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Title: Understanding LCR/LR+M Mixing
Post by: Dave Heath on January 02, 2007, 07:49:56 am
Hi guys,

I have a question (see notes) about "LCR" and "LR and/or M" and how they work.
As my career as a live sound engineer picks up, I have started to be allowed to play with larger desks in larger venues and increasingly they are having these 3 faders for the master out.

Now at the moment I am only working in venues that just have a Left and Right speaker setup and so the C or M fader doesn't get used, but I can only imagine that these desks have this control for a reason and that one day I might need to know about it.

So my question is, would someone please be kind enough to explain how it works and when I would use it? (with main focus on FoH, but interested in Mons too)

Many thanks for all who have managed to read this far down and even great thanks in advance to all who reply.

Dave Heath


Examples of desks I have encountered LCR or LRM (enter newbie-big-head-mode)
A&H GL2800
Soundcraft MH4
Midas Verona

Note to the nice moderators:  If this is in the wrong section, I apologies, please move this thread to where it is best. (hopefully not the basement)

Note to the search police: I did have a search here and in google, but all I can find are posts/articles saying that LCR mixing exists and is possible with this or that desk.
Title: Re: Understanding LCR/LR+M Mixing
Post by: Mike {AB} Butler on January 02, 2007, 09:09:17 am
Dave,
I love systems with LCR, as it gives me the ability to separate stuff, such as instruments from vocals. My usual Modus Operandi is to put vocals in the Center, and place instruments in L/R (subs are still always Aux-fed).
My reason for this is simple. I have actually had cases in  using only a L/R configuration where vocals were just so-so.  Moving them to a center cluster - much better in terms of overall sound quality.
People can say line array all they want.. but for me the real bee's knee's is in a LCR system..
HTH,
Title: Re: Understanding LCR/LR+M Mixing
Post by: Eric Dodson on January 02, 2007, 10:10:05 am
Mike Butler is right on with this.
LCR rigs in theaters or on the road give you the ability to seperate the vocals and get more "acoustic imaging" on your stage.
What I find myself doing when I'm mixing a band on a LCR rig is not only putting vocals in the center cluster, but when someone is soloing like a guitar or keyboard part, I'll mix that in to get the same effect.
I always have a smile when I encounter a LCR rig. The proper use of one can really improve you mix to the audience.
Cheers.
Eric Dodson
Title: Re: Understanding LCR/LR+M Mixing
Post by: Carey Davies on January 02, 2007, 11:21:06 am
Dave Heath wrote on Tue, 02 January 2007 12:49

Now at the moment I am only working in venues that just have a Left and Right speaker setup and so the C or M fader doesn't get used, but I can only imagine that these desks have this control for a reason and that one day I might need to know about it.

So my question is, would someone please be kind enough to explain how it works and when I would use it? (with main focus on FoH, but interested in Mons too)


Hi Dave, good question.

LCR rigs can give you much better coverage and intelligibility, but only if properly installed and set up. This requires three speaker setups, one either side of the stage as you would find with the typical LR system, and one in the centre, usually hung to get it out of view of the action on stage, and to ensure enough throw to the rear of the room.

The success of these systems relies on all speakers being heard equally by all listeners. The centre (C) speaker is as important as the sides and not simply a fill for the front rows as is the case in many LR equipped venues. This can present the installer with several challenges, and the venue with a meaty budget requirement. For this reason it is mostly the top end venues and large scale touring rigs that offer LCR.

Many consoles provide the capability to run different types of multi-speaker rigs including LCR, independently driven sub, or added fills. The GL2800 provides 3 master faders, L, R and M. Although you can't pan between L C and R, you could assign your prime sources such as vocals and kick to the C speakers by routing to M, and the other instruments to LR. Even if you do not have an LCR system you could use the M output to feed the subs, for example kick and bass, to clean up the mix by preventing unwanted low frequency pickup from the other mics getting to the subs. In monitor mixing, consoles like the 2800 can reconfigure the M master as the engineer's wedge speaker controller, leaving the LR masters available for side fills.

Hope that makes sense. Let us know if you weant more chat on this.
All the best,
Carey
Title: Re: Understanding LCR/LR+M Mixing
Post by: Scott Van Den Elzen on January 02, 2007, 11:28:42 am
This topic is intriguing...  I have a relatively small rig and cover relatively small rooms.  Thus, I have never been in a situation where LCR is useful (or really possible.)  

