| TomJ |
| It has begun to intrest me the loss of quality when a CD track is turned into MP3 or downloaded on P2P software with a quality of 128k/sec what the loss of quality and what is lost. I know the basics of MP3 from .howstuffworks.com . Is the loss of quality diffrent say if you are listening to it on a personal stereo compared to a soundsystem. |
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| Cobra2 |
MP3 converted to 128k/s gives something like 12:1 compression (or loss), and is like pictures in .jpg a lossy compression.
Wich means that parts of the information are removed, and cannot be restored.
On boom-boxes or pc's, most people hardly notices, but as soon as you try on a better stereo, you will notice the low quality...
Arne K |
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| GLF |
I have noticed that the highs suffer the most degradation when you rip them into an mp3. If what ever they are played out of has a decent tweeter you will notice a difference.
Andrew |
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| Thomas |
The harder compressed, MP3 removes much of the ambience and atmosphere in the music. There are also a big difference between different enchoders. I think LAME and BLADE is the two best. Audio Catalyst the worst, wich destroyed the sound totaly.
Played thrugh a good system the difference between the original CD and MP3 are very clear. I think 192kb/s is 'minimum' for good quality.
The best way to find out is by experimenting. Try different enchoders at different bitrates and try to compare the sound. If you own a good system you will notice the differnce, if you got PC speakers, I think not... :rolleyes: |
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| Sch3mat1c |
Yeah, MP3s are pretty crappy... I can usually get away with it by adjusting the tone controls a bit. :) The higher the bitrate, the higher the quality, if ***** ;) comes up with two bitrates, take the higher..
Tim |
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| jpg |
MP3 = ****? frankly, that's BS. not only IMO, but also as the conclusion of a couple of professionally done listening tests and technical analyses i know of. people who say MP3 is **** usually refer to the **** they download with ***** instead of doing decent testing or analysing (not all MP3s one can find with ***** are ****!).
LAME v3.9x is by far the best encoder. don't use anything else. other encoders may produce ****.
128 kbps: not enough in many cases.
160 kbps: very hard to tell what's original and what's MP3, even on good headphones.
192 kbps: should be sufficient (=CD quality) for almost every music and almost every stereo. i don't know anyone who is able to tell what's 192 kbps and what's 256 kbps, even with difficult to compress audio material.
regards
peter |
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| SkinnyBoy |
| Well, for a start, i don't have good headphones, I have good speakers... SECOND!!! using a good quality CD player, not one of those cheap ones will yeild better results than a 192kb MP3... and.. 192 is by NO stretch CD quality.. :rolleyes: |
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| jpg |
"192 is by NO stretch CD quality.. "
hi skinnyboy,
as i said, i'm referring to decent listening tests and technical analyses.
my personal experience is that with most speakers (and i'm not talking of 300$ mini boxes), one can't tell the difference.
over a year ago, the webmaster of one of the biggest german DIY audio boards (who is a passionate gambler and loves betting) started the following "contest":
-each "contestant" yould choose a five music tracks from his own CDs
-the webmaster then burned the tracks on CDR, each encoded with different bitrates (LAME 128, 192, 320) AND as an 1:1 copy, with the different qualities being in mixed up order
-the contestant now had to tell which tracks were MP3 and which were original (and which MP3 were 128, 192 and 320)
-anyone who could tell which track is which quality was granted EUR 10.000 (=US$ 10.000).
the contest is over now. most contestants were able to recognize the 128 kbps MP3 (which is easy), but no one was able to fully recognize the quality order of the five tracks (and among the contestants, there were not only hobbyists, but also musicians, audio pro's, engineers and even gold ears who claimed before that even 320 kbps MP3s are worthless **** that one can't listen to even on a PC and who had to learn that they can't even tell what's original and what's MP3).
nuff said, i think.
regards
peter |
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| jpg |
| PS: get me right: i don't make my living with MP3s (;)) and i'm always open to good arguments. i want the best sound possible in my room, too! but i haven't seen (better: heard) a system that offered the possibilty to tell the difference between an excellent MP3 and CD. |
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| Wombat |
mp3 really isn´t crappy at all!
