Best way to sum to mono (live)

[ABECK]

For playing with a Mono FOH, or a wide enough spread that stereo doesn't make sense, what's the best way to sum to mono?  Typically I would tap the single L/Mono output on my keys and be done with it.  But, I started wondering, is it any better to just run both L & R outputs to the PA, and let the summing happen there?  Is there any benefit?  Increased potential for phasing issues?   I've tried both at home and frankly, it sounds a little better using the latter approach (but that may just be because the signal is a little hotter).  Worm can opened.....

[Mr -G-]

Clavia appears to have mentioned in an interview that the "mono" button in their instrument does a weighted sum of L & R, rather than L+R, so it might depend on the instrument.

[ElmerJFudd]

This topic comes up a lot. Unfortunately there is no cut and dry answer because patch to patch you will get different results using different methods. 
 

Taking L(mono) is basically a feed of both your Left and Right Outputs already summed together.  This often works fine - but there is always the possibility of phasing issues where material that is really identical can cancel each other out.   Another option is to take just the Right out which will be really just the right signal - no summing.  With a band this probably works fine on stereo patches where you don’t want the low end loud anyway when playing with a bass player.  No phase issues when using just the R out.  But for solo playing - a stereo piano patch for example, this isn’t ideal as you lose a lot from taking just the Right out.  A better solution is to call up a mono piano patch and take just the right out.  
 

Clavia has a workaround as mentioned above.  Their mono button seems to be the best attempt by any manufacturer to deal with this issue. 

[CEB]

Several ways. I’ve had production crews take both my Right and Left DI output and combine them with a XLR Y or run both channels to the front desk and it’s ran fine.   I’ve had them mono DI each board for the feed to the mains.  It is totally their call. I am generally blessed to be working with competent people.   My point is there are different approaches that work. 
 

This stuff is not in my job description. I let production worry about it. It’s their job and what they are paid to do. 

[Baldwin Funster]

I prefer to just listen to see which side sounds best by itself and use that side as the mono feed. The only time that might cause a problem is if any modulation auto pans. You might have to minimize any mod effect in the patch. 

[Delaware Dave]

I asked this same question in the past; not sure that there is a good answer.

[Reezekeys]

20 minutes ago, Mr -G- said:

Clavia appears to have mentioned in an interview that the "mono" button in their instrument does a weighted sum of L & R, rather than L+R,

 

I'm usually a little dense on many of these topics, so forgive me - what exactly is a "weighted sum" of L & R? A little more left or right depending on... what? Or something completely different?

[CEB]

Not sure if it’s relevant but I monitor my Keyboard submix in mono even when to FOH is stereo. and it sounds great. I use Shure mono mix mode. This is the easiest way for me to take a monitor send from a desk that has no keyboards and mix in my keys myself and have great control over hearing myself. 
 

Maybe because I personally test all my sounds sounds with a mono mix helped me avoid any issues.  

[Mr -G-]

5 minutes ago, Reezekeys said:

 what exactly is a "weighted sum" of L & R? A little more left or right depending on...

... the key position. I suppose the balance of the mix of  L and R is per key. Key in the most to the left is only L output, that in the most to the right only R and the rest a mixture depending where they are nearest to. The ones in the middle should be a 50% mix of L & R. I have no idea if that is true and if so how they achieve this, but the claim was that it made the pianos sound better in mono as there is less phase cancellation. Caveat emptor!

[Anderton]

Consider creating a set of mono presets solely for live use, which may be as simple as panning everything full left or right. Then you can listen to the mono output and decide if there are any sonic compromises. This may also make it easier to balance levels so you don't get surprise level changes when going from one preset to another.

[SMcD]

How would summing at FOH differ from summing at the keyboard? Either way, you're adding L + R at the electronic level.

[Floyd Tatum]

1 hour ago, ElmerJFudd said:

Another option is to take just the Right out which will be really just the right signal - no summing.  With a band this probably works fine on stereo patches where you don’t want the low end loud anyway when playing with a bass player.  No phase issues when using just the R out.  But for solo playing - a stereo piano patch for example, this isn’t ideal as you lose a lot from taking just the Right out.

I used to do that (take only the R out) when I wanted mono.   I don't think you lose much - I think you might lose a little bit of low end, but not much.   But the best thing to do, in my opinion, is listen to the R only output, and then listen to the L+R (either summed or stereo), and decide for yourself how much low end you're losing, and if it's a workable solution for you or not.   Trust your own judgment, is my motto!  🙂

 

[ElmerJFudd]

Just now, Floyd Tatum said:

I used to do that (take only the R out) when I wanted mono.   I don't think you lose much - I think you might lose a little bit of low end.   But the best thing to to, in my opinion, is listen to the R only output, and then listen to the L+R (either summed or stereo), and decide for yourself how much low end you're losing, and if it's a workable solution for you or not.   Trust your own judgment, is my motto!  🙂

 

That’s right.  For this reason when doing solo piano especially I typically use L+R on the L(mono) out on the PX560.  It just sounds better than R only.  

[ABECK]

9 minutes ago, SMcD said:

How would summing at FOH differ from summing at the keyboard? Either way, you're adding L + R at the electronic level.

That's where my head was too.  I suppose the only difference would be if somehow the keyboard is more optimized for summing in regards to phase issues.  I'm going to hit the venue early tonight and maybe do some A/B comparisons.  

 

[ProfD]

1 hour ago, ABECK said:

Typically I would tap the single L/Mono output on my keys and be done with it.

Right.  Most KBs offering that option (L/Mono or R/Mono) the sounds are optimized to take advantage of it. 

