OK, I'm not a kid.
I'm 53 years old and have heard every type of sound reproduction
since the Edison lathe. I was quite alarmed at the sound of CDs
when they first appeared. The original CDP-101 from Sony put out
a bizarre collection of harsh and other-worldly sounds. As I said in an
earlier post, I have a friend who sought out this model when his own
died because of a preference for that sound. Denon players had a
gritty quality to the sound at low volume levels. We all remember the
bad old days of CD mastering and playback.
My computer is equalized to hear every little detail in the upper frequencies
because I'm getting older. I like to hear the high frequencies. When I
began downloading a few mp3s, I was surprised at the 'sweetness' of
the high frequencies in well-recorded mp3s set at maximum bitrate.
Compared to CD sound, which can sound harsh and processed, and now
compared to my old records that I'm attempting to save to digital files.
The records -- even the newest and most pristine -- have a lot of
distortion in the high end. When I convert them to CD and play them
through a Yamaha 7.1 system, they are smoothed out again.
I have also experimented around with different compression rates and
algorithms. I had grand hopes of extreme compression, but had those
dashed with the shortwave sound they induced. But standard mp3 is
pretty good. I don't know beans about the psychoacoustics, but someone
had done their homework. Like in PhotoShop, where you can tweak a
photo to sharpen it up and actually remove half it's file size.
Computers had MIDI sound, which was based on your specific player's
repertoire of 'instruments' rather than the file. Maybe mp3 has used some
of the MIDI technology to create the music at the source of playback from
an instruction in the file. This is speculation.
When I listen to DVD 5.1 sound, I'm thinking I'm hearing a limited gamut
of upper frequency sounds -- sort of like a really really good MIDI player.
I hear less of that in mp3 sound.
It's a new age, folks. I can't keep up, but I know what I like.
Joined: 27 Mar 2004
Posts: 951
Location: South Africa
Posted: Wed May 27, 2009 11:22 pm Post subject:
I posted this before - but it seems to have got lost... I can't see it, so I'll redo:
Regenerating the lost high end from badly recorded music is nothing new. Aural exciters from Aphex and others have been available for decades, using valves (tubes) to do it. Modern boxes just do it digitally - Creative labs has some gizmo called Crystal - something.
There are no instrument fundamentals in the top octave - above 10kHz, only harmonics. The harmonics can be regenerated fairly easily, if the fundamentals are present - which they, are unless the recording medium is of seriously poor quality. The exciter simply generates and adds harmonic distortion in a controlled way.
Harmonic distortion is certainly 'liked' by some people; valve (tube) amps produce it, and some listeners love the characteristic sound. Analogue tape does it too - particularly at saturation - a very desirable 'sound' to some people.
"5.1" as they call it - the coding algorithm is Dolby AC3 - also chucks out what it thinks is not audible to 'most people'.
Laservision Digital is uncompresed.
JPEG is also a lossy compression algorithm, and you can certainly see the difference between a BMP and a JPG file; if you can't, it's just because the resolution of your monitor has been exceeded.
Quote:
The records -- even the newest and most pristine -- have a lot of
distortion in the high end. When I convert them to CD and play them
through a Yamaha 7.1 system, they are smoothed out again
That certainly sounds like a description of loss of information - low pass filtering. Which isn't necesarily a bad thing - tone controls and graphic equalisers are very popular, and very seldom set to give a flat response.
Personally, I can't say specifically what bugs me about mp3 sound - I can't claim to hear harmonic distortion, or a loss of a certain frequency content, but it just gives music a 'background' quality; it doesn't have magic, or realism.
Joined: 08 Mar 2009
Posts: 589
Location: Secession State
Posted: Wed May 27, 2009 11:45 pm Post subject:
Steerpike_jhb wrote:
...There are no instrument fundamentals in the top octave - above 10kHz, only harmonics. The harmonics can be regenerated fairly easily, if the fundamentals are present - which they, are unless the recording medium is of seriously poor quality. The exciter simply generates and adds harmonic distortion in a controlled way...
Personally, I can't say specifically what bugs me about mp3 sound - I can't claim to hear harmonic distortion, or a loss of a certain frequency content, but it just gives music a 'background' quality; it doesn't have magic, or realism.
