Topic: Synching 2 + 2

[stevetoney]

Is it really that big of a deal if you have two separate recording decks just to run separate rigs and synch the two recordings afterwards?  I've never had any trouble with stretching or shrinking one recording to synch/match another.  The reason I ask this is that it seems like a reasonable money saving option to buy...say...a second M10 as opposed to selling and putting $800 or $1000 into a DR680 or R-44.  I'm not considering doing this, only curious about peoples responses because it seems like it's never mentioned.   

[Patrick]

Obtaining perfect sync between two separate word clocks is virtually impossible.  Even if you can line up waveforms, there is still drift between the two sources that can result in some pretty terrible things like smearing the stereo image, phase cancellation, and at worse a slapback delay sound.  Even if it is easy to run two separate recording decks in different locations, I don't have time to do the tedious post work and therefore always try to get all my channels run to a centralized point in the venue.  Sometimes the effort is worth it, but most of the time it simply isn't. 

[macdaddy]

one machine is preferable to two when in the field, imo. plus since i dont carry both p2s with me at all times, i miss the last minute matrix option (when asked on the spot if i want a sbd signal). i am looking at the two machines in the original post so that all i would need to do is carry an extra set of cables and the pair of attenuators and i would have the ability to add a sbd source at any time. thetime saved by not having to sync tracks by hand is a nice side benefit (but i get that by sync'g two p2s). finally, further down the line, the only mic i see myself buying is the soundfield, and the four channel recorder would be needed for that. but in reality, i am simply considering thw move to a 4ch recorder because it is one machine instead of two in the bag, and i will always be ready when given the permission to record a sbd feed...

[acidjack]

A lot of guys say it's no big deal but I personally have had a hell of a time doing it.  The last time I had to do it I had to ask another member here for his help.  When he did it, it worked well.

You can of course link two decks perfectly using a USBPre2, but that may not really save you much.  If you just wanted 4 channels, obviously an R-44 is cheaper. 

If I already had a 2-channel rig that included a USBPre2, it would be an economical and easy option to just buy the least expensive second deck with digi in that you could get (which I think would now be the DR-100mkII, IIRC).

[adrianf74]

If I have the choice, I'll use my friend's DR-680 to handle the multiple sources.  This will make synching the recording extremely easy once I've lined up beats and checked them at varying points throughout the recording.

However, there have been times where I've had to use an M10 or two M10's and the DR-680 to record a show.  I've then had to reclock one source against another.  If it's done with extreme care (and precise measurements) you can get the files to match within hundredths of a second in a 2-and-a-half hour show.   Most recently, I had a show where I had a soundboard feed, AKG 480's (hypers0 and DPA 4061's (omnis) and was able to matrix the entire 140 minute show without incident.  The AKGs and SBD were run to the 680 and the 4061's were run to the M10.  I hadn't yet received my PFA's from Jon so I couldn't use them for this show.  I listened to this both with headphones and over speakers and the quality is just superb. 

Likewise, I posted my the New Deal recording from Toronto which is a matrix of my 4061's and my friends 480's.  Again, didn't have the PFA on-hand until just after the show otherwise my life would've been made easier, however, since I had the sample length for the other shows I'd already run, the sample lengths on the 4061/M10 were ahead by less than a second over 2 hours.   Fixed and now up on LMA. 

If I had my way, I'd run a deck that has the ability to run two sources simulatenously but since I don't do this often enough, I can't justify dropping a grand on a R-44.  My friend has had NO issues with the 680 but I know many people in these parts have so I would tend to shy away from that option.

[acidjack]

Adrian also makes a great point - how often do you plan to run 4-channel, Steve? 

I run 4-channel at almost every single show, and I'm mixing down several shows a week.  The extra time of syncing two clocks in post would kill me - I don't have the time to mix down what I have as it is.  But if I was only doing it, say, once per month, I tend to agree that it's harder to justify spending big bucks on a multi-channel deck. 

[stevetoney]

Adrian also makes a great point - how often do you plan to run 4-channel, Steve? 

I was doing 4 channel into an R4 Pro for awhile but my recordings would sound better than the 2 channel versions in only a handful of situations, so I stopped. 

I asked the question more out of curiosity since it seems like people consider it sorta taboo, but since digital recorders exhibit no wow and flutter, I've never had much trouble synching two sources spot on perfect with the software I use and it usually doesn't take much more than 10 to 15 minutes to get them lined up and get one of the files changed if I'm using a fast computer. 

I do agree though that if you do 4 channel often it wouldn't make sense to not have a 4 channel recorder.

[adrianf74]

That's the thing.  It's a matter of "how often" are you gonna be doing it?  If I was doing multiple shows per week like AcidJack, I'd be running a 680 or 44 pronto.  If it's the odd show that you want to matrix because both mics sounded like crap on their own (but complement each other well) or you had board access and wanted to spruce it up, then I'd run the two recorders and "fix it in post." 

