STEREO: OK, Im stupid...

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Barometer

Barometer

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and embarrassed to be asking something that is probably so basic. But I'm having a hard time undertanding stereo. What I mean is, I've heard lots of stuff in the clinic where there's say a rhythm guitar panned out that sounds like it lingers on the outsides with maybe a lead cutting through the center. Or the same example with vocals, backups panned out and sounding separate with a lead in the center. When I try to do things like this, the rhythm guitar or backup vocal still sounds centered. Does that make sense? Or I've seen alot of suggestions about having the piano or drums be stereo. I have panning and placement in my drum tracks, but not stereo. Will the left and right signals actually be different? How is this done and what are the advantages (for the piano or drums I mean)? Anyway, even the most elementary explanation of these concepts would be greatly appreciated.....and sorry for posting such a dud (scurries away with his tail between his legs) :rolleyes:

I hope this is the right forum for this question
 
Often I see here people mess up the whole stereo idea... I'll let someone else get in to it, but here is what stereo is NOT...
NOT a mono track panned L or R
NOT a mono track copied and delayed a little and panned off somewhere.

Stereo only comes by having 2 mics on the same source in different places and has a lot to do with phase relationships between the mics and lots of other crazy shit I am too tired to get in to. Someone else probably will though. The left and right signals WILL be different, especially on things like drum and piano. Part of the idea is that, say on piano, the left mic will pick up MUCH more bass end than the right mic. Opposite for high end. BUT, the left mic WILL still pick up a little bit of bass end and stuff towards the middle. Both mics pick up stuff towards the middle. When these are panned, they give a realistic seperation with bass left, midle in the middle, and high end on the right. Gives a sense of space.
I'm sleepy.
 
I'll take a crack, barometer.

Stereo is simply the fact of sound eminating from two sources at the same time - i.e., your left and right speakers. However, it was discovered early on that the amount of signal sent to one speaker versus the other can decieve the ears into thinking the signal is eminating from different points within the stereo spectrum.

So, for example, let's take a mono guitar signal as our source. If I put 100% of the guitar signal into the left channel, and 0% in the right channel, the sound will seem to eminate from the farthest left point (and in fact, it does). If I reverse the settings the sound will seem to eminate from the farthest right point (and again, it does).

Now comes the magic :) . If I put an equal amount of the signal into both the left and right channels, the signal will seem to eminate from the center point between the two speakers. In fact it is not, it is actually eminating from the left and right speakers - but it sounds like it is coming from the center.

Now by varying the amount of signal reaching the left and right speakers, you can make the signal appear to "move" anywhere inbetween the speakers. This is controlled by your pan setting, which is simply varying (unbalancing) the amount of signal being sent to the speakers. Move the pan to the left, and more signal will be sent to the left than the right. The further you move the pan in any direction, the more unbalanced the signal becomes, until you have the entire signal being sent to just one side.

So far I've been talking about a mono signal. (I suspect some of your confusion may be the result of you recording your trackes in stereo rather than mono, since panning a stereo signal is a somewhat different animal). You can "move" a mono signal anywhere within the stereo spectrum, BUT it will still always eminate from a single point. That point can be full left, full right, or somewhere inbetween, but it is still a single point.

Sometimes, however, you want the source to "sound" wider. A piano is a good example. If you record a piano in stereo, you can have the lower register keys sounding from a different place in the spectrum than the higher keys. This gives the instrument a feeling of width - which in real life a piano has. If you stood in front of a piano in the real world, you would hear the lower keys coming from one side, the middle keys from the center, and the higher keys from the other side (at least if you're standing in the middle of the piano :) ). Recording a piano in stereo attempts to capture this width. If you recorded it in mono, all the keys would sound as if they came from the same spot. This would be fine if the sound you are trying to capture is that of a piano up on a stage. But if you're trying to capture a more intimate sound, with the listener in the same room as the piano, recording in stereo would be the way to go, as will better approximate the way the piano would really sound.