There is a forum that tuned the Lame encoder to a quality it will
surprise every "Audiophile". You can find recommended settings for
every particular bitrate there at hydrogenaudio.org (audio-illumination)
http://www.hydrogenaudio.org/index....f=15&t=203&st=0
Myself i prefer the variable bitrate encoding. This is why i did a little
testing for lame and offered some test samples.
--alt-preset standard -Z together with lame is my limit where i can´t
really discern from the original with good headphones.
Be aware that all counts for lame 3.90 to lame 3.92.
The newer versions have better algorythms but are not tested to a big
extend.
For more info just search hydrogen or ask your question. There you will be helped
further for sure! |
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| Cradle22 |
Hi!
Most important is that people start to learn to encode their music with VBR or ABR, not CBR.
The most often used format is CBR (=constant bitrate) at 128 kbit/s. Nowadays I see a lot of people who want to get decent sound quality and encode at CBR 192 kbit/s or even CBR 256 kbit/s.
Ha?
That's crappy! VBR (= variable bitrate) is the only good thing that Xing ever brought the mp3 community, and people should start using it. I recommend the presets of LAME, which (at quality settings) all use ABR (=average bitrate).
I use ABR set to 192 kbit/s, with bitrate boundaries set to 96 kbit/s as lower boundary, and 320 kbit/s as high boundary. And I say nobody will hear a difference to the original material, or if you hear it, most often the mp3 sounds a little bit better (that was the actual result that listening tests often produced - its the same with people liking the "sound" of the Son of Zen, for example, which also reproduces the sound not exactly like it should, but since most listeners like the music better that way, who cares? LCAudio's The End Millenium for example preserves sound quality I would say as much as possible, and people find it sounding too harsh... )
So that is what psychoacoustics are for.
I still buy CDs, but after some initial listening I rip all the tracks I like with EAC (exact audio copy, makes 100% correct digital copies), and then convert the wavs to mp3s (would like to use OGG Vorbis, which is even better at slightly lower bitrates, but still most portable players - and my car radio - can't play it...).
So, let's say together: Use VBR/ABR! Use VBR/ABR! Use VBR/ABR! Use VBR/ABR! ;) ;) ;)
G' night,
Arndt |
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| jpg |
And I say nobody will hear a difference to the original material, or if you hear it, most often the mp3 sounds a little bit better (that was the actual result that listening tests often produced - its the same with people liking the "sound" of the Son of Zen, for example, which also reproduces the sound not exactly like it should, but since most listeners like the music better that way, who cares?
I SECOND THAT!
regards
peter
PS: what's up with this forum? it took ~10 minutes for my first and ~30 minutes for my second posting to show up, my third posting got even lost! |
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| traderbam |
| quote: | jpg wrote:
who had to learn that they can't even tell what's original and what's MP3 |
What was the reproduction equipment?
I thought CD bit rate is 705.6kbps (16x44.1kHz). A recording in MP3 at 128kbps will certainly sound worse, and a 300kbps recording will sound less bad but will be noticeable on a high quality system. Otherwise people would not recognize the differences among CD players. |
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| Wombat |
Well, i still have to find the music that sounds better encoded to mp3!
The fraunhofer codecs tend to sound a bit washed out what results in a smoother
sound but this is for sure not "better" than the original.
To be more exact you won´t notice a difference with a well made encoding
when the encoded sample don´t mess up the psycho-acoustic that tries to filter
out the not to be heard parts of the music. Unfortunately there are parts in music
that never will sound clean with mp3 cause of its limitations.
Believe me, i did more testing of mp3 than it is healthy ;) and know what i talk
about, at least about this topic.
As said before, it will be a pain to start mp3 quality discussion here on this board
when there are better places where lossy encoding is discussed since they exist.
On hydrogenaudio.org you will find all answers and test samples that will show you
what the limits of mp3 are.
btw. traderman, CD audio is ~1400kbps
edit: There is also this clipping problem with mp3s and other lossy
codecs that can cause ugly sound when not handled properly. |
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| jpg |
| quote: | | What was the reproduction equipment? |
no idea. the thing is that this guy stated that he heared just anything with his golden ears and his high end stereo.
all the same, i mentioned that just for fun, it's not generally applicable (it's funny, though, that what someone really hears in blind tests quite often seems to be reversly proportional to what he thinks he can hear).
| quote: | | Otherwise people would not recognize the differences among CD players. |
MP3 compression losses vs. CD players? hrmm... well... wombat is right, i guess... no point in broadly discussing that stuff. ;)
bye
peter |
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| Cradle22 |
Hi!| quote: | Originally posted by Wombat
Well, i still have to find the music that sounds better encoded to mp3!
...
Believe me, i did more testing of mp3 than it is healthy ;) and know what i talk
about, at least about this topic.
|
Of course there are differences in sound quality. But I've already discussed this on another audio board, and I can only repeat time and again that if you can really always hear it, or at least more than half of the time (and again, I don't talk about 128 kbit/s CBR), you all have better ears (AND equipment) than those producers and studio musicians that took part in those ANONYMOUS A/B tests. If it comes down to this, most of the people who claim to hear the differences did not do listening tests in a proper A/B way (that is, with no access whatsoever to what data source feeds the listening equipment, and no switching noises being noticeable) - often those are the same people owning multi-thousand-euros equipment, refusing A/B comparisons with cheaper (maybe DIY?) equipment, because it might prove that they've spent a lot of money for nothing...).
And since you are from Germany, you know ct, which did thoses tests two times over the last two years, and the last time mp3 and ogg clearly won the contest - that means people noticing no difference and / or comressed audio even "sounding" better to their ears. One of those contestants was musician / producer Mousse T, to name one person.
And I personally talked with Siggi Bemm, the producer at Germany's biggest Hard Rock / Metal studio (Woodhouse Studios in Hagen, you can even look up their equipment at their internet site), and he also underlined that if done properly there is no way of telling the difference.
But believe what you will, I think that it will take a long time to overcome those predjudice against "lossy" compressions...
Btw, do you reject DVD, since MPEG really is a lossy codec? |
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| sangram |
Dunno, maybe all the decoders I've tried are bad. I can tell even on my car radio when an MP3 is played, opposed to the audio CD. "Jangly" high end is a reality of the MP3 world. After 256 KBPS gets very very difficult, and not at all noticeable in the car, but midnight listening cofirms it. Even CDs burnt from MP3s lose their sheen and are caught very easily.
And that is without A/B. At night, in the absence of ambient noise, even badly recorded CDs (some old rock compilations come to mind, or even some hurried U2 compilation) sound pathetic, let alone MP3... |
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| DIY_Peter |
| quote: | Originally posted by Cradle22
Hi!
And since you are from Germany, you know ct, which did thoses tests two times over the last two years, and the last time mp3 and ogg clearly won the contest - that means people noticing no difference and / or comressed audio even "sounding" better to their ears. One of those contestants was musician / producer Mousse T, to name one person.
|
I read those tests in the ducth version of ct. They weren't really good tests in my opinion. Most people listened to the tracks with different equipement. Some even used small KOSS headphones.
Anyway, I can hear a difference. Maybe it was the decoding, I dont know, but most mp3's sounds harsh to me. |
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| nobody special |
I can definitely hear the difference... and this on a system with a cheap receiver with good DIY speakers. If you listen to rock, the main difference will be that the bass loses it's dynamic quality, and that the cymbals and other higher frequency sounds become harder (all the above statements refering to 300 kb/s rate). Also, there is the "jangly" treble someone mentioned that becomes worse as compression goes up/ bitrate goes down. It sounds a lot like "flutter" you would hear on a cassette.
If you listen to classical, or anything that is critical in the midrange, the soundstage is substantially reduced, as is ambience or "air" around the instruments. Dynamic range is also compromised.
A lot of people will prefer the mp3 format because of the compression they hear. Many people prefer the sound of FM radio! That is why so many pop recordings of the last 20 years have a ton of compression added to them at the mastering stage. It presents a "louder" in-your-face sound that people generally prefer (especially with their cheap systems) Those of us who have performed music, or have heard good live music, generally know better and are intolerant of this garbage.