The problem here is that the particular spectrum of harmonics gives instruments and voices their characteristic timbre. Removal of harmonics is what makes French Horns blend into Flugelhorns, and English Horns indistinguishable from Oboes. _________________ I can't help about the shape I'm in
I can't sing, I ain't pretty and my legs are thin
But don't ask me what I think of you
I might not give the answer that you want me to...
Joined: 27 Mar 2004
Posts: 951
Location: South Africa
Posted: Thu May 28, 2009 10:42 am Post subject:
CallMeJoe wrote:
what makes French Horns blend into Flugelhorns, and English Horns indistinguishable from Oboes.
Indeed! I know people who enjoy music, and yet don't really know much about what they are listening to - they can't tell a string section from a synthesizer. Any old harmonic will do!
Joined: 23 Feb 2009
Posts: 962
Location: Phildelphia, Pennsylvania
Posted: Thu May 28, 2009 2:50 pm Post subject:
Johnfull:
If MP3's sound good to you, I truly hope you enjoy them. Myself, at 61 I find MP3 encoded files to be unlistenable at 128kbps. They are just barely tolerable at backround music levels when encoded at 320kbps.
Fortunately Philadelphia is large enough to support all the classic arts. I regularly attend live music events including concerts by the Philadelphia Orchestra and The Philly Pops. I also take advantage of the live Jazz at various clubs.
Although it's a given that my hearing has deteriated the last thing I would do is adjust my system to sound like a memory. For me the best reproduction has always been as close to live as I can get. Regular exposure to live music is my base for comparison. Consequently I want my system to sound like what I hear at live events now.
Like you I've found the high end of many CD's to sound a little bright. There are also lots of LP's reissued as CD's that are all but unlistenable.
The CD reissue of Stickey Fingers sounds so awful I gave the CD away. My friends will tell you I never give CD's or LP's away. They sure were wrong about that one.
When "perfect sound forever" was introduced I bought a first generation Sony. It sounded pretty bad. I became one of the loud minority that thought CD's sucked. The players and converters have imrproved a lot since then. Today's CD players when outputting to a good DtoA sound quite good to my ears. When the high end on your CD's is bad enough to make you resort to MP3 files and digital EQ the problem may be your DtoA converter. A better DtoA converter may make all the editorializing your currently doing unnecessary.
Although I've said lots of CD's have an awful top end, converting them to MP3 files never crossed my mind. In extreme circumstances I might consider some Eq. Discarding part of the music by conversion to MP3 files to make upleasant sounds more pleasant is extremely drastic.
The real problem with MP3's is that music is thrown away. What's thrown away is gone with no chance for recovery. MLP or another no loss compression scheme is the way to go if you're trying to minimize file size. The fils may be larger but all the music is still there. _________________ ARC SP9 MKIII, VPI HW19jr, Rega RB300, Marcof PPA1, Shure, Sumiko, Ortofon cartridges, 2 modified Hafler DH200, 1 Adcom GFA-545, 2 radically modified Dyna MK-III's. Acoustat Spectra 22/SPW-1 (front), Acoustat Model 1(rear), 2 12" Transmission Line subs
Yes, lossless compression would be preferred.
JPEG/JPG images can be created losslessly as
well, which was my point of comparison of the
audio and visual perceptions. In early days,
digital cameras produced images that seemed a
bit 'soft' and sharpening algorithms were used
to bring out edge details. Nowadays, this is far
less necessary, but can still be done and it saves
a ton of storage space. It's not good for archival
purposes because enlargements will show the
damage done by the process. Same for any music
that you might wish to re-equalize at a future date.
I have been storing all my records at 44khz in
.wav format on my hard drive. My system can store
up to 96khz, but I'm not at all sure that's
necessary, with the possible exception of discs
that are encoded with Quadraphonic signals...
Joined: 15 Apr 2002
Posts: 6916
Location: Dark Peak
Posted: Fri May 29, 2009 2:38 pm Post subject:
Johnfull wrote:
Computers had MIDI sound, which was based on your specific player's repertoire of 'instruments' rather than the file. Maybe mp3 has used some of the MIDI technology to create the music at the source of playback from an instruction in the file. This is speculation.
