# Flac vs Mp3 Quality



## Markwinstanley (Mar 28, 2014)

Is it worth to download huge size flac over small size mp3 playing on 2.1ch speakers and headphone?does it make any difference to music quality experience?


----------



## tonyvdb (Sep 5, 2007)

Yes it does, FLAC maintains all of the original quality. MP3 is a compression format and when you compress you remove bits. The more bits you remove the less dynamic and crisp the recording will sound. mp3 sounds just fine if you keep the bitrate high (above 256kbs) but anything lower and the highs really start to get crushed and you start hearing noise.


----------



## Savjac (Apr 17, 2008)

I agree with Tony in that the more bits, assuming a good recording in the first place, the better the end result. However, this will be very dependent of what equipment will be used as well as what the listener finds important. 

Personally, with space being so cheap, I would always go go for the least destructive recording


----------



## bkeeler10 (Mar 26, 2008)

Agreed, if you listen on a hifi system or through a good pair of headphones, go with the least destructive compression -- that is, lossless compression like flac or alac. For background music low-bitrate mp3 is probably fine, but for any serious, focused listening on a hifi system, I would expect (though haven't personally tried it) that even 256 kbps mp3 is audibly lower fidelity than flac.


----------



## gazoink (Apr 17, 2013)

Once you've heard what low-bit-rate .mp3 sounds like, you can pick it out of background, foreground music, on the radio, anywhere, in seconds. It's a curse.


----------



## chashint (Jan 12, 2011)

What is low bit rate ?


----------



## redsandvb (Dec 2, 2009)

Markwinstanley said:


> Is it worth to download huge size flac over small size mp3 playing on 2.1ch speakers and headphone?does it make any difference to music quality experience?


Like the others have said, FLAC is worth it.

But it also depends on your speakers/headphones, hearing, the mp3 encoder & bitrate, etc. If you don't, or can't hear the difference you might not care about it. It's quite possible that an mp3 encoded with LAME set at -V 2 (which would result in a bitrate of maybe ~200 kbps + or -, depending on the type of music) would sound exactly like the CD. I say ~200kbps, but that setting uses VBR so sections of the music may be encoded at 32kbps or up to 320 kbps.


----------



## gazoink (Apr 17, 2013)

chashint said:


> What is low bit rate ?


Anything below 256Kbps. 

The lower the bit rate the more audible .mp3 compression is. Technically, "compression" is the wrong term, though. It's actually "bit-rate reduction", a way to use less bits per second to represent audio. 128Kbps .mp3 uses less than 1/10 the data in an original CD rip. In other words, it's thrown away 90% of the original data. Small files, fast to download, takes up less storage space, sounds awful.


----------



## chashint (Jan 12, 2011)

gazoink said:


> Anything below 256Kbps.
> 
> The lower the bit rate the more audible .mp3 compression is. Technically, "compression" is the wrong term, though. It's actually "bit-rate reduction", a way to use less bits per second to represent audio. 128Kbps .mp3 uses less than 1/10 the data in an original CD rip. In other words, it's thrown away 90% of the original data. Small files, fast to download, takes up less storage space, sounds awful.


Thanks, I just wanted to be calibrated to what y'all considered low bit rate in this conversation.


----------



## gorb (Sep 5, 2010)

I would understand thinking that flacs are big if we still had dialup and small hard drives...but broadband is pretty much everywhere (although it's still terrible throughout most of the US) and 2-4TB drives are relatively cheap.

flac is of course better and worth it. Lossless = perfect copies. With that being said, I don't mind having mp3s on my phone or in the car. mp3s encoded with lame using the v2 or v0 presets sound just fine to me.


----------



## 3dbinCanada (Sep 13, 2012)

I ripped my CD collection to a hard drive at 320Kbps. I did a quick a/b comparison between teh CD and teh mp3 and I could not tell a difference when the SPL averaged between 70 - 75 db


----------



## chashint (Jan 12, 2011)

I have not been able to hear the difference between 320kbps MP3 and CD audio either.
I can't really do real time A/B testing though.
I went kicking and screaming but for better or worse the deed is done and I have gone with ALAC.


