Why does the crossover matter so much?

Because it decides which content ends up in which band, and therefore what each compressor is reacting to. A low to mid crossover at 250 hertz puts everything below the bass region, while moving it to 500 hertz pulls in the lower parts of voices and instruments. Setting it around the problem region is what makes the tool useful.

Is the band split lossless?

Yes, in the sense that matters. The crossover is complementary, so with the ratio at 1 to 1 the three bands sum back to the exact input. That means any change in the sound comes from the compression rather than from the filtering, which is verified behaviour rather than an assumption.

Why is the threshold shared across all bands?

It keeps the interface to one decision per parameter and is a deliberate simplification. The consequence is that a quiet band and a loud band are judged against the same level, so the loudest band does most of the work unless the crossovers isolate the problem well. A per band threshold would be more precise but also more to set up.

Why is there no make-up gain?

So the reported level change reflects the compression honestly rather than the compensation. Without make-up gain a heavily compressed result comes back quieter, and the footer figure tells you by how much. Raising the level afterwards with a normaliser or an amplifier keeps the two decisions separate.

Can this fix a harsh vocal?

Partly. If the harshness is a level problem in the upper midrange, moving the low to mid crossover up and compressing the mid band will reduce it. If it is a fixed tonal characteristic of the voice, no compressor will help and the equaliser is where the cutting belongs.

Multiband Compressor

You Might Also Need

Dynamic Range Compressor

Professional-grade audio compression

Equalizer / 3-band EQ

Adjust bass, mid and treble with a 3-band equalizer

Bass Booster

Boost low frequencies with a bass shelf filter

Audio Compressor

Dynamic range compression for audio

Multiband Compressor splits a file into low, mid and high bands and compresses each one separately, so a boomy bass can be controlled without dulling the top. The crossover is mathematically complementary, so the bands sum back to the input exactly.

What is Multiband Compressor?

Drop a file, choose where the bands divide and set a shared threshold and ratio, then read the report. The footer names the two crossover frequencies and gives the average level change per channel, so you can see how much each pass moved.

What the panel gives you:

A low to mid crossover from 80 to 800 hertz in steps of 10, defaulting to 250.
A mid to high crossover from 1000 to 8000 hertz in steps of 100, defaulting to 2500.
A threshold from minus 48 to minus 6 dBFS in single decibel steps, applied to all three bands.
A ratio from 1 to 10 in half steps, defaulting to 3, again shared across the bands.
A footer naming both crossover frequencies and reporting the average level change per channel.

The signal is divided once, each band is compressed in place with the shared threshold and a 3 decibel knee, and the three are summed back together. The crossover is designed to be complementary, which means that with the ratio at 1 to 1, where no compression happens at all, the sum of the three bands reproduces the input exactly. That property is what makes the tool trustworthy: the reconstruction of the three bands is exact at a ratio of unity, so any change in the sound comes from the compression rather than from the filtering. Each band's gain moves only when that band's own level demands it, which is the whole point of the approach. A bass that booms while the vocal is steady gets pulled down only in the low band, and the vocal is untouched. Fixed attack and release times of 5 and 120 milliseconds keep the bands from fighting one another, and no make-up gain is applied by default, so the report's level change reflects the compression honestly rather than the compensation. Only two channels are accepted.

What it does not give you:

The threshold and ratio are shared, so a per band threshold is not available and quiet bands are compressed by the same rule as loud ones.
There is no make-up gain, so a heavily compressed result is simply quieter and has to be raised afterwards.
Only three bands exist, and the crossovers are moved rather than added, so this is not a full band-splitting chain.
Attack and release are fixed and not exposed, so the response time cannot be tuned to the material.
Gain reduction is not metered per band, so the only feedback is the average level change in the footer.
It cannot correct a tonal imbalance that is static; that is a job for the equaliser rather than for a compressor.

Use it when one region of the spectrum is the problem: a low end that moves too much, a midrange that gets shouty, or a top end that spikes. Set the crossovers around the region in question rather than at arbitrary round numbers, bring the ratio up from unity until the movement settles, and check that the result still sounds like the original performance rather than a compressed version of it. If the whole file needs control rather than one band, the single band compressor is the simpler tool.

How to use Multiband Compressor

Drop an audio file onto the panel; the tool accepts up to two channels.
Set the low to mid and mid to high crossovers around the region you want to control.
Set the threshold and ratio, starting from the defaults and raising the ratio until the movement settles.
Read the reported level change per channel, then download the multiband processed WAV.

When to use Multiband Compressor vs related tools

Multiband Compressor is the tool for a problem that lives in one part of the spectrum, which makes it the first choice for a boomy low end or a spiky top. Dynamic Range Compressor is the single band alternative when the whole file needs controlling, and Equalizer is the right tool for a tonal imbalance that never changes. When the specific concern is low frequency weight rather than low frequency movement, Bass Booster shapes it with a shelf instead.

Privacy & Security

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