VikasSharma - 29 August 2012 08:29 AM

5pinDIN - 29 August 2012 08:18 AM

VikasSharma - 29 August 2012 08:02 AM

[...]Also, please tell if using just the L/MONO output of the Motif could possibly lead to any phase cancellation.

Yes - just as much so as any other total mixing of the Left and Right outputs.

Thanks for replying!

So, how do people deal with it? Most (if not all) venues have a mono PA system, not stereo.

The need to “deal with it” depends on the degree of out-of-phase material in one channel versus the other. If that’s minimal, obviously there won’t be much cancellation, and perhaps there will be no need to do anything. If the quality of the sound is sufficiently impacted, then EQ and level adjustments might resolve the problem. That could be done at either the Motif or at a mixing board.

Sometimes it’s difficult to get things to sound acceptable. If the phase differences happen within a relatively narrow range of frequencies, there can be “suckout” in only that range, making correction a bit more challenging. Worse, the suckout might occur in multiple isolated ranges - with patience, careful multi-band parametric equalization might resolve that. If the sound isn’t decent after a good attempt is made, it might be best to try another Voice.
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VikasSharma -

Also, in one of his replies in this thread, Bad_Mister suggested using just the L/MONO output to avoid phase cancellation issues.

Bad_Mister - 06 June 2010 03:07 PM

If you want to record your Motif XS in mono, we highly recommend the following (correct) procedure. Take a single cable and connect it to the L/MONO analog output on the back panel of the Motif XS and connect it to a signal input on your audio interface.

The L/MONO jack is specifically for when you want to output signal from the Motif XS in mono. It phase coherently combines the left and right channel information within the XS and routes it to that specific jack. When you want a mono output use just 1 cable connected to that output jack.

I respect Bad_Mister‘s vast knowledge, but unfortunately I have to disagree with him on this. There’s nothing magical about the L/MONO output. When only that output is used, the Motif just resistively mixes the Left and Right channels. Here’s what I’ve previously said about that:
http://www.motifator.com/index.php/forum/viewthread/458170/

5pinDIN - 29 August 2012 09:24 AM

The need to “deal with it” depends on the degree of out-of-phase material in one channel versus the other. If that’s minimal, obviously there won’t be much cancellation, and perhaps there will be no need to do anything. If the quality of the sound is sufficiently impacted, then EQ and level adjustments might resolve the problem. That could be done at either the Motif or at a mixing board.

Sometimes it’s difficult to get things to sound acceptable. If the phase differences happen within a relatively narrow range of frequencies, there can be “suckout” in only that range, making correction a bit more challenging. Worse, the suckout might occur in multiple isolated ranges - with patience, careful multi-band parametric equalization might resolve that. If the sound isn’t decent after a good attempt is made, it might be best to try another Voice.

Thanks for your reply.

A few more questions, if you don’t mind.

Q1: From the audience’ perspective, is there any benefit in having a stereo Piano sound at all?

I can understand the realism a stereo Piano sound would provide from the player’s perspective, but from the audience’ perspective, I think a mono Piano sound coming from where the Piano is placed on the stage would more accurately represent a real world scenario. So (maybe) it’s more about panning than about having a stereo Piano sound. Or am I missing something?

5pinDIN - 29 August 2012 09:24 AM

There’s nothing magical about the L/MONO output. When only that output is used, the Motif just resistively mixes the Left and Right channels. Here’s what I’ve previously said about that:
http://www.motifator.com/index.php/forum/viewthread/458170/

Q2: Are there any other better ways of summing the L and R channels of a stereo sound to a mono sound?

Q3:How does a typical mono tape/CD player or radio sum up the channels? Is it basically the same method that is adopted by the Motif?

Q4: Even if we do get the option for a stereo PA system, are there still any possibilities of any phase cancellation adversely affecting the sound being heard by some of the audiences?

I’m sorry if asked one too many questions.

VikasSharma, I think we can all agree that when playing live the ability to monitor yourself in stereo is much more satisfying and inspirational than mono, so I’ll set that aside as a given.

The question of stereo vs. mono for FOH has been answered for me by doing some empirical listening and testing.

Roland keyboard amps (Like ‘em or hate ‘em) come in very comparable models where the major difference is simply stereo vs. mono.  The stereo models have no separation (Or minimal is probably more precise) as the speakers are set side-by-side in the same cabinet.  However, I can tell you that the same stereo keyboard signal running through the stereo version vs. the mono version sounds much better in all respects.  Why?  I don’t know, I don’t have the electronic expertise to explain why, but it does.

Armed with this knowledge, I experimented with the same dynamic in a FOH PA system, running the same comparison with stereo keyboard output, and sure enough the stereo version sounded much better...clearer, cleaner, crisper...better.  This happened regardless of room position, standing right...left...center.  Why?  Again, I don’t know, but it did.

So...I now make the sound guy run stereo.  He can do whatever he wants with the mono sounds like a vocal or cowbell, but at least I know my stereo output is being given the best chance of sounding the way it is supposed to sound.