----------



## gazoink (Apr 17, 2013)

ALAC is also lossless, works with IOS devices. And for lower bit rates, AAC is more efficient, meaning less audible damage for a given bit rate than mp3.


----------



## tonyvdb (Sep 5, 2007)

AAC has a low pass filter and tends to chop everything above about 16K to keep the rest of the file at a better quality.


----------



## gazoink (Apr 17, 2013)

tonyvdb said:


> AAC has a low pass filter and tends to chop everything above about 16K to keep the rest of the file at a better quality.


Another myth raises it's ugly head.

Here's the experiment, easily duplicated if you like. 

Generate a 20Hz to 20KHz, 20 second sweep. Audition will do it nicely. Generate the file at 16/48 or 24/48. Looking at the original file, notice the amplitude over the entire 20 seconds. Play the file and observe the meters don't change for the entire length of the file.

Import the file into iTunes.

Generate an AAC version. I tried 320Kbps, 256Kbps, and 128Kbps. Anything below that doesn't really interest me, but you can try anything you like.

Locate the generated AAC versions, open them in your editor of choice, Audition or Audacity, or whatever. Look at the amplitude over the entire length of the file. Then play the file while watching the meters.

I see not even .1dB variance from 20Hz t0 20KHz for any of the three bit rate AAC files.

Myth busted. AAC has no such 16KHz filter at any reasonable bit rate.


----------



## lcaillo (May 2, 2006)

tonyvdb said:


> AAC has a low pass filter and tends to chop everything above about 16K to keep the rest of the file at a better quality.


Actually, MP3 has, effectively, little response above 16kHz, but I am not aware of any LPF or even effect in AAC that is similar. Higher frequencies are not encoded when they fall below the masking amplitude of the content, but where there is primarily high frequency content it is all encoded. AAC actually sounds considerably better to me than MP3. I hear much less difference between AAC and FLAC or similar than between AAC and MP3.


----------



## tonyvdb (Sep 5, 2007)

Very possibly a myth but I've tried AAC and my preference is 256 VBR mp3 set at high quality. The same song defiantly sounded better in the high end using mp3 VBR


----------



## redsandvb (Dec 2, 2009)

chashint said:


> What is low bit rate ?





gazoink said:


> Anything below 256Kbps.


I, myself, would probably consider something more like 128 or 160 kbps CBR low bitrate. Most of the time LAME -V 2 encoded mp3s sound pretty much transparent (to the original CD) to me, certainly -V 0 (that typically averages above 256 kbps though, maybe ~275ish +/-).



gazoink said:


> 128Kbps .mp3 uses less than 1/10 the data in an original CD rip. In other words, it's thrown away 90% of the original data. Small files, fast to download, takes up less storage space, sounds awful.


Are you certain? Maybe the file compression/size ratio is about 1:10 for 128 kbps, but listening to an mp3 at that bitrate I can't honestly say it sounds like 90% of the original data is gone.



tonyvdb said:


> Very possibly a myth but I've tried AAC and my preference is 256 VBR mp3 set at high quality. The same song defiantly sounded better in the high end using mp3 VBR





lcaillo said:


> Actually, MP3 has, effectively, little response above 16kHz, but I am not aware of any LPF or even effect in AAC that is similar. Higher frequencies are not encoded when they fall below the masking amplitude of the content, but where there is primarily high frequency content it is all encoded.


Maybe, in part, because the LAME encoder has been constantly fine tuned over many years and a number of blind listening tests by the community to improve upon ^^^that^^^ (among other things). Anyone remember '--alt-preset', '--vbr-new', '-Y', etc? :yes:
As stated, mp3 has its limits, though...


----------



## 3dbinCanada (Sep 13, 2012)

redsandvb said:


> Maybe, in part, because the LAME encoder has been constantly fine tuned over many years and a number of blind listening tests by the community to improve upon ^^^that^^^ (among other things). Anyone remember '--alt-preset', '--vbr-new', '-Y', etc? :yes:
> As stated, mp3 has its limits, though...


At 320Kbps, I cannot tell the difference in sound between CD and mp3.


----------



## Lulimet (Apr 4, 2014)

When I ripped my CD collection, I ripped it in 4 different formats. WAV, ALAC, FLAC, and 320kbps MP3.
I too haven't been able to hear a difference between the 320kbps MP3 from any of the other 3 lossless formats.


----------



## gorb (Sep 5, 2010)

You should have only ripped each cd once to wav and then you could have converted the wav file to the other three formats


----------



## GCG (Aug 22, 2013)

3dbinCanada said:


> At 320Kbps, I cannot tell the difference in sound between CD and mp3.





Lulimet said:


> When I ripped my CD collection, I ripped it in 4 different formats. WAV, ALAC, FLAC, and 320kbps MP3.
> I too haven't been able to hear a difference between the 320kbps MP3 from any of the other 3 lossless formats.


Different ears, different responses. I'm mildly color blind. A little red or green tint in something otherwise white is lost on me. My wife'll pick it out a mile away. Hearing is like that, too. Not everyone can hear the stuff that is lost in 320kbps MP3's.


----------



## Lulimet (Apr 4, 2014)

gorb said:


> You should have only ripped each cd once to wav and then you could have converted the wav file to the other three formats


That's what I did. It would have taken me a year to rip each CD 4 times (900 CD collection)


----------



## chashint (Jan 12, 2011)

My problem with wave files is iTunes doesn't keep the metadata with them.
I have spent many hours ripping the music collection in multiple formats for different applications.


----------



## gazoink (Apr 17, 2013)

tonyvdb said:


> AAC has a low pass filter and tends to chop everything above about 16K to keep the rest of the file at a better quality.





lcaillo said:


> Actually, MP3 has, effectively, little response above 16kHz, but I am not aware of any LPF or even effect in AAC that is similar. Higher frequencies are not encoded when they fall below the masking amplitude of the content, but where there is primarily high frequency content it is all encoded. AAC actually sounds considerably better to me than MP3. I hear much less difference between AAC and FLAC or similar than between AAC and MP3.


I need to correct my previous post re: AAC's low pass filter being a myth. Apologies to tonyvdb, I screwed up my tests. The sweep was not properly generated due to a glitch in Audition. I discovered this when I dug deeper and tried to see what extremely low-rate codecs did...which was nothing, in my test, so something was wrong. 

I generated new sweep files, this time 10KHz to 24KHz, linear, in an effort to reveal any frequency limiting mechanisms. The sweep files were generated at 48KHz, 24 bit, and imported to iTunes.

Test files were made using AAC and MP3 at three rates, 320Kbps, 256Kbps, and 128Kbps. The resulting six files were then brought into Audition again where they were decoded and presented for spectrum analysis.

Before we go any farther, it's important to realize that frequency response, as measured with a sweep test signal, isn't a good representation of the overall sound quality of a given codec set for a given bit rate. It does show frequency response limitations *for the test signal*, which may not be the same for music. 

It's generally accepted that AAC achieves higher audio quality for a given bit rate than mp3. Clearly, what we learn from a swept frequency response test is far from the whole story. And clearly, the trick to highest quality, regardless of codec, is using the highest possible bit rate.

So, here's what I found, plots notated. You will note that sampling frequency also has an impact. What wasn't tested is what happens to the response of a 44.1 CD rip resampled to 48KHz AAC. Perhaps someone else can test that.

The answer is, there is no 16KHz low pass filter in AAC until you get to 128Kpbs. At 256Kpbs the LPF is at 19KHz, and at 320Kbps it's no longer a factor. MP3 is different, not showing quite the same effects, but also showing LPF in some conditions, particularly 44.1KHz sample frequency. The last graph shows 44.1MP3 vs 44.1AAC. The difference might look large, but it's a linear frequency scale, and the results would be extremely hard to hear, if not impossible. 

