Real World 192 kHZ

[Risky truth]

Hello all.

With the increase in sampling frequencies I can't help but think that there are going to be subsequent 'issues'. Not only are these files huge, but the data throughput becomes an issue as well.

I am looking at building a new system based on the Mac G4 dual processor platform. RAM and a SCSI Raid will be added to this base system. Anyone have some examples (or non-intimidating math formula) with respect to the following:

What is the file size for each 24-bit track minute sampled at 96 kHZ and 192 kHZ?

With the new ProTools HD capable of 192 kHZ as well as the MOTU HD192, how many tracks can we actually expect before 'it can't take it anymore'?

Adding it all up, what are we looking at for a four minute, 24 track session?

Thanks for your help!

[Brandon Hook]

I'mnot sure about the hardware's robusticity, however, I've got some hard drive space information. at 24/96, you're looking at 17.28MB/min per track. so lets say you're doing a 24 track recording @ 24/96 and the song is 5 minutes long; this ultimately means you've used 2073.6 MB or roughly 2 Gigs.

at 24/192 you can basically expect to double this amount. This rate gives you 34.56 MB/min.

I hope this was somewhat helpful

Good luck

[JeffBarnett]

Here's some non-intimidating numbers for you:

1 minute (mono) at 48kHz, 24 bit = approx. 8 MB
" " at 96 kHz = 16 MB
" " at 192 kHz = 32 MB

Double all of these numbers for stereo audio.

So... four minutes with 24 mono tracks would be

32MB/minute x 4 minutes x 32 tracks = 3,072 MB (3 GB)
For 24 stereo tracks, that'd be 6 GB.

If you have a hard drive that is capabale of recording 24 simultaneous tracks at a standard sampling rate, then you can do 12 at 96 kHz, and 6 at 192. In other words, it takes 4 times as much bandwidth to record the same number of tracks at 192 as it does at 48.

[Brandon Hook]

sorry, I should have also included the math.

formula: ((bit rate * sample rate)/8)/1000 = MB/sec

MB/sec * 60 = MB/min


Good luck

[Risky truth]

Thank you both for the info (and math).

From this, I am looking at just under 15 megs per second I/O for a 24-track session @ 192 kHZ. Is that correct?

Is this something that would (theoretically) require a SCSI Raid or would the new Firewire 800 drive(s) handle it?

Anyone have experience recording at 192 kHZ?

I am looking towards SACD and other 'standards' which may ultimately make sense of recording at this level.

Thanks again !