Topic: 4 channel recorders question...

[lordbelial]

Hi,

I'm thinking about jumping on 4-channel recording in the near future.

I've always been doin' 2 recordings (Aud+SDB) so I can matrix in post, but never used my UA-5 to matrix both sources because I was afraid of possible delay problems (I use to place mics 10-12 meters far from the stage, usually near the soundboard area 70% of the times I do open)

Actually I'm pointing my next recorder to be an Edirol R-44, so I can do 4 channels (2 for audience and 2 for SDB, or even 4 audience), I think this will prevent me for losing time doin' matrix in post, but I think that the main problem (delay between sources because of mic distance from PA) will still remain the same....

I've tried to found information on the Edirol R-44 but my main answer cannot be answered: Does the Edirol R-44 records 4 channel independently? I mean, is it possible to have those four mono tracks separated? Or are they recorded as one file, mixed and sync'ed?

Thanks for the space!
Víctor.

[stevetoney]

This is an interesting question.  I'm an engineer so I'm intrigued by the question.

I recently was mixing a recording and had to match the right and left channels.  What I discovered is that in the final mixdown, if I had the right and left matched to within .01 second, then I couldn't hear any noticeable delay effect.  If they were .02 seconds or more mismatched, you could hear the difference between the two as reverb.  So, let's use .01 sec as our acceptance criteria.

OK, according to wikipedia, sound travels at 343m/s at 20C, dry air.  You say that your mics are 10 to 12 meters away from the stage.  That means that there is a sound delay from the stage to your mics of 12m / 343m/s...or roughly 0.03 sec (or three times the length of Michael Phelps' fingernails  )

I'd say based on this, that you'd probably have some issues with delay. 

However, even if you do have to make a 0.03 second adjustment in post, you only have to do one minor adjustment, since the overall clock of the two sources (SBD and mics) would be the same if you were recording with an R-44.  IOW, just shift your mic source 0.03 seconds back on the timeline and your two sources will be perfectly synched for the whole show. 

This would still be far easier than synching sources from two separate recorders...and I think worth having a 4 channel recorder for, especially since you only have to babysit one recorder in one location.

[lordbelial]

(or three times the length of Michael Phelps' fingernails  )

Hahahaha, that's what I will define as: Owned olimpics.

By the other hand, quite right, main problem sync'n sources is time clock, delay problems will always happen (physics are that funny) but having 4 channels with the same time clock will help for sure.

So now I only need to know if the R-44 records each channel in a single track (or each stereo pair in a single track), because if it does not, no delay issues would be ever fixed in post...

Thanks tonedeaf.

[John Willett]

So now I only need to know if the R-44 records each channel in a single track (or each stereo pair in a single track), because if it does not, no delay issues would be ever fixed in post...

Is this important?

All tracks *have* to be on the same clock time to record at all.

But if it worries you, just give the manufacturers (or their agent) a ring and they'll have the answer.

On my Nagra VI you can choose to record mono files or poly files, it makes no real difernce to the result as they are all clocked together.

[lordbelial]

So now I only need to know if the R-44 records each channel in a single track (or each stereo pair in a single track), because if it does not, no delay issues would be ever fixed in post...

Is this important?

All tracks *have* to be on the same clock time to record at all.

But if it worries you, just give the manufacturers (or their agent) a ring and they'll have the answer.

On my Nagra VI you can choose to record mono files or poly files, it makes no real difernce to the result as they are all clocked together.

Well, it may seem a silly question, no doubt about it... but that's what I'd like to know, if there's the possibility of choosing on the recorder to make mono files or poly files and having all 4 tracks clocked together.

Since I'll use it mainly as a field recorder it does not matter at all, but I've planning to use it as a 4-track mixer for personal music or even 4-track recorder for video/studio purposes...

[DSatz]

I'm in a hurry right now so I can't double check with the manual, but if I recall correctly the R-44 lets you choose the format. I think it can be two two-channel files, a single four-channel file, or four separate single-channel files at the user's option.

There's been some discussion of this on the forums because for uninterrupted recording, the 2 GB maximum size for a WAV file (a limit which can only sometimes be exceeded) is naturally reached sooner if you record all your tracks in one file.

--best regards

[Roving Sign]

I never understand this "delay" issue when it comes to 4 tracking?

We are simply juxtaposing two stereo track sets in time...delay becomes irrelevant.

You're making a "synthetic" recording - you only heard the AUD...part. The SBD is "fake"

I understand delay as far as making the sources sound as one...but it really seems like a non-issue.

[stevetoney]

I never understand this "delay" issue when it comes to 4 tracking?

We are simply juxtaposing two stereo track sets in time...delay becomes irrelevant.

You're making a "synthetic" recording - you only heard the AUD...part. The SBD is "fake"

I understand delay as far as making the sources sound as one...but it really seems like a non-issue.

