Product description

ABLM is a gain control which enables level matched and sample accurate AB comparison of FX chains.

We at TBProAudio found us very often in mixing or mastering situations where we need to quickly identify the contribution of a certain plugin (FX) or even a complex FX chain to the sound.

Most DAWs can easily enable/disable (AB) single plug-in or even whole FX chains, but in most case there is an audible loudness difference between both cases. In order to compare the impact of a plugin chain objectively the loudness of the incoming signal should match with the loudness of outgoing signal.

Comparing the plugin effect at equal loudness levels avoids the "louder is better" - pitfall.

Mode & Link Channel

Sets the mode of the plugin, either Sender or Receiver and the link channel for the communication. Sender is placed before the plugin(s) which should be AB level matched, Receiver is inserted after. Use the "L"-button (auto) to quickly set next highest (free) sender/receiver channel. In addition ABLM makes suggestions for channel auto link, which may work depending on DAW/plug-in type.

Latency Compensation

Some plug-in add latency to the plugin chain. For a sample-exact AB loudness comparison audio streams need to be synchronized. This can be done automatically (just press PDC button and wait 1-2 seconds) or manually by entering the latency value (in samples).

Pre-FX Loudness

This meter shows the current and maximum loudness of the audio stream just before the plugin(s). Many plug-in work best at a certain loudness level (e.g. -18 dBFS)

Post-FX Gain

This meter shows the loudness difference of pre and post-FX signal. The match button lets you set the additional post-FX gain (match mode "manual") based on current loudness difference. Match mode "Auto" does this automatically. 

Match Modes

AB-LM lets you match the loudness either manually, or automatically. The match gain is added after FX chain. If "inverse" is enabled match gain is added before FX chain. The mode "Gain Stage" works differently: The additional FX drive gain is just removed from the audio stream right after the FX chain for "pure" gain staging purposes.

Snapshot Slots

ABLM provides 4 snapshot slots to store and recall settings for FX drive and Post-FX gain. So you can test your plugin chain with different gain levels, all loudness matched.

FX Drive

This parameter adjusts the additional pre-FX gain.

AB Switch

This button lets you seamless switch between pre and pre-FX audio signal.

Pre-FX Gain

This meter shows how close the loudness of the incoming signal is matched with a certain reference level. Many engineers work with loudness calibrated audio systems.


  • simple GUI
  • match pre and post-FX loudness
  • match pre-FX loudness with reference level
  • 3 loudness match modes: manual, auto and gain stage
  • FX chain drive
  • over protection
  • up to 256 sender/receiver pairs including auto channel select
  • automatic latency measurement/compensation
  • 6 measurement modes: RMS Sum, RMS Avg, EBU R 128 SL, EBU R 128 ML, VU, Max Peak
  • adjustable RMS measurement window
  • bypass ABLM
  • 4 snapshot slots
  • very CPU friendly
  • free GUI scaling
  • product needs to be activated with license key
  • free upgrade for existing AB_LM customers
  • demo version available

How to use


  • Version: 2.2.5
  • Last update: 21.02.2024
  • PDF manual: Download
  • Changelog: View

Buy now

€ 49.00
﹡VAT may apply based on your location.

Important notes:

Before downloading and installing please check the system requirements!

Demo version versus Registered version:
In demo mode (without registering) the plugin mutes audio every 90 seconds for a short period. This could be circumvented by clicking on the "TBProAudio" logo within 90 seconds.

After installation product is in demo mode and needs to be activated. Please follow the steps described in the manual or here.

Before any purchase please test the product, read and accept the terms listed here.


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Customer feedback

Looked into loudness matching plugins today and looked into this one because it was a better value than some of the others out there. WOW. A lot of the wow comes from the concept of loudness matching, but the plugin did all the work, and was pretty easy to use

-- Obe1 (gearslutz.com)

An amazing loudness and latency matching tool with some extremely useful features at a very fair price. 

-- Sound-Guy