Most stuff is recorded as a mono signal - voices, guitars, bass, horns, etc. (although remember there are NO RULES!). It usually doesn't make sense to give "width" to a vocal, because that's not the way it sounds in the real world. Drums, piano's, and other instruments with real world "width," are a different story. Those you might want to consider recording in stereo. (In both cases, however, recording in stereo versus mono is based on the effect you are trying to achieve).

This was longer than I expected. Hope it helps somewhat.

Mike
 
Great explanation Mike.

One follow up question - when recording in stereo (two mikes), would you record each mike to a separate track or would you use a single stereo track (SONAR allows this). Any advantage to either method?

Thanks.
 
Barometer,
This is a great question. I must be retarded or something as I still don't understand.

If you take 5 mono tracks and pan them H-L, H-R, and ect. do you have now have a stereo mix? If you look at it on a stereo analyzer it shows up as mono. It seems as though tubedude understands but was to tired to explain. I think what makes a mix stereo must be the phase issue. When you have a bunch of mono tracks panned I think you still have a mono mix. The stereo part has to come from the differential signal that does not exist in a mono track.

So more help please:
1. Do a bunch of panned mono tracks make a stereo mix?
2. What steps do you go thru to make a stereo mix from several mono tracks?

Sorry I don't understand, but from what I have read around here this seems to be a much misunderstood topic.

Thanks,
Larrye
 
OK, let me try again. :rolleyes:

When you pan a mono track dead center it sends an equal signal to the left channel and the right channel. If you have mix with 5 mono tracks and they are all panned dead center, what plays from the left speaker is identical to what plays from the right speaker. Now although technically this is stereo (since stereo simply means two speakers or two signals) it will sound no different than mono. All the sound will "appear" to eminate from the center (which would sound the same as having a single speaker - i.e., mono!).

However, once I pan even just one of these tracks off-center, I have now created a situation where what is playing from one speaker is DIFFERENT than what is playing in the other. Voila, true stereo!

Let's take the 5 mono track example. Vox, bass, guitar, sax and drums. I'm going to pan the guitar hard left, and the sax hard right, and leave everything else centered. If I listen to the left speaker only, I will only hear 4 instruments (no sax). If I listen to the right speaker only I will hear the sax, but no guitar. Now if I listen to BOTH speakers, I will hear the vox, drums and bass coming from directly in front of me (center), while I will hear the guitar off to my left and the sax off to the right. Now we gots stereo going!!!! :) What is playing from the left speaker is DIFFERENT from what is playing from the right speaker, creating an illusion of width. Obviously using various degrees of panning on each instrument, I can "spread out" the group in front of me (although it is common practice to leave bass, lead vox, snare and kick centered).

Phasing, as tubedude was referring to it, is essentially discussing stereo micing techniques. Stereo mixing has more to do with panning of the signals - which simply makes takes a signal and makes it stronger to one or the other side of the stereo mix.

when recording in stereo (two mikes), would you record each mike to a separate track or would you use a single stereo track
Click to expand...
Phyl - Good question. I'll leave this for some of the other guys who have done more work with stereo micing. Personally I would record as a stereo track, but as mentioned earlier, panning a stereo track can be tricky.
 
Dachay,
I agree, by defination, 5 mono tracks panned create a stereo mix, but when viewed with a stereo analyzer, it will show as almost straight mono and it will not sound like what most people perceive as true stereo.

Why not ?
How can you mix mono tracks to get the same effect as you would if they had been stereo miced?

Larrye
 
larrye said:
Dachay,
I agree, by defination, 5 mono tracks panned create a stereo mix, but when viewed with a stereo analyzer, it will show as almost straight mono and it will not sound like what most people perceive as true stereo.

Why not ?
How can you mix mono tracks to get the same effect as you would if they had been stereo miced?

Larrye
Click to expand...
First of all, Larrye, what is it that you are analyzing? The panned mono track? If so, well that's going to look mono because IT IS mono. What is stereo is the complete mix, not the individual tracks. The individual tracks will either be mono or stereo depending on whether they were recorded as mono tracks or stereo tracks. Moving the pan does not turn a mono track into a stereo track. It only changes where that instrument is "placed" in the context of the overall mix.