Not sure your point and what you mean by 'fake', but if you record them both at the same clock time, they're out of phase by the time it takes sound to reach the mics that are farther away.  Sound travels through air at a slow rate compared to electricity traveling through wires.  In one case, the sound reaches the stage mics (and thus the SBD) 0.03 seconds sooner than the mics that are 10-12 meters into the audience.  Since you're recording 4 tracks simultaneously on the same clock, in Michael Phelps style, the sounds on the SBD tracks beat the sounds on the mic tracks onto the recording, in this case by 0.03 secs.  Obviously, if you listen to all 4 tracks at the same time with no adjustment, you may hear the delay as a reverby sound.  So, in post, you either move the SBD track forward by 0.03 seconds or move the mic tracks back by 0.03 seconds to make them line up right and to eliminate the delay effect.

[lordbelial]

I never understand this "delay" issue when it comes to 4 tracking?

We are simply juxtaposing two stereo track sets in time...delay becomes irrelevant.

You're making a "synthetic" recording - you only heard the AUD...part. The SBD is "fake"

I understand delay as far as making the sources sound as one...but it really seems like a non-issue.

Not sure your point and what you mean by 'fake', but if you record them both at the same clock time, they're out of phase by the time it takes sound to reach the mics that are farther away.  Sound travels through air at a slow rate compared to electricity traveling through wires.  In one case, the sound reaches the stage mics (and thus the SBD) 0.03 seconds sooner than the mics that are 10-12 meters into the audience.  Since you're recording 4 tracks simultaneously on the same clock, in Michael Phelps style, the sounds on the SBD tracks beat the sounds on the mic tracks onto the recording, in this case by 0.03 secs.  Obviously, if you listen to all 4 tracks at the same time with no adjustment, you may hear the delay as a reverby sound.  So, in post, you either move the SBD track forward by 0.03 seconds or move the mic tracks back by 0.03 seconds to make them line up right and to eliminate the delay effect.

Great explanation. We should start talk about delay between SDB and AUD as "Michael Phelps" effect.

[Gutbucket]

I'm in a hurry right now so I can't double check with the manual, but if I recall correctly the R-44 lets you choose the format. I think it can be two two-channel files, a single four-channel file, or four separate single-channel files at the user's option.

There's been some discussion of this on the forums because for uninterrupted recording, the 2 GB maximum size for a WAV file (a limit which can only sometimes be exceeded) is naturally reached sooner if you record all your tracks in one file.

--best regards

^^^^
This is correct. I don't own one yet, but I've been following the device & the threads.

.. planning to use it as a 4-track mixer for personal music or even 4-track recorder for video/studio purposes...

General consensus seems to be that it's a great little 4 track recorder, but has limited mixer and track monitoring functions.  Check the R44 threads for details.

[ghellquist]

If you use the right software at home in your PC or Mac it does not matter how the recorder delivers the material. If worst comes to worst you could always convert from the quad format to 4x mono, but you do what fits your setup.

But yes, according to the manual, the R44 can deliver 4x mono, 2x stereo or 1x quad. It is on page 67.
http://www.edirol.com/images/stories/products/r44/R-44_e1.pdf

Gunnar

[OFOTD]

To answer the original question.....

Yes you can record four individual tracks OR two stereo pairs.   Use your favorite audio editor with either format and you're good to go.  I very much prefer recording four individual tracks.

One of the greatest benefits I have found in four channel recording with one device is the ease in which I can line things up in post.  Having both stereo pairs recorded on the same clock makes lining things up to account for any delay super easy.


Lots of threads on delay and all forms of it.  Just search.

[Gutbucket]

I very much prefer recording four individual tracks.

OFOTD, do you prefer that because you get longer recording times per file (2GB splits) or some other reason?

[OFOTD]

I very much prefer recording four individual tracks.

OFOTD, do you prefer that because you get longer recording times per file (2GB splits) or some other reason?

That is certainly one of the main advantages for sure.  Most software packages will allow you to open a larger combination of files together so that helps.   It also allows me to cut out several steps along the editing process where its easier to make changes on a track by track basis instead of a stereo pair basis.. 

If I was strictly doing two channel recording i'd probably be using 2xSTEREO instead of 4x1 though.

I think the biggest decision to run 4x1 or 2xSTEREO is based upon which software package you're using and how it functions with multiple pairs and/or individual channels.   Currently i'm using SoundForge 9 and the 4x1 is now just what i'm used to.

[rowjimmytour]

To answer the original question.....

Yes you can record four individual tracks OR two stereo pairs.   Use your favorite audio editor with either format and you're good to go.  I very much prefer recording four individual tracks.

One of the greatest benefits I have found in four channel recording with one device is the ease in which I can line things up in post.  Having both stereo pairs recorded on the same clock makes lining things up to account for any delay super easy.


Lots of threads on delay and all forms of it.  Just search.

Dito for me and recording four track w/ my R4. And for the record I have only had delay issues one time running matrix out side where I was about 45' away from the stage uphill. As long as you are around 20'-25' you should be alright w/o any delay. I use Vegas to render my files together and to take care of delay all you have to do is shrink or expand the two audience tracks. I found it easier to shrink the aud tracks to fit the SDB but when you get it right you will know by the reverb. I like the fact that I can tweak all the mono files in post edit so I can fine tune into some thing if I have to. Not sure about the R44 but the R4 the highest sample rate at 4 x mono is 48khz at 24 bit. I forgot to mention that easyjim was my mentor for recording 4 x mono and helped anwer millions ?'s I had and showed me the pluses on 4x.
Peace