DP-24SD slightly too slow?

[Gert-Jan]

Hi all!
I just bought a Tascam DP-24SD and recorded a theater show with it (7 tracks with microphones).
At the same time the show was recorded in seperate tracks from a Soundcraft mixer into a laptop, and a 'stand-alone' mic on a video camera.
All recordings were set to 48KHz, 24 bit.
While afterwards putting all tracks together in a DAW, I noticed that at the end of the recording the Tascam tracks were about 1 second slower/later than the tracks from both the video camera and the Soundcraft mixer.

The Teac/Tascam support people in Germany answered that this problem is caused by the individual and not-synced wordclock. There suggestion is to use time-stretching in post-production.
I find this a bit strange, because other recorders don't seem to have this problem.

Anyone with the same experience?

 

[Old No7]

I've not experienced this, but then again, I just got a DP-24SD and have nothing to compare it against (yet). The Tascam Support comment about "synching the clocks" seems to make sense. (Could be human error of pushing the REC button?)

If that was a 90-minutes show, then that 1 second calculates out to 1/5,400 or 0.185185%; or said another way, that's 99.9814815% clock accuracy for the Tascam (or maybe the "user"?) as compared to the others; or 1.85 DPM (defects per million).

I get it, that one second is not the result you wanted to see; but that's darn good for any manufactured product -- I'll bet the smartphone you carry and/or car you drive aren't nearly that good overall.

Now I'm curious to see what others might say...

Old No7

 

[Phil Tipping]

This isn't unexpected when there's no sync system, but I'm not sure if the Tascam machine is any worse than others. Free-standing machines usually calculate time from a built in oscillator based on a crystal, so it depends how accurate that is in absolute terms, and then how much it's affected by temperature, voltage etc. It may even vary from machine to machine. Imho it's just luck how much different systems will drift against each other.
I did a 4 hour show using 3 camcorders (all different makes) and a DP-32SD. Lining up the start times was no problem, but all of the feeds drifted with each other throughout the show. I don't remember if the Tascam was the worst.
I didn't try time-stretching during the editing; I just slid sections backwards/forwards in time by eye/ear.
A sync system would have avoided all this, but you have to weigh up the cost of providing this against time spent editing.
Just my 2c.

 

[Gert-Jan]

I think I have to accept it and put more time and energy in post-production.
Thanks for all your replies!

 

[Saxomohawh]

There may be a difference, but you cannot say the DP is "slower" because that would affect both record and playback. (Final result=no diff.). I wonder how much difference you would get between two separate PC's, maybe the same? I don't know.

 

[-mjk-]

It also depends what your DAW does with it when you import. What you have is basically a third machine interpreting files that were created by two other machines.

 

[shredd]

Hi Kidz...the wise and all-knowing Phil T pointed me at this thread, because (SHOCKING, I know) I have just experienced the OP's exact problem. I'm just too stewpyd to have located this thread. For THAT I apologize!

I have a 2488neo (pretty old now) and an original-design DP-32; both of THOSE keep the EXACT same time...probably have the same "chip" that Phil refers to in my thread creating the clock.

BUT: I also have a couple of BOSS "BR" series portable MTR's: the terrific BR-800, and the teeny little Micro BR. They're both fine units - great features, capabilities, and sound...

BUT - I recently recorded trax to use in a "main studio" (on my big P/Studio's) project, and found that when I'd set the BPM of the BOSS's drum machine or metronome to xxxBPM, those tracks DID NOT MATCH the rhythm of the project that was set to the SAME bpm.

I thought it was just a problem with that BR - then I recorded on the OTHER BR, and had the same result.

SO: I recorded several drum machines (which I've recorded into the 2488 & DP with bpm's set to match the project, and kept perfect time) into the BOSS units, with the bpm settings of both identical.
SURPRISE SUPRISE - they do NOT match. The BOSS would lose that micro-bit of time on each beat, so that by 25-30-40 measures into a take, it was behind by at LEAST a full beat of 4/4 time. I was gobsmacked and had no idea how this was possible - I'd assumed xxxBPM is xxxBPM, no matter how or where it's "calculated".
It turns out this is NOT SO! Read Phil T's reply to my thread, which is the likely explanation for this.

I'm devastated because it means my various recording resources will not "play nice together" - I'd intended to do things like go to a friends' house with a track recorded on my DP, record them playing bass or whatever to my portable, then export the tracks on to my DP to mix in. NOT gonna work!

Unfortunately, the BOSS units do not accept MIDI clocks, and I don't use DAW's, so I'm not able to "time-stretch".

So it appears that the BOSS portables will be used for fun & playtime w/friends, not for my original intent of capturning tracks portably/remotely. I'm PIECED!!!