Original WAV comparison · high-frequency roll-off · cVBRb boosts
How do the build families compare against the original WAV?
This page uses extracted DeltaWave aligned-spectrum curves. Each chart compares decoded MP3 output against the same original WAV, making it easier to see historical high-frequency roll-off and the later cVBRb boost extensions.
It is a lab page rather than a listening test. The charts show that older builds roll off earlier, 3.100 and 3.101b3 sit close together, and the cVBRb boost levels extend the response progressively on this sample.
3.98.4 rolls off earliest, with 3.99.5 showing a later but still obvious cut in the extracted response curve.
3.100 and 3.101b3 cluster closely against the original WAV in the extracted aligned-spectrum curves.
The cVBRb boost levels extend the high-frequency response progressively when compared with the unboosted 3.101b3 cVBR build on the same sample.
The derived metric charts back up the visual story by showing later drop points and lower average upper-band loss for the boosted variants.
This is still not a listening-test verdict. These are extracted DeltaWave aligned-spectrum curves, useful for illustrating behaviour against the original WAV rather than proving subjective transparency.
Historical response progression against the original WAV
These charts are extracted from embedded DeltaWave aligned-spectrum plots. They provide a direct visual comparison between the decoded MP3 outputs and the original WAV reference.
Historical progression against the original WAV. This view shows the earlier high-frequency roll-off in 3.98.4 and 3.99.5, then the much closer modern family formed by 3.100 and 3.101b3.
How to read it: the dashed line is the original WAV reference extracted from the same DeltaWave plots. Solid lines are the decoded build outputs. Click any response chart to open a larger version.
Measured upper-band summary
These derived charts make fuller use of the extracted aligned-spectrum curves by quantifying where each build begins to fall away from the original WAV and how much average upper-band loss remains.
Deviation from the original WAV in the upper band. The early 3.98.4 roll-off stands out clearly, while 3.99.5, 3.100, and 3.101b3 cluster much closer together.
Boost family deviation view. The cVBRb boost variants sit progressively lower, which is consistent with a gradual high-frequency extension on this sample.
How to read it: lower deviation means the extracted curve is closer to the original WAV in the upper band. Click any response chart to open a larger version.
Derived response metrics
Series
3 dB drop
6 dB drop
12 dB drop
Mean loss 18–21 kHz
Mean loss 19–22 kHz
3.98.4 MinGW
18.98 kHz
18.99 kHz
19.00 kHz
27.12 dB
38.05 dB
3.99.5 MinGW
18.66 kHz
19.98 kHz
21.51 kHz
4.29 dB
7.84 dB
3.100 MinGW
18.66 kHz
19.98 kHz
21.51 kHz
4.29 dB
7.84 dB
3.101b3 cVBR MinGW
18.66 kHz
19.98 kHz
21.50 kHz
4.30 dB
7.84 dB
3.101b3 cVBR (unboosted)
18.66 kHz
19.98 kHz
21.51 kHz
4.30 dB
7.86 dB
3.101b3 cVBRb boost 1
19.30 kHz
20.15 kHz
21.51 kHz
3.84 dB
7.40 dB
3.101b3 cVBRb boost 2
19.34 kHz
20.52 kHz
21.52 kHz
3.48 dB
7.05 dB
3.101b3 cVBRb boost 3
19.36 kHz
20.53 kHz
21.52 kHz
3.11 dB
6.66 dB
These metrics are derived from the extracted aligned-spectrum curves. They are based on extracted chart geometry rather than direct FFT export data.
Supporting proxy summary
The source is 44.1 kHz, so the Nyquist limit is 22.05 kHz. This bar chart is retained as a quick proxy summary; the aligned-spectrum charts above are the primary view on this page.
Approximate high-frequency extent derived from the embedded DeltaWave images. Treat this as a proxy for visible filtering/floor behaviour.
How to read it: higher kHz means the image-derived proxy found activity extending higher in frequency. It does not automatically mean better audible quality.
VBR frequency-range proxy table
Compile / configuration
Approx. high-frequency extent
3.95.1 standard VBR
18.91 kHz
3.96.1 standard VBR
18.91 kHz
3.97 standard VBR
18.50 kHz
3.98.4 standard VBR
18.84 kHz
3.99.5 standard VBR
20.63 kHz
3.100 standard VBR
20.63 kHz
3.100 cVBR
20.56 kHz
3.101b3 standard VBR
20.61 kHz
3.101b3 cVBR
20.61 kHz
3.101b3 cVBRb Optimized
20.59 kHz
VBR/cVBRb visual proxy derived from the embedded DeltaWave report image. Treat this as approximate, not as a laboratory frequency-response measurement.
cVBRb bitrate-boost response against the original WAV
These charts compare the unboosted 3.101b3 cVBR build with the three cVBRb boost levels. These are extracted from the aligned-spectrum plots in the DeltaWave reports.
Boost level 1 against the unboosted 3.101b3 cVBR build.
All three boost levels together. On this sample, the response extension is incremental, with the boosted variants tracking progressively higher than the unboosted cVBR line through much of the upper band.
Important: these are extracted from DeltaWave aligned-spectrum images. They are much closer to the intended original-WAV comparison story, but they are still extracted curves rather than direct raw FFT exports.
Embedded report images
Embedded DeltaWave report images. Horizontal floors or high-frequency truncation can affect how residual metrics should be interpreted.
How to read it: visible horizontal floors or early high-frequency drop-offs are diagnostic clues, not standalone quality scores.
Method notes and limitations
The main response charts on this page are extracted from embedded DeltaWave aligned-spectrum SVG plots. They compare each decoded output with the original WAV reference while keeping the workflow lightweight.
The response charts use the IBM Carbon data-visualization palette for categorical series, with a neutral dashed reference line for the original WAV.
The supporting high-frequency-extent bar chart is retained as a compact summary, but it is secondary. The new response charts and derived metrics are the primary narrative: they show the historical roll-off story, the closeness of 3.100 and 3.101b3, the extension introduced by the cVBRb boost levels.
The derived metrics here include 3 dB / 6 dB / 12 dB drop points and average loss across the 18–21 kHz and 19–22 kHz bands. Those measures are approximate because they come from extracted plot geometry rather than direct numeric spectral exports.
For more exact cutoff, roll-off, and high-frequency energy measurements, numeric spectral exports or a repeatable FFT-based workflow would be preferable.
FAQ
Is this a precise frequency-response measurement?
No. The main charts are extracted from DeltaWave aligned-spectrum images, not from raw FFT exports. They are useful for comparing build behaviour, but they remain extracted visual data rather than lab-grade response measurements.
Does a wider visible range automatically mean better sound?
No. A wider visible range is not automatically a quality verdict. The chart shows output behaviour against this reference sample, not listener preference or transparency.
Are the boost response charts raw FFT exports?
No. Both the cVBRb and ABR boost charts on this page are extracted from DeltaWave aligned-spectrum plots. They are useful for comparing the tested builds, but they remain extracted chart data rather than direct raw FFT exports.