Can you fill in some blanks for me?  Does the center cluster cover the same area as LR?  I'm assuming the center cluster has to cover the whole room if vocals will only be present in the center mix.  So, where frequency overlap occurs between vox and instruments, how is comb filtering avoided?
Title: Re: Understanding LCR/LR+M Mixing
Post by: Jeremy Johnston on January 02, 2007, 11:28:53 am
Hi dave,

As long as each loudspeaker (array, cluster etc) can cover the entire room, then separating things across the sources will allow a cleaner mix and better "Stereo".  As I understand it, the first true stereo systems developed used three channels; Left, Center and Right.  They discovered that a "sweet spot" existed between the left and right loudspeakers that created a "phantom image" so that the center loudspeaker wasn't needed and voila you have what we call "stereo" today.  But that's only in one seating position.  If you have a properly designed LCR system to mix on you can create a stereo image for a much larger percentage of the audience.

Then there's the whole issue of speech intelligibility. I know this is mostly a music performance audio forum, but some of us mix in churches or at talking head events and the true facts are that speech intelligibility is important.  The better people can understand what's being communicated the more likely they are to respond to whatever is being said.  A single center source that simply amplifies the speech is less distracting to a listener. Multiple sources that conflict with one another cause that "whooshing, phasing" sound when you move your head or make you listen to a talker from one side of the room while seeing him (or her) on the other side of the room.

The center system can allow excellent speech intelligibility and localization while the stereo system offers good stereo imaging for music. A properly designed LCR or LR+M system can allow both excellent music AND excellent speech in those events where you need both.

Jeremy J
Title: Re: Understanding LCR/LR+M Mixing
Post by: Yngve Hoeyland on January 02, 2007, 11:53:13 am
This is interesting. I've done a few LCR productions but mainly in theatres where the dialogue usually goes center for intelligibility  reasons.

I'm just thinking of the practical side of things here - if say for  a music-only production you want to fly a center cluster but your front truss is fairly low so you can't really put a whole cluster there or the people on stage will be looking straight into the back of your C fill? Is it worth just putting a single box or two up there? Any experiences on this? I'm specifically thinking of smaller "semi-linearray" systems such as the JBL VRX etc. which have quite wide dispersion angles (120)?

Anyone tried this out for -1000 seaters?
Title: Re: Understanding LCR/LR+M Mixing
Post by: Brad Weber on January 02, 2007, 12:11:10 pm
Since no one else has apparently addressed it, you noted the two variations on this.  In L/C/R there are three output buses and the signal routing to these is via panning.  As you pan a signal from left to center to right it literally pans across the three outputs.  At center the signal goes just to the center output with no left or right output, full left and only left output and between left and center splits the signal between the left and center outputs.

In L/R + Mono you still have thee output buses but whether something is L/R or mono is a result of an output bus assignment rather than a pan.  You can assign a signal to either or both outputs.  If a signal is assigned L/R and panned center, it comes equally from both left and right and not from the mono output.  A mono send is just that and pan does not affect it.

L/R + Mono is often used to have a mono center speech speaker/cluster/array and then split left and right stereo speakers/clusters/arrays.  Using a single point for the speech reinforcement can reduce the timing and localization issues that would result if the same signal is reproduced from multiple locations.  At the same time, the L/R arrangement allows for greater stereo separation for stereo playback.  Since the center speaker/cluster/array is typically used primarily for speech sources, the speaker array components used are often selected based on voice reproduction (maybe a 12" woofer and usually no sub) while the left and right speaker array components are typically selected based more on music reproduction.

L/C/R also uses three speakers/clusters/arrays and allows for greater flexibility in imaging.  However, in many system panning a single channel source across multiple speakers can result in combfiltering and other anomalies, so these systems have to be designed with this in mind.

In both approaches, for the system to work properly the left, center and right speakers/clusters/arrays must each properly cover the listener area, as others have already noted.

As far as vox and music causing combfiltering, you get summation and cancellation at different frequencies any time you mix two signals.  However, combfiltering in speaker systems is normally caused by the same signal coming from multiple sources such that those signals arrive out of phase with one another.  This issue affects the original signal component rather than how that signal combines with different signals.

