CD Blues

[Johnno]

Our school had a Sports Awards evening last week. A member of the PE staff made a CD at home to play when the children collected their prizes, one track per pupil. Well, that was the theory anyway.

 

I was given the CD five minutes before the show was to start and promptly found that it sounded awful on the old domestic CD player we use. Some sort of digital noise screech over every track. Total panic by the PE staff turned up a laptop and we used that instead. Or we would have if we hadn't noticed the awful racket the CD made. We noticed this when we started playing the CD as the first pupil collected his prize. So the ceremony was conducted in silence. I got the blame, of course, but I'm a real technician and I can take it.

 

waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhh blubblubblub

 

Anyone suggest why the CD would not play?

 

I forgot to say that the PE department kept the CD to themselves because they wanted it to be a surprise to the pupils. Thick or what?

[Bobbsy]

Only a guess, but I had something like this a few years back when I accidentally burned a music CD with some of the files at the wrong bit depth (I use 32 bit floating point for tracking and editing). Modern CD burning software won't let you burn a music (as opposed to data) CD at the wrong settings, but the earlier version of Nero I had back then would accept non-standard files.

 

Bob

[Tomo]

Almost certainly a poor recording.

 

When recording from MP3 onto a CD, the recoridng program decompresses into the proper Redbook CD-audio stream.

There are a lot of decompressing programs that badly mess this up for certain MP3 bitrates.

 

Alternatively the CD may have been recorded at too high a level - adding massive digital distortion.

 

I remember doing a corporate event where we were supposed to play a video showing clips from the conference.

The video guy spent the last few hours completing the edit, then dropped the tape on my desk fifteen minutes before we were due to play it - this is while the conference was running live onstage of course.

 

A quick PFL indicated that the sound had been recorded at far too high a level, with no time to rerecord...

- So we dug up the backing track on the sound engineers CD, spent a couple of minutes practicing a simultaneous start and pretty nearly nailed it.

 

All the while still running the conference of course - multitasking is fun.

Dealing with this kind of thing is probably why I enjoy live events so much!

[Shez]

I come across this kind of thing quite a lot.

 

It's almost always caused by people not understanding how to create an audio CD properly. They assume that just because windoze says it can do the job in less than 20 seconds, that must be fine. They'll use a rubbish brand of CD, burnt at an inappropriate speed, in a free-in-a-cereal-box recorder and expect it to be just like an actual pressed CD. And they're always amazed when I tell them that these things do actually matter!