Subject:newbie question never heard before

Posted by: Doc K

Date:3/4/2010 1:41:10 AM

Audio afficianados may snicker and sneer, but this aspect is just not clear to me yet. Please help clarify this concept.

How does recording a track in stereeo differ from compositing 2 individual, identical mono tracks?

In the illustration on page 196 of the ACIDPro70_manual.pdf, the diagram shows a waveform of a bass guitar being recorded into a stereo track. How does that work when a bass puts out a mono signal?

How do you know when an instrument should be recorded in stereo, or in mono? Vocal recordings should be recorded in mono, right? I thought guitars as well, but there is something here that I am missing/just not clear about.

Don't even go to surround-sound yet. Let me figure thise one out first!

Subject:RE: newbie question never heard before

Reply by: Bremen Cole

Date:3/4/2010 4:42:37 AM

If you are recording a mono source, than there would be no difference. I record vocals in mono, tweak it.... then duplicate the mono track and pan one hard left and the other hard right.....

For me I found it to give a "fuller" sound than recording a mono source into a stereo track.....

Subject:RE: newbie question never heard before

Reply by: Doc K

Date:3/4/2010 5:08:06 AM

So what are some examples of sources that are not mono?

What is the difference between the left channel and the right channel of a true stereo signal. (not a duplicated one like the l/r vocals you mentioned) that I might need to record?

Subject:RE: newbie question never heard before

Reply by: Bremen Cole

Date:3/4/2010 5:42:41 AM

Non mono sources would be choirs, drums, piano (if you want it to sound good).... etc... anything that has a "field" of sound. Example, a drum set sound different if you are standing to the left of it, rather than to the right. The reason is a particular drum will be closer to you, so you will hear it more. So when recording drums you use at least 2 mics, and therefore simulate it's field of sound.

So the difference between left channel and right channel of our drum set would be perhaps you would hear the snare or high hat a bit louder standing to the left, than on the right. So if I hard pan the stereo track of our drum I would hear the same. When centered the sound would simulate the complete drum set, simulated as it would be in a live setting.... Recording the drum set in mono there would be no difference in the sound when panned hard left or right....

I know my examples are lame... but I hope they help you get the idea.....

Subject:RE: newbie question never heard before

Reply by: Doc K

Date:3/4/2010 6:10:02 AM

So any solo instrument, rock, orchestral, ethnic, whatever, with the exception of multi-part instruments that have a field of sound like a drum kit,should be recorded in mono, and doubled and panned into stereo only if more 'beef' is needed from the sound?

Also, how should stereo be handled with electronic and virtual instruments?

Subject:RE: newbie question never heard before

Reply by: Bremen Cole

Date:3/4/2010 7:19:11 AM

By "solo" instrument, it depends. A piano is a solo instrument, but must be recorded with at least two mics to get the real sound. Again, you are playing the piano. I stand to your right in front of the piano and I hear the high notes more. To the left and I hear the low notes. If I stand in the center I hear the high notes out of my left ear, and low notes out of my right. So in the center the sound is the full field of sound from that piano. When I record a piano I would at least put a mic on the left and one on the right. The left would mic into the left channel of my stereo mix, and the right into the right of the mix. Then when someone listens to the piano track, and the set in the center of the stereo field, they will experience the full field of the piano.

It is a personal preference and a technique issue of recording mono instruments (or singer) into mono and panning.... no hard and fast rules. I think it improves vocals, but do not use it for a bass guitar.

Recording a bass guitar into a stereo track allows you to place the bass guitar into the stereo field of the whole mix. If you are listening to a live band, and standing in the center, you hear the instruments in their places. Perhaps the bass player is to the left.... so mixing you might pan the bass a bit to the left to simulate the real experience. You could also record the bass into a mono track, clone it and pan each one to get the same effect...... but only for a mono recording. If you hard pan a true stereo track to the left, you will not be able to hear the audio information that is in the right channel.

Virtual instruments are the same. If you have AP7 then you can look in Kitcore and see that you can adjust the panning of the individual drums within the drum kit. This is to simulate the way a real drum set is. A stereo piano patch on a many synths or romplers are the same as a real piano, high notes on one side, low on the other. So most synth are stereo tracks by default. In true stereo there is different and unique audio information in each side. When played back and centered they create the stereo field of sound.

Subject:RE: newbie question never heard before

Reply by: Doc K

Date:3/4/2010 7:38:13 AM

Thank you for clarifying that. That is the kind of stuff you don't learn in high school!

Subject:RE: newbie question never heard before

Reply by: Bremen Cole

Date:3/4/2010 9:09:51 AM

Glad I was able to help a little. Just to be clear.... you use panning, and to a certain extent eq, to place an instrument in the stereo field. A real bass and a virtual instrument bass are really treated the same way. You want to give them their own space in the mix, so you dial in a spot for them in the stereo field. No matter in other words if it is real or virtual, you still need to create a place for it, otherwise everything get muddled.

Surround sound is the same as stereo, except you add the dimensions of front and back (and in some cases up and down) to the left and right of stereo. So instead of unique audio data on two channels, you might have it on 4, 5 or more.

Stereo has been around for over 50 years, and I have found that most people still think is just means you have two speakers instead of one......

Subject:RE: newbie question never heard before

Reply by: Doc K

Date:3/4/2010 3:31:43 PM

So when all your tracks are mixed properly and they're all sitting in the field in a believable way, you render them down to a stereo clip.

Panning said clip at this stage will still reveal the same 'stereo positions' setup in each of the individual tracks.

Then the clip gets mastered and burned to a CD.

Right?

Why then, when I rip a cd (a real store bought one, not a homemade one) to an audio file and insert it into ACID, does it not have all these features we've just been discussing?

Kent

Subject:RE: newbie question never heard before

Reply by: Bremen Cole

Date:3/4/2010 3:58:00 PM

When your individual tracks are rendered to a stereo track, they become in essence one track. You cannot then change the position of the bass, drums...etc. The rendered stereo track is designed to be played with the "balance" on a stereo set to center, and the listener setting at a mid point between the speakers. Headphone will often give the best stereo sound because seldom do we really listen to speaker from that ideal center position.

If you rip a cd, and get a stereo file it has all the properties of a rendered stereo file in Acid (or any other program). A professional recording studio does all the things we have talked about (though on much more expensive equipment) and render the finished product just like we do in our programs.

If you take that stereo file from a cd, and hard pan it left or right... each channel contains unique audio data. On one channel you may here the bass a bit more, or whatever. Sometime on a song you will here them pan something from one channel to another. If you were to find such a spot on your cd ripped file, you could hear it in one channel and not the other, and then hear in the other and not the first.

So the files are just like what we have been discussing. But again, because it is a mixdown you cannot adjust individual instruments.

Subject:RE: newbie question never heard before

Reply by: Geoff_Wood

Date:3/4/2010 7:24:49 PM

A stereo signal (or rather pair of signals) includes differences that give 2 dimensional spatial information.

A stereo signal could be from a stereo playback device, a stereo synth or drum machine output, a pair of microphones set up for stereo recording.

Recording a mono signal in stereo and doing the panning thing should only make a small difference if there is something wrong somewhere, apart from a 3dB level rise from adding 2 identical signals.

However for more control, I often record stereo drum overheads to 2 mono tracks.

The advantage of recordng a stereo track is that you only need to add effects to that one track, rather than in pairs for te dual-mono scenario.

geoff

Subject:RE: newbie question never heard before

Reply by: Doc K

Date:3/5/2010 1:53:55 AM

OK Geoff,

I was following along with Bremen fairly well, but now I am right back out in the wilderness somewhere again.

Let me go through your points one by one and clear them up, if you don't mind.

"A stereo signal (or rather pair of signals) includes differences that give 2 dimensional spatial information."

Solid! Clear. I get it. Most should.


"A stereo signal could be from a stereo playback device, a stereo synth or drum machine output, a pair of microphones set up for stereo recording."

How do you setup 1 stereo audio track to record 2 different mics. When I click on the record input button, and select a STEREO source, which shows 2 separate inputs of my ai, is that all I need to do from within AP7.

Picture Barbara Streisand talking to the audience in her snyde NYC Jewish girl accent. "I think I'm loining as I'm writing"

Next:

Recording a mono signal in stereo and doing the panning thing should only make a small difference if there is something wrong somewhere, apart from a 3dB level rise from adding 2 identical signals.

OK


However for more control, I often record stereo drum overheads to 2 mono tracks.

I'm not clear how or what you are saying here. So you take the feeds from the 2 OH mics, plug them into the same 2 input jacks on the ai, but then in AP7, instead of recording them into 1 stereo track, you record them into 2 separate mono tracks. Right?

