Video tutorial: x42-dpl: an excellent and easy limiter

Here’s my new video about x42-dpl:

Thanks to @rgareus for his help on making sure all the information is accurate!
(and for creating this excellent plug-in!)


Thanks for pitching the plugin!

It never occurred to me to use it on kick-drum sample :slight_smile:

The plugin is intended for the master-bus, as it is very audibly transparent on a overall mix, and true-peak limiting to -1 dBTP is required for various streaming services (youtube for example).

Testing limiters on a kick with a sharp onset is interesting; both on a musical level, as well as on a technical one:

As for your comment around 2:58, and 6:56 the is no high-freq content is because there is an internal short hold (low pass filtered peak) and the limiter looks ahead to detect “future peaks”, so there is no amplitude modulation even for sharp onsets. Combined with a minimum release time of 1ms you cannot get amplitude modulation over 1kHz.

Different limiters may behave differently though… made me curious:

Is it just me or is there no card at 9:18 for limiter comparisons?

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You are right - there is no card at 9:18 - that’s the next video I’m making, and I’ll link back between the two.

I’ve already recorded all the footage, so what’s left is all the editing and post-production (which in my case often takes the longest).

looking forward already.

I know what you mean, one can easily spend a week on a 3 minute song.

This is quite normal, I’m surprised you haven’t encountered it before - have a look at any review / tutorial of a fairchild or similar limiter (renowned for its fast attack) also read up on the Fairchild 670 / 660 - for example: Vintage Rewind: Fairchild 660 and 670 | MusicTech

Quoting from the article, regarding The Beatles recordings “…then we put the sound through Fairchild 660 valve limiters and compressors. It became the sound of Revolver and Pepper. Drums had never been heard like that before.”

Almost all limiters have some kind of sonic character - to design good studio equipment (and plug-ins) you need to understand how they are used creatively in the real world, not just with a spectrum analyser.

@x42 This is my newer favorite plugin for limiters. IMO simple is better, and as unfa said it gets the job done quickly. Your x42 plugins seem to use a lot less CPU than other more complex plugins which is great for even non-high end computers. Thanks for your contributions.

Am I the only one perceiving an overtone here? :sweat_smile:

Not intentionally :slight_smile: x42 limiter is based on Fons Adriaensen’s zita-audiotools so I’m sure its technically very fine - my comment wasn’t directed at the x42 limiter specifically, but time spent understanding how real mix engineers use these tools, creatively, in their environment - is as important as the technical performance. And the article I referenced is a prime example.

On the other hand, sometimes nobody knows how a tool will be used until somebody does it, often for reasons that are hard to explain. The classic example would be the gated reverb via the talkback channel that became a critical part of 80’s era drum sounds (initially thanks to Phil Collins). Hugh Padgham discovered this by accident, and I think it’s likely that if anyone had told the device makers involved about this idea, they’d have designed something with quite different characteristics.

That’s exactly my point - and why there is no substitute for becoming familiar with how these things are used in a real creative setting

I got some people suggesting I shouldn’t be testing limiters on a single kickdrum, and I should use a full mix instead. I think the kickdrum is a very revealing sound (I’ve synthesize that one specifically to have a high transient and very low bass). I am not sure how I’d compare how a limiter does on a full mix, maybe I’ll have to try that probably.

It is certainly valid to try x42-dpl on a kick. That doesn’t mean it will be the best tool for that task!

To fatten up a kick drum, you’ll likely want some soft-clipping distortion, pre-emphasis on the signal and/or detector, and perhaps several “stages” of envelope detection using different time-constants. That’s not just “limiting” but rather a distortion-plus-compression-plus-eq effect.

Unfortunately the FOSS world doesn’t have many (any?) plugins with that kind of sound because although someone can know the general concepts, the actual implementation details can require intense experimentation over months, years or even decades of full-time work. I mean: I know ‘how’ to play piano but a professional pianist does it much better, because she has a lot more practice.

I can’t speak to the authenticity of overtone’s Fairchild clone but it’s likely more appropriate as a “kick-drum-effector” than x42-dpl is.

Harrison’s “Drum Character” is also a strong contender if you want to dramatically change the sound of your kick.

On the other hand if I am maximizing a mix I will often add DPL somewhere to catch the loudest bits (and show me the history graph). It’s the right tool for the job.

-Ben at Harrison

I oten use a few layers of saturation, compression and EQ to shape the sound my my (in most cases synthetic) drums - often I also use x42-dpl to cleanly limit the transients if clipping is too much, or not enough.

To really fatten up a kick of course, Pultec style EQs (with or without compression) are still the go-to in many studios. Because it has separate LF boost and attenuate controls you can ‘push and pull’ the LF EQ curve - push the bass with some boost at around 30 (or 60) Hz, then pull it down using the attenuate control. Rather than cancel out as you might expect, this causes a low-end boost and a slight mid-range dip tightening up the kick sound. Being a passive EQ followed by a transformer-coupled tube gain stage adds some saturation and natural tube ‘compression’ also.

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Ooh! That sounds interesting!

@mike: Agreed. “fattening up” implies a bass-boost which a limiter (probably) isn’t going to give you. That was probably not the best terminology choice on my part.

@unfa: yes that makes sense. Craft your sound with effects and then (if necessary) limit the transients with something like x42-dpl

Good stuff!

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I know what I want from a limiter for 99% off the floor analog recording with real instruments and what @unfa does with a limiter for his great EDM stuff could never be covered by a single plugin only… The sounds and desired attributes to attenuate and accentuate are vastly different…

I love the x42-dpl on individual tracks to keep the lid on cleanly but I want an FC-70 or Presswerk or even the Mixbus Tape emulation on that master bus. Same with the Harrison Drum character Plugins and Mike’s Pultec emulations… one may not work in all desired cases but having a choice is magical and I say vive le difference!

hah. I’d have thought the other way 'round.

Perhaps try x42 Compressor on the tracks instead of the limiter. That has a soft knee, dedicated attack control and aids with overall gain-staging due to auto-makeup gain. I love to use it on vocal tracks.

The motivation for the true-peak limiter is clearly to be the last stage on the master-bus, in order to meet various broadcast spec. It is rather rather “colorless”, so it won’t affect the sound of the mix.

I find lookahead-limiters less useful for cases where one would use a hard driven compressor like the Fairchild. As opposed to a digital peak limiter, analog gear cannot “look ahead” to prepare for future data and hence does introduce some coloration or other artifacts.

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This is definitely a “put 6 amateur recording enthusiasts in the same room and you’ll get 6 different answers” kind of thing I’m sure… I just do what my ears like… :man_shrugging: