Axiom Home Page Forums General Discussion The Water Cooler MP3 Quality test

A little disappointed, yet pleasantly suprised.

I ripped a store bought CD into my computer at 128 bps MP3 format. I then burned a CD of the album in MP3. The album I chose was from the band a perfect circle due to the large range of dynamics of the music and the high quality of the recording.

I placed the original in my first DVD playerand the MP3 version in my other DVD player. I started both discs simultaneously and then switched the sources back and forth. Well I was sure I was going to hear a difference and at first I could. The MP3 disc was quiter. I utilized my Onyko's intellivolume feature to match the loudness of both sources and then I couldn't hear any discernable difference. I was really hoping that my ears would be able to detect the loss of quality due to compression that I have been telling people exists when you go to MP3, but I just couldn't hear it. I listened on both a nice set of headphones and with my lovely axioms. They sounded the same. Which is good news, but I just thought I would be able to tell the difference.

Anybody done any similar tests with MP3 quality??

Not quite to the detail that you have, since I don't have the equipment. I have ripped some tracks at various encoding levels though and really haven't been able to hear the difference from the source once I got up above 128kbs or so. I guess that's a good thing, since it saves on disk space!

I rip everything at 320kbs and have A/B'd to the original disc with a ton of people and nobody to date can pick the disc from the MP3 or vice versa. Only problem with ripping at 320kbs is the required hard disc space. I'm currently running two 200gig hard drives and one is 85% full.

Neverhappy, how did you come to choose 320kbs? Did you have problems or notice degradation with lower bitrates?

That is what I ripped a bunch of stuff into my computer at as well but it seems that even at 128 you can't tell the difference.

I've noticed more sibilance and high-freq noise with some mp3's burned to cd when compared A/B to the original. Not all though. Also some seem to be, I don't know, drier. I rip at 320. Now with mp3 files on cd, I can hear quite a difference, like the atmosphere has been sucked out of the music.

I listen to nothing but mp3's. My Mazda's have come with kenwood mp3 players since 2001 as well so even in the car, it's all mp3.

Anything below 192 bit, I don't waste my time with. 128 is really poor quality, and I can easily tell the difference between it and a cd audio. It sounds tin'y, sibilance is more, less bass, almost muddy etc.

320 is great, but file size is a problem. So I try to get nothing but 192's or around 192. I think it's a good compromise. The difference between 192 to 320, at least to my ears is min.

Hmm... I find it strange you can't tell the difference. I can tell the difference even with 320 kbps MP3s when there's a lot going on in the music.

Higher frequencies are mainly where the flaws show up. Cymbals are especially good at revealing MP3 compression artifacts. I've never really heard cymbals sound correct. I can also readily tell with piano, but I am willing to guess that this is because I played the piano for 12 years.

If I may ask, how old are you? As you age, your ability to hear higher frequencies drops dramatically. I am guessing that people who can't tell the difference would be older than I am or have ears that have been abused by loud music.

Personally, I can't stand listening to MP3s when I'm actually paying attention to my music (lights off, door closed, eyes closed, and so on). The artifacts just jump out at me.

EDIT: newf and NeverHappy: that is what VBR with -q 11 in LAME is for. It gives you the same quality as CBR 320 but with nice space savings when a lower bitrate can be used without degrading the quality

I have always done everything everything with Exact Audio at 320kps and like I said, NOBODY has yet to sit in my house and pick out which is which.

I went 320kps only because I have always had big hard drives and anything below 320kps I seem to be able to pick out some things I don't like. 128kps for example sounds not bad but on some stuff a lot of bass that is normally there is gone or on some music it seems to add bass that was never there.

At the end of the day this like so many other things in audio comes down to personal taste and what the music is being played through. If you have a revealing system, chances are better you will be able to pick out the flaws associated with each respective bit rate.

.............and I'm 38 years old and just had my hearing checked. According to the Doc, it's as good as when I tested with him at 22. So far, so good.

I can hear the difference between 192 and 320. Just that I make cd's for the car, and I make the compromise at 192 so I can get more on a cd. So generally, all mp3's are ~192 or better.

I am 30

I found this on Wikipedia and thought it was interesting, especially the "Quality of MP3 Audio" and the suggestion to use "Lossless compression algorithms". It's a good and informative read, I really enjoyed it.

Here's the direct link to the relevant section: Wikipedia MP3