NVH Source Locator vs Heel Drop

NVH Source Locator is a TDOA-based measurement tool for finding noise and vibration sources in structures using accelerometer signals captured on your oscilloscope or measurement system. Built for NVH engineers, automotive diagnostics, machinery troubleshooting, and structural analysis. Works fully offline — no data leaves your device. HOW IT WORKS Place 2–6 accelerometers on a structure, capture the time difference between sensors when they detect the noise/vibration event, and the app calculates where the source is. More sensors mean more precise localization: - 2 sensors → distance along a line - 3 sensors → 2D position - 4 sensors → 3D position - Up to 6 sensors with over-determined least-squares solver for maximum accuracy FEATURES - Seven measurement modes: 2-Sensor, 3-Sensor, 3-Sen+, 4-Sensor, 4-Sen+, 3D, 3D+ - Sound speed library with 100+ engineering materials (metals, polymers, glass, fluids) - Temperature compensation for 14 commonly-used metals (Aluminum, Steel, Copper, etc.) - Custom material support — calibrate in-situ and save the result - Photo annotation — overlay sensor markers on a photo of your setup - PDF report generation with custom header for your company - Backup & restore of all settings, custom materials, favorites, and history FULLY LOCALIZED Complete app interface and on-device user guide in 30 languages: English, Deutsch, Español, Français, Italiano, Português, Polski, Čeština, Slovenčina, Русский, Magyar, Hrvatski, Български, Беларуская, Svenska, Norsk, Suomi, Română, Türkçe, 中文, 日本語, 한국어, العربية, فارسی, हिन्दी, ไทย, Tiếng Việt, Bahasa Indonesia, Bahasa Melayu, Filipino. Complete online documentation at nvh.evdiag.net mirrors the in-app help in every language. FREE VS PRO The 2-Sensor mode is fully free with no limits. Pro unlocks all advanced modes (3-Sensor through 3D+), photo annotation, PDF reports, custom materials, and backup/restore — a single one-time purchase, lifetime access. WHO IT'S FOR - NVH engineers in automotive, aerospace, and electric vehicle development - Diagnostic specialists tracking down rattles, squeaks, and vibration sources - Structural analysts and acoustic consultants - Machinery maintenance teams locating bearing failures and resonance issues PRIVACY NVH Source Locator works entirely offline. No measurement data leaves your device. No analytics, no tracking. Developed by EVDiag. Full user manual at https://nvh.evdiag.net

Heel Drop turns your phone into a real vibration-analysis instrument. Every FFT spectrum comes from your own accelerometer, computed live. No external hardware required. See live time-domain, FFT, and power spectral density views while you record. Save sessions to a history list with peak frequency and RMS acceleration. Export raw data to CSV or a professional PDF report. Every report includes a free comparison against AISC Design Guide 11 walking-excitation limits. This is a simplified reference for engineering judgment, not a certified compliance calculation. You interpret the result, same as with any raw instrument reading. Built for structural and civil engineers, architects, and NVH technicians doing floor-serviceability checks. Bay slabs, mezzanines, gyms, rooftop equipment platforms. One phone, one measurement, no setup. Free tier includes live time-domain and FFT views with peak-frequency detection, saved sessions, and PDF reports. Heel Drop Pro adds PSD analysis, velocity and displacement integration, raw CSV export, and unlimited saved sessions. A phone-level check runs before every recording, so you know when tilt is contaminating the vertical reading. Heel Drop reports raw measured data from a consumer-grade accelerometer. It is not a certified compliance tool and does not replace a licensed engineer's judgment. SUBSCRIPTION TERMS Heel Drop Pro is an auto-renewable subscription, available monthly or annually. Prices are shown in the app in your local currency. Payment is charged to your Apple ID account at confirmation of purchase. The subscription renews automatically unless auto-renew is turned off at least 24 hours before the end of the current period. Your account is charged for renewal within 24 hours before the period ends. You can manage or cancel your subscription in your App Store account settings after purchase. Terms of Use (EULA): https://codeensis.com/heeldrop/terms Privacy Policy: https://codeensis.com/heeldrop/privacy