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Mastering Engineer Explains Types of Compression, Effects On Today's Music
Stowie101 writes "Today is Dynamic Range Day, which is an event to educate the public about the 'Loudness Wars' that are compressing and harming the quality of today's music. Ian Shepherd, a mastering engineer and founder of Dynamic Range Day, explains why music lovers should avoid MP3 files. 'The one that springs to mind is to avoid MP3, especially if it's 128 kbps. Apple uses a more advanced technology called AAC, but if someone can get lossless files like FLAC that's a better place to start.' Shepherd says it's actually harder to make a good 'lossy' encode of something that has been heavily musically compressed. Very heavy dynamic compression and limiting makes MP3s sound worse, so the loudness wars indirectly make MP3s sound worse."
It's also known as ALAC. I don't believe that it's an option for the iTunes store, but if you own a CD and want to get it into your iDevice environment, it's a good option.
All this switching back and forth between dynamic range compression and data compression makes my head hurt.
So to clear things up... dynamic range compression is a form of signal processing that is usually used to make the average level of a signal louder, hence the loudness wars.
Data compression probably doesn't need to be explained to this crowd. But you know... MP3s and stuff.
every other technology I use takes advantage of MP3. Asterisk can't use FLAC. Which would be hilarious if it did because the standard codecs are about the worst way to transmit music anyways. A phone call is terrible for quality.
Phone calls don't use MP3. The wired phones are uncompressed 7-bit PCM, while the cell phones use a codec designed specifically for speech and barely stream faster than 4-5 kbit/s. (Yes that's right... 1/10th the speed of a 56k dialup connection.)
My AC stalker: " I personally agree with your posts most of the time, but that won't keep me from modding you troll"
You should be so lucky. These days most mastering engineers shoot for 4 dB of dynamic range at most because, otherwise, the soft passages will be lost in the car noise.
That is all.
Wikipedia's article on the "loudness war" does a good job of explaining the problem.
http://en.wikipedia.org/wiki/Loudness_war
I used to work for JJ Johnston. He took a popular music track (I won't say which one) and ripped a .wav file from the CD, and then ran a simple Matlab script that tallied how many samples there were of each value. CDs use 16-bit samples, so there were 64K bins in this histogram. You would expect a pretty much Bell-curve shape to the histogram. With this particular song, over half of all samples were either +1 or -1 (i.e., 16-bit sample values of either +32767 or -32768).
That music is so horribly overcompressed that most of the wave forms are sawed-off into square waves. Square waves, in turn, add unpleasant harmonics, which make the music harder to enjoy, and make it louder (in the psychoacoustic meaning of "louder").
I'm hoping that "audiophile" versions of songs become available, not because I think I need all my music in 24-bit 192KHz but because I'm hoping the mix engineers will be allowed to do the mix properly, instead of mixing it far too hot.
I'm sort of afraid to buy remastered versions of old classic rock albums, because I'm worried they will actually sound worse than the originals!
steveha
lf(1): it's like ls(1) but sorts filenames by extension, tersely
Yes, the connections to the PSTN don't use the MP3 codec, and it would be very strange to use MP3 between phones on a PBX system. However, PBX systems like Asterisk do transcode MP3 files to play as MOH or even system sounds on a channel.
If you build a jukebox system to provide MOH, typically the end user uses MP3's to load their music, not FLAC.
Also, if you are doing anything scripted on a Linux system for dynamic content generation Sox does not fully support FLAC. FFMPEG does have support for it, but I am not sure about any others.
So while it is possible to convert FLAC to MP3, so it can be converted to g729 or whatever codec you prefer it does not make a lot of sense when the codecs actually used for transport to most PSTNs are terrible for music and audio fidelity in general.
Which is kind of my point. Unless you are talking about some in-house conference systems, even MP3 is wasted.
More research into your platforms? You really have to make it something you look for, rather than something you expect to just appear.
Personally, I use MediaMonkey as a library app and have a Cowon S9 for music/movies on the go (battery life is fantastic with the screen off). They both support FLAC, OGG, and a bunch of other filetypes. Heck even my phone (Galaxy Nexus) supports FLAC and OGG.
you do know that the propellor at the front of the airplane is just a fan to keep the pilot cool ? I mean, when the fan stops turning, the pilot invariably breaks out in sweat.. there are 3 good things for a pilot: a good landing, a good orgasm, and a good bowel movement A night landing on a carrier is one of those rare moments in life where you get all 3 at thesame time
Please sir, I only use knobs made from the finest of unicorn horn. It may have cost several million dollars but once you hear the warmth on the midrange of the complete catalog of Right Said Fred you'll understand why.
so that article links to a list of 9 good albums, one of which is Nirvana's Nevermind. note: the 2011 remaster is smashed to the wall, and, iirc, you could even hear clipping: http://i.imgur.com/i0Vag.png
.MP3 is capable of far, far greater dynamic range than any vinyl. Lossy compression has its issues, but dynamic range isn't one of them.
