After using an audio equalizer, review the raw and output peaks—especially the 0.99 safety ceiling—then compare tone at a matched level and verify the final WAV’s sample rate, frame count, and format.
The Audio Equalizer supports a three-pass review: check numeric safety and file integrity, compare the sound fairly, then verify the exported WAV. This order separates technical validity from subjective sound quality, so a louder or quieter result is not mistaken for a better or worse adjustment.
Pass 1: Audit the peak and safety numbers
Start with the raw peak, the absolute peak measured across every processed sample and channel before safety scaling. If it exceeds 0.99, one uniform factor reduces the entire processed result so its largest magnitude becomes 0.99. This prevents the PCM encoder from chopping individual peaks, but it can lower the overall level. The output peak and exact safety scale show what happened; neither is a quality score.
The safety scale is not RMS, replay-gain, LUFS, or streaming-platform normalization. A scale below 1 is therefore a level-change warning, not proof of a bad mix.
Next, confirm the decoded sample rate and frame count. Each accepted channel retains the same number of frames, and the end is not silently truncated. Web Audio may resample while decoding, so the tool reports and writes the decoded rate rather than claiming that the source container rate survived unchanged.
| Reading | What it represents | What to review |
|---|---|---|
| Raw peak | Absolute peak across all processed samples and channels before scaling | Check whether it exceeded 0.99 |
| Output peak | Peak after any uniform safety scaling | Confirm it is 0.99 when scaling was triggered |
| Safety scale | One factor applied to the whole processed result | A value below 1 means the entire output was reduced uniformly |
| Decoded sample rate | The rate used after browser decoding | Use the reported rate rather than assuming the source rate was preserved |
| Frame count | Number of sample frames in each accepted channel | Confirm a complete ending and equal channel lengths |
| Band centers | Bass at 100 Hz, Mid at 1,000 Hz, and normally Treble at 10,000 Hz | At low sample rates, Treble is reduced to 45% of the decoded rate |
Read these values before deciding whether to listen again, lower a band, or keep the file.
Pass 2: Compare tone at a matched level
Preview the processed audio on the speakers or headphones that matter, then play the original separately at a similar perceived level. Do not judge only from louder output. The safety scale may have reduced the equalized version, so a level-matched comparison gives a fairer view of the tonal change.
Remember that these are broad peaking adjustments, not changes at hard frequency boundaries. Positive values boost energy around a band center, while negative values cut that region. Each band uses a fixed Q of 1, and the Bass, Mid, and Treble sections are cascaded in that order. With all three controls at zero, the decoded samples follow a genuine flat processing path.
- Bass: Listen for excessive weight, boom, or rumble rather than assuming more bass is automatically better.
- Mid: Check for boxiness, honk, or masking that makes nearby voices and instruments harder to distinguish.
- Treble: Listen for harshness, glare, or sibilance, especially if the source already contains bright noise.
- Noise and distortion: Strong boosts can emphasize existing noise, sibilance, rumble, or distortion, so listen for artifacts that were less obvious in the original.
- Overall level: If the result is quieter than expected, check the safety scale before adding another boost. A cut is often safer than stacking several boosts.
Run the three-pass review in order
- Confirm that the source is eligible. Choose one browser-decodable file no larger than 50 MiB. After decoding, it must be five minutes or shorter, contain one through eight channels, use a sample rate from 8,000 through 192,000 Hz, and contain no more than 30 million channel samples. MP3, WAV, M4A, AAC, Ogg, WebM, and FLAC work only when the current browser and operating system support the codec inside the file. An over-limit file is rejected before filtering, while a decode failure produces an error and no stale download.
- Set and apply the three bands. Choose whole-number gains from -12 through +12 dB for Bass, Mid, and Treble, then apply the equalizer locally. For a controlled first pass, begin with all three controls at zero and adjust one band at a time. The deterministic biquad filters run in Bass, Mid, then Treble order, with centers at 100 Hz, 1,000 Hz, and normally 10,000 Hz. At a low sample rate, the Treble center falls to 45% of the decoded rate.
- Record the numerical result. Check the raw peak, output peak, safety scale, decoded sample rate, and frame count. If the raw peak is above 0.99, expect a uniform scale factor and an output peak of 0.99. Note that a safety scale below 1 also means the entire processed signal was attenuated.
- Preview against the original. Listen to the processed result on the intended playback system, then compare it with the original at a similar perceived level. Give particular attention to bass rumble, midrange masking, treble harshness, noise, and distortion.
- Revise and recheck when necessary. If a region sounds worse, reduce that band or apply a cut, then run the equalizer again. Recheck the peak readings after each change because cascaded adjustments can alter the processed peak.
- Download only the version that passes the review. Once the sound, measurements, and file expectations look right, preview and download the new PCM16 WAV rather than keeping an unintended earlier render.
Pass 3: Verify the exported WAV
The download is a new deliverable rather than an edited copy of the original container, so inspect its encoding and structure before delivering it.
| Export property | Expected result |
|---|---|
| Format | A new uncompressed PCM16 WAV |
| Sample representation | Float samples converted to signed 16-bit little-endian PCM and interleaved by frame |
| Frame structure | All accepted channels have equal length and the same frame count, with the complete ending included |
| WAV header | Actual channel count, decoded sample rate, byte rate, block alignment, bit depth, and complete data length |
| Source encoding and metadata | The original codec, bitrate, compression mode, tags, artwork, chapters, loop markers, and container metadata are not preserved |
Do not expect the source bitrate or container rate to carry into the result. If codec choice, metadata preservation, or other advanced delivery requirements matter, use a full audio editor instead.
Know where the equalizer’s scope ends
This is a compact three-band peaking equalizer, not a graphic 10-band system, linear-phase mastering processor, automatic room-correction system, or guarantee that one setting will improve every recording. The Q value is fixed at 1 and cannot be changed on the page.
Use a full editor when you need precise center frequencies, adjustable Q, spectrum analysis, automation, linear-phase processing, loudness metering, dithering controls, codec selection, or metadata preservation. The safety scale can prevent PCM clipping, but it cannot supply those advanced mastering controls.
Confirm local processing and make a final decision
Processing remains in the current browser tab. The source is not uploaded, and the service does not receive the audio bytes, decoded samples, EQ settings, filename, or result.
- Safety: You understand the raw peak, output peak, and any uniform level reduction.
- Integrity: The decoded sample rate, frame count, and equal channel lengths meet your expectations.
- Sound: A matched-level comparison reveals no unwanted rumble, sibilance, noise, masking, or emphasized distortion.
- Delivery: The downloaded file is the intended PCM16 WAV, and you have accounted for the loss of the source encoding and metadata.
- Scope: The three-band result meets the task; otherwise, a fuller editor is required.
For a deeper look, see What Should I Review After I Use an Audio Speed Changer?.
For a deeper look, see When Should I Use an Audio Equalizer? A/B Listening Test.