When you add the vast array of stereo effects the Motif puts out, this becomes even more stark.  A Phase or Rotary effect that is sent in stereo and is projected in stereo has a markedly more dramatic effect in the house...even if you are sitting/standing on the left or right side (In my experimentation).

VikasSharma - 29 August 2012 11:35 AM

Q1: From the audience’ perspective, is there any benefit in having a stereo Piano sound at all?

I can understand the realism a stereo Piano sound would provide from the player’s perspective, but from the audience’ perspective, I think a mono Piano sound coming from where the Piano is placed on the stage would more accurately represent a real world scenario. So (maybe) it’s more about panning than about having a stereo Piano sound. Or am I missing something?

It depends on the size of the hypothetical venue. If the listening distance is significant, then indeed an unamplified acoustic piano will sound to the listener as if it is a point source. Of course, indoors there will still be reverberation, etc., due to the hall’s acoustic characteristics, which will vary with frequency. I suppose under those circumstances, a single speaker, located where the “real” piano would have been, might sound similar to a distant listener.

However, in anything other than a small room, using a single speaker isn’t a typical sound reinforcement technique. As soon as multiple speakers are used (even if the source is mono), things change. Since venues typically aren’t anechoic ( ;-) ), the listener will not only hear the direct sound from two or more speaker locations, but also reverberant sounds due to each of them as well. Is that “real”?

With respect to panning - there’s certainly a difference between true stereophonic sound that captures both level and phase differences between the channels, and a monaural sound that is just panned to simulate stereo (L/R positioning). Summing left and right of a true stereo source is likely to create phase cancellation to some degree, while doing the same to a panned mono source shouldn’t (if that simulated stereo source hasn’t been processed in a manner that introduces phase variation between the channels).
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VikasSharma -

Q2: Are there any other better ways of summing the L and R channels of a stereo sound to a mono sound?

Without getting overly sophisticated - sometimes changing the ratio between left and right in the mono mix can be better than straight 50/50 L/R. Slight time delay can selectively be applied to the “leading” source in some circumstances, better matching the channels.
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VikasSharma -

Q3:How does a typical mono tape/CD player or radio sum up the channels? Is it basically the same method that is adopted by the Motif?

Yes, the manner is basically the same.
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VikasSharma -

Q4: Even if we do get the option for a stereo PA system, are there still any possibilities of any phase cancellation adversely affecting the sound being heard by some of the audiences?

Yes - even if from an audio electronics perspective there isn’t a problem, the acoustic environment itself has lots of opportunities to cause grief. To a great degree, this is because the wavelength of sound in air is fairly short, especially at higher audible frequencies. See http://www.mcsquared.com/wavelength.htm

Imagine an audience member sitting in some random seat in a large venue that has multiple speaker arrays. Sound reaching that position might be coming from several direct sources that are at various distances, as well as the reverberant sound. At that person’s ears, all kinds of reinforcement and cancellation might be occuring. In some cases, moving one’s head just a few inches can dramatically affect what is heard. Sound system designers do the best they can to minimize those problems, but they can’t eliminate them completely.

Perhaps we should just issue IEMs to the entire audience, as is done with 3D glasses. :-)
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VikasSharma -

I’m sorry if asked one too many questions.

Not yet… ;-)

When you cannot aim your speakers, there are tools that can blend (or narrow) the stereo spread. But this is for when you cannot aim your speakers - here’s an example, you are playing in a place where the speakers are located in the ceiling pointing straight down (like those spread out throughout a restaurant) where a large portion of the audience cannot see both a Left and a Right speaker (that is, if a large part of your audience cannot see both speakers) you can use this “blend function” to mix some of the left and right signals in each channel. This creates a narrowing of the stereo image.

But in most musical performance situations the audience can see (line-of-sight) both the left and the right speakers. In fact in most musical performance situation the majority of the audience is between the speakers (and in venues that are larger than that… well, a different set of rules take over). If you try and worry about the people on the outside of your speaker spread - ultimately you will conclude you need an entirely different speaker deployment strategy - unfortunately those folks are just there for the “event”.

People rush to find the good seats at a concert. Those who don’t know rush to the very front. Those that have some experience go toward the center of the venue, quite a bit back from the stage. (If you don’t know what I’m talking about then you are one of those that ‘don’t know’, Know what I mean?)

No one rushes to the seats outside the sweet spot (if you get my meaning). You know where to sit!!! and intuitively you know WHY! I will not argue the point, I only invite you to experience yourself.

How much you pan something in a large venue is really up to what the room will support. The thing about stereo is that its size is adjustable by you when you mix it. It is not automatic, it still takes mixing skill to use it. Stereo sounds better - you don’t have to agree, but I think if you try it, you’ll agree. Doesn’t matter what most people do, it matters only what YOU do. And what sounds good to you.