Title: Re: Understanding LCR/LR+M Mixing
Post by: Mike {AB} Butler on January 02, 2007, 03:23:13 pm
As Brad points out below, comb filtering is most common when the SAME source material appears from different speakers. Different sources from different speakers don't negate each other as badly.. hence, the intelligibiity advantage.
Regards,
Title: Re: Understanding LCR/LR+M Mixing
Post by: Mike {AB} Butler on January 02, 2007, 03:34:59 pm
Carey Davies wrote on Tue, 02 January 2007 11:21



LCR rigs can give you much better coverage and intelligibility, but only if properly installed and set up. This requires three speaker setups, one either side of the stage as you would find with the typical LR system, and one in the centre, usually hung to get it out of view of the action on stage, and to ensure enough throw to the rear of the room.

The success of these systems relies on all speakers being heard equally by all listeners. The centre (C) speaker is as important as the sides and not simply a fill for the front rows as is the case in many LR equipped venues. This can present the installer with several challenges, and the venue with a meaty budget requirement. For this reason it is mostly the top end venues and large scale touring rigs that offer LCR.

Many consoles provide the capability to run different types of multi-speaker rigs including LCR, independently driven sub, or added fills. The GL2800 provides 3 master faders, L, R and M. Although you can't pan between L C and R, you could assign your prime sources such as vocals and kick to the C speakers by routing to M, and the other instruments to LR. Even if you do not have an LCR system you could use the M output to feed the subs, for example kick and bass, to clean up the mix by preventing unwanted low frequency pickup from the other mics getting to the subs. In monitor mixing, consoles like the 2800 can reconfigure the M master as the engineer's wedge speaker controller, leaving the LR masters available for side fills.


Carey,
I think you are correct this would be costly to do as a rental system. But, as an install, I have installed 3 low budget LCR (or LMR) systems - provided the Center gets used for vocals, and the lows only get reproduced through subs. Typically smaller, less expensive speakers are needed for Vox reproduction.. as long as they have the SPL to keep up.. which is NOT true of the instrumental parts, in nearly all cases. As far as the console.. any console which has a switch to disconnect a subgroup from the mains.. AND a dedicated subgroup output for it will suffice. The only drawback is now that you either have to use mute groups to mute unused vox.. or have to pull unused vox inputs down.
Anyway, I have done smaller auditoriums for this.. and you would be surprised how much better a smaller, overly live room can benefit from such an implementation.
Regards,
Title: Re: Understanding LCR/LR+M Mixing
Post by: Patrick Tracy on January 02, 2007, 03:42:34 pm
Jeremy Johnston wrote on Tue, 02 January 2007 09:28

As I understand it, the first true stereo systems developed used three channels; Left, Center and Right.


Two- and three-channel stereo were both proposed quite early.
Jeremy Johnston wrote on Tue, 02 January 2007 09:28


They discovered that a "sweet spot" existed between the left and right loudspeakers that created a "phantom image" so that the center loudspeaker wasn't needed and voila you have what we call "stereo" today.

I think this was more of an excuse for using the simpler two-channel method and avoiding the expense of an extra signal path. Plus, audiophiles were using one speaker cabinet and convincing then to use three seemed like too much of a challenge.
Title: Re: Understanding LCR/LR+M Mixing
Post by: Dave Dermont on January 02, 2007, 07:13:41 pm
LCR is often used in House-of-Worship systems for speech in much the same way it's used in theatre to anchor dialog.

Yes, proper system installation is very important.

You can use smaller consoles that have a 'Center' or 'Mono' bus, as long as there is a way to assign to that bus, and only that bus. Some consoles only derive the mono signal by summing L&R.

Also, different consoles built with LCR in mind handle it differently. Midas calls is "SIS" for "Spatial Image System", where the Pan goes from left, to center, to right. In this system, things panned to the center are ONLY in the center. They don't go to Left or Right. It does this when 'SIS' is engaged. When "SIS" is not engaged, it pans normally.

The Soundcraft MH works like this too, but they just call it "LCR". I guess they did not feel the need to make up a new term to confuse people.