I can see how that might make it easier to add effects and such and apply panning and volume automation. Is this a common practice among recording engineers?

Then when you get them the way you want them, you can render them to 1 track to save resources?

Subject:RE: newbie question never heard before

Reply by: Geoff_Wood

Date:3/6/2010 4:40:05 PM

How do you setup 1 stereo audio track to record 2 different mics ?

You have L mic plugged into channel 3 of your interface, and R mic plugged into channel 4.

Acid automatically 'pairs' say Ch3+Ch4 to make (stereo) Input 2. If you click on the Record Input tool on the track header, select which interface/driver, and scroll down - it's becomes pretty obvious, if you have a more han 2-channel device. Else it's REALLY easy - just 3 choices, Left, Right, and the Stereo pair. MAybe the description vary slightly depending on how your driver describes the inputs.

Then when you get them the way you want them, you can render them to 1 track to save resources?

You could, or not. I don't often have a resources problem. I most - if compressing or EQing I either buss them, or apply the (simple) setting to each channel separately. The purpose is to be able to control the stereo span, which could also be done on a stereo track with a stereo width control plugin. But I don't.

geoff

Subject:RE: newbie question never heard before

Reply by: inocmusic

Date:3/7/2010 6:23:30 PM

How does recording a track in stereeo differ from compositing 2 individual, identical mono tracks?


Mono through 2 speakers = identical information from left and right speaker which makes the soound appear to be coming from dead center

Stereo through 2 speakers= slightly different information from each speaker that can make something appear to be coming from anywhere in a 180 degree range from left to right
this somewhat mimics the effect of our hearing since sounds reach our ears at different times, combined with some masking from the head itself which allows our brain to determine the position in space of the sound based on minute phase and timing and dampening differences in the sound in the left ear vs. the right ear

1 mono track = same info from both speakers
2 identical mono tracks panned hard left and hard right = same info from both speakers (just potentially louder because there are 2 signals instead of 1). due to the non linear response of our hearing, louder may fool you into thinking it sounds better but actually it is the same as 1 track panned center

Subject:RE: newbie question never heard before

Reply by: Geoff_Wood

Date:3/7/2010 6:26:46 PM

"Mono through 2 speakers = identical information from left and right speaker which makes the sound appear to be coming from dead center"

Kind of depends where you pan the mono signal, no ...?

geoff

Subject:RE: newbie question never heard before

Reply by: inocmusic

Date:3/7/2010 10:00:40 PM

if you pan off center then the signal from each speaker is no longer identical. One becomes louder than the other creating an ilusion that the signal has moved either left or right, creating a "stereo" effect since it requires 2 channels/speakers to achieve and we say we have placed the instrument in the stereo field. There is no stereo field in mono output since mono is single channel only
if you were to then render this Panned Mono track to a mono file it would once again be dead center with identical information from both speakers.
true mono is a single channel/signal. we have the ability to split it to 2 outputs/speakers but as soon as you pan it and change the balance between channels/speakers the output is no longer truely mono since it is the difference between channels that produces the effect of stereo
but I take your point

Subject:RE: newbie question never heard before

Reply by: deusx

Date:3/8/2010 10:11:59 AM

I wouldn't complicate too much. It depends on the kind of music you want to record, but for most pop, rock stuff; bass, kick drum and snare drum are recorded in mono and dead center, the rest of the drums are placed slightly off center ( it's up to you ).

Vocals are usually also dead center. Where stereo tracks are most useful is rhythm guitars and other rhythm instruments. Best and fullest sound is achieved not by recording one instrument to stereo or mono and then doubling to stereo, but by actually playing the rhythm part twice and recording 2 ( or more if you wish ) mono tracks which are then panned all the way left and right. It's impossible to play same part exactly the same and that subtle difference is what creates that full sound you can' t really get by just recording once to stereo or by doubling a mono track.

If your rhythm depends heavily on delays ( U2 guitar sound ) then you may want to record a single guitar track to stereo and having the dry signal in the center, 2 bouncing delay sounds left and right ). This will also work well with vocals and Pink Floyd type bass guitars.

Of course if you record every single thing to its own ( mono ) track you'll have more flexibility when creating the final mix ( in the above example where you record a guitar to a stereo track , dry in the middle and delays left and right, you will not be able to alter the volume of delayed sound relative to the dry one, you'll only be able to change the volume of the whole thing since it's all one track )