audioatlas_demo.wav

Measurement-based findings, not quality judgments.

Local-first listening context: measurements, not grades. AudioAtlas analyzes the selected file on this machine and does not intentionally upload it.

View
Duration 70.98s (1:11)
Sample rate 44100 Hz
Channels 2
Format WAV / PCM_16
Profile Full
Generated 2026-08-02T21:49:58Z
AudioAtlas 0.2.0a8
Git unavailable
Release public alpha 8 · desktop release hardening

How to read this report

Start with Key metrics for level and headroom context, scan Findings for checks worth prioritizing, then inspect the relevant plots and verify by listening.

This report provides descriptive context, not professional mastering approval or a universal pass/fail result.

Relative dB values use this track's strongest measured content as 0 dB. They show shape within this song and are not calibrated dBFS.

Check before delivery / worth a listen / for reference indicate priority, not quality.

A report can have no prioritized findings; the plots still describe the track's measured shape.

Key metrics

-13.125
Integrated LUFS
LUFS
-0.439
True peak
dBTP
-0.458
Sample peak
dBFS
-17.437
RMS
dBFS
12.686
PLR
dB
0
Clipped samples
0
Near-clipping samples
0.800
Median stereo correlation
Pearson r
-9.003
Median side/mid ratio
dB

Findings

Findings are measurement-based observations derived from the analysis. They highlight values or regions worth checking by ear; they are not quality judgments.

for reference stereo

Stereo field shows sustained low-correlation / side-heavy regions

Evidence:
  • Minimum frame correlation: -0.473.
  • Total time below 0 correlation: 0.511 seconds across 2 region(s).
  • Total time below 0.3 correlation: 1.115 seconds across 3 region(s).

Why it matters: Low correlation and higher side energy can point to passages where mono playback may change tone, level, apparent width, or center focus.

Does not mean: This does not mean the stereo image is incorrect; wide and phase-rich material can be intentional.

Suggested listening checks

  • Inspect the stereo correlation timeline around the lowest-correlation regions.
  • Listen in mono around sustained low-correlation regions if mono compatibility matters.
  • Inspect the mid/side energy plot around side-heavy regions.
3 regions, total 1.115s, longest 0.511s.
  • 47.067s-47.415s
  • 54.567s-54.822s
  • 70.310s-70.821s

Back to top

Plots

Visual maps generated from the analysis.

Waveform + RMS Envelope

waveform_rms.png

What this shows: raw samples with the RMS envelope overlaid. It is amplitude context, not a quality judgment.

Frame RMS Timeline

rms_timeline.png

What this shows: frame-by-frame RMS energy over time. It describes energy movement within this track, not a loudness target.

Frame Crest Factor Timeline

crest_factor_timeline.png

What this shows: per-frame peak-to-RMS contrast in dB. Higher values mean more transient-like frames within this track; this is not punch or quality.

Sample Histogram

sample_histogram.png

What this shows: sample-value distribution with clipping and near-clipping thresholds. Threshold markers do not prove audible distortion.

Spectral Shape Timeline

spectral_shape.png

What this shows: spectral centroid, rolloff, and bandwidth movement over time. It shows shape within this track, not brightness quality.

Sample-Peak Timeline

peak_timeline.png

What this shows: per-frame sample peak level over time. Clipping and near-clipping markers identify threshold crossings; they do not prove audible distortion.

Peak vs RMS Levels

peak_vs_rms.png

What this shows: sample-peak and RMS level movement on the same dBFS axis. This is a levels and contrast view, not a dynamics judgment.

RMS Level Distribution

rms_histogram.png

What this shows: distribution of per-frame RMS levels. This is a distribution, not a loudness target.

Stereo Correlation Distribution

stereo_correlation_histogram.png

What this shows: distribution of defined left/right correlation frames; undefined low-energy frames are excluded. This is a distribution, not a mono-compatibility verdict.

Log-Frequency Spectrogram

log_spectrogram.png

What this shows: frequency content over time on a log-frequency axis. Relative dB values use this track's strongest measured content as 0 dB. They show shape within this song and are not calibrated dBFS.

Welch Average Spectrum

average_spectrum.png

What this shows: the track's long-term Welch average spectrum. Relative dB values use this track's strongest measured content as 0 dB. They show shape within this song and are not calibrated dBFS.