The Allen & Heath ML series has a system they call "LCR PLUS". This system has an additional "blend" control that "pans" signals from L&R to Center. (or in A&H's case, Centre) It looks like the photo below.

index.php/fa/7188/0/

Inter-M has a console they call Kensington that uses this type of system. I was involved with Inter-M and the Kensington before they moved US operations from PA to CA. This is why I am so well schooled in LCR console offerings.
Title: Re: Understanding LCR/LR+M Mixing
Post by: Mats Fagerkull on January 02, 2007, 11:41:15 pm
Dave Dermont wrote on Wed, 03 January 2007 01:13


Also, different consoles built with LCR in mind handle it differently. Midas calls is "SIS" for "Spatial Image System", where the Pan goes from left, to center, to right. In this system, things panned to the center are ONLY in the center. They don't go to Left or Right. It does this when 'SIS' is engaged. When "SIS" is not engaged, it pans normally.



Just a quick question, is the "SIS" acronym really a product of MIDAS origin ? I know DDA was using this and thought MIDAS (as a sibling) might have adopted it when that brand was discontinued. Am I totally wrong here or what?

/mats
Title: Re: Understanding LCR/LR+M Mixing
Post by: Brad Weber on January 03, 2007, 11:58:39 am
It sounds a lot like how the DDA CS3 and CS8 consoles worked (the QII as well if I remeber correctly), assigning each channel and group as either L/C/R or L/R.
Title: Re: Understanding LCR/LR+M Mixing
Post by: Tom Young on January 04, 2007, 10:41:35 am
I know we have discussed the basic requirements for LCR here on LAB befor. Try some other searches.

Jim Brown has at least one reference paper for proper LCR ldspkr system design and I think he also defines how the electrical design of the console must be, as well.

see: www.audiosystemsgroup.com

Crest consoles and now APB Dynasonics not only have LCR done correctly.... they also have several other innovative design features.  Just FYI.
Title: Re: Understanding LCR/LR+M Mixing
Post by: Briand Parenteau on January 12, 2007, 10:19:06 am
I'd like to add another variable to this discussion.  It pertains to the differentioan on what is more specifically known as a LCR Cross Matrix system.  I have added a couple of links to AES White Papers for this, so that everyone can read and understand the complexities of this design.  The reason I'd like to bring this up, is that the design is a bit different and this thread has really not addressed it.  Any installers out there may be more aware of this.  It is most often found in churches.

I have encountered a couple of these systems, they are a different animal of sorts.  I'd like to hear from people that have used these and what their respective experiences were.  Note, as written in the tech papers, that if you do not set up your bus assignments specifically as detailed, you will end up with a mess.  Lots of time smearing and phase issues.  I have a number of issues with these designs, but I'll save that for a later response.

Please follow the links below to read up on LCR Cross Matrix design and mixing principles

http://www.sound-technology.com/Research2/Breshears%20multic hannel%20design%20for%20AES-98.pdf

http://www.sound-technology.com/Research2/Multichannel%20Mix ing%20AES01.pdf

B. Parenteau
Showmix
Title: Breshears LCR Cross Matrix multichannel mixing
Post by: Michael 'Bink' Knowles on January 12, 2007, 11:37:44 am
Great swerve topic! I think if I were to encounter a system like this I'd make sure to plan my miking carefully and use the L+R elements of the speaker system to best effect by doing things such as hard panning two different mics on the same source. For instance, I'd be interested in trying out a mic on guitar amp front sent to Left and another one polarity flipped on guitar amp back sent to Right. Or the same thing with top and bottom snare mics. Or Don Henley's dual tom miking system where he has a Beta98 and an MD421 on each tom. Of course piano would provide a wealth of fun tricks...

Not many desks can deal with this kind of matrixing with delay. Have you seen it accomplished with an external matrix?

-Bink
Title: Re: Breshears LCR Cross Matrix multichannel mixing
Post by: Michael 'Bink' Knowles on January 12, 2007, 11:39:24 am
BTW, Briand, this subject is totally LAB Classic.  Cool

-Bink
Title: Re: Breshears LCR Cross Matrix multichannel mixing
Post by: Briand Parenteau on January 12, 2007, 12:27:31 pm
Thanks Bink,

This topic opens up a pretty controversial discussion in my opinion.  Maybe it's just because I have a beef with the design!  Anyway, the way that I have seen it implemented is ONLY with external matricing via multiple audio processors.  Essentially, every box needs discrete processing and amplification. The install contractor takes L/C/R busses off the desk than does all the matricing at the head end before the amps with DSP.

