ratings6 — better—
Update frequencyEvery 9 monthsEvery 8 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaid—
DevicesiPhoneiPhone, iPad, iPod — better
Requires iOS26.213.0 — better
Further details — not scored
Size1 MB4 MB
Age rating4+4+
DeveloperTOON,LLCTimothy Alan Verrelli

In-app purchases

None

Low Frequency Detector

No in-app purchases

None

SCT Calculator 3

No in-app purchases

Questions

Is Low Frequency Detector free?
Low Frequency Detector costs $9.99, with no in-app purchases.
Is SCT Calculator 3 free?
SCT Calculator 3 costs $0.99, with no in-app purchases.
Do Low Frequency Detector or SCT Calculator 3 have ads?
Neither Low Frequency Detector nor SCT Calculator 3 shows ads.
Which is updated more often, Low Frequency Detector or SCT Calculator 3?
Low Frequency Detector ships an update every 9 months, and SCT Calculator 3 every 8 months. Most recently, Low Frequency Detector was updated on October 26, 2026 and SCT Calculator 3 on October 25, 2026.

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