Though it does exhibit certain artifacts when the dynamic range and the bit rate are both low. Of course, vinyl has its own issues with hot signals.
Neither the article you linked to, nor the suspect Bauman paper it references measured a real 112db dynamic range from an actual record. They measured the noise floor of a pickup, did some measurements of the pre-amp, did some hand waving about how a skilled ear can add a magic 30 dB below the noise floor and claimed that as the theoretical dynamic range of actually playing a record on high quality equipment. It totally ignores the physical limitations of the vinyl and pickup. It also ignores the other issues with records such as rumble, wow and flutter, poor stereo separation, non-linear response, and other distortions. Their own measurements show the pre-amp SNR in in the 70s, which shows the 112dB claim to be BS.
I label any review as suspect when it uses fluffy wording like this:
As you might expect, the resolution of low-level detail was outstanding. Against a dead-black background, finely layered images floated in three dimensions on what was a somewhat wider soundstage than I'd become accustomed to
Ian Shepherd's mentioning that one should avoid 128kbit/s encoded MP3. This is leaving out a critical piece of information. Luckily he mentioned himself that heavily (audio) compressed music (data) compresses very badly. This will be especially evident if you force the encoder to only allocate a fixed number of bits to a section, called "Constant Bitrate" (CBR) in MP3 encoders. "Busy" sections will get the same data allotment as quiet sections. This problem can be diminished by using "Variable Bitrate" (VBR) mode when encoding, which encodes to a specific target quality rather than file size. With that, (LAME) MP3s can still sound good enough around 128kbit/s, since the encoder is free to allocate more bits to critical sections and less bits to non-critical section.
In short, there is no reason to use CBR encoding, unless your target device is unable to decode VBR encoded files, or you absolutely need to know the exact bandwidth requirement of a stream. It defeats the whole point of lossy encoding, which is to reproduce the original with highest possible fidelity, not reach a target file size.
112dB? Ha! Hilarious.
You're lucky to get 70dB out of audiophile grade vinyl. See http://wiki.hydrogenaudio.org/index.php?title=Vinyl_Myths
There's also an interesting discussion of the dynamic range of both vinyl and 16-bit/44kHz digital audio here:
http://www.hydrogenaudio.org/forums/index.php?showtopic=47827&st=0&p=425794&#entry425794
The dynamic range of vinyl does vary by frequency. For example, in that thread a poster notes he measured 84dB at 300Hz for vinyl. A 300Hz tone recorded to a 16-bit wave file with noise shaped dither exhibited a dynamic rage of 151dB!
Vinyl has extremely limited dynamic range in the bass - something like 30dB at 20Hz. The needle would pop out of the groove if you tried to record more than that. Vinyl also suffers from constant negative signal to noise ratio incidents, when impulse noise (clicks and pops from scratches, dust and defects in the groove, static discharge) completely drowns out the signal. Unacceptable, in any format.
See also this recent article, which, while skewering the distribution of 24-bit/192kHz audio, notes that 16-bit digital audio has an overall dynamic range of 120dB with dither:
http://people.xiph.org/~xiphmont/demo/neil-young.html
Vinyl's a shitty format for reasons apart from its inferior dynamic range, but that's not terribly surprising since it's like 100 years old, mechanical, and prone to a plethora of issues - rumble, wow and flutter, phase issues caused by the RIAA equalization / de-equalization process, scads of unwanted harmonics and harmonic distortion, ultrasonic noise, preamp hum, static clicks, etc., etc., etc.
Probably should have been replaced by some other analog disc-based format by the early '70s - maybe something based on RCA's capacitance discs, which wound up being used for video, and had scads of bandwidth - more than enough for near-flawless reproduction of the original studio master tapes. But at the time most industry attention was focused on the emerging lo-fi but convenient tape formats, first 8-track then cassette, as well as the failed competing quad systems. And then by the middle of the decade everybody knew a digital format was coming, with Sony and Philips working first separately, and then by '79 or so together on what would become the Compact Disc.