-NS |
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| Cradle22 |
| quote: | Originally posted by nobody special
(all the above statements refering to 300 kb/s rate)
-NS |
There is no such thing as 300 kbit/s bitrate in mp3... |
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| Wombat |
If you want some testing, download samples that are provided here
and encode them with your encoder of choice!
http://www.hydrogenaudio.org/index....ST&f=16&t=4601&
If you want to go further have a deep look into ff123s site
http://www.ff123.net/
When you look thru hydrogenaudio.org there you will find
parts of music that sound different to the original with
whatever setting they are encoded into mp3! Also abxed
from others...
Some of these test-samples are found by me btw. ;) |
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| UrSv |
| quote: | Originally posted by Cradle22
There is no such thing as 300 kbit/s bitrate in mp3... |
Probably meant 320 kbit/s. Pretty close though... |
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| tiroth |
My main gripe with MP3 is the loss of fine detail. The little things in complex recordings seem to just disappear.
Unless you know the recording, or A/B it, you tend not to notice, but something is missing. Even >192kHz. I doubt that I could line up 128 vs 192 vs 320 in the correct order, but on the right recordings I can tell the difference from a CD every time.
I've noticed treble "jangly-ness" but I think this may be encoder-specific. I'm not convinced it is a problem with MP3.
MP3 is a great format for many things. It is unfortunately just inferior to CD. |
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| Cradle22 |
Like I said, of course there are differences. But if you don't know WHICH of the two sources you are hearing, and maybe were not in the least biased (in other words: trying to find out which one is the mp3), and simply pick the one you liked best, mp3 would probably win...
Maybe this is due to distortions and "wrong" taste of people, but then why do a lot of high enders prefer LP records over CD, I don't think because of the cleaner sound...
And people like Wombat and the others from hydrogenaudio, who actually use ABX comparison programs, they also use "special" audio clips, which are known to produce problems (I have to admit that I did not hear the "fatboy.wav" clip before, and yes, one can de3finitely pick the mp3 even at ABR 192 kbit/s, with OGG at 192 kbit/s it get's better, but still not completely right)
But I would say about 98% of the average material (at least on my HD, but I don't listen to much electronic sounds like Fatboy Slim) those "special situations" won't occur.
It's like a real, real classical music fan, who has listenend to the same composition played by different artists over and over again, when he goes to a concert, of course he can pick out faults by some musicians, but the rest of the audience can't. And he probably could not hear any "faults" in a track by Metallica or something else, encoded to mp3, simply because he doesn't know it well.
But yeah, the frontlines are somewhat hardened in this discussion, so I won't pursue this any longer (done that enough in this thread already...) ;)
Bye,
Arndt |
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| nobody special |
Cradle22,
Whatever... close enough. Yes, I meant 320.
-NS |
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| vacuumhead |
Guys,
what do You think of Musicmatch Jukebox and their mp3pro format?
Jack |
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| MWP |
Ogg Vorbis IS the only way to go.
It really does leave MP3s behind...
I encode at 180kbps average, and find it very hard to pick the difference between it and the original.
One of the best things about Ogg is there is only one encoder avaliable, so you also know that other Ogg encodings are going to be of good quality.
Not like MP3s where a lot of 192kbps MP3s off the net are comparable to 128kbps because they used a bad encoder.
http://www.vorbis.com/download.psp |
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| VEC7OR |
First of all I have to say quality depends on the material you encode - some things sound nice and rich even at 128, some need no less than 192-256, in general electronic music encodes better than rock or classics(IMO classics on MP3 = plain wrong, POPs encodes best at 128... thats pops). Frequency responce of MP3 at 160-192+ is fairly good BUT phasing is worse - you get "muddy" sound with so so stereoscene and sound source placement(english is not my native language so explaining this is rather hard). MP3's are listener dependent - some say 128 is OK some say - 192, No way give me 256+ - thats where psycho-acoustic model plays its role - it for more or less "generic" ears, I've read an article about human ears - there are so many parameters that can differ from ear to ear, take for example acoustic masking - there are 3 types - when 2 sounds differ in loudness, delay and frequency...
As for the audiophiles there are lossless codecs - monkey audio etc, but dont expect 10:1 or even 5:1 compression ratios... |
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| phreeky82 |
| quote: | Originally posted by MWP
Ogg Vorbis IS the only way to go.
It really does leave MP3s behind...
I encode at 180kbps average, and find it very hard to pick the difference between it and the original.
One of the best things about Ogg is there is only one encoder avaliable, so you also know that other Ogg encodings are going to be of good quality.
Not like MP3s where a lot of 192kbps MP3s off the net are comparable to 128kbps because they used a bad encoder.
http://www.vorbis.com/download.psp |
i second that!
basically it will give a better representation of the original than mp3 with an equal file size. and if still isn't up to your standard, increase the quality level till it is. |
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| Sawzall |
in which I was a participant. It used aac+, along with some pre-processing. The general test was using three samples of the same material, one "natural", one aac at a pretty low bitrate and the final with same bitrate with pre-processing.
The testing objective was "which do you like better" - and this objective is different than most of the other testing I have been involved in along the way. The stuff in the past was mostly performed by people who had trained thier ears to listen for artifacts and such. Nothing quite so bad as plucked strings at LBR's. I remember a test with Lucent's PAC a few years ago that was almost unlistenable - this was much better, and points to the improvements that have happened in the last 3 or 4 years.
The end result? The average person actually preferred the encoded and processed sample. It is still being studied to determine what about that sample made them prefer it over the "natural" sample. I know for my ears, the pre-processing was critical to overall performance of the codec, regardless of the bitrate used. |
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| stokessd |
I'm just finishing composing a CD to play with different MP3 bit rates and encoding schemes.
I took the song "Honey Pie" from Lavay Smith and her Red Hot Skillet Lickers. See:
http://www.lavaysmith.com/
Which is contemporay big band jazz and is recorded well and has a variety of instruments which should show up the shortcomings of MP3.
I started by ripping the track to an AIFF file with no compression. This will be track 1 and my reference. I then ripped the same track (from the original CD) tyo MP3 using a fixed bit rate at 128,160,192, and 320 Kbps. I then ripped the same track using a variable bit rate at the above average bit rates.
Finally I encoded the same track using AAC at the same bit rates.
I'll report my findings after I listen for a while. BTW I have a very high resolution system based around electrostatic loudspeakers.
Any interest in this disk? I can post an ISO image if there is enough interest.
Sheldon |
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| Variac |
| Hell yes, there'd be interest. I need a copy of that to hand out to the ignorant- or discover that I'm the ignorant one and then shut up ;) |
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| stokessd |
I'll describe what I hear, but first a bit about my system:
My speakers are DIY electrostatic hybrids with and active crossover. The details can be seen here:
http://quadesl.com/diy_esl1.shtml
They are amazing in terms of tonal neutrality and dynamic punch. (the panel has the same Sd as 28 8" woofers and 3mm of Xmax). The active crossover makes a huge difference in terms of transparency and neutrality.
The source is my Tube based DAC, seen here:
http://quadesl.com/dac.shtml
Comments here:
http://quadesl.com/dac_comments.html
http://www.audioasylum.com/forums/b...ages/51120.html
I'm also using a modified Counterpoint preamp driving my active crossover. My panel amps are rebuilt Heath W5M's and the bass amp is an Adcom 555.
Here's what I heard:
The original: Lavay Smith is reasonably well recorded with good instrument placement and noticable air around the instruments. There is drums, an acoustic bass, piano, a variety of brass, and female voice. The miking is minimal and non-intrusive, there is a good amount of information in this recording; a rich palette.
AAC: I'm not sure what the difference between AAC and MP3 encoding is, and I'm not sure it's all that universal, so I'm not going to dwell on it here. This compression was quite similar to the MP3 VBR in terms of the artifacts I heard vs. bit rate.
