Freebie of the Month – Lagrange from Ursa DSP

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What if a delay VST and a granular synth VST had a love child?  Well, that offspring might be something like this month’s freebie plug-in, Lagrange.


by David Baer, Jan. 2017


Our Freebie of the Month this time is an effect that is almost guaranteed to be unlike anything you already have in your DAW system.  Think what would happen if you applied genetic engineering techniques to a delay by injecting the DNA of a granular synth.  The result would probably be something like Lagrange.  Do not pass this by thinking that the last thing you need is another delay, free or otherwise.  You do not have a delay like this – nothing even close.

Lagrange is currently available as PC VST only (32-bit VST 2, 64-bit VST 2, and 64-bit VST 3), but a Mac version is promised sometime in 2017.  You may download the plug-in here:

Lagrange was an entry in the latest KVR Developer Challenge, a competition in which developers of computer-music-related creations submit entries for free download and evaluation. Lagrange did not win, but to my mind, it easily could have.  It is that innovative and unique.

The UI seen to the right (click on image to view full size) is simple enough.  There is no manual, but the UI is the manual since information about the controls appears in the bottom panel when the mouse cursor is over the control.

There are five algorithms, all of which do things to audio that beg the use of adjectives like: ethereal, atmospheric, mesmerizing.  For some reason, only the final three of the five algorithm choices have help responses.  These are as follows:

Smooth Random: Random early reflections with tamed feedback.  Each delay grain has a delay of at least the Fixed Delay up to the combination of the Fixed and Variable Delay.  Left and right channels select new grains at alternate times.  Delays are affected by a subtle but dirty modulation.

Clean Random:  Random early reflections with clear echoes.  Each delay grain has a delay of at least the Fixed Delay up to the combination of the Fixed and Variable Delay.   Left and right channels select new grains at the same time.

Marching Random: Evolving random.  Similar to Smooth Random, however the grains inch forward by a random amount through the delay buffer.  Left and right channels select new grains at alternate times.  Delays are subtly modulated.

OK, so we’re all clear on how this thing works, right?  Actually, you simply need to play with Lagrange for a bit to understand what it does to audio.  Words alone are inadequate to convey what this plug-in does to sound.  Unfortunately, there are not any presets included to get one started in the right direction (I know … bad form to complain when something is free).  But a little experimentation will get you headed in the right direction.  You will be confidently creating your own presets in no time.

Most of the controls on the UI’s single panel are easily understood.  Grain Rate, Density, Feedback should not be too hard to grasp.  In the second row of controls are two limiter functions: Peak Limit dB and RMS Limit dB.  Given the ease with which Lagrange can have a runaway response due to pronounced feedback and density settings, these are your friend.  The peak limiter has a very short attack.  The more important RMS limiter has a longer attack and offers visual feedback in the form of a red band of illumination around the knob when limiting is occurring.

Finally, the Sidechain limiter in the bottom row of controls merits some explanation.  A very commonly employed technique is to duck the wet signal of a delay based upon the strength of the dry signal.  We don’t want the delay to clutter up the direct sound but want it to kick in when the direct sound gets out of the way.  In a lot of delays you need to either do this with external sends to gates, or you need to employ modulation courtesy of an envelope follower.  Lagrange very conveniently gives you an immediate and effortless means to set this up.

So there you have it.  This one is highly recommended and we encourage all to check it out.  And thank you, Ursa DSP, for generously making this freely available.

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