Engine RPM vs SoundTach

Measure the RPM of an engine by analyzing the sound it makes. Engine RPM listens to the sound of a running engine and uses advanced signal processing algorithms to extract the frequency of that sound and calculate the RPM. This app is primarily for setup and diagnostics of engines. After setting the the number of cylinders and whether the engine is a 2-stroke or 4-stroke engine, the app can work with any internal combustion engine, from diesel tractors to aircraft engines to motorcycles to chainsaws. To use the app you must set an expected RPM range to guide the analysis algorithms to the correct RPM. A real-time graph of the autocorrelation graph is displayed to help in troubleshooting and adjusting the expected RPM range. The analysis requires a clear sound from the engine without excessive interference from extraneous sounds. Do not expect to read the RPM of an engine while other things are making too much noise at the same time. The analysis also requires that the RPM be stable. It cannot read the RPM of an engine that is rapidly accelerating. For this reason, and because of the need for adjusting the expected RPM range, this app should not be considered a drop-in replacement for an operational tachometer. Setup options include update periods from 93 milliseconds to 1.5 seconds, one to 12 cylinders, 2-stroke or 4-stroke, low-pass filtering, and signal clipping. The overall RPM range is 400 to 90,000 RPM (although at any one time, the operational range is typically +/- 30% around a nominal expected RPM). Precision is usually about +/- 10 RPM.

MEASURE ENGINE RPM FROM SOUND - NO TOOLS NEEDED SoundTach is the easiest way to measure engine RPM on motorcycles, cars, lawn mowers, chainsaws, and small engines. Simply point your phone at the exhaust and see accurate RPM readings in seconds. HOW IT WORKS SoundTach uses advanced audio analysis to detect engine RPM from exhaust sound. No OBD adapter, wires, or manual calibration needed. Just: 1. Select the engine type 2. Point your phone at the exhaust 3. See real-time RPM readings The app automatically filters background noise and provides confidence indicators so you know when readings are accurate. KEY FEATURES - Automatic RPM Detection - Works with a wide variety of engines - 2-Stroke & 4-Stroke Support - Motorcycles, dirt bikes, ATVs, scooters - No Manual Configuration - Automatic gain and filtering - Real-Time RPM Display - Smooth, accurate readings - Signal Quality Indicator - Know when to move closer or back - Clean, Professional Interface - Easy to read outdoors SUPPORTED ENGINES - Motorcycles (street bikes, sport bikes, cruisers) - Dirt bikes and motocross - Scooters and mopeds - ATVs and UTVs - Lawn mowers and tractors - Chainsaws and trimmers - Generators and pumps - Go-karts and mini bikes - Small aircraft engines PERFECT FOR Motorcycle Tuning - Set idle RPM precisely without expensive equipment. Perfect for carbureted bikes like vintage motorcycles, cafe racers, and classics. Mechanic Tools - Add SoundTach to your diagnostic toolkit. Great for quick RPM checks on customer vehicles. Small Engine Repair - Tune lawn equipment, chainsaws, and generators to manufacturer specifications. DIY Maintenance - Save money by tuning your own equipment. No need to buy dedicated tachometer gauges. WHY SOUNDTACH? SoundTach works automatically. No gain adjustments, no filter configuration, no threshold tuning. Just point and measure. Our advanced signal processing handles: - Automatic gain normalization - Intelligent noise filtering - Harmonic verification - Adaptive smoothing GET STARTED FREE Try SoundTach free for 7 days with unlimited measurements. No purchase required. SUPPORT Questions? Contact us at support@soundtach.com Visit soundtach.com for tutorials and tips