How can I give the impression of stereo from a mono song??

[bayswater]

Mike, the explanation is fine. The math is the problem. M=M+R. That cannot be. Subtract M from both sides of the equation, basic algebra, and you get R=0.

Uhhh... I never wrote M=M+R.

I haven't had my coffee yet either.

OK. R=M+R. My coffee hadn't kicked in yet. Same problem though.

[stubbsonic]

M-S is both a microphone technique and a stereo processing technique.

The principles are similar, as are the math(s).

M-S as a processing technique is great because rather than dealing with the left & right sides as the two components, you can deal with the Mid (audio that is common to both sides) and the Side (audio that is unique to each side). This lets you control the EQ and dynamics of these two components with the same ease as the L/R processing.

But as Mike suggests, this doesn't apply to the OP because there isn't a "Side" to process.

[ghobish]

If you have Waves, try the PS22 Stereo Maker.

Personally I have had the most success with the PSP Pseudo Stereo and more recently, the Brainworks BX-Stereomaker which is really excellent at maintaining true mono compatibility. Run that on the music track.

[mikehalloran]

...Personally I have had the most success with the PSP Pseudo Stereo

Regular $49. On sale through today – 35% off plus any previous customer purchases you are entitled to. Discount code is SummerTime
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and more recently, the Brainworks BX-Stereomaker which is really excellent at maintaining true mono compatibility. Run that on the music track.

$69 through Plugin Alliance, may be more or less through other resellers.
https://www.plugin-alliance.com/en/prod ... maker.html

[bayswater]

Personally I have had the most success with the PSP Pseudo Stereo

Same here. It uses comb filters, rather than mid side. The Stereo pack (4 plugins) has been sold at no brainer prices. I think the pack is about $33 today.

[mikehalloran]

Mike, the explanation is fine. The math is the problem. M=M+R. That cannot be. Subtract M from both sides of the equation, basic algebra, and you get R=0.

Uhhh... I never wrote M=M+R.

I haven't had my coffee yet either.

OK. R=M+R. My coffee hadn't kicked in yet. Same problem though.

No. You are incorrect and since it involves basic algebra... I do not understand what you are not seeing and why you think the math is wrong. Now I could show you with a three channel mixer and a set of mics but we aren't in the same room. The following will have to do:

Three mic M/S setup. The three mics are at 90° angles with the middle pointed to the source and the other 180° opposed and facing R/L. Pan the M to 0. Pan the other two hard L & R. Combine the Mid with the two Sides. What do you get?

R=M+R
L=M+L

Using the + sign implies that there is positive pressure on all three capsules which is correct. The L and R mics are out of polarity because they are back to back. If you reversed the 2&3 wires on one of them, you would make a 2-mic figure 8 and would have to send the resulting signal through an M/S decoder to flip the signal 180°. Two opposed cardioids accomplishes the same result mechanically. This is why the formula I gave is correct. If you understand, you can stop here. If not, keep reading.

Subtract L+R to get M which will be mono. Subtract M to get hard L and hard R without the middle. Pan L and R to middle and this mono signal will cancel any common signals – as happened in the freakish example I mentioned where it saves my butt.

Perhaps you are confused by the math for a 2-mic M/S setup. R=M+R; L=M-L is an illustration. The correct formula is L=M-S; R=M+S or vise versa. The MS decoder matrix reverses the polarity of the mono signal and sends it to one channel only – that is how you can get an R and L signal out of the mono signal coming from a figure 8. Without the decoder you have R=M+S and L=M+S. This gives you a mono signal with some weird phase issues.

I did the 3 mic M/S setup for over 20 years before I bought DP 2.7 and could finally use a figure 8 for my side mic.

Around 1975 or so, I built a homemade M/S decoder using some connectors and cable. On the plus side, it worked. On the minus side, I had no control over the levels of the signal and the output did not load either mic correctly in my Shure mixer (Ohm's – it's the law). It was about that time that I figured out that, if the 2-mic with a figure 8 was R=M+S; L=M-S, then a 3 mic setup would be R=M+R and L=M+L.

Try it some time. A/B a 3-mic M/S array against a standard 2-mic M/S array through a decoder. It sounds a little different because of the microphones involved but otherwise works quite well.