Hope this helps, and sorry for the sloppy original post.

Looks like the best quality would be AAC at 320Kbps, 48KHz. Or, FLAC/ALC of course.


----------



## gazoink (Apr 17, 2013)

chashint said:


> My problem with wave files is iTunes doesn't keep the metadata with them.
> I have spent many hours ripping the music collection in multiple formats for different applications.


iTunes handles ALAC files more gracefully...


----------



## lcaillo (May 2, 2006)

Does it do the same thing with the sweep at different rates? I wonder why it is looking like a LPF. My understanding of the coding is that it should not do this, but maybe most lower bit rate implementations are? Or is this an artifact of the sweep rate interacting with the windowing?


----------



## gazoink (Apr 17, 2013)

lcaillo said:


> Does it do the same thing with the sweep at different rates? I wonder why it is looking like a LPF. My understanding of the coding is that it should not do this, but maybe most lower bit rate implementations are? Or is this an artifact of the sweep rate interacting with the windowing?


I dunno. The sweep was slow, a 14 second 10KHz to 24KHz linear, the idea being 1KHz per second, so I could verify without doing an FFT that the response was actually correct.

I tried a sweep at 10x the rate (1.4 seconds), it shows the same LPF, though the FFT resolution starts to fail a bit so the plots aren't as nice. Same cutoff frequencies though.


----------



## redsandvb (Dec 2, 2009)

gazoink said:


> MP3 is different, not showing quite the same effects, but also showing LPF in some conditions, particularly 44.1KHz sample frequency.


In case anyone is interested, the LAME mp3 encoder's lowpass frequencies for a given VBR setting are listed in the table on this page http://wiki.hydrogenaud.io/index.php?title=LAME#Technical_information
The wiki is a bit out of date in parts, but I think the lowpass info is correct. If I remember correctly, the target bitrate for -V 0 has been raised from what's shown in the table, starting in one of LAME's 3.99 versions.

I have just about no experience w/ iTunes, but I think it uses the Fhg (Fraunhofer) encoder (for mp3) instead of LAME and does not, or did not, do VBR. Does it do VBR/ABR AAC?


----------



## gazoink (Apr 17, 2013)

redsandvb said:


> I have just about no experience w/ iTunes, but I think it uses the Fhg (Fraunhofer) encoder (for mp3) instead of LAME and does not, or did not, do VBR. Does it do VBR/ABR AAC?


iTunes does use the Fraunhofer encoder, not LAME, and does do VBR for both mp3 and AAC, if you choose a custom setting. You can also rip with LAME via third-party software.


----------



## redsandvb (Dec 2, 2009)

gazoink said:


> iTunes does use the Fraunhofer encoder, not LAME, and does do VBR for both mp3 and AAC, if you choose a custom setting.


Thanks 



> You can also rip with LAME via third-party software.


Wow cool, I guess that's new? Apple finally loosening up a bit?


----------



## Lulimet (Apr 4, 2014)

redsandvb said:


> Apple finally loosening up a bit?


ALAC has been open source since 2011. And believe it or not, even Windows Media Player can play ALAC files.


----------



## gazoink (Apr 17, 2013)

redsandvb said:


> Thanks
> 
> 
> 
> Wow cool, I guess that's new? Apple finally loosening up a bit?


No, third-party software means Apple had nothing to do with it. Google "lame for iTunes" and go nuts.


----------



## redsandvb (Dec 2, 2009)

I understood third-party just fine. I took your previous post to mean iTunes allows for external encoding options, something similar to EAC's external command line options. After a quick Google lookup, as you said it looks like something sort of similar is available. Looks like it's been possible for a long time actually...?

Anyway, sorry to others following this thread for getting off-topic.


----------



## AudiocRaver (Jun 6, 2012)

3dbinCanada said:


> At 320Kbps, I cannot tell the difference in sound between CD and mp3.


It will depend on the particular music being played. Well recorded cymbals is where it is easiest for me to hear the difference, even with 320K mp3 encoding.

