A One Hour Wave file

My colleague and I are toying with the idea of delivering radio shows as wave files. He uses Audition as I do. I cannot understand how his 2 hour wave file comes to around 500MB and mine comes to 2.1GB! The first obvious question we asked ourselves was the possibility that I'm exporting 32bit Waves and he is exporting 16bit Waves. the only place I can find to change the bit rate is at the export/save stage, and even when I change it to 16bit my 2 hour wave is still over 2GB. Inside the mulitrack, bottom-right it says 16bit mixing. The content of the waves are the same, a music and chat radio show.

Can anyone shine a light on this please?

Something is definately wrong.  I don't have too many ideas, but a 2 hour stereo, 16-bit, 44,100 file should be around 1 gig.  Mono should be half that.  Maybe the "save non-audio information" box?

Are you working at 44.1 KHz sampling rate?

The question that I have is simply 'how accurate is your 2 hrs?'

Let me run the math for you, then you can work it out for yourself - it's not difficult.

Firstly, recall that 16 bits = 2 bytes. Secondly, that 44.1 k/samples per sec is per channel. So:

2 channels x 44.1k x 2 bytes = 176.4 kbytes/second. That's our base rate for 16-bit 44.1k stereo.

176.4k x 60 = 10,584 kbytes/minute (10.584 Megabytes)

10.584 x 60 = 635.04 Megabytes/hr. (When they claim that a 700 MB CD will run for 80 minutes, they are rounding this up slightly - this would actually require 846.72 MB - but the total storage time on a CD varies a bit anyway, depending on the stamper it was made from)

Anyway, 2 hrs would require 635.04 x 2 = 1.27 Gigabytes - and that's neither 2.1GB nor 500MB.

2hrs @ 32-bit = 2.56 GB (twice the number of bytes) and 2hrs @ 16-bit  mono = 635.04 MB (half the number of bytes).

So what's really going on?

Hmmmmm--

WELL my real first question is:  Why are you wanting to save the file as a wave?  I understand the whole quality thing, but I have produced syndicated shows in 15 to 20 minute chunks as well as whole hour and two hour long segments AND I personally know producers/image guy/girls that consistently produced their shows (which are also 1 hour plus in length) and we all save as super high quality MP3s.  I may be opening a can of worms that I will wish I hadnt opened--BUT why not try saving as high quality mp3s?  1 gig or 2, thats just too much space to consume for a one time show OR esp an on going basis.  Just my opinion.


Smiles,

Could be 32k sampling at 16-bit resolution. This gives you the full 15kHz bandwidth of FM broadcasting and was the standard sampling rate (in mono though) of the BBC's D-Cart news system that replaced tape...

(According to AA this comes in at 439MB for an hour in stereo)

(According to AA this comes in at 439MB for an hour in stereo)

Interesting discrepancy - it should come out at 460.8MB. It may be that all these small errors are because of the standard roundings applied to MB and GB - 1 MB is 1024 KB and 1 GB is 1024MB. This would make the real number of bytes in a GB rather more - like about 73.74 million more, by the time you've taken the kB to MB error into account as well - and that's enough for another 7+ minutes of 44.1k stereo.

the standard roundings applied to MB and GB - 1 MB is 1024 KB and 1 GB is 1024MB.

There's an IEC (but not SI) standard for binary prefixes, in an attempt to resolve this ambiguity (or misuse, really!); read here.  The informal usage gets worse when you discover that there are situations in which 1MB is being used to mean 1,024,000!

Paul

Yes, I was vaguely aware that they'd got all these strange names for some of the multipliers. So they want to call that thing I've got with the extra 73 point whatever MB a Gigibyte (as in gigabinary), do they?  Well, that makes about as much sense as anything does...

So they want to call that thing I've got with the extra 73 point whatever MB a Gigibyte (as in gigabinary), do they?

Try Gibibyte (GiB).  I've seen no sign of anyone taking this up, though.

Paul

[OF THEM.]

So they want to call that thing I've got with the extra 73 point whatever MB a Gigibyte (as in gigabinary), do they?

Try Gibibyte (GiB).  I've seen no sign of anyone taking this up, though.

Paul

Oh, yes - how stupid - OF THEM. That's not quite unpronouncible, but getting on that way. It's hardly surprising that there appears to be no takeup, is it? What on earth is the point? It's only when you start to do things like calculate real file sizes that this ever becomes an issue. Mercifully, this is pretty rare...

Anyway, the solution was to save Waves from the Edit View rather than from the Multitrack View and then the Waves are the size they should be. Still have no idea why waves saved from the Multitrack View are so large though.

Still have no idea why waves saved from the Multitrack View are so large though.

If you set it to mix in 32-bit, that's what it will save the wav files as... basically the same as the session settings.

Could it be that in multitrack mode its adding in the "empty" unused tracks? Just a thought....

Could it be that in multitrack mode its adding in the "empty" unused tracks? Just a thought....

Shouldn't do - it saves each track as an individual file. The ses file is what links them all together.