29 Nov 2017

Stereo is obsolete. L-Acoustics L-ISA is here

By Julius Grafton.

At the L-Acoustics (inventors of V-Dosc) headquarters in France I heard something more wonderful, more startling, and more exciting than anything ever before.

It is called L-ISA, and it is a new way to mix, deliver and to hear audio.


What they have done is pull down the left and right (and left – centre – right) speaker system and replace them with a minimum of five systems, hung no more than 5m apart, across the top of the stage.

You still use subwoofers in the normal way, and the best deployment is as a centre hang behind the system speakers. Note I am using the term ‘speakers’, short for speaker system – because you don’t have to hang line arrays to use this. The speakers could be any L-Acoustics speaker, be it single point source, colinear source, such as Syva or a constant curvature array such as ARCS..

It doesn’t matter what model L-Acoustic speaker you use – you just design (in Soundvision, the L-Acoustics software package) your system so each of the speakers covers the area in front of it, at best the whole audience area.


A processor takes EVERY channel of your mix, post fader, and supplies the outputs to the speakers. To do this, you need a console system with MADI out. That processor has ironed out any comb filtering confusions caused by nearby speakers overlapping, because most speakers used this way WILL have to overlap in coverage.

Now the audio designer and sound engineer take over and get creative. On the user interface screen, which is called the L-ISA Controller, you bring your inputs on to the stage area of the graphic representation of the L-ISA system in the room.

Then you can MOVE (position) each channel around, left and right or up and down. As you do this, the sound moves. In the demo we heard an orchestra from the perspective of the conductor’s lectern. Suddenly we were almost in the middle, the strings over there, all elements spaced out as if we were just standing there.

With a band you’d spread the channels around, across and downstage. The result is deep and lush, and a by-product is that a mix seems less loud. You are no longer pouring everything into one speaker system, instead you’re spreading it around.

The concept of splitting vocals into one system and band mix into a second, adjacent system is not new. But this is very, very different to that.

With this, you can put a channel, or a group (like, maybe you’ve grouped a brass section) into one system, and a voice into another. More likely, as with almost all the demonstrations I heard in France, most parts would be spread across a few speakers, just with some parts centralized or loudest on one.

However you mix it, stereo is redundant. Every audience member in the listening zone gets multi-dimensional sound. L-Acoustics call it ‘immersive’, I hate that handle but it does jive with what is happening to your listening perceptions.

From an artist point of view this should be universally desirable since it better presents a performance. The words ‘lush’ and ‘natural’ spring forth, without my over-hyping this story.

OK so what happens outside the L-ISA listening zone? L-Acoustics say that, depending on the rigging capabilities and audience geometry, not every venue could be fully covered with the overlapping L-ISA speaker system. However the processor comes with a possible 96 inputs and 64 outputs, and of course they have sorted out a range of deployments.

You could have ‘the listening zone’ in front of the stage, then where the shorter line arrays cut off, set a delay ring that is traditional mono or stereo. The area on the sides of the stage could be covered by a conventional mono or out-fill.

You can also place effects speakers at the rear, and design some ambience or ancillary ‘some-things’ to mix back from them. One demo was an audio book, or a film without vision. It was mesmerizing. The sound scape artists will go nuts using this.

At the demo were some theatre sound guys. They were keen to know how L-ISA handles scenes and cross fades. It does. It can also ‘track’, an example would be to follow an actor across a set. Tracking is still in Beta test, the rest of L-ISA is shipping now.


What you see is what you hear. Here’s how you use L-ISA.

The GUI (user interface) tells the story. Build the room on Soundvision, their visualizer and audio planning software. If you already have that venue on file, then load the speaker system into L-ISA’s processor.

On screen, you now have, the speaker positions, and the stage. You then enter the input channels list, so that each is shown as a small blue circle. Drag and position each channel where you want it. Left, right, up, down and wide. Now you have a ‘Q’ control for each audio source, where ‘Q’ is the width. Do you want this one in just one of your speakers, or do you want it to go up to 90 degrees wide?

Store each setting, so that you can have snapshot recall or cross fades where the sound is moving, or repositioning, during or between a scene, cue, or song.

DiGiCo have an add on to their SD Series consoles for this too. Now you have all these extra possibilities on where to mix to. You’d probably use the processor GUI mostly, but having a console ‘go-to’ is neat. One more thing on this – the processor takes the console master outputs too, so when you turn the whole system down on the desk it all turns down.

The theatre guys were excited about phase cancellation from multiple microphones. They are always excited about this, and today they have several standard procedures for when two actors or singers move closer together. Option one is to mute judiciously, almost word for word. Option two is the dual A-B speaker system. This tends to cost a lot, since you have two of everything, side by side.

L-ISA fixes this for good, because you start off with 5 speaker systems, and all you have to do is send performer # 1 to a different speaker than performer # 2. The processor looks after the rest.


I think this will be very popular. The DJ doofheads will be all over it, at least the ones that are creative and don’t just have a stick with MP3 files will be. Theatre will love it. Concerts will love it. Even rich bastards with huge home theatre rooms will love it, thanks to the channel that L-Acoustics are setting up for them.

Musicians will join Blububbles, an artistic entity that will become a future recording/remixing company using the L-ISA format.

Potentially tours and EDM gigs will feature the L-ISA logo, kind of like how Dolby has done with films. Concert ticket buyers will preference or premium pay to be in ‘The Zone.’ (Note ‘The Zone’ is a CX handle, L-Acoustics may call it something else entirely).

L-Acoustics are different to most. It is owned by a guy who will only do things his own way, and that is Dr. Christian Heil, a physicist in the field of elementary particles. It means everything is done according to science.

When it started with V-DOSC in the late 1990’s, he reasoned that there was one way to set the system up, one way to cable it, and one way to amplify it. Any other way would degrade the system and in those early days, kill or maim the future of modern line source arrays.

The V-DOSC was such a paradigm shift that engineers had to relearn the design and setup workflow. In 1993, L-Acoustics had eight employees on its payroll and the system was only available for rent in the French market. The very progressive introduction in export markets was necessary to fully support the users in the education domain and as the system was exposed to the real world. For a long time, this prudent approach led to the perception that the system was not available for purchase..

Now that L-ISA is here, the company is taking a similar tack, closely accompanying the venues and events that rent or install the system in order to ensure that a period of education and training takes place. The system is currently installed in a theme park in France and an entertainment venue is Moscow. It’s also been used on several live events in Europe and a tour for French artist Renaud, as well as in experiential performances at Coachella and Panorama Festivals. Just this October, Odesza debuted L-ISA for a live performance at the Santa Barbara Bowl in California.

It will end up in touring productions and probably sooner rather than later. But for now, L-Acoustics is controlling what happens with L-ISA and playing a long game.

They will collaborate on design, installation, and a batch of training will happen before each system is deployed.

This is one of a series of articles on the Spatial Audio revolution, in the December edition of CX Magazine. Read the magazine and explore our free archive, at


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