Relative Mean Band Power Timeline

band_energy_timeline.png

What this shows: relative mean spectral power per FFT bin in broad frequency bands over time. It is not integrated band energy. Relative dB values use this track's strongest measured content as 0 dB. They show shape within this song and are not calibrated dBFS.

Onset / Transient Density Timeline

onset_density.png

What this shows: attack/activity movement within this track, not punch or quality.

Chroma CQT (Pitch-Class Energy)

chroma_cqt.png

What this shows: pitch-class energy over time within this track. This is not key detection and values are not calibrated across unrelated songs.

Short-term LUFS Timeline

short_term_lufs.png

What this shows: K-weighted short-term loudness in 3 s windows over time. This is distinct from the RMS timeline and from integrated LUFS. It is descriptive context, not a delivery pass/fail result.

Back to top

Understanding these numbers

Metric glossary

LUFS

Integrated LUFS is a whole-track loudness measurement weighted toward human hearing. It gives delivery context, not a quality judgment.

Short-term LUFS

Short-term LUFS is a time-varying K-weighted loudness measurement using 3 s windows. It shows where this track is louder or quieter over time and is distinct from RMS.

True peak

True peak estimates reconstructed peaks between samples. Values above 0 dBTP can matter for playback, conversion, or encoding headroom.

Sample peak

Sample peak is the largest stored sample value in the file. It is not loudness or density.

RMS

RMS is average signal energy. The RMS timeline is useful for seeing where energy rises or falls across the track.

Crest factor

Crest factor is peak-to-RMS contrast in dB. It describes measured peak contrast, not punch, quality, or dynamic range.

PLR

PLR is approximate true peak minus integrated loudness. It describes the measured distance between those two values; it does not by itself identify compression, transient quality, or a delivery problem.

Clipping / near-clipping

Clipping counts samples at the configured ceiling; near-clipping counts samples close to it. Use the waveform and histogram to inspect where these samples occur.

Stereo correlation

Stereo correlation describes the L/R relationship. +1 means nearly identical channels; 0 means loosely related; negative values indicate opposite-polarity/decorrelated content.

Side/mid ratio

Side/mid ratio compares stereo-difference energy with center energy. 0 dB means side and mid energy are similar; more negative means mid-dominant; closer to 0 means more side energy.

Spectral centroid

Spectral centroid is the spectrum's center-of-mass frequency. It moves higher when energy shifts upward in frequency, and lower when energy is weighted toward lows/mids.

Rolloff

Spectral rolloff marks the frequency below which most measured spectral energy sits.

Spectral bandwidth

Spectral bandwidth describes how spread out the spectrum is around the centroid.

Average spectrum

Average spectrum is the long-term frequency profile of the track. Relative values show shape within the file.

Relative mean band power

This view averages spectral power per included FFT bin in each broad frequency band, then normalizes values within the file. It is not integrated total band energy and does not indicate absolute dBFS level.

Onset density

Onset density is an attack/activity map for this track. It is not punch, groove quality, drum hits per second, or mix quality. Absolute onset-density values are not reliable quality comparisons across songs.

Chroma CQT

Chroma CQT shows pitch-class energy within this track. It is not key detection, chord detection, or harmonic-quality analysis.

Relative dB

Relative dB plots show shape within this track. They are useful for shape within this track; not comparable to dBFS values from meters or other songs.