Remember the first rule of speaker placement: Aim them at your audience!
Also add to your discussion - what it is you have coming from your Motif XF. What role, or roles are you playing in the act that is on stage? This too, should figure into how you decide to setup your system. And being an engineer (I really don’t care how easy or difficult it is for the engineer to deal with the signal… that is the gig) perhaps my ideas on where the good sound is focuses too much on those who know where to sit… but I don’t think so. Stereo makes music more intelligible ("clearer"… yes, exactly)… assuming you are sitting on the business side of my speaker cabinets.

Thank you very much cmayhle, 5pinDIN, and Bad_Mister for your views and advice!

I do prefer stereo over mono when listening to recordings or playing Piano/Keyboard at home. I was just not sure about the practical benefits and feasibility of having a stereo sound system for live performances.

I did a lot of search on the Internet and apparently I’m not the only one having this dilemma.

Here are a few links:

- Live Sound - Mono or Stereo?
- Should we run our PA System in Mono or Stereo?
- Sound Systems - Mono versus Stereo

Regarding speaker placement and sound amplification, I found the following interesting whitepaper by Bose:

Applying the Benefits of Unamplified Acoustic Music to Performances with Amplification

I think Bad_Mister sums it up pretty well.

Bad_Mister - 29 August 2012 05:55 PM

Doesn’t matter what most people do, it matters only what YOU do. And what sounds good to you.

In his 2nd sentence, however, I’d follow the ’you‘ with ’and your audience‘.

Thanks very much once again folks!

Regards,
Vikas

VikasSharma - 30 August 2012 03:55 AM

[...]Here are a few links:[...]

Thanks for the links. I located some that might also be interesting:
http://www.soundonsound.com/sos/apr08/articles/phasedemystified.htm

http://www.prosoundweb.com/article/print/acoustic_characteristics_for_live_sound_reinforcement

http://www.rightround.org/content/howtorock/20/

Back to your original question:

VikasSharma - 29 August 2012 08:02 AM

I would like to know from the members here if gigging in medium to large venues in stereo is practically feasible.

It’s feasible for the house mix if the house system is in stereo. But most monitoring systems are mono even when the house mix is stereo. So the audience hears a great stereo sound while you hear a less great mono sound through the monitors.

VikasSharma - 29 August 2012 08:02 AM

Also, please tell if using just the L/MONO output of the Motif could possibly lead to any phase cancellation.

Yes, it can...possibly.

If a particular voice uses stereo samples in any of the elements, you might get some phase cancellation, but it will vary from sample to sample. If all elements of the voice use mono samples there should be no difference.

If you use effects that use phase reversal to simulate a stereo effect (common in cheap FX processors, not sure if any of the onboard effects do this), the effect will get washed out in mono.

Now back to the real world: the few times I have gigged my XF, I used the L/MONO output. For recording, I always use stereo.

Thanks very much 5pinDIN for those links. Very good information there, esp. w.r.t. miking techniques.

meatballfulton - 30 August 2012 12:44 PM

It’s feasible for the house mix if the house system is in stereo. But most monitoring systems are mono even when the house mix is stereo. So the audience hears a great stereo sound while you hear a less great mono sound through the monitors.

Thanks meatballfulton, for sharing your views.

I’d say that monitoring in stereo is perhaps much more feasible and important although I agree that most monitoring systems are mono.

To quote cmayhle:

cmayhle - 29 August 2012 01:43 PM

...we can all agree that when playing live the ability to monitor yourself in stereo is much more satisfying and inspirational than mono…

Although most FOH systems are stereo-capable, they’re mostly run in mono. At least that’s what I observed and precisely why I asked this question to get feedback from the knowledgeable forum members here. Maybe the reason is that those good seats or the seats within the sweet spot (referred by Bad_Mister) are only a small percentage of the house capacity. Or perhaps, due to my limited exposure, I’ve not experienced the real joy of a true stereo FOH system.

Now back to the real world: the few times I have gigged my XF, I used the L/MONO output. For recording, I always use stereo.

Thanks very much for your feedback!

Hi, I have just a yamaha motif xf6 and i would like to know how to configure my motif to play in stereo Mode. Could you please advise as to how i go about doing this.

Regards
Julius

kj23owusu - 14 July 2013 08:59 PM

Hi, I have just a yamaha motif xf6 and i would like to know how to configure my motif to play in stereo Mode. Could you please advise as to how i go about doing this.

Regards
Julius

Julius, there is really nothing to configure.  Simply connect the Left (L) and Right (R) outputs of your XF to the matching Left and Right inputs of a stereo amplifier, mixer, or recorder...and you are good to go!

Remember that you need (2) separate channels (or a single stereo channel) for your signals from the XF, and (2) separate speakers connected to these channels to achieve true stereo separation.

You have posted in the XS Forum, but it really doesn’t matter for this question!  Stereo is stereo...XS or XF.

Remember that you need (2) separate channels (or a single stereo channel) for your signals from the XF, and (2) separate speakers connected to these channels to achieve true stereo separation.

Correct!

I’d only add: and two (2) ears… Life itself is stereo!
:-)