How do I level-match an outboard chain?

Put one Trim before the chain and set it to Source. Put another on the chain's return and set it to Analyzer. Play the same passage and press Match. The gain is corrected before the chain, so your gear gets the balanced signal.

Can I do it with one instance?

On macOS, yes. Single mode sends to your converters and listens to the return. Ping keeps your DAW in time.

Will matching clip my converters?

Not with DA dBTP on, which is the default. Match keeps what it sends under that ceiling, based on the loudest audio heard so far.

Can it work in mid/side?

Yes. Switch the domain to M/S, and Mirror becomes a width control.

Yes. Make a free account, check out Trim for $0.00 and sign in from the plugin. No trial period.

Does it work in Pro Tools?

Not natively. There is no AAX version yet, but you can run the VST3 in a free host such as Modalics Plugin Buddy.

Free gain and chain-matching plugin Trim

Precise gain anywhere in your session, stereo balance you can see, and a one-click level match for your outboard chain.

A free gain plugin for Mac and Windows. It gives you fine gain in L/R or M/S, plus loudness, balance and correlation meters. Chain Match level-matches an analog outboard chain and keeps it under a true-peak ceiling.

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Controls

Gain

Gain knobsFine gain for each channel. Double-click to reset, or click the readout to type.
DomainWork on left and right, or on mid and side, which is the center and the width. Each keeps its own settings.
LinkStereo moves both knobs together. Mirror moves them opposite. Dual Mono frees them.
MonitorSolos one channel to both speakers. Turns off when a session loads.
BypassGlides both gains smoothly back to zero.
MeterTurns the meters on or off. Off, they use no CPU.
Chain MatchTurns matching on or off for this instance.

Chain Match

RoleSource goes before your outboard chain, Analyzer on its return.
BusPairs a Source with its Analyzer. Give each chain its own bus.
WindowHow long Match listens before it offers the first press. A steady chain can be ready sooner, and after a press it keeps listening and gets more precise.
ModeImage fixes only the difference between the two sides and leaves your level alone. Full also restores the level the chain gained or lost. Drive fixes the sides, then raises the level until the loudest peak reaches your ceiling.
WeightingPerceptual judges level across the frequency range the way hearing does, so a chain that tilts the tone or adds harmonics is matched by how loud it sounds. Flat matches plain average level, like an RMS meter.
DA dBTPThe highest true peak Match will send to your converters.
AD dBTPThe same limit on what comes back from the chain.
MasterReads true peak more exactly, so the ceilings are held closer, especially in M/S. Uses more CPU while the window is open.
MatchWrites the correction to the Source's gain knobs, in front of your gear, so the hardware and converters get a balanced signal instead of being patched up afterward.
ResetStarts the analysis over. Use it after changing the chain.

One instance or two

Single and DualDual uses a Trim on each side of the chain. Single does it all from one Trim, on macOS only.
OutputThe interface outputs that feed your chain.
InputThe interface inputs your chain comes back on.
PingMeasures the round trip so your DAW stays in time.

Metering

Short-term LUFSThe loudness of each channel.
L/R BalanceLeft against right loudness. In M/S it becomes M/S Balance.
CorrelationHow much left and right have in common.

Match results

Perceptual and FlatHow much each side needs to change, judged by ear and by plain level. The one Match will apply is lit.
True peakThe same comparison by peak level, for reference. Match never applies it.
ClipCounts clips going out and coming back since the last Reset.
DA / AD TPTrue peak at the send and the return, amber when over a ceiling.
ObserverHow close a press of Match would land, and how far apart the two sides are right now. OK means no press would get closer.
Result plotShows whether the chain changed the level, the tone, or added distortion.

Under the hood

It uses perceptually weighted matching across the frequency range, K-weighted loudness metering and 64-bit double-precision processing.

Specifications

Formats	AU, VST3 and standalone on macOS; VST3 and standalone on Windows
Hosts	Any DAW that loads AU or VST3, such as Logic Pro, Ableton Live, Cubase, Studio One, Reaper, FL Studio and Bitwig. No AAX yet. In Pro Tools, try the VST3 in a free host such as Modalics Plugin Buddy.
Range	Plus or minus 12 dB, in 0.001 dB steps
Domains	L/R or M/S, linked, mirrored or dual mono
Matching	Source and Analyzer pairs; Image, Full or Drive; Perceptual or Flat; true-peak ceilings
Requirements	See the support page
Price	Free

Questions

How do I level-match an outboard chain?
Put one Trim before the chain and set it to Source. Put another on the chain's return and set it to Analyzer. Play the same passage and press Match. The gain is corrected before the chain, so your gear gets the balanced signal.
Can I do it with one instance?
On macOS, yes. Single mode sends to your converters and listens to the return. Ping keeps your DAW in time.
Will matching clip my converters?
Not with DA dBTP on, which is the default. Match keeps what it sends under that ceiling, based on the loudest audio heard so far.
Can it work in mid/side?
Yes. Switch the domain to M/S, and Mirror becomes a width control.
Is it really free?
Yes. Make a free account, check out Trim for $0.00 and sign in from the plugin. No trial period.
Does it work in Pro Tools?
Not natively. There is no AAX version yet, but you can run the VST3 in a free host such as Modalics Plugin Buddy.
Guide: How to gain-match an outboard analog chain