I've done quite a few matrix recordings in the past year (about 15 of them) but I still wouldn't spend the extra cash for that few shows.   Now that I have the PFA, I have to figure out how I'm gonna use inputs 5+6 on the 680 and if I'm gonna have to attenuate the board feed from XLR > RCA in order to best utilise my inputs - but that's another story/thread.

[page]

Obtaining perfect sync between two separate word clocks is virtually impossible.  Even if you can line up waveforms, there is still drift between the two sources that can result in some pretty terrible things like smearing the stereo image, phase cancellation, and at worse a slapback delay sound. 

Completely agree, even when you get really good at reclocking stuff, there can be minor amounts of non-linear drift during a set (depending on individual units, not brands or models). I've done 2+ hour sets and heard instruments and soundstage move around slightly due to cancelation/emphasis that I don't hear on either of the sources and it gradually occurs over a period of time (e.g. not a mix adjustment in the room). It's not bad, I only notice it if I'm really doing analytical listening on a few really good setups, and all of my sync points line up visually down to the sample, but I've never been able to eliminate that teeny tiny bit of change when it shows up. My 4ch clocked stuff doesn't have this issue.

If I already had a 2-channel rig that included a USBPre2, it would be an economical and easy option to just buy the least expensive second deck with digi in that you could get (which I think would now be the DR-100mkII, IIRC).

bingo, that's what I did. I have a 722 which is my workhorse recorder, and bought a usbpre2 as a dac/amp, but it also doubles as a second preamp/adc that can clock against the 722 if needed. So since I sold my old dac/amp and used that cash to buy the pre2, I was out the cost of a D50 for what essentially is a slightly bigger footprint and 4 clock-able channels (or 2+2 if I want to run on separate stages simultaneously). So while the pre2 isn't a perfect box, it's damned close in that aspect.

I only record 4ch about 3 times a year, so there was no good reason for me to blow cash on it, but this option allowed me to pick up gear I like the sound of and do it on the relative cheap.

[hi and lo]

The clock drift between recorders might not be consistent over time. Trying to use different decks really isn't an option and you'll waste countless hours trying to get it to work , if it works at all.

[runonce]

Arent there certain gear combos that allow you to sync the second deck's A/D to the firsts clock....?
HD-P2?

[stevetoney]

The clock drift between recorders might not be consistent over time. Trying to use different decks really isn't an option and you'll waste countless hours trying to get it to work , if it works at all.

That really hasn't been my experience the time's I've synched two different sources that were sourced from digital recorders.  The drift between the two is linear so it's straight forward to address and the synch is consistent throughout the recording after correcting one or the other, but yeah I definitely agree that if one of the two clocks isn't linear or if one of the recorders drops bits here and there then it wouldn't be very easy to synch the two sources together.

[justink]

The clock drift between recorders might not be consistent over time. Trying to use different decks really isn't an option and you'll waste countless hours trying to get it to work , if it works at all.

That really hasn't been my experience the time's I've synched two different sources that were sourced from digital recorders.  The drift between the two is linear so it's straight forward to address and the synch is consistent throughout the recording after correcting one or the other, but yeah I definitely agree that if one of the two clocks isn't linear or if one of the recorders drops bits here and there then it wouldn't be very easy to synch the two sources together.

the drift between my R-44 and another recorder was consistent three straight nights actually.

[stevetoney]

Arent there certain gear combos that allow you to sync the second deck's A/D to the firsts clock....?
HD-P2?

Yeah, for sure.  HD-P2 can link to other HD-P2's and the 2 channel Sound Devices can also.  I'm sure there are others.

[acidjack]

Adrian also makes a great point - how often do you plan to run 4-channel, Steve? 

I was doing 4 channel into an R4 Pro for awhile but my recordings would sound better than the 2 channel versions in only a handful of situations, so I stopped. 

I asked the question more out of curiosity since it seems like people consider it sorta taboo, but since digital recorders exhibit no wow and flutter, I've never had much trouble synching two sources spot on perfect with the software I use and it usually doesn't take much more than 10 to 15 minutes to get them lined up and get one of the files changed if I'm using a fast computer. 

I do agree though that if you do 4 channel often it wouldn't make sense to not have a 4 channel recorder.

FWIW, also, when I say "four channel" I generally mean SBD+mics.  Four mics (or six mics) can be interesting, especially if the mics are placed in different locations (i.e., one pair onstage, one pair FOB), but I tend to agree with you that for just throwing up some mics somewhere in a room, I'm not sure running four mics together is always that beneficial, esp for how much of a PITA it is.