There are a number of complications in running this sort of rig and being able to reproduce consistent results, especially in an install when you have various sound tech's operating the desk.  A simple stereo source like a CD or VTR will not sound right unless you use a Dolby processor! FX returns will be impacted by this as well.  I have operated one of these systems and the results were less than impressive, in my experience.    I am keeping an open mind though and going back for another go at it this weekend.

I am going to paste some of my thoughts below, that I presented to an installer (in blue) who has done a lot of these systems. These thoughts were location specific, my reflections on a system that I utilized installed by his company.  He never formally responded.  Also please see the note (in red) about CD playback. This comes from the engineer who submitted the AES papers.

CD PLAYBACK-
Due to the speaker locations in many of these systems, the stereo playback of a CD through theLeft and Right speakers can cause some problems, particularly at the sides of the room.Differences in arrival times of the direct sound for percussive instruments when sourced through both speakers creates a flanging or phasing effect that can be quite annoying. Instead of just playing back a CD through the Left and Right channels, it is best to use a Dolby Pro Logic processor that will take a stereo input and create left, center and right channels. This created center channel signal provides a discrete mono source for all of the instruments andvocals that would otherwise be reproduced through the left and right channels.


I have been studying up on the LCR cross matrix theory and implementation by way of a number of AES White Papers.  Although this is a pretty cool approach and it can work, I think there are a couple of big issues with reproducing live bands in a venue where there are going to be variable changes.   As noted(see white paper excerpts)to really get the stereo imaging to work you need to double mic any source that you desire to be reproduced in the stereo field.  Also, the buss assignment is critical in order for this system to work as designed.

There has to be strict uniformity in how the band is mic'd up and bussed, in a way that does not lend itself to changes.  This is rigid and okay for an environment that has little change, but as soon as you introduce change in the form of different instrumentation, visiting bands, varying sound engineers, etc...  the design becomes extremely susceptible to failing and producing a multi-source, multi-arrival nightmare akin to what I experienced when first listening to the system.  Even at it's best the amount of audio sources (loudspeakers) that exist and their respective locations create an environment where there is a lack of uniformity in the listening area.  The shear number of sources, even with the proper DSP, are still going to lend to a generous amount of comb filtering and lobing, especially in the near field extremes prior to reaching the delay zones.  

B. Parenteau
Showmix

Title: Re: Understanding LCR/LR+M Mixing
Post by: Tony "T" Tissot on January 12, 2007, 01:16:22 pm
No arguments with the above responses -

If I were to put this in very simple language:

- For speaking / singing parts in the theater (particularly musical theater)   makes it seem less like the speaking / singing parts are amplified. (Precedence effect - slight delay for height). As in "we all know it's amplified" - but we want to preserve the illusion that it is not amplified. Center cluster achieves this.

- A "true" C channel - The signal to the "C" has to be separately derived. I used the group matrix function to get that or group assignments. The vocal mics do not deliver any signal to the L and R channels and vice versa.

- C is a completely discrete channel with full coverage. If you have delay or balcony fills it's also fully discrete from the L and R.

- Orchestra, EFX typically just to LR.
Title: Re: Breshears LCR Cross Matrix multichannel mixing
Post by: Michael 'Bink' Knowles on January 12, 2007, 01:58:22 pm
Good point about CD playback. A sound system like LCR Cross Matrix is something nobody in the record industry is thinking about so of course they aren't mixing with 3 channels in mind. I don't have a problem with taking all normal stereo playback channels and dumping them to a stereo group that feeds a Dolby (or whoever) LCR separator which then feeds the matrix with three channels. It won't be very pretty but it will get by.

Another concern at venues with LCR systems is how to route sources to make a good stereo recording. Nothing's easy when you have to do both tasks at the same time.

-Bink
Title: Re: Understanding LCR/LR+M Mixing
Post by: Brad Weber on January 12, 2007, 03:29:21 pm
Valuable discussion, but also highlights why I intentionally avoided bringing up cross matrix systems.