MIDI doesn't have a sound and the instruction set isn't imprinted into a sound file; it's merely a method of sharing information between instruments such as what note to play and when.
MP3 is just a filter which reduces resolution for no other reason than to reduce file size - it was never designed to improve on the original source and is a poor format for archival because it throws away part of the recorded signal, stripping out fine detail and atmosphere and adding compression artifacts at lower bitrates.
If you've recorded vinyl that sounds fine on the turntable but harsh in WAV format then it's the ADC or DAC that are at fault. Running an additional process of compression by saving the file in MP3 format may mask the problem but it will also reduce the resolution.
Quote:
Like in PhotoShop, where you can tweak a photo to sharpen it up and actually remove half it's file size.
Zoom into a RAW image file then one converted to Jpeg and marvel at the compression artifacts. MP3 does exactly the same thing to a sound file. If you're printing out the image as a 6x4 or listening to the sound file on a low resolution system this may not matter. Similarly, a picture taken with a sharp lens may not need any extra sharpening, as a well recorded piece of music won't need lots of additional processing, but MP3 will apply it's 'mask' regardless. It's the equivalent of in camera image processing.
I'm not saying some folks won't prefer MP3 to CD as the 'inaudible' compression is anything but, I just think archived recordings should be as high resolution as possible and to my ears post-studio processing, be it a compressor, graphic equaliser or psychoacoustic filtering take away the hi from fi
Regards,
JaS
PS I've used compressed formats ranging from PASC, through ATRAC to MP3 for 15+ years and still occasionally play mini-discs in my car so I'm not completely averse to the benefits!
Someone suggested that mp3s can add harmonics
without the bitrate to actually carry the harmonic
information. I think that's as close as what I was
asking about in relation to manufacturing part of
the sound at the playback.
I think we hit on a good analogy with the photo
and the music, vis a vis .jpg and .mp3.
Any music that you want to reprocess with
equalization or click and pop filtering or the like
should definitely be recorded in .wav format and
preferrably at 96khz.
Once all the work is done, though, compression
to the highest rate of .mp3 for use in most devices
will yield good results. Similar to working on a
photo in PhotoShop at the highest practicable
resolution first and then compressing.
Jpegs can actually be uncompressed, unlike
mp3 music, so the analogy breaks down at the
extreme...
Joined: 27 Mar 2004
Posts: 951
Location: South Africa
Posted: Fri May 29, 2009 3:58 pm Post subject:
Quote:
Jpegs can actually be uncompressed
There are lossless forms of JPEG, but they are rare and not commoly used.
The majority of jpeg images and tools to create them throw out imasge information that can never be recovered.
I'm not sure what you mean by saying mp3 cannot be uncompressed whereas JPG can. Its perfectly easy to turn an mp3 file back into a wave file, it just doesn't have the same information content as the original wave file from which the mp3 was created.
An interesting experiment you can do with most ssimple wave manipulation programs:
Record a wave file on your PC, or pull it off a commercial CD. Convert it to mp3. Convert the MP3 back into a wave file.
Invert this wave file and add it to the ORIGINAL wave file. Now listen to the result - which contains only that which the mp3 codec removed.
That sounds like a cool experiment!
I'll bet I could do it with GoldWave somehow,
but it would take some figuring out.
Maybe a weekend project. Have you done it?
As for uncompressed .jpg files; modern digital
cameras save photos in this format.
An 8.5 megapixel puts out a 3500kb jpeg typically.
This is much smaller than the equivalent .bmp
or .tiff would be. Is .jpg vector graphic or is that
only for fonts and ciip art? I've wondered if .jpgs
weren't more scalable than bitmaps...
Joined: 15 Apr 2002
Posts: 6916
Location: Dark Peak
Posted: Fri May 29, 2009 8:12 pm Post subject:
Johnfull wrote:
As for uncompressed .jpg files; modern digital cameras save photos in this format. An 8.5 megapixel puts out a 3500kb jpeg typically.
I've never had a camera with lossless Jpeg? Mine have all had a RAW option (which also avoids the crappy in-camera processing) but not lossless Jpeg. I've only owned Nikons and Canons in recent years though.
Part of the problem with Jpeg (and MP3) is the inability to do editing without further loss on saving. FWIW Jpeg isn't a vector graphic and they don't scale well, unlike say lossless PNG files which are great for designing web graphics.