What you need to do is export your mix to a stereo wave file, then analyze the wave file. It will now look like stereo, because now it is stereo.

As to your last question, you cannot make a track that was recorded in mono sound like it was recorded in stereo. If you want a stereo TRACK (as opposed to a stereo MIX) you need to record it in stereo (i.e., use two mics to record).
 
Dachay,
What I'm analyzing is a stereo mix.
Pan 5 mono tracks, mixdown to a single stereo track, analyize, and it will look and sound mono. If you have a guitar panned hard left it will come out of the left speaker but I don't believe this is what most people are refering to when they talk about a "stereo recording". It will not have the sense of space and width that most people associate with a stereo track. I think that "spacious sound" is what barometer is refering to.

The stereo sound I (and I think Barometer) am refering to is the type of stereo sound you would get from a stereo enhancer plug-in.
Larrye
 
BRAVO Dachay!! That was an excellent explanation. I have totally been in the dark when it comes to recording in stereo and your explanation has shed a ton of light onto the subject.

What would happen if you were to record with two mics and leave the pan dead center on both tracks?? This is probably a REALLY stupid question but I'm just curious what effect, if any, you would get.

Thanks again,

God Bless!
 
larrye said:
Dachay,
What I'm analyzing is a stereo mix.
Pan 5 mono tracks, mixdown to a single stereo track, analyize, and it will look and sound mono. If you have a guitar panned hard left it will come out of the left speaker but I don't believe this is what most people are refering to when they talk about a "stereo recording". It will not have the sense of space and width that most people associate with a stereo track. I think that "spacious sound" is what barometer is refering to.

The stereo sound I (and I think Barometer) am refering to is the type of stereo sound you would get from a stereo enhancer plug-in.
Larrye
Click to expand...

Larrye, There is a difference in sound between simply panning one source or using a stereo effect but they are both technically stereo. Dach is very correct with his definitions.

There is a BIG difference between creating a realistic 'stereo image' and panning a mono track but to be honest a realistic stereo image is usually much more subtle then hard panned mono tracks and that subtlety can easily be lost on poor playback systems. We could write volumes on how to acheive different stereo effects.

I think Barometer is having more of a monitoring or mixing issue where he is not actually hearing a stereo mix. If you pan stuff around the results should be very obvious. If it still sounds the same then there is another issue going on. What are you using and how do you have your monitors hooked up? Do you hear the panning when listening with headphones?
 
"What would happen if you were to record with two mics and leave the pan dead center on both tracks?? " -

You would get one mono track, effectively, only 6 dB louder. If you then panned those tracks hard Left and Right, you would hear one track coming from the center, and, assuming your gear is set to reduce tracks panned center by -3 dB, the same loudness as just one track panned center.

The reason stereo-miced tracks sound stereo is largely because of the natural comb-filtering tendencies of an acoustic space. When you try to duplicate this effect with a box, the box normally takes a mono input and fucks it up differently for each channel, making the input sound like stereo on the output. The problem with this is if you then collapse the mix to mono, all the comb-filtering* comes back and bites you in the ass - now, you have bad mono with freq response anomalies, warts, etc.

Keep in mind that psycho-acoustics is not a simple science - If you take a mono track, split it into two identical tracks, send the exact same amount to both speakers, you will hear a center positioning. Now, take one of those channels, delay it by 1-2 milliseconds, NO OTHER CHANGES in level or ANYTHING, and the sound will appear to come from the NON-delayed speaker. This is part of the human survival characteristic - it helped to know which direction the Grizzly bear was coming from, so the first ear that hears it is the winner. (Provided you can run fast enough) -

Things that affect stereo placement - panning left or right, level, reverb (more = distant, less = up front) and channel TIMING. You can make a mono signal much larger (even in mono) if you feed it into a chorus or pitch shifter - take the direct out into one track, + a few cents pitch into another track, - a few cents into another track, pan the direct center, the + slightly left, the - slightly right, adjust the + and - wider for more effect - If you use chorus instead of pitch shift, panning of the two chorused copies as well as depth of chorus affects the degree of "huge" = Just remember, though, that doing that to EVERYTHING will result in what's normally called "BIG MONO" - If everything's huge, then NOTHING is huge.

