Hello to the HA community
Here’s the result of my first ABX test.
I listen to mp3 files for about ten years now, and I use Vorbis since 2002 (the first final release). I hate badly compressed songs, but however I never really tried to know if I was able to distinguish an encoded sound. I love to listen high quality music, but what quality do I need ? Is the quality of a high VBR vorbis or mp3 really this good ? I began this test to answer these simples questions… and for fun, of course !
I wasn’t planning to share the results on a forum, so don’t blame me if I made mistakes, or if my comments are not always perfect… and sorry for my average english, I’m french.
I used the following samples from my own collection of CDs:
01 - Alain Souchon - Au Ras Des Pâquerettes - Au Ras Des Pâquerettes
02 - Björk - Homogenic - Hunter
03 - Björk - Homogenic - Pluto
04 - Ben Harper - Diamonds On The Inside - When It's Good
05 - Mogwaï - Mr Beast - Acid Food
06 - American Head Charge - The War Of Art - A Violent Reaction
07 - Guem - Percussions Africaines Pour La Transe - Le Serpent
08 - Dredg - Leitmotif - Lechium
09 - FSOL - The Isness - High Tide On The Sea Of Flesh
10 - Soulfly - Primitive - Back To The Primitive
11 - U2 - War - Seconds
12 - FSOL - Dead Cities - Antique Toy
13 - The Chemical Brothers - Dig Your Own Hole - Elektrobank
14 - Genesis - Foxtrot – Horizons
I tried to choose interesting samples, despite the fact that it was my first attempt to find ones by myself.
I used EAC 0.95 beta 4 with secure mode to rip every songs. Each CDs are originals ones of course.
I wanted to generate encoded samples that I would be supposed to listen in real life. So I used well know compiles of encoders:
- oggdropXPd V1.8.9 Lancer[20061110] with SSE3 and MultiThreading, using aoTuV b5
- lamedropXPd V2.0 using Lame 3.97 final
The settings are quite simples as well. For lamedrop:
- Target Quality : 50 / VBR mode : Standard / Encoding Engine Quality : High (132kbps)
- Target Quality : 80 / VBR mode : Standard / Encoding Engine Quality : High (190kbps)
- Target Quality : 100 / VBR mode : Standard / Encoding Engine Quality : High (240kbps)
And for oggdrop:
- Standard Quality Mode : q1 (80kbps)
- Standard Quality Mode : q3 (112kbps)
- Standard Quality Mode : q5 (160kbps)
Assuming mp3 @ 132kbps is 100%, then 240 is 182%.
Assuming Vorbis @ 80kbps is 100%, then 160 is 200%, so we will see how these encoders behave when the data rate is doubled.
Here is the hardware used for ripping, encoding and ABX:
Intel E6600
Asus P5B Deluxe no Wifi
Hitachi Deskstar T7K250 160 Go P-ATA
Pioneer DVR-110D modded with DVR-A10XL firmware (v 1.41). Used to rip every samples.
Creative Audigy LS
Sony MDR-EX51 (not killer earphones, but quite good, and the intra auricular design is good to ear sharp sounds).
I used the tool ABC/HR 1.1b2 to randomize my samples.
So here are the results:
Each sample is described with a special notation, from ‘very easy’ to ‘perfect’. Very easy means it’s easy to distinguish encoded from original, perfect means it’s impossible
Let’s begin with mp3 samples. I was able to distinguish most of the sample when they were encoded with 132kbps, but the quality was really better with 190kbps. I was extremely surprised when I realised that the advantage of 240kbps was so small over 190.
Thanks to HA for all the informations gathered here
PS : this is the link to my PCM [a href="http://rapidshare.com/files/5168835/sources_flac.zip" target="_blank"]samples (http://img299.imageshack.us/my.php?image=abxmp3kv1.gif)
Thx for sharing your experience. Interesting read. aoTuV q-5 is amazing since b4. If I'm free from H/W compatiblity issue, I don't hesitate to use this.
BTW what kind of test method did you use in this test? ABC/HR with 3/6 competitor? or simple ABX with reference then rate it?
3 competitors at a time ; I tested mp3 and vorbis separately.
3 competitors at a time ; I tested mp3 and vorbis separately.
Thanks for clarification.
I just noticed one thing concerning encoding.
- Target Quality : 50 / VBR mode : Standard / Encoding Engine Quality : High (132kbps)
This is an old VBR algorithm aka --vbr-old. --vbr-new is current recommendation.
- Target Quality : 50 / VBR mode : Standard / Encoding Engine Quality : High (132kbps)
This is an old VBR algorithm aka --vbr-old. --vbr-new is current recommendation.
I didn't knew this, thanks for the info.
I don't really know what is the influence of "Variable Bitrate Mode" setting in Lamedrop. Do you know if it is related to --vbr-new / --vbr-old ?
I don't really know what is the influence of "Variable Bitrate Mode" setting in Lamedrop. Do you know if it is related to --vbr-new / --vbr-old ?
"Variable Bitrate Mode" Fast = --vbr-new
"Variable Bitrate Mode" Standard = --vbr-old
You should leave "Encoding Engine Quality" as it is. It's identical to -q switch of lame.exe.
Thanks for explanations
Nice work and thanks for sharing your results.
Nice work and thanks for sharing your results.
I just received my Shure e2c today.
So I think I will ABX again with the same samples when Lame 3.98 will be out.
A new version of aoTuV would be fine too
Nice work, if my ipod supportted ogg (without having to install rockbox) I would choose aoTuV to encode into ogg and use that instead of mp3. I prefer ogg to mp3 when at lower bitrates.
I have my Shure E500 earphones, maybe I should try and do some abx testing.
I prefer ogg to mp3 when at lower bitrates.
Any sane person would.