Explaining things to non-audiophiles

2003-04-25 17:20:15

Every once in a while I find myself conversing with someone about audio encoding/ripping and related subjects. During those conversations I often hear things like:

"Who cares which ripper? CDs are digital anyway, it's always the same"

or

"You can't hear differences between different encoders at the same bitrate, that's impossible"

Getting people to understand that those kind of statements are incorrect isn't easy, especially if you yourself aren't too sure WHY they're untrue (I still don't understand why DAE is always so error-prone)  and you don't want to get into a big one-sided conversation about lowpasses and psymodels.

Are there any easy 1-2 liners that you can throw at people that will make them think twice about what they know about audio ripping/encoding? Somethings along the lines of:

"LAME is the best because many people have been tuning it for years"

...for example.

Explaining things to non-audiophiles

Reply #1 – 2003-04-25 17:35:10

Try the FAQs.

The brief answers are:

a) because audio CDs have much poorer error correction than CD-ROMs, and almost no synchronisation information.

Because of the lack of synchronisation information, it's very difficult to get most CD-ROM drives to go back to exactly the same place on an audio CD, so (especially on older drives) it's easy to miss or repeat a few samples, even on perfect condition discs. Many CD-ROM drives don't even correct the errors on a scratched CD which an audio CD player (or even a CD-ROM drive playing an audio CD) will happily ignore. Both problems give unexpected clicks in the rips.

B ) because the MPEG standard defines the mp3 bitstream and the decoder, but not the encoder.

This means all encoders are either based on an "example" encoder from MPEG which barely works, or are developed independently - so they are all very different!

The encoder has the difficult job of choosing which information to discard, and which to keep - it needs to know your ears better than you do. This is not easy! However, it is easy to make an mp3 file which is perfectly valid, but contains audio which sounds almost nothing like the original. If that's what you want, pick the worst encoder you can find. It won't worry what the result sounds like - it'll just stick something in the mp3 file and hope for the best.

Cheers,
David.

Edit : removed the false smiley

Explaining things to non-audiophiles

Reply #2 – 2003-04-25 18:28:27

Cars:
MPEG standard defines what is a car, and how to use it (should have wheels, be usable on roads to go from one point to another one, should have tires,...).
But is does not defines how to build it.

You, as a user, are mostly able to drive any car. But are they all identical? Of course no: some are faster, some more powerfull, some more luxurious or more comfortables.

Even when using a specific car brand (encoder), there are differences between models (encoding modes and bitrates)