Clear as muddd, right?

*Comb filtering, in case you've been naughty and not done your homework, refers to the phenomenon of time-shifted sounds either adding or canceling each other at different frequencies. Every room has different places in it that support or cancel frequencies according to wavelength, all of which will shift depending on the source and mic position. When you mic in stereo, each mic gets a different path from the source to the mic, so each signal has different frequencies boosted or cut acoustically. When you add these two signals together to make MONO, frequencies that are boosted in both channels ADD, and frequencies that are cut in both channels SUBTRACT, while freq's that are strong in one channel and weak in the other channel end up sounding about right.

If you look at a resultant graph of freq response, it has peaks and valleys, which makes the graph look like a COMB. Hence the name.

This whole can of worms is caused MOSTLY by TIME anomalies, NOT level or EQ - This is why you can't correct NearField monitors for your room by using EQ instead of acoustic treatment. The minute you move your head, or a speaker, or anything that will change the acoustic path in the room, you've just negated your adjustments.
 
Great answers so far, thanks so much. The concepts of panning different mono tracks to get a stereo effect are pretty clear, even more so now (thanks Mike). In my first attempts I was able to have separation between the guitar and piano (slightly left and right), the bass was straight up and my drums were recorded in stereo, which did give some nice pannning effects.

So I will further elaborate since this doesn't seem to be the lame topic I thought it was. I'm starting with a mono piano track and a stereo drum track. I think I can now deal with the drums better, but the piano goes straight into the board (it's not a real piano :( ). I can hook up a left and right from the keys to the board, will this result in the same stereo effect as micing a real piano from the left and right? If not, can I split this track and EQ the two differently to try to "fake" the low-left/high-right that was mentioned for piano earlier? Also can I put some delay on one of the track, just milliseconds, to try to "fake" the phase?

Woah, I just saw knightfly's post. He's definitely hitting on more of what I'm talking about with the piano, but I think it's a bit over my head. Well it seems I did post in the right forum, since I'm seeing this as a "I need to learn alot about mixing" problem, time to do my homework. Thanks again everyone and keep 'em coming :cool:
 
Barometer said:
I'm starting with a mono piano track and a stereo drum track. I think I can now deal with the drums better, but the piano goes straight into the board (it's not a real piano :( ). I can hook up a left and right from the keys to the board, will this result in the same stereo effect as micing a real piano from the left and right?
Click to expand...
It should. Most keyboards have a stereo output. If you record that to a stereo track it should be very similar to the effect you get with stereo micing.

It's similar to Roland V-Drums, which also have a stereo out. Recording them in stereo will place the high hat slightly right, the toms slightly to the left, and the snare/kick center. In other words, it's designed to simulate the breadth and placement of the components of a real kit. You'll note the panning will not be too dramatic. Otherwise it would sound like you have a drummer with 20 foot long arms. :)

Your keys should do essentially the same thing.

However, they will be panned "around" center. If you want to move it to the left or right, it gets tricky. Try it and you'll see what I mean. Maybe Tex or Knight can elaborate on how to move (pan) a stereo track to the left or right.
 
Hey Mr. Weatherman :=) depends on which "Piano" you're using. I have a couple of the Roland kbds (XP-50, RS-9) that the stereo outs is already low-left/high-right, sounds kinda fakey if you pan them hard, so I usually bring them in to about 9 and 3 oclock. Other kbds just chorus the outs, and you'd be better off usually using just the left output and "making stereo" with your own effects, some of which I covered above. Keep in mind that if you boost freq's in one channel to try and duplicate stereo micing, you'll also boost noise and cause phase shifting, which hurts the mono imaging of the track.