Back to top

Technical details

Level metrics
duration_seconds 70.984
sample_rate 44100
channels 2
sample_peak_linear 0.949
sample_peak_dbfs -0.458
true_peak_linear 0.951
true_peak_dbtp -0.439
rms_linear 0.134
rms_dbfs -17.437
crest_factor_db 16.979
integrated_lufs -13.125
plr_db 12.686
clipped_samples 0
clipped_percent 0.000
near_clipping_samples 0
near_clipping_percent 0.000
dc_offset_per_channel 0.000, 0.000
peak_dbfs_per_channel -0.458, -1.382
rms_dbfs_per_channel -17.535, -17.341
true_peak_linear_per_channel 0.951, 0.853
true_peak_dbtp_per_channel -0.439, -1.376
Crest factor timeline
frame_length 4096
hop_length 1024
frames 3058
crest_factor_db_min 5.422
crest_factor_db_median 10.583
crest_factor_db_max 22.800
Stereo metrics
frame_length 4096
hop_length 1024
frames 3058
defined_frames 3050
undefined_frames 8
correlation_min -0.473
correlation_max 0.999
correlation_mean 0.746
correlation_median 0.800
overall_correlation 0.728
correlation_below_0_time_ranges start: 5.921, end: 6.107, duration: 0.186, start: 16.672, end: 16.765, duration: 0.093, start: 47.137, end: 47.392, duration: 0.255, start: 53.267, end: 53.313, duration: 0.046, start: 54.590, end: 54.683, duration: 0.093, start: 62.531, end: 62.647, duration: 0.116, start: 70.356, end: 70.612, duration: 0.255
correlation_below_0_3_time_ranges 22 item(s)
warnings one or more frames are below correlation_min_rms_dbfs; correlation is undefined
Spectrum metrics
nperseg 8192
bins 4097
strongest_bin_hz 64.600
strongest_bin_db 0.000
band_measurement relative_mean_power_per_fft_bin
band_mean_power sub: low_hz: 20.000, high_hz: 60.000, mean_power_db: -3.560, energy_db: -3.560, bass: low_hz: 60.000, high_hz: 120.000, mean_power_db: -2.108, energy_db: -2.108, low_mid: low_hz: 120.000, high_hz: 350.000, mean_power_db: -8.105, energy_db: -8.105, mid: low_hz: 350.000, high_hz: 2000.000, mean_power_db: -13.736, energy_db: -13.736, presence: low_hz: 2000.000, high_hz: 5000.000, mean_power_db: -19.835, energy_db: -19.835, high: low_hz: 5000.000, high_hz: 10000.000, mean_power_db: -27.270, energy_db: -27.270, air: low_hz: 10000.000, high_hz: 20000.000, mean_power_db: -36.817, energy_db: -36.817
highest_mean_power_band bass
band_energies sub: low_hz: 20.000, high_hz: 60.000, mean_power_db: -3.560, energy_db: -3.560, bass: low_hz: 60.000, high_hz: 120.000, mean_power_db: -2.108, energy_db: -2.108, low_mid: low_hz: 120.000, high_hz: 350.000, mean_power_db: -8.105, energy_db: -8.105, mid: low_hz: 350.000, high_hz: 2000.000, mean_power_db: -13.736, energy_db: -13.736, presence: low_hz: 2000.000, high_hz: 5000.000, mean_power_db: -19.835, energy_db: -19.835, high: low_hz: 5000.000, high_hz: 10000.000, mean_power_db: -27.270, energy_db: -27.270, air: low_hz: 10000.000, high_hz: 20000.000, mean_power_db: -36.817, energy_db: -36.817
strongest_band bass
Spectral shape
n_fft 4096
hop_length 1024
frames 3058
valid_frames 3058
undefined_frames 0
centroid_mean_hz 3584.593
centroid_median_hz 3758.430
centroid_min_hz 624.737
centroid_max_hz 11085.554
rolloff_85_median_hz 8118.018
rolloff_95_median_hz 11660.229
bandwidth_median_hz 3816.067
centroid_elevated_threshold_hz 5637.646
centroid_reduced_threshold_hz 1879.215
centroid_large_shift_threshold_hz 2818.823
centroid_elevated_time_ranges 76 item(s)
centroid_reduced_time_ranges 66 item(s)
centroid_large_shift_time_ranges 13 item(s)
Relative mean band power timeline
measurement relative_mean_power_per_fft_bin
n_fft 4096
hop_length 1024
frames 3058
valid_frames 3058
undefined_frames 0
band_names sub, bass, low_mid, mid, presence, high, air