For those who have never done M/S, the M can be anything, cardioid, omni, figure 8, hyper or super cardioid etc. I prefer cardioid but have used an omni for 'choral in a cathedral' and figure 8 in the studio. There are those using shotgun mics as the M in film work but that sounds weird unless you really know what you are doing. One-piece stereo ribbons can work as X/Y or M/S through a decoder depending on how you angle the mic.

M/S works best in a great sounding room or hall or even outdoors if the environment isn't very noisy. My opinion only. Do what you want and have fun.

[bayswater]

We start with R=M+R
Subtract R from both sides of this equation: (R-R)=(M+R)-R
Simplify, and solve, and you get 0=M, or M=0
Same with the other equation. It resolves to M=0. So according to your math, Mid is always silent.
The only way to add something and end up with the same thing, is to add nothing. You're adding M to R, and ending up with R. So necessarily, you added nothing. So something is not right. Maybe the R on the left side of your equation is not the same R you have on the right side.

[stubbsonic]

First of all, if the OP has Reaktor, there's a free stereo expander ensemble called "ContraBand + StereoExpander", which allows you to pan individual frequency bands. Mono-compatible.

http://www.native-instruments.com/en/co ... show/8662/

As for the conversation about M/S, it is kind of a tricky subject-- because there is "mics & mixer math", i.e., adding channels and inverting phase; and there is math-math.

In the purest/purist mic setup, you have a cardioid mic facing the sound source: the MID. And you have a figure 8 mic facing sideways as close to the MID capsule as possible. With proper matrixing, this produces an X/Y stereo image. So even though the figure 8 is pointing perpendicular to the source, the resulting width of an M/S is fascinatingly adjustable after recording.

Sounds originating from the right hit the mid and right side of the fig-8 as "upright" waves. The nature of the figure 8 is that the same "right" signal will appear inverted on the opposite side of the capsule. And vice versa. So the phase relationship of the side channel to the mid channel is where all the spacial info is recreated. It's beautifully elegant.

Here's a great article on the subject over at UA.

http://www.uaudio.com/blog/mid-side-mic-recording/

[FMiguelez]

Thank you all for your comments. It's been quite enlightening, but I admit I still need to do further research, if I really want to understand this and how to effectively use these tools and techniques.

I tried most of the things you told me. The filtering of different frequencies in each side worked Ok. I tried the pseudostereo setting in my Q10. It definitely makes it sound stereo, but I found the PSS the most convincing so far.

Even then, I see that whatever I do, it will come at a cost, and it will be some kind of compromise.
I'm still experimenting with the settings, but if I overdo it, then the punch and energy seem to suffer.

I also played with DP's SpatialMaximizer, and it definitely does something if I place it AFTER the PSS plug. I haven't read the manual yet, so I don't know what I'm doing, but I see its potential (and the related MS techniques') now.
It may be that the perfect setting could be a subtle combination of PSS and SpacialMaximizer, or even some S1...

The Reaktor suggestion sounds promising. I do have it, but I haven't even opened it yet. This VI is like the 5th in my VIs-to-learn list

I have reading and experimental material for a good while now. I'm learning something cool and new

Thanks, guys!

[Don T]

Hello,
Try using a phony stereo technique. Create a stereo aux, add the chorus plug and a trim after that. Invert one side of the trim. Adjust the chorus for a short delay with a fairly narrow slow sweep. Feed this via a bus from your mono audio. Mix and adjust to taste.
OK, basically you are mixing in a chorus that will harmonically enhance and comb filter the original. Since the left and right are out of phase the resulting enhancement is spectrally opposite thus expanding the image yet retaining the full spectrum. Do the same for the vocal only create a second aux with the chorus at different settings and invert the opposite side. The images will move to the positive phase side yet be at equal amplitude. Now create and mix in a reverb that does not compete (yes, you now have three stereo buses for your 2 mono tracks). The result is a surprising 3D image when adjusted properly.

FYI: This is ear candy and REAL easy to overdo when listening in the studio and sitting in the sweet spot. Less is more...........

Don T

P.S. You can use a single short swept delay (in place of the chorus) to the same affect.

[aerolis]

MeldaProduction MStereoSpread.

This is the best plugin I have used. It has been a life saver for me in a lot of situations where the source was mono (e.g. piano or guitar) or when you need to make space for the vocal in center. It works really good on all kinds of sources (piano, guitar, pads, mono synths, etc.). Another good thing is that it doesn't add that over the top brightness like some of the others do, and I find that to be a good thing if you want to widen without changing the tone. You can demo and see if you like it, and it's not necessary to buy it if its only for this project.

