TBProAudio releases AB_LM, a gain control which enables level matched and sample accurate A/B comparison of FX chains.




AB_LM offers following features:

• 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
• up to 256 sender/receiver pairs including auto channel set/link
• automatic latency measurement/compensation
• 4 measurement modes: RMS Sum, RMS Avg, EBU R128 SL, EBU R128 ML
• adjustable RMS measurement window
• bypass AB_LM
• 4 snapshot slots
• very CPU friendly
• large and easy to use GUI

System Requirements:

• Windows XP or newer
• Mac OS X 10.5 or newer
• Win: 32/64 Bit VST, 32/64 Bit VST3, 32 Bit RTAS, 32/64 Bit AAX
• OS X: 32/64 Bit VST, 32/64 Bit VST3, 32/64 Bit AU, 32 Bit RTAS, 32/64 Bit AAX
• Tested with: Cockos Reaper, Steinberg Cubase/Nuendo/Wavelab 6/7/8, FL Studio 12.x, PT10/12

Price: 49€ (excl. VAT)

This actually looks really awesome. I'd love to see a video demonstration of suggested usage! Either way, really cool idea.

Interesting. I'd like to try it, but the link to the pdf manual doesn't work. It's hard to understand how to use it without the manual. Can you please fix the link? Thanks

If I can make a request it'd be a "lite" version of this plugin with only the gain staging ability. The plugin above is way too complicated and hard to use (I never got it working at all properly.. frankly I think the layout and GUI is not at all intuitive. It's quite horrible).

What I want is a plugin that can split into two parts and seamlessly provide gain staging for whatever other plugins that I put in between.

Say if I put -12dB in the first instance the second instance would automatically adjust +12dB at the other end. Then all it needs is an "offset" so that I can run either the input or output a bit hotter or lower in volume (in case the plugins in the middle increase or decrease the signal level).

Frankly I'm surprised nobody has created such a thing properly yet. It could also include Mid/Side encoding and decoding. Would be a handy thing.

EDIT: Blue Cat Audio seems to have a free gain staging plugin with linking capabilities!

Link to manual is now fixed.

Thank you, video is under preparation, coming soon.

Well, this is exactly what AB_LM can do:

1) Insert 2 instances of AB_LM
2) put your plugin(s) in between
3) Choose "Auto Gain Stage" as match mode
4) Set "FX Drive" to -12 dB

=> AB_LM decreases gain by -12 dB before (sic) your plugin(s) and automatically increases gain by +12dB after your plugin(s).

5) If your plugin chain creates latency, just do latency measurement (PDC button)
6) Control input loudness of plugin(s) with Pre FX meter.

I just tried quickly. It seeems absolutely excellent.
Its direct competitor seems to be Ian Shepherd's Perception. I am not sure what the difference is between the two, but at first glance they seem to provide exactly the same functionality - but, as I said, there could be some differences that I don't know, because I don't have Perception. I would love to hear about the difference between the two from people who know better than me.
The price is very, VERY different though. 149 for Perception, 49 for AB_LM.
That's probably gonna be the key factor for me.
Gonna try it a little bit more though.

Thank you.

Bug Warning!
Nasty audio stutter and high volume clicks happening in Studio One 3 Win 10 64bit

Thank you, i will check this.

Hmm, no issues here. Which Studio One version?

Latest one

Hmm, 2 AB_LM instances, sender first, receiver last, both with link 1 (orange link symbols) and no plugin in between?

Does this work if you have the sender on one track the receiver on another?

That is often crucial in Cubase since you only get 6 insert slots + 2 post fader ones, and my mastering chain is always over two tracks rather than one.

I think this maybe a mixup with the demo limitation? After 90 secs there is a horrible stutter until you click AB LM to reset it. Unless that's a mistake, a silence would have been better. Almost fell off my chair!

This should not be, sorry. Its a bug, we will fix this.

This function not guaranteed, as sender needs to be before receiver in the audio stream. If you can make this sure, no prob.
We will also check.

I put sender and receiver on master with Pro Q 2 in between...both on channel 1 of course

im on the Mac 10.9.5 using Pro tools 11 and Im also gettting this weird stutter sound effect when i press the match button =[

Update to V1.0.1: Demo "Stutter" fix

I've tested it and I'm pleased to say it's working great.

The one feature i'm missing, but have maybe just overlooked, is how to get playback at the volume I want. My unmastered mixes will usually peak around -6db, and AB LM will as designed attenuate the final master to that, which is fine, but is there a way within the plugin I can change it so I will be able to AB at closer to 0db?

Great.

Well, AB_LM works only with RMS, no peak.
But you could use reference level matching to adjust overall loudness...

Can you give me a quick guide as to how that can be done in the plugin please?

You could set the ref level to 0 db and the window to 10ms.
Then after some seconds click the balance button on the left side.
This should push your audio close to 0 dB...

Thanks. I'll try that.

I just tried it, and is is not a direct competitor to Perception unfortunately.
The sender ander receiver plugin needs to be on the same track according to the manual.
In my setup I need to go out to my hardware chain and back in PT so this is not possible with AB_LM.

For plugin only chains it seems like a great tool.

It may say so in the manual but it's not true. I'm using it in Cubase and it works across tracks.

Yeah I tried it to, and did get audio trough, but It does not seem to work correctly this way?
At least it does not seem to play the correct A/B stream in my case.

Strange.

In my master template in Cubase I have the sender as insert 1 on one track routed to my master, with inserts on that track and the master, and the receiver as the last insert on the master, and it auto level matches as it should and allows me to A/B pre and post.