MP3: First of all, the VBR at a given bit rate (average) was noticeably better than the FBR at the same rate. VBR at a given bit rate was about as good as FBR at the next higher rate. However the file size for VBR was about the same as FBR at the next higher rate. So in terms of compression, they are like apples to apples. Here's what I heard: At 128 kbps, the cymbals lost their shimmering "ride" and sounded a lot more like air escaping (or a cheap dome tweeter). Brass instruments didn't sound lifelike; they sounded synthesized like a good midi synth. The air around instruments and the decay of notes is largely gone. There is a hint of it, but it's not right. Female voice takes on a hard metal quality and loses the tonal subtleties, it's like the levels have been more discretized. At 128 kbps the difference is fairly obvious, if I had a helper and did a blind test, I feel pretty confident that I could pick them out every time. At 160 kbps, it's a little less obvious but still a difference. The air is still largely messed up. At 192 kbps, the air starts to return and the brass instruments and sounding more real. Cymbals are still a bit of a problem but less glaringly so. At 320 kbps, things are really looking up, most of the air is back, and the cymbals are sounding a lot more real. Going back and forth, I can tell the difference, but without an a/b I could be happy with that level of quality. The difference is subtle and one of smoothness and "rightness" There is a harshness at all MP3 settings, and it's not a typical bad recording harshness, but one that changes with transient content. It's hard to describe without hearing it.
I would also like to point out that on my okara speakers or my Jordan JX-92 based TLs' this would be a lot less conclusive test. The absolute transparency, low distortion, and neutrality of the ESL's makes differences pop out.
Sheldon |
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| SY |
| Put me down as "extremely interested." |
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| pinkmouse |
| quote: | Originally posted by stokessd
Any interest in this disk? I can post an ISO image if there is enough interest. |
As long as the ISO only contains partial tracks, say a minute or so, otherwise those RIAA boys could be down on us like a ton of bricks! ;) |
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| Wombat |
@stokessd
As you are talking about creating aif files i think
you use a MAC for that.
When you use a MAC it is most likely you use a mp3
codec that is based on Fraunhofers mp3.
If that is true you don´t have the best mp3 encoder
for high bitrates. The lame encoder is superior from 160kBit
up. The vbr implementation of fraunhofer is worse even
to the highest quality setting. You don´t need a high-end
system to hear that. I use a simple HD-590 and my soundcard
on the PC. Try to get lame mp3 encoded files and try again. |
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| Variac |
| I have also read here that the encoder is everything. Better try the Lame encoder too... |
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| stokessd |
I don't know what AAC encoding really is. Apple in their typical style isn't saying anything useful on their technical support pages either.
I'm now ripping the same track with Audion which has a lame (3.92) encoder. I can easily pick the fixed bit rates, but I can't seem to be able to set the variable bit rates numerically, just with settings like "insane" and "excellent"
I'll report later when the disk is burned and I'm listening.
With regards to my MP3 disk, I'm a little hesitant to post it given that it's full tracks. I'll be passing it around our Albuquerque Speaker Society though.
Sheldon |
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| stokessd |
for all you mac weenies (back off; I'm also a unix and peecee weenie) out there:
There is a really nice interface to LAME (3.92) for iTunes, it's here:
http://www.blacktree.com/apps/
It has the typical aqua interface and is easy to use, and for us control freaks, it has a mini command line to pass the standard LAME parameters to the encoder.
Good stuff.
Sheldon |
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| stokessd |
Here's my finding after playing with the LAME (3.92) encoder:
Fixed bit rate: 128, 160, 192, 320
Presets:
--alt-preset standard.mp3
--alt-preset extreme.mp3
--alt-preset insane.mp3
Note: I didn't play around with noise shaping etc, I could drive myself nuts with all the combinations.
This is better! I like this a lot better than the Fraunhofer encoder built into iTunes. At all bit rates, the Lame decoder sounds like at least one bit rate higher in the Fraunhofer decoder. But it has a better handle on transients like cymbal splash and piano notes at all rates.
However, you don't get something for nothing, with all that compression there are still artifacts. What interesting to me is that the variable bit rate artifacts are different for LAME than VBR Fraunhofer where the fixed bit rate artifacts in both methods are more or less the same.