I have tested a lot of pseudo stereo plugins and this is by far the best plugin I've come across, and also the one that sounds most natural. It retains the tone of the original material which I think is important. It's kind of similar to Waves PS22 Stereo Maker (X-split) but I find Melda a lot better in terms of sound and algorithms.

When using MStereoSpread you can choose between Spectral Generator and the Delay-based Generator. The stock setting in the Spectral Generator sounds good, but you should dial in the spread percentage to taste and increase the number of bands as see fit. Spectral Generator splits the signal into a frequency bands that spread alternately left and right to create a natural stereo width. The Delay-based Generator uses more traditional techniques of stereo widening and generally has a more pronounced sound. Just don't push the delay-based generator too hard because then it can go out of phase (not more than 95% maybe). The Spectral Generator is generally the safest one to use in terms of phase.

Phase issues is something to be aware of when using pseudo stereo plugins. Some of the pseudo stereo plugins have really bad mono compatibility and causes the audio to go way out of phase: If collapsed back to mono at a later time some of the audio can be cancelled out. The result is a thinner and worse sounding track. MStereoSpread is on the other hand very mono compatible. It can be wise to make your song mono compatible because at some point it may be played through e.g. those cute small mobile mono speakers.

A lot of the other pseudo stereo plugins radically changes the tone too much, like the PSP PseudoStereo which is OK but sounds a little too bright for my taste. Such a change in tone may work in some cases, however if you push the PSP too hard it measures -0.50 on a correlation meter which is way out of phase, and it should stay above 0.

A good tip is when you're testing different pseudo stereo plugins you should check how your track sounds when summed back to mono after the stereo processing. A good way to do this is to turn your DAW or Audio Interface into "Mono Mode". I use the RME Babyface which has a global Mono button. Alternatively you can use the DP Trim plugin and insert it on the master bus and turn the pan knobs to the center position. This way everything in DP becomes mono:

Insert the pseudo stereo plugin on your track and dial in som stereo spread (maybe 80% - 90% or more). Then go into "Mono Mode" in your DAW and flick the bypass a couple of times on the pseudo stereo plugin. Now you can hear if the plugin's algorithm is doing something to your audio. If your track becomes more quiet when you enable the pseudo stereo plugin then that's a sign of audio being cancelled out because the plugin has caused phase issues. If that's the case then you should problably avoid that particular plugin.

There is also another plugin called NuGen Audio Stereoizer 3 which also works but uses totally different processing techniques. You have to be careful with that one though cause it alters the frequency content of the track to some degree, which is most of the time not a big problem but still something to be aware of. It's algorithm is also older and IMO not as good as the one in Melda.


But I really recommend the MStereoSpread. It's a great plugin. You can demo and see if it's the right tool for the job.

[mikehalloran]

...when summed back to mono after the stereo processing. A good way to do this is to turn your DAW or Audio Interface into "Mono Mode".

Many of us use dedicated monitor controllers for this. Hit the Mono switch and you know without making any changes in your DAW or interface.

[Tritonemusic]

Alternatively you can use the DP Trim plugin and insert it on the master bus and turn the pan knobs to the center position. This way everything in DP becomes mono

No need to insert Trim (unless you have other uses for it). Just use the Folddown feature on the Master Track. No plug-in or external equipment required.

[Prime Mover]

If you ever end up delaying one side, a curious thing happens: even if the channels are identical, the one that lands first will appear to be louder. I've done this a few times to thicken vocals without getting the phasing that chorus effects have, it actually does fatten the sound a bit, however, you always are tempted to grab the panner and throw it over to the opposite side. I suspect that psychoacoustically, our brains are programmed to think that the first sound to hit is the primary, and the second is secondary, and tells us the sound is coming from the primary direction. It probably helped us identify what direction a predator's noises were coming from in an echoey environment.

[daniel.sneed]

[...] I suspect that psychoacoustically, our brains are programmed to think that the first sound to hit is the primary, and the second is secondary, and tells us the sound is coming from the primary direction. [...].

Yes, it's know as Haas effect:
Within a *specific* time window, if the secondary sound is *somewhat* louder, human brain has perception of primary sound direction.