How do I do the math - Hard Disk space needed for Bitrate/Samplerate?

[wes480]

Hey

I am getting confused. Just trying to work out the "formula" to tell how much hard disk space audio recording is going to take up. Lest say for example...20 bit, at 48k sample rate.

Here is what I have so far - 8 bits in a byte. really, that's about it. i don't know how sample rate etc. all figures into the calculation. Anyone let me know? i am trying to figure out how much space I will need. I'd like to be able to hold like....12 tracks of 20/48 audio....74 minutes each (full cd length)...I wonder if that would come in at under 40 gigs or so? Help me out, thanks.

-wes

 

[wes480]

eureka!

after I stopped and thought about it it made sense. I was just losing sight of what "sample rate" really is. This math seems to work...but, someone let me know if I am doing something wrong....

to figure out 1 minute of audio (mono track)

(Sample Rate) * (Bit Rate) / 8 [bits in a byte]/ 1024 [bytes in a killobyte] * 60 [seconds in a minute]

so in other words, say 16 bit audio..at 44,100 sample rate.

16*44100/8/1024*60 = 5167.97 killobytes per minute.

or..like, 10.3 megs a minute for a stereo track - which is just about right.


now to answer my own question, for the hell of it. At 20/48...audio is 7031.25 k/minute. About 508 megs an hour. Hmm, 12 tracks would take less than 7 gigs. Hooray.

which leaves only one thing unanswered - If it takes a chicken and a half, a day and a half, to lay an egg and a half...then how many pancakes does it take to shingle a roof?

 

[Shazukura]

42?

 

[charger]

3.14?