Setup and operation of LCR cross matrix systems is critical, it's not something for just anybody to try.  I believe that Ivan has worked with a number of these systems, maybe he'll add his comments.

I have used a hybrid approach with a traditional L/C/R mains and cross matrixed fills, simply with the idea that the fills better represent the left, center and right signal content levels and timing relative to the natural sound at the fill location from the mains.
Title: Re: Understanding LCR/LR+M Mixing
Post by: Ivan Beaver on January 12, 2007, 04:37:16 pm
Yes I have quite a few.  First the room has to be "right" in order for it to work well.  The loudspeaker system has to be properly designed for such a system (different than a regular mono or stereo system) and you have to have enough seperate amps and DSP channels for it to work properly.

I have heard it used to some amazing results that made me go WOW-That is great.  

And I have also seen people totally violate the rules of routing and make mud out of it.

Don't blame the tool, blame the operator.

It is quite a bit of work to get it setup (aligned) properly, but when done well with a good room and a good operator and good source material, the results can be quite good.  Other times a mono system would be much better.

Sometimes having great flexability just allows people to shoot themselves in the foot.
Title: Re: Breshears LCR Cross Matrix multichannel mixing
Post by: Ivan Beaver on January 12, 2007, 04:55:12 pm
With a proper cross matrixed LCR system, the areas that the system fails is on the sides (mostly extreme) and you have the same signal sent to both the left and right channels.  Depending on the size of the room, this can get to be quite bad.

You will notice it mostly on prerecorded material that has stuff panned to the center.  You will get a delay that can be quite bad.  

With single sources this can be greatly reduced (eliminated) by panning the particular input into ONLY one of the 3 channels.  In a properly setup system everybody will still hear it just fine.

On the extreme sides the timing of the different input signals can sometimes get odd.  This is really only noticable on impulsive instruments such as drums.  Ie two drums played at the same time and panned to opposite sides will arrive to the extreme side listeners at different times.  Part of the "art" of aligning a system such as this is to reduce this problem.

I approach the alignment purely from a "scientific" standpoint first.  Then I go for the artistic side to try and get the system to "blend" properly.  I usually end up adjusting quite a few previous settings.

The real problem is getting it as right as possible to as many seats as possible, without causing to much damage to other seats.

Every time I do one, I learn something new, mostly problems that I have overlooked before.  The more I do this, the harder it gets, because I get pickier each time about what I expect, and realizing what I can and can't do.

It is real easy to get one seat right, but trying to get all of them "right" at the same time becomes a real challenge.
Title: Re: Breshears LCR Cross Matrix multichannel mixing
Post by: Briand Parenteau on January 15, 2007, 11:13:58 pm
Ivan,

Sounds like you have a good amount of experience with these systems.  I am trying to keep an open mind with this approach, but my experience has not been positive.  I am adhearing to all of the rules when assigning inputs, and I understand well the principles behind the design and proper utilization of one of these rigs. But I still am not happy with the results.  I do believe that the installer's calibration and set-up is perhaps flawed and contributing to my ill perceptions.

The main thing that bugs me is if you adhere to the bussing principles you are essentially setting up 3 discrete mixes.  For the sake of keeping this simpler we can call it 2 discrete mixes, a ctr mix & a L/R mix.  As instructed in the AES papers, ( http://www.sound-technology.com/Research2/Multichannel%20Mix ing%20AES01.pdf), nothing is to be bussed to multiple mixes, everything is discretely bussed to either ctr, L or R.  With Kick, snare, percusiive instruments, lead vocals going to the ctr mix and all other instruments discretely going to L or R (everything must be double mic'd and discretley assigned to L or R), you now have 2 programs that are completely different in their respective content.  

So it is absoultely essential that all 3 speaker clusters have a perfect balance (SPL & freq response) of each of these mixes, otherwise you end up with multiple programs coming from multiple locations.  When I walked through the listening field, and placed myself in proximity to one of the L or R clusters I could distinctly hear a program content (my L or R mix) that was different than the program content that I was receiving from the Ctr cluster, and vice versa.  Yes I can hear some of the Ctr in the L or R and I can hear some of the L & R in the Ctr, but not a seamless blend in such a way that the individual mixes were indiscernable.  So now I not only have multiple sources arriving at my ear, I also have mutiple programs arriving at my ear.  This is chaotic nonsense.  