If you're into hard copy books, check out Bobby Owsinski's Mixing Engineers Handbook at Amazon.com - otherwise, check out here

http://www.studiocovers.com/articles12.htm

Check out the one near the bottom, by Lionel Dumond... Steve
 
Thanks for the link knightfly.

In your first post the thing that's a bit confusing to me is your reference to BIG MONO. If you wouldn't mind, dumbing it down a bit may be in order for a dummy like me :o :rolleyes: :cool:
 
Barometer said:
So I will further elaborate since this doesn't seem to be the lame topic I thought it was. I'm starting with a mono piano track and a stereo drum track. I think I can now deal with the drums better, but the piano goes straight into the board (it's not a real piano :( ). I can hook up a left and right from the keys to the board, will this result in the same stereo effect as micing a real piano from the left and right? If not, can I split this track and EQ the two differently to try to "fake" the low-left/high-right that was mentioned for piano earlier? Also can I put some delay on one of the track, just milliseconds, to try to "fake" the phase?
Click to expand...

Like the others have said most digital pianos already pan the keys somewhat left/right. If you record both outputs and hard pan them you should have some noticeable seperation. No it wont be exactly like micing a real piano because that is when the whole room sound as captured by the stereo mics will come into play. To give the piano a more natural stereo sound you should also add some stereo reverb of an appropriate room size. Sometimes running a mono track through a stereo reverb is actually better than starting with a stereo source.

There are some fantastic articles on capturing and creating depth and spacial ambience at www.digido.com Once you understand the sound clues that your brain uses to say "that sounds like it's in a small room in the corner" then you can use reverb, delays and EQ to help simulate a specific environment. It's very handy to learn that stuff if you have to match up a dry part to a more live sounding part and have them sound like they are in the same acoustic space.

A few tips-
-A diffused reverb blurs the spacial location of a track.
-The farther away something is the more the highs are attenuated.
-A fast slap back delay will sound like you are next to a wall, the time of the slap back delay determines how far away the nearest wall is.
-Any direct (not diffused) delay less than 30ms will be interpreted by your brain as an echo and not another discreet source so it will not change the location of a sound, just the environment.

Those are the types of things that your brain picks up on and really makes stuff sound 'stereo'. They also determine whether that stereo effect is more of a spacial definition or simply an effect where the L and R are just a little different.
 
Wow Tex, this is a great expalination and tells me ALOT about some things I was wondering about concerning spacial relationships. Thanks so much.

There's one more things that's still mighty confusing for me. Say there's the rhythm/lead example I gave above. Both are guitars and would be recorded in mono right? If I want the lead to cut through the middle and have the rhythm distinctly sitting maybe 9 and 3 oclock, how would I accomplish this with just the mono rhythm track? Would the stereo reverb aid with this or would it require more, like adding delay or something?
 
MAN am I learning a lot from this post!!!!!!!

Thanks guys,

Larrye
 
Barometer said:
There's one more things that's still mighty confusing for me. Say there's the rhythm/lead example I gave above. Both are guitars and would be recorded in mono right? If I want the lead to cut through the middle and have the rhythm distinctly sitting maybe 9 and 3 oclock, how would I accomplish this with just the mono rhythm track? Would the stereo reverb aid with this or would it require more, like adding delay or something?
Click to expand...

The best and easiest way to do that is to record 2 mono rythm tracks and pan them accordingly. It's easy and by far will give you the best stereo speration. You can use delays but remember the 30ms rule because if you delay less then that it will still sound like the guitar is coming from one side but with an echo. The only way to compensate is to turn up the volume on the echo which creates problems with your levels or make sure the delay is longer than 30ms but that can cause weird phase problems (or effects depending on how you look at it).

Stereo reverb will actually obscure the panning more (remember the rule above about diffusion) and make the panning of the sound less discernable. To really notice the panning of a sound you want more direct sound and less diffusion (reverb). Use reverb if you want to obscure the placement of a sound.

I only find using delay for subtle stereo effects to work well on percussive sounds like a finger picked guitar or percussion (duh). On sounds with a long decay time the chorus effect bugs me too much unless that is something I am trying to achieve.
 
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