# Measured impulse response analyzer Analyze an existing measured IR with broadband Schroeder decay, EDT/T20/T30 fits, C50/C80 and D50. > Canonical page: https://elysiatools.com/en/tools/impulse-response-analyzer - **Category:** Media - **Keywords:** impulse response, decay, clarity ## Overview Upload an already measured/deconvolved IR, not a sweep, MLS excitation, music or speech. Maximum 30 seconds, mono/stereo, 8–96 kHz. Fits require sufficient decay range, tail/noise headroom and R² ≥0.98. EDT (0 to −10 dB), T20 (−5 to −25 dB), and T30 (−5 to −35 dB) extrapolate a straight-line slope to 60 dB. Times are onset-relative; clarity uses captured energy. Download JSON, CSV, SVG and an offline report. No recording, deconvolution, octave-band analysis or certified room-acoustics RT60 measurement. Conservative completeness check: tail power must fall at least 45 dB below onset-block power, with at least 10 dB fit headroom. Trailing silence or negligible padding is excluded from tail diagnostics; abrupt active-tail drops invalidate fits. This may withhold otherwise usable EDT estimates. ## Inputs - **Measured IR audio** (file) ## When to use - You have a deconvolved room or chamber impulse response and need objective broadband reverberation times (EDT, T20, T30). - You need speech and music clarity parameters (C50, C80, and D50) calculated directly from recorded impulse response files. - You want to verify impulse decay quality and ensure measurements meet tail-to-noise headroom thresholds without manual curve fitting. ## How it works - Upload a measured, already deconvolved impulse response file in WAV, FLAC, or AIFF format (mono or stereo, 8 kHz to 96 kHz, up to 30 seconds). - The analyzer detects the impulse onset, computes the backward Schroeder integration, and checks that tail power drops at least 45 dB below onset power with at least 10 dB headroom. - Straight-line linear regressions are fitted across standard intervals (EDT: 0 to −10 dB, T20: −5 to −25 dB, T30: −5 to −35 dB) requiring R² ≥ 0.98, alongside C50, C80, and D50 ratios. - Download a ZIP package containing structured numerical results in JSON and CSV, vector Schroeder decay plots in SVG, and a self-contained offline report. ## Use cases - Validating synthetic room impulse responses against simulated exponential decay targets. - Benchmarking deconvolved auditorium or studio acoustic measurements for speech clarity (C50) and music articulation (C80). - Screening measured impulse response archives for noise floor truncation or corrupted tail artifacts before further DSP processing. ## Frequently asked questions ### Can I upload raw sine sweeps or MLS recordings directly? No. The analyzer requires an already deconvolved impulse response file, not an active test sweep, MLS excitation signal, music, or continuous speech. ### Why are T20, T30, or EDT reported as unavailable for my file? Fits require a linear correlation of R² ≥ 0.98, at least 10 dB of fit headroom above the tail, and an uncorrupted decay curve. Incomplete tails or abrupt cuts invalidate regressions. ### Does this tool provide fractional octave-band analysis? No. The tool computes broadband Schroeder decay and broadband clarity metrics across the full audible spectrum of the uploaded audio. ### How are C50, C80, and D50 calculated? They are calculated from the detected arrival onset using captured impulse energy, integrating early-to-late energy ratios at 50 ms and 80 ms boundaries. ### What export formats are included in the downloaded archive? The output archive includes raw decay and fit metrics in JSON and CSV, vector decay graphics in SVG, and an offline HTML summary report. ## Related tools - [Bit Depth Analyzer](https://elysiatools.com/en/tools/bit-depth-analyzer): Inspect container precision and per-channel integer low-bit occupancy; download an offline ZIP report. - [Audio Chord Progression Detector](https://elysiatools.com/en/tools/audio-chord-progression-detector): Estimate an audio file's chord sequence locally and download CSV, JSON, SVG, and method notes in one ZIP. - [THD Analyzer](https://elysiatools.com/en/tools/thd-analyzer): Measure single-tone harmonic distortion per channel and download a ZIP report. - [Audio Digital Release Packager](https://elysiatools.com/en/tools/audio-digital-release-packager): Package an album for digital distribution: distributor-profile compliance checks, cover-art validation, MP3 previews, FLAC archive copies and a delivery ZIP with a README and machine-readable manifest. - [Audio SNR Estimator](https://elysiatools.com/en/tools/audio-snr-estimator): Estimate per-channel signal-to-noise ratio from separate program and noise-only regions, with an offline ZIP report. - [Image Particle Music Visualizer](https://elysiatools.com/en/tools/image-particle-music-visualizer): Turn a picture into an audio-reactive point cloud. Preview locally, then export a 30 fps MP4 with music, a PNG poster and settings JSON. - [Batch Audio Converter](https://elysiatools.com/en/tools/audio-batch-converter): Convert multiple audio files between different formats like MP3, WAV, FLAC, AAC, OGG, Opus with quality settings and batch processing - [Audio Format Converter](https://elysiatools.com/en/tools/audio-converter): Convert audio files between different formats like MP3, WAV, FLAC, AAC, OGG with quality settings and volume adjustment ## Samples - [Copyright-Free FLAC Audio Samples](https://elysiatools.com/en/samples/flac-samples): Lossless FLAC audio samples for testing and development, mirrored from MP3 set with nature sounds and meditation music - [Copyright-Free MP3 Audio Samples](https://elysiatools.com/en/samples/mp3-samples): Collection of royalty-free audio samples for testing and development purposes including nature sounds, meditation music, and ambient audio - [Copyright-Free WAV Audio Samples](https://elysiatools.com/en/samples/wav-samples): Uncompressed PCM WAV audio samples for testing and development, mirrored from MP3 set with nature sounds and meditation music - [Copyright-Free Raw PCM Audio Samples](https://elysiatools.com/en/samples/pcm-samples): Raw PCM s16le audio samples featuring nature ambience and relaxing music for waveform, playback, and conversion workflows