The fact that these systems are so highly susceptible to misuse since they require exact adherence to source mic'ing principles and signal routing, and furthermore take the uptmost precision in the installation & proper deployment of such systems is enough reason to dismiss them as incapable of providing consistent reproduceable results in a church environment that is going to involve multiple users who are most often not skilled enough or of the volunteer nature.  I would have a hard time sleeping at night if I was advocating the use of, selling and installing these systems in churches.  The end product when it is not dialed up with exact precision will be far worse than any mono rig, or alternating L/R rig.  That point can not be argued.  

B. Parenteau
Showmix
Title: Re: Breshears LCR Cross Matrix multichannel mixing
Post by: Ivan Beaver on January 16, 2007, 06:56:50 am
I agree totally.  As with any precision anything, the extra flexability that can be really good in the hands of someone who knows how to use it, can be worse in the hands of a beginner.

We do not install that many crossmatrixed systems.  The church HAS to have someone who knows how to use it AND be of the right layout in order for it to work properly.

The alignment is EVERYTHING with these systems.  As a general rule it takes at lest twice and very often three times as long to setup a crossmatrixed system, as compaired to a normal mono system.  Most of this time is in the listening phase and trying to "place the image" where it belongs.

As with everything, it is a compromise.

When done good it is good, but when done wrong, you are correct, a mono system would be MUCH better.
Title: Re: Breshears LCR Cross Matrix multichannel mixing
Post by: Tom Young on January 16, 2007, 08:00:46 am
I have zero experience with mixing on this type of system. I have heard 1-2 of them demonstrated.

I frankly think we have enough hurdles to overcome when designing and (even more so) commissioning/optimizing traditionally set up loudspeaker systems. I also do not consider churches to be a suitable arena for (what I consider to be) almost "maverick" designs and operating restrictions. If you happen to have a very technically capable sound person, will he/she be there in 3, 5 or 10 years ? Because they rely so heavily on volunteers from within the church body, churches often do not get high caliber sound mixing staff ..... period. In a secular environment, the likelihood that you can hire folks (and replacements) with excellent technical chops is much greater. And yet it appears that cross-matrixed ldspkr systems have very little, if any, presence in that (secular) market.

FWIW
Title: Re: Breshears LCR Cross Matrix multichannel mixing
Post by: Mike {AB} Butler on January 16, 2007, 09:22:54 am
Briand Parenteau wrote on Mon, 15 January 2007 23:13


The fact that these systems are so highly susceptible to misuse since they require exact adherence to source mic'ing principles and signal routing, and furthermore take the uptmost precision in the installation & proper deployment of such systems is enough reason to dismiss them as incapable of providing consistent reproduceable results in a church environment that is going to involve multiple users who are most often not skilled enough or of the volunteer nature.  I would have a hard time sleeping at night if I was advocating the use of, selling and installing these systems in churches.  The end product when it is not dialed up with exact precision will be far worse than any mono rig, or alternating L/R rig.  That point can not be argued.  


Briand,
Actually, it doesn't matter whether the system is stereo, mono, OR LCR, volunteers can quickly undo a properly set up system.  Rolling Eyes

Strangely enough, I have had fewer problems with a LCR approach.. than with a stereo system. Generally, the volunteers running the system realize that vocals always come from the middle, and instruments from the sides. Sure, the EQ, balance, and miking can be terrible.. but as I said above, that can happen with even a mono system.
After 35 years of having to go into churches and fix their various issues, the number one issue contiunues to be the fact that a "wrong" approach gets untilized on a "right" (properly optimized) system. And the fun part is, each party believes they are doing the right thing to fix a problem that was already fixed by the optimized system! So, either A.) The Contractor didn't understand (or assumed) they understood what the customer wanted; B.) Didn't fully train the customer (common problem.. a 4 hour seminar isn't enough!); C.) The customer's "volunteer" thinks they can do it better than the Contractor; D.) The needs of the customer changed.. and a contractor wasn't called to upgrade.
I'm not saying you don't have a valid point. I am saying you have to remember that a customer can mess up a properly working system.. regardless of how simple it is. And LCR, in my experience, fares no worse...
Regards,