Piano notes and their decay were noticeably effected even at the highest bit rates. As were the transients from plucked acoustic bass notes. As bit rate increases, they become less and less noticeable.
With LAME's ability to handle transients better, I'd have a hard time at the higher bit rates being able to pick mp3 vs. original in a blind test. I think I can still pick them pretty well at 128 kbps, at 192 kbps I'd guess, I'd be missing a few. At 320 kbps I'd be better than random but close.
This is with a very revealing system which I'm familiar with, and music which I know well. I can't imagine doing a bind test on this stuff with a marginal unfamiliar system and unfamiliar music. Those famous MP3 tests are **** for that reason.
Sheldon |
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| Wombat |
Nice you took the time and invented into playing around with
lame. Looks like you are real a pro at it now!
May it be possible to offer or send me a short test clip,
lossless compressed (flac for example) with the part of the sample
showing the most obvious problem for --alt-preset standard?
I spent much time with testing this preset and welcome every
sample that really messes it up.
regards |
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| fivaxis |
| Lame, 320. Nuff said. |
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| dmitriy167 |
| Not really. What like to do with LAME (built into CDex) is set the VBR from 32 to 320 kb/s and to New and the quality to 0 (best). This way, the MP3 doesn't waste space when high bitrate is not required, like in passages without highs or lows, and when they are present, it uses up only as much as needed. I did a blind test on myself between a .wav and an .mp3 of the same song encoded in this way. I could VERY barely tell the difference, but the filesize was about hald as large as with a 320kb/s CBR. |
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| brsanko |
| the first calculation of the bit rate of CDs was correct @ 705.6 kbps, you just forgot about the fact that there are 2 tracks on a stereo recording. So if you multiply 705.6 x 2 you get 1411.2kbps the total bit rate of a CD. |
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| 5th element |
Dont have time atm to read all the posts in this thread but I dont understand where all the MP3 bashing comes from really.
I have a good system so if MP3's are really to sound rubbish then id hear it. I use a computer as a transport with uncompressed Wavs from CD's. The comps better at this then my TEAC T1 transport so dont tell me the comps not got a good enough digiout.
To say you cant hear a difference between MP3 and wavs is daft, a wav always sounds better then the MP3, I did a few comparisons. But to say the MP3 is not good is daft too. I get lots of enjoyment out of my MP3's most are 128 or above and I dont pine for better quality when I do. They dont sound thin or lacking in anything and the trebble quality is fine too. |
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| angel |
Referring to the original layer 3 trials, the average score was in the range of 4.5, with 4 being excellent, and 5 being indistinguishable from the original signal.
Now, for my two cents:
Listening tests I have performed on the Stax Signature system, with a decent-but-noisy bitstream dac, indicates that (with the music I sampled) an MP3 of 256kbps or higher is equivalent to the original signal, if you don't explicitly try to discover errors, and are not used to pinpointing MP3 distortion. Lower bitrates were clearly distinguishable. At all bitrates I tried (up to 320kbps), listening fatigue set in at some point, which it did not do with the original signal.
Using the MusePack (MPC) encoder, which (amongst other things) does not set its lowpass at 16kHz, the quality 8 setting (averages 220kbps) is usually indistinguishable from the original, unless the material plays tricks with the phase, such as the dog on Three Wishes (which btw sounds marvellous on the Stax Signatures, due to the excellent low frequency reproduction). I have not yet experienced listening fatigue from MusePack.
I've not yet pinpointed the patterns to look for in MusePack, nor do I intend to try, since I am actually happy listening to it.
However, in MP3, the patterns will be rather clear if you listen to a certain piece (preferrably a clear one, with few instruments and very high detail) at low bitrates, and then higher bitrates, until you hit 256kbps. Do that a couple of times, and you will be able to identify the patterns in 320kbps materials. I've not tried >320kbps, but expect the same will be the case there.
MP3 is less offensive in-room than in-head. YMMV; if you're not a earspeaker person, you may already have trouble with the soundscape-in-your-head effect that might interfere with the listening itself.
