Latency and Phase Issue?
I noticed that some of the newer multi-track recorders, such as the Zoom R16, can sync up with each other and record up to 16 tracks at once. However, I read in a user forum that someone tried this and found that the two machines were actually 1-2ms off from each other. For him, that made it impossible to work with. The manual itselfs reports that there is a 1-2ms latency between the two machines, even when in sync. To me, a 1/1000th or 2/1000th of a second difference seems insignificant. But now I am being told that this type of latency causes a phase problem and is noticible in the recordings.
Can somebody tell me to why a 1-2ms difference in track alignments would make an audible difference? Talk down to me because I really am stumped on this one. It just does not seem that a 1-2ms latency difference would ever matter.
The reason why I would like to know, is that I might want to add tracks to an exisiting project I have recorded, and God forbid, that I be 1/1000th of a second off and have phase issues. I have multiple recorders and input devices for computer recording, and none of them are capable of syncing up to each other perfectly. I don't even know how to achieve a perfect sync with our DAW software.
I'm a pretty reasonable guy, I think. The example I used was that when I play bass, if my bandmates told me that I was 1/1000th of a second later than the drummer and to tighten up, I'd probably hit him over the head with my bass and leave him for dead! But now I hear people on these forums telling me it creates a phase issue on the audio recording!!?? Have we all lost our minds? Or it just that I don't understand the underlying problem here? Well, I probably lost my mind a long time ago. If anyone can explain this to me, I thank you in advance.
Can somebody tell me to why a 1-2ms difference in track alignments would make an audible difference? Talk down to me because I really am stumped on this one. It just does not seem that a 1-2ms latency difference would ever matter.
The reason why I would like to know, is that I might want to add tracks to an exisiting project I have recorded, and God forbid, that I be 1/1000th of a second off and have phase issues. I have multiple recorders and input devices for computer recording, and none of them are capable of syncing up to each other perfectly. I don't even know how to achieve a perfect sync with our DAW software.
I'm a pretty reasonable guy, I think. The example I used was that when I play bass, if my bandmates told me that I was 1/1000th of a second later than the drummer and to tighten up, I'd probably hit him over the head with my bass and leave him for dead! But now I hear people on these forums telling me it creates a phase issue on the audio recording!!?? Have we all lost our minds? Or it just that I don't understand the underlying problem here? Well, I probably lost my mind a long time ago. If anyone can explain this to me, I thank you in advance.
Comments
That said, I chucked PTP/computer recording ages ago 'cuz of an array of problems, not the least of which was latency issues, especially as they related to performance.
I'd like to think that recording hardware wouldn't be as susceptible to such problems, but I've never done it either. Only those who've done it could say...myself, I'll stick with my Tascam and save the brain space I used to torment with computer problems for pining after Shania. :P
Well, I agree. But the scenario here was using two Zoom R16 multi-track recorders, each recording 8 tracks live, both units sync'd to each other to give 16 tracks recording. However, there is a 1-2ms latency difference between the two recorders. There are some guys out there saying this 1-2ms difference renders the project \"unworkable.\" When I asked if they could hear a 1-2ms difference, the response I got was that it was a phase issue!!?? WTF, over? I thought I understood latency, and I thought I understood what a phase difference was, but I can't see how a 1-2ms difference would affect a recording either way, latency or phase.
But, if it does, the follow-up question would have to be, is there a way in software to align tracks so that you don't have this 1-2ms difference causing all these problems? I'm just hoping that someone with a background in audio engineering can either confirm or deny the asserations made by others in regard to this 1-2ms difference. I'm willing to learn, but nobody yet has explained to me what the big problem is. Again, for me, I had planned on maybe collaborating with other musicians and adding their tracks to a master project. If a 1-2ms difference kills a recording, it's game over for me because I can't split a hair that fine.
Tell ya what. Fix me up w/Shania and I'll come be your sound man and solve all your problems... 8)
My Zoom HD16CD can also trim down to .001 second (1ms). I was refering more to the concept that I would even know/hear/recognize that two tracks were off by 1 or 2ms, and then being able to trim them to the exact time. It's not me that is suggesting there is a phase issue when two tracks are off by 1 or 2ms, someone else was suggesting that was an \"issue\" for them. The whole concept of two tracks being off by 1 or 2ms and therefore, \"unworkable\", just does not seem right to me. Personally, I don't think the human brain is able to discern a 1/1000th of a second difference between tracks. I would not even try in my case. My wife complains that she tells me to take the garbage out on Monday and I don't hear her until Wednesday....