 

Of course, it makes sense to insure favorite sounds come through mono fully with no issues.😎

[Reezekeys]

I find it sad that everyone here is talking about the best way to least degrade the sound of the same musical instruments we debate about which ones have the better sounds. I understand the need of course - it's just sad!

[ElmerJFudd]

7 minutes ago, Reezekeys said:

I find it sad that everyone here is talking about the best way to least degrade the sound of the same musical instruments we debate about which ones have the better sounds. I understand the need of course - it's just sad!

Truly.  Perhaps a greater effort from the MI community to offer more great sounding sample libraries in mono on pro boards. But the focus seems to be make it sound great in stereo for the player sitting in the sweet spot.  Which makes me say, heck with it. I’ll bring two monitors, set it up so it sounds good to me and leave it at that. 

[CEB]

It’s a Much ado about nothing.  More often than not gigs are through stereo systems. (Stereo systems with bridged mono subs).   This type of stuff may impact the less experienced players more.   A lot of the good young cats cut their teeth playing in churches with great production and monitoring.  But Hell us old guys played without monitors.  If we were lucky we had sidefills.   To day it’s all good unless you are working with wankers that don’t know anything.   Just work really hard on your chops and charm and get yourself out of the really bad band situations.   It beats the heck out of the 70s.  
 

PS The 70s were a lot of fun.   

[hrestov]

I think that only nord try to solve the phase cancellation with the “mono” button, they probably doesn’t do the simple L+R. But when I tried the mono button I at last prefer to use only R. But the problem is that all nord pianos are much stereo oriented, so they doesn’t sound good from one speaker. now I have a yamaha Cp73, the Cfx is good with the R output (the best mono piano that I play). Less good with the L+R output. 

[ShadowMan]

Instead of converting your patches to mono, you could also take a look at the Radial  Stage Bug 2 DI box… which seems to do a dual 1/4” to XLR sum for the house. 

 

[stoken6]

21 hours ago, hrestov said:

I think that only nord try to solve the phase cancellation with the “mono” button, they probably doesn’t do the simple L+R

I have not seen any hard evidence that Nord do anything special/magical/voodoo beyond simple L+R. (Not too difficult to test: record two identical MIDI performances, one with the mono button pressed. Sum the stereo one to mono. Phase-align in a DAW and phase-reverse one of them. Anything you hear is special/magical/voodoo).

 

Cheers, Mike.

[b3plyr]

A few years ago I asked Nord what they did with the mono button. Their answer is much simpler than you might expect. They take the best sounding samples from either left or right. That's it.  So when you go to mono you are hearing the best individual sample from either the right or left channel. No fancy algorithm or phase cancellation technique, etc.

[Reezekeys]

3 minutes ago, b3plyr said:

A few years ago I asked Nord what they did with the mono button. Their answer is much simpler than you might expect. They take the best sounding samples from either left or right. That's it.

 

No offense to you at all but I'm not buying this! "Best sounding sample"? Let me understand - you play a note, the Nord sw looks at the L&R samples and somehow determines which of the two "sounds best"? By what measurable criteria?

 

I imagine a very weird-sounding piano, if the "better sounding" samples involve lots of switching between left & right!

[b3plyr]

2 hours ago, Reezekeys said:

 

No offense to you at all but I'm not buying this! "Best sounding sample"? Let me understand - you play a note, the Nord sw looks at the L&R samples and somehow determines which of the two "sounds best"? By what measurable criteria?

 

I imagine a very weird-sounding piano, if the "better sounding" samples involve lots of switching between left & right!

No offense taken - just repeating what I was told. If they did implement such a thing, it would be building a different lookup table for the sample playback. The Nord would not real time make the decisions. In other words, Nord people would determine which samples to use for the mono and then include a “mapping” of the sounds when mono is selected. If they were ambitious, they could even EQ and level tweak. I doubt they do this.

 

You have good points.

[Reezekeys]

Your thought that the L&R samples are examined then mapped for mono beforehand makes total sense. It still begs the question - how does Nord determine which sample 'half' sounds best? And would this work for user samples or only ones from the factory? (Nord lets you load in your own samples, correct?).

 

These are more or less rhetorical Qs - none of this affects me, since I hardly ever encounter a mono PA system for the gigs where I'm actually going into a PA. I am curious to know if some super-nerd software engineer has made an algorithm that can look at a stereo sample and determine which side sounds "best"! 🙂 

[elif]

Regarding stereo output, my Nord's acoustic pianos weigh the manual bottom to the left channel and manual top to the right.  Is this how it is commonly done?  For stereo FOH, I wonder whether a better presentation might be had using something that sounds like a piano mic'd at some distance, like with an outside X-Y mic array.  Piano recording technique including X-Y array and others.

[AnotherScott]

2 hours ago, Reezekeys said:

(Nord lets you load in your own samples, correct?)

Not for the piano library.

[hrestov]

We have to do a protest to Keyboard manufacturers to force them to do a more “live friendly” piano samples. Nobody cares in a live situation that from a speaker come out the basses and from other the highs… it doesn’t make sense…

 

if you listen a real piano  from 2 meters it is quite a mono source. 

[Spider76]

2 hours ago, hrestov said:

Nobody cares in a live situation that from a speaker come out the basses and from other the highs… it doesn’t make sense…

 

if you listen a real piano  from 2 meters it is quite a mono source. 

Exactly. The whole fuss of manufacturers to provide the best possible stereo samples is only a bonus for the player, to better recreate the experience of sitting at a real piano. But for the audience, it actually makes the sound worse.

[Delaware Dave]

So in regard to ABECKS question of summing stereo to mono, the answer is ...........   ?