One thing I would suggest that someone try, if we've got any MP3 software coders here, is to introduce a delay to signals whose phase is negative. Our ears are based on absolute-phase sensitive resonators, that do not get excited by the first negative halfcycle of a signal, or at least not until at least 5ms later on. If you introduced this filter into the encoder, you would probably greatly improve the perceived lack of ambience.
Loss patterns are interesting. If you listen to a minidisc, on certain pieces of music, it will seem as though (visualized) the sound is built up of 2D layers at different depths, and you can suddenly get an angled view, revealing the flaws in a most annoying manner. This description is probably rather vague, though. ;)
Anyway..
Just so noone gets the wrong idea, I am certainly in favour of trying to find more compact ways of transporting sound to the consumer. I just don't think we've gotten there yet.
There is also the argument that simplifying the sound, by removing components that are inaudible (just make sure they are inaudible to everyone, on all equipment, not just on poor equipment, or on unaware subjects), should improve reproduction.
Certainly, having a simpler waveform to reproduce will allow amplifiers and speakers to perform better. This may be the source of some of the characterizations as "better sounding". IMD distortion, for one, should be reduced significantly.
And, to clarify again, MP3 at high bitrates does sound good. Just not as good as I'd like. MPC is almost there. |
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| Tawnos |
MP3 quality is acoustically indistinguishable from the CD if done properly. One of the key mistakes people make is to use CBR or even ABR, and also "stereo" thinking it will give better channel separation.
Listen to an MP3 ripped using EAC then encoded joint-stereo VBR1 from 32-320 using LAME. Amazing quality.
If you TRULY believe you can tell the difference: Take a single song that you know well from a new cd, rip it using CBR from 128-320 then do a VBR recording as set up above. Put them all in winamp, no shuffle, no repeat. Choose Misc-> shuffle (but DO NOT look at the song order). Play the songs through as many times as you'd like... write down what you think each song is... go back and check.
I will BET you'd be surprised. |
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| MWP |
Why is the MP3 format still being discussed?
There are much better lossy formats out there now like OGG Vorbis and MPC. |
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| Wombat |
mp3 is the most widely supportet. There are so many media out there that can handle mp3.
mpc has near to nothing to use it outside your PC.
vorbis doesn´t sound better at high bitrates |
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| flieslikeabeagl |
Well, I'm not going to touch the "mp3's sound perfect vs mp3's sound awful" debate, as nothing useful will come out of arguing over individual preferences.
I would, however, like to tell everyone about a very interesting alternative codec. It's called FLAC, for Fully Lossless Audio Codec. And it is exactly that - completely lossless, meaning that there is NO lost information - nothing whatever is thrown away from the original .wav file, but through the magic of compression algorithms, compression is still possible. This is similar to the way you can zip a text file, compressing its size, but without losing a single character contained in the file when you finally unzip it.
FLAC does not produce the huge compression ratios that mp3 does - in my experience, the output .flac file is about one-third the size of the input .wav file. That means you can compress the average CD to about 200 MB instead of the original 600 MB. That still means
you can put about 5 CD's of material on one gig of hard drive space, or about one thousand CD's on a single 200 Gigabyte drive.
With the rate at which hard-drive and flash-memory capacity is increasing, in a very few years many of us will be deciding that it wasn't worth throwing away some audible quality for the sake of compressing our CD-quality audio files into mp3's. When that happens, most people will have to re-rip their entire collection. If you use FLAC, there won't be a need to do that: you can convert FLAC back into .wav without any missing bits, and re-convert it into any future codec standard that may come.
I'm one of the people who think I hear degradation when going from CD to mp3. So I now only use FLAC.
FLAC is easy to use with Linux - plug it into Grip or your other favourite ripper in place of Lame or Bladeenc or Oggenc. I haven't used it with other OS'es, but I think it can be used with Windows and Mac's too.
You can read about FLAC and download it at http://flac.sourceforge.net/
-flieslikeabeagle |
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| Wombat |
| Flac is known here for a while now, good choice! ;) |
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