If I had any influence with Shania, I would not be at home on Christmas posting to a guitar forum! Sorry, Shredd.
Actually, we have a winter storm going on here in northern Minnesota so we have been more or less shut in since Thursday. Storm expected to end Saturday afternoon. So posting to the forum is just one way for me to pass my cabin fever time while waiting out the storm. Take care.
As you mentioned before being 1/1000th off the drummer who cares.. What abot that humanize feature on some stuff ain't that moving a track a clip 1/1000th or more? Then again I don't really know what your talking about when it comes to the phase?..
No, I haven't heard the outcome. Like I said, the discussion was the ability to sync two Zoom R16's (which I don't have) together but the tech manual states that there is a 1-2ms latency difference in alignment. Someone who \"claims\" to have tried this stated that he could not work with a 1-2ms latency on the tracks between the machines. When I asked how he could hear a 1/1000th of a second difference, the topic quickly got changed to a \"phase\" issue. When I asked what in the world he meant by a phase issue caused by a 1/1000th of a second delay, he has not replied. Don't know if he is just busy during the Holiday Season, or if can't defend his statements, or maybe he just doesn't want to respond.
The reason I am interested in the topic is because I was thinking about expanding my recording capabilities and maybe purchasing an additional multi-track recorder. Since I cannot sync my Zoom HD16CD with a Zoom R16, I would have to manually align the tracks in software after the machines recorded their tracks. Until now, I've always used one machine and/or software program to complete a project, from start to finish. So I was surprised to hear someone claim that using two sync'd machines with a 1-2ms latency resulted in an unworkable project. If that was the case, I would not have a chance trying to manually align tracks by ear later in my software.
I'm just hoping that someone lots smarter than me on this issue can either confirm or deny the allegation that a 1-2ms latency issue will create a phase issue making the recording unworkable. I don't believe it, based on my personal experience. But I could be wrong. I can hear latency issues, just not down to 1ms. Also, just recently, I have tried to work on a project with mixed midi tracks and VST tracks. There was indeed a timing issue between the tracks and it sounded terrible. But, again, the difference was about 250ms, or more.
I know it isn't the same as what you want to know... So what would be the difference? But I can't see why it would be a problem doing what you want to do... Sorry I don't have the knowledge you seek ....
But I just do this for fun an don't push myself more than I probably should to learn stuff... Why I hang out here! LoL To see what lil tidbits I can pick up!
If the clocks of the machines are synced, there really should not be any real noticeable latency.
However, in the situation that we were talking about, syncing two Zoom R16 together, I was under the understanding that both machines recorded with the same timing, but the only difference was that one machine could possibly be 1-2ms later than the other, and that this difference would remain constant no matter how long the recording, in other words, no cumulative effect. That was my understanding. But maybe you are right and issue is the cummulative effect of two machines recording at the same time but one machine actually recording slower than the other. But, if that was the case, how could you say that the machines were in sync to begin with?
This idea of a cumulative effect difference had me worried before as I had envisioned using two different multi-track recorders to record a gig and then transferring the files back to Cubase. If the machines cannot be sync'd, and one machine does record 1-2ms faster/slower than another machine over a given period of time, the cumulative effect of that difference may be great at the end of a recording, especially in my case where I want to record 4+ hours a night. I understood that. I could not wrap my head around a 1-2ms difference being \"unworkable\" where the machines were sync'd and that latency of 1-2ms was constant over any period of recording.
I would assume the units to sync properly if the spec is as stated. The difference in latency would depend on the length of cable connecting device hardware (which can add minor latency), but most of the time, when devices are made with multi unit connectivity and sync, the recorded audio is NOT enabled until the master sync clock feedback signal is returned to the master machine from the slave machine. The 1-2 msec latency thus would only be related to signal loss over certain cable inter-connectivity. In most cases, that would be very minimal.