An introduction and a question re: lossy and lossless compressions (eg: MP3 and FLAC)

[zomicon]

Hello,

First, I'd like to introduce myself. I wouldn't call myself and audiophile but I do enjoy good, high quality music. I think I am balanced, but some of my friends call me crazy. That said, I am also a value hound and I tend to run cost-benefit analyses on things. I often ask myself: does some incremental increase in potentially inaudible "quality" really justify the cost, time and hassle? Sometimes yes, sometimes no. I am also a researcher and statistician who is generally incredulous when it comes to subjective measurements. That is why I appreciate this forum.

Now to my question: I am going to go through the laborious process of ripping my CD collection and storing it on hard-drive. I will most likely use a lossless format because storage is cheap these days, and why not store ALL of the original information? However, lossless is not appropriate for all applications (e.g., where storage space is at a premium). That said, I'd like to understand at what point a lossy compression algorithm is *virtually* indistinguishable from a lossless one. Can someone provide a rationally grounded opinion around which lossy compression algorithm and what bit rate the difference should undetectable?

Thanks!

Kyle

 

[zomicon]

BTW - Apologies if this question is answered elsewhere. I searched for an answer and was unable to find it.

Thanks!

 

[zhimbo]

There isn't an easy answer - it greatly depends on the content. High bit-rate MP3s are really very good on the vast majority of recordings, but direct comparison of, say, a brief recording of castanets, will reveal differences more readily. It also depends on one's ears - a lot of the loss of fidelity occurs at higher frequencies, where many people are insensitive or completely deaf. Average Middle-aged men may be effectively deaf above 14kHz or even lower thresholds. There's certainly work on this, both formal and informal. A google search on (blind test mp3 lossless) or just (blind test lossless) will keep you busy for a while.

 

[zomicon]

Hi Zhimbo,

Thanks for the reply. I'll check the Googles. I did recently find an online test and found that my ability to hear a tone conked out at right around 14khz (I am 40), which is consistent with your average middle aged man.

Kyle

 

[zhimbo]

Yeah, I'm right around there myself (mid 40s, lose it right around 14kHz).

 

[its phillip]

When it comes to mp3 encoding, LAME presets of v2 and above (v1, v0) should be audibly transparent. I rip everything to flac and convert them to v2 mp3s for my phone.