bands sub: median_db: -36.521, mean_db: -42.613, max_db: -0.761, min_db: -100.000, elevated_threshold_db: -30.521, reduced_threshold_db: -48.521, elevated_time_ranges: 49 item(s), reduced_time_ranges: 42 item(s), bass: median_db: -24.023, mean_db: -34.126, max_db: 0.000, min_db: -100.000, elevated_threshold_db: -18.023, reduced_threshold_db: -36.023, elevated_time_ranges: 74 item(s), reduced_time_ranges: 21 item(s), low_mid: median_db: -24.461, mean_db: -27.491, max_db: -8.770, min_db: -100.000, elevated_threshold_db: -18.461, reduced_threshold_db: -36.461, elevated_time_ranges: 117 item(s), reduced_time_ranges: 55 item(s), mid: median_db: -29.394, mean_db: -31.039, max_db: -15.319, min_db: -100.000, elevated_threshold_db: -23.394, reduced_threshold_db: -41.394, elevated_time_ranges: 85 item(s), reduced_time_ranges: 58 item(s), presence: median_db: -35.632, mean_db: -44.293, max_db: -19.445, min_db: -100.000, elevated_threshold_db: -29.632, reduced_threshold_db: -47.632, elevated_time_ranges: 103 item(s), reduced_time_ranges: 50 item(s), high: median_db: -44.104, mean_db: -52.353, max_db: -26.706, min_db: -100.000, elevated_threshold_db: -38.104, reduced_threshold_db: -56.104, elevated_time_ranges: 90 item(s), reduced_time_ranges: 60 item(s), air: median_db: -54.293, mean_db: -61.318, max_db: -35.887, min_db: -100.000, elevated_threshold_db: -48.293, reduced_threshold_db: -66.293, elevated_time_ranges: 97 item(s), reduced_time_ranges: 69 item(s)
highest_mean_power_band_by_median bass
strongest_band_by_median bass
Onset density
hop_length 1024
frames 3058
smoothing_window_seconds 1.000
smoothing_window_frames 43
mel_bands 128
onset_strength_mean 1.298
onset_strength_median 0.722
onset_strength_max 23.542
onset_density_mean 1.295
onset_density_median 1.233
onset_density_max 2.530
high_onset_density_threshold 1.849
high_onset_density_time_ranges 21 item(s)
strongest_onset_density_time 17.067
Chroma CQT
frames 3058
hop_length 1024
pitch_classes 12 item(s)
mean_chroma 12 item(s)
dominant_pitch_class C
Short-term LUFS
window_seconds 3.000
hop_seconds 0.100
frames 681
lufs_min -29.823
lufs_median -13.560
lufs_max -9.928
Analysis config
n_fft 4096
hop_length 1024
window hann
db_floor -100.000
rms_frame_length 4096
clipping_threshold 0.999
near_clipping_threshold 0.990
true_peak_oversample 4
welch_nperseg 8192
max_plot_points 250000
correlation_min_rms_dbfs -80.000
onset_density_window_seconds 1.000
short_term_lufs_window_seconds 3.000
short_term_lufs_hop_seconds 0.100
max_findings 8
band_finding_min_duration_seconds 0.500
band_finding_min_relative_db -80.000
finding_min_time_range_seconds 0.250
report_max_time_ranges 8
Analysis provenance
format_version 1
audioatlas_version 0.2.0a8
summary_schema_version 0.2.1
finding_ruleset_version 0.2.0a2
analysis_config_sha256 25ae6d74ba8d101215c84b9d5316aea585c1c95f4cfe782873c701b1d804d689
measurement_code_sha256 2210006b8fa8d05456ce0f6bfd25c8df75e7b7f4d8c653f63adc5a68fbcd1299
finding_rule_code_sha256 236348735a92f4b6f4d5da87d0ac6aac09222def14533b5a8dc7a2cb8e3b6a16
dependencies numpy: 2.4.6, scipy: 1.18.0, soundfile: 0.14.0, librosa: 0.11.0, numba: 0.65.1, pyloudnorm: 0.2.0
decoder python_binding: soundfile, soundfile_version: 0.14.0, libsndfile_version: 1.2.2
measurement_methods approximate_true_peak: method: scipy.signal.resample_poly, oversample_factor: 4, standards_grade_meter: False, integrated_loudness: method: pyloudnorm.Meter.integrated_loudness
environment python_version: 3.13.14, python_implementation: CPython, platform_system: Linux, platform_machine: x86_64, byteorder: little
compatible_analysis_sha256 37a8fabf799300d774d4ee4901b4ad1d6ba61be195dc1adeaa61cf85a5e6d424
exact_environment_sha256 94c19d4e0482dac0d6056954c084255c4c2bf6bf9f803c5d1a122a47df039f35

Back to top

Human notes

Notes stay in this browser for this report path. They are never written into the report files or sent over a network.

Notes are saved locally as you type.

Back to top

AudioAtlas reports measured facts and visual maps. The listener decides what matters for the track.