ZL Splitter

Name: ZL Splitter
Author: ZL Audio

by ZL Audio · Utility · Signal splitter

Not rated yet

ZL Splitter is a free, open-source utility that splits audio into left/right, mid/side, low/high, transient/steady or peak/steady parts.

Each part goes to its own output, so you can process them separately in the DAW.

Best for: Drums, Mix Bus, Sound Design, Vocals. Genres: all genres.

Keywords: mid/side, free, open source, bus processing, drums, utility, FFT-based, multi-band, parallel processing, built-in analyzer, bass, corrective, creative, full mix, mix bus, mixing, percussion, simple, smooth, sound design, vocals.

What it does

ZL Splitter is a free, open-source tool from ZL Audio that splits a signal into two complementary parts, so each can go through its own effects chain before the two are recombined. The developer calls it "a multifunctional audio splitter plugin".

Left/Right and Mid/Side: sends the left and right channels, or the mid and side components, to separate outputs, each with a mix control.
Low/High: a band split with an adjustable cutoff and 12, 24 or 48 dB/oct slopes.
Filter structure: SVF (which alters phase) or FIR (zero-phase, with latency that depends on sample rate and slope).
Transient/Steady: an FFT-based split with strength, balance, hold and spectrum smoothness controls (0 to 100).
Peak/Steady: a compressor-style split with attack, balance, hold and smooth controls.
Routing: two outputs, a swap button to exchange them and a bypass switch; all parameters can be automated.
Display and setup: FFT and magnitude analyzers, plus UI options for colours, slider sensitivity, knob style and refresh rate, with settings import and export.

The current version is 0.3.0. It is free and open source under AGPLv3.

Source: ZL Audio product page

When to use it

ZL Splitter is the pick when you want to process parts of a sound separately, not measure it. Unlike Insight 2 or SPAN, it is a routing tool rather than a meter, though it has its own analyzers for checking the split. Compared with Voxengo MSED, which handles mid/side encoding, it adds band, transient and peak splits in the same plugin. Its Transient/Steady mode is the standout, since it sends the attack and the sustain of a sound to different effects, which a plain crossover can't do. It is most useful in DAWs that lack a native splitter, and it is free.

Best for: parallel and split processing: transients versus sustain on drums, lows versus highs on a bass or bus, and mid/side treatment.
Genres: any.
Look elsewhere if: you only need metering (Insight 2 or SPAN), or your DAW already has a band or mid/side splitter you prefer.
Tip: in Transient/Steady mode, add reverb or saturation only to the steady part to tame harsh percussion while the attack stays intact.

What producers say

The little coverage it has is positive, with praise for the range of split modes.

Bedroom Producers Blog called it "a nice pick" for creative routing, parallel processing and mid/side tricks, singling out Transient/Steady for taming harsh percussion.
KVR users rate it 5 out of 5 from 1 review, which praised the intuitive design and the multiple outputs, asking only for small UI refinements.

Where to buy

ZL Audio: Free

Tutorials and reviews

Similar plugins

SpectrumAnalyzer by SIR Audio Tools · Spectrum analyzer · $39
MultiFreqs by HoRNet · Multitrack spectrum analyzer · $17.02
MStereoScope by MeldaProduction · Stereo field analyzer · Free
UNMIX::DRUMS by Zynaptiq · Drum level de-mixer · $127
SPAN by Voxengo · Spectrum analyzer · Free
Plugindoctor by DDMF · Plugin analyzer · $49
Visualizer by NUGEN Audio · Audio analysis suite · $199
MRatioMB by MeldaProduction · Multiband main/side-chain crossfader · Free
schOPE by Stillwell Audio · Multi-signal analyzer · $39
Freqs by HoRNet · Spectrum analyzer · Free

All metering & utility