Pocket Seismograph vs SpecWave

See how hard a surface is shaking, and at what frequency. Pocket Seismograph reads your iPhone's accelerometer at 100 Hz, draws the vibration live, and names the strongest frequency it can find in it. WHAT YOU GET - Dominant frequency in Hz, with a full spectrum chart behind it - Live trace with NOW, MAX, AVG and RMS, as magnitude or full XYZ - Rotation-speed readout in rpm, offered as a hypothesis when the reading looks like a rotating part - Estimated felt intensity and estimated peak ground velocity - Three processing modes: Raw, Stable and Vibration - Sessions you can name, tag, search and reopen - CSV export through the system save dialog, with locale-aware profiles - Calibration wizard that measures your own device's noise floor - Works offline. No account, no sign-in. GREAT FOR - A washing machine that walks across the floor. A spin cycle sits around 17 to 27 Hz, and the app names it. - HVAC units and fans: read the running frequency, then the rpm it implies. - Floors, stairs and beams that move when someone walks past. - Construction, traffic or machinery you want recorded with a timestamp. - Feeling a tremor and wanting the next one captured. HOW IT WORKS 1. Put the phone flat on the surface, screen up. 2. Press Start. Watch the trace and the frequency card. 3. Save the session, add a note, export CSV when you need to show someone. WHAT IT WILL NOT DO Frequency analysis reads reliably from about 1 Hz to 40 Hz, and only indicatively up to roughly 50 Hz. Vibration faster than half the sampling rate does not simply disappear, it folds back and can appear as a false low-frequency line. Amplitude is indicative: the case, how firmly the phone rests on the surface, and filtering inside the sensor itself all color the number. The frequency is the more trustworthy half of the reading. When nothing stands clearly above the noise, the app says "No clear frequency" rather than inventing one. That is the correct reading for a phone lying still on a desk. This is not a certified seismic instrument and it is not calibrated for legal evidence. It is not a medical or diagnostic device. It sends no seismic alerts, so for early warnings use your country's official system. It cannot see the 60 Hz to 500 Hz range where bearing and gear features live, so finding nothing here says nothing about them. Available in 49 languages. Built by an independent developer who thinks a measurement tool should tell you when it does not know. If it is useful to you, a review is the best thanks.

Key Features Real-time Spectrum Analysis (See Your Sound) - Instant Visualization: Captures ambient sound via microphone and presents it in beautiful "Line" or "Bar" chart styles, making pitch and volume crystal clear. - Key Data Capture: Displays the current peak frequency and total decibel level in real time, while automatically logging the maximum and minimum decibels for your session. - One-Tap Display Freeze: Tap the spectrum chart anytime to freeze the current frame, allowing you to observe and compare sound details at your own pace. - Multi-Source & Parameter Toggles: Switch between built-in and external microphones with a single tap, and toggle between log/linear frequency axes to suit your needs. - Microphone Gain Control: Easily adjust input sensitivity to your liking. *(Note: This app outputs raw relative values only; for high-precision acoustic measurement, please calibrate with a sound level meter first)* Audio Signal Generation (A Fun Health Check for Headphones & Speakers) - 3 Classic Waveforms: Built-in sine, square, and triangle wave audio signals to instantly turn your phone into a versatile sound transmitter. - Fun Dynamic Frequency Sweeps: Supports fixed frequency playback alongside single, loop, or round-trip dynamic sweep modes. Easily test speaker bass depth or fine-tune audio gear. - Precise Gesture Tuning: Use smooth swipe gestures for silky, precise micro-adjustments to both output frequency and volume gain. Common Use Cases - Measure room insulation or ambient noise decibels at home or in the office. - Test newly purchased headphones or speakers to see if the bass is deep enough and the treble is crisp. - Assist with instrument tuning by viewing the exact sound pitch and frequency. - Explore fun acoustics by playing curious sweep tones with the signal generator.