192K is what I consider the compression listenability limit.


----------



## gazoink (Apr 17, 2013)

AudiocRaver said:


> It will depend on the particular music being played. Well recorded cymbals is where it is easiest for me to hear the difference, even with 320K mp3 encoding.


You might try AAC at 320Kbps.


AudiocRaver said:


> 192K is what I consider the compression listenability limit.


I'm at 256K for mp3, 192K for AAC, and both at 48KHz sampling rate. Lower it to 44.1 and the audibility limit tends to go up. I'm also putting fewer tracks on my portable device so I can do uncompressed. It's just easier, takes this whole audibility thing out of the picture. Takes a bit more thought when you synch, but that's not a big deal. Absolutely no need to store rips on the PC at anything less than uncompressed.


----------



## Savjac (Apr 17, 2008)

Interesting answers here, informative to be sure.
I would think that 320 would be the low bit rate selection imho as anything below that seems to have a forced midrange as if the tops and bottoms are lopped off and the midrange sounds strangely enhanced. 
Never the less, I guess I think that as fast as things are changing and improving, I tend to rip at a higher rate, FLAC or Apple Lossless because I believe I can hear a difference and space is cheap. But even if my hearing does not stay sharp, I think, and this is where I am not sure, but I think that once the file is changed, it cannot be brought back to its original state. Also isn't it easier on the computer to rip at a higher bit rate and not have to work so hard trying to compress bits ?


----------



## gorb (Sep 5, 2010)

You are correct that you can never recover the lost information from a lossy compression - another reason why transcoding lossy files is a bad idea.

Regarding how hard your computer is working when it comes to compressing music, it really shouldn't make a difference as to what level of compression you are using (ie maximum vs minimum lossless compression) unless your computer is super duper old and can't handle it.


----------



## gazoink (Apr 17, 2013)

Savjac said:


> Interesting answers here, informative to be sure.
> I would think that 320 would be the low bit rate selection imho as anything below that seems to have a forced midrange as if the tops and bottoms are lopped off and the midrange sounds strangely enhanced.


The bottoms aren't lopped off, at lower sampling frequencies the top is taken off somewhat, questionable how audible that is. Limited frequency response isn't the big problem though.

The artifacts of low a bit rate are hard to describe in words, I would encourage everyone to deliberately create a few files at 64Kbps and listen for the exaggerated effects. Mostly they occur mid band, not as enhancement, but as a swishy character, and as bit rates go lower, sharp attacks are altered and almost seem to have their timing skewed. If you've heard recordings reversed, it's sort of like that, but not quite. See what I mean? Hard to describe. Make a few low rate files and listen. Once you've heard the artifacts you can pick them out easily.


Savjac said:


> Never the less, I guess I think that as fast as things are changing and improving, I tend to rip at a higher rate, FLAC or Apple Lossless because I believe I can hear a difference and space is cheap. But even if my hearing does not stay sharp, I think, and this is where I am not sure, but I think that once the file is changed, it cannot be brought back to its original state. Also isn't it easier on the computer to rip at a higher bit rate and not have to work so hard trying to compress bits ?


As mentioned, lossy compression is a one-way street. You can't un-loss it. Since much of the damage becomes audible in the mid band even those with hearing loss can hear the lossy artifacts. I also find I can hear artifacts even when material is played very quietly.


----------



## AudiocRaver (Jun 6, 2012)

My MP3 Listenability Threshold:

To clarify:

There are some older, rarely-accessed tracks in my library - tracks that I either cannot find the source for or that I use so seldom that re-ripping is not worth the trouble - that are in mp3 format. On the occasion that I access one, the 320K and 256K tracks are very listenable and I can usually "tune out" any subtle artifacts and enjoy the music. Tracks at 192K are usually enjoyable as well, with a bit more "tuning out." Tracks with encoding at 128K or below are almost always distracting enough that I will not even bother with them, just erase them on the spot.

Any more, I never rip to any kind of lossy compressed format. All new rips are flac &/or wav.


----------