Joined: 27 Mar 2004
Posts: 951
Location: South Africa
Posted: Fri May 29, 2009 10:15 pm Post subject:
Johnfull wrote:
That sounds like a cool experiment!
Have you done it?
Yes, I just did it again. Here's the spectrum of the 'removed part', shifted by +15dB (i.e. the original level is 15dB lower than my spectrogram shows).
It sounds like.. umm... if a waterfall could sing, that's what it might sound like.
Interestingly, it's taking a lot out in the midband, and not so much at the extreme high end. That extreme notch around 16kHz is odd - it's persistent throughout th track. The track used is "The Breaking of the Fellowship" from the LOTR soundtrack CD.
http://web.eject.co.za/s8nspawn/hifi/mp3remval.jpg
The codec is Lame 3.93.
LAME incidentally is not an MP3 codec (even the name tells it: L.A.M.E being a recursive acronym, "Lame Ain't an Mp3 Encoder". Mp3 is a proprietary technology of Fraunhofer Gesellschaft, so Lame was created as an Mp3 compatible, public domain technology.
Joined: 08 Mar 2009
Posts: 589
Location: Secession State
Posted: Fri May 29, 2009 10:17 pm Post subject:
Johnfull wrote:
Someone suggested that mp3s can add harmonics
without the bitrate to actually carry the harmonic
information...
Any harmonics "restored" in mp3 playback are de facto distortion products of a bad system. There is no way harmonics can be correctly restored in an "uncompressed" recording without a great deal of information that is not put into mp3 files. As I said earlier, French Horns blend into Flugelhorns, and English Horns indistinguishable from Oboes. I could add cornets reduced to trumpets, euphoniums morphed into common baritone horns, and Barbara Streisand a vocal twin to Tiny Tim... _________________ I can't help about the shape I'm in
I can't sing, I ain't pretty and my legs are thin
But don't ask me what I think of you
I might not give the answer that you want me to...
Joined: 23 Feb 2009
Posts: 962
Location: Phildelphia, Pennsylvania
Posted: Sat May 30, 2009 7:48 am Post subject:
Johnfull wrote:
OK, I'm not a kid.
The records -- even the newest and most pristine -- have a lot of
distortion in the high end. When I convert them to CD and play them
through a Yamaha 7.1 system, they are smoothed out again.
Okay, I've gone back and read this thread from the beginning. You may not want to hear this but you should. I believe that a major part of your feelings about MP3 files is caused by the inferior performance of HT receivers when called upon to reproduce 2 channel stereo.
In my experience HT receivers just don't cut it where 2 channel stereo is concerned. Even dedicated surround processors such as my Lexicon CP-8 sound less than stellar in 2 channel. My solution is to use my ARC SP-9 for all 2 channel source material. When playing DVD movies, TV and music recorded for surround playback my preamp is used a a pass through device. This way I get the benefits of a very good 2 channel preamp driving my front ESL's. When in surround mode my preamp is in bypass and all my speakers, front's included are driven by my Lexicon. This is something you might want to consider.
While all that DSP stuff in the Yamaha may sound good while watching Saving Private Ryan it just doesn't sound as good as a dedicated 2 channel preamp.
I only have one more "smart ass" comment. Playing music recorded, mixed and mastered for 2 channel playback in any surround mode through an HT receiver could be part of the reason CD's sound so bad to you. The sound of Sony CDP-101's is not the sound of a modern CD deck into a decent DtoA converter. There has been a lot of progress made. My modified Marantz CD-63SE and MSB DAC sound pretty good to me and others. _________________ ARC SP9 MKIII, VPI HW19jr, Rega RB300, Marcof PPA1, Shure, Sumiko, Ortofon cartridges, 2 modified Hafler DH200, 1 Adcom GFA-545, 2 radically modified Dyna MK-III's. Acoustat Spectra 22/SPW-1 (front), Acoustat Model 1(rear), 2 12" Transmission Line subs
I listen to CDs on a modern Sony changer,
played through SAE equipment into giant
JBL speakers. It's the fine detail that gets lost
on CDs as opposed to vinyl and some of that
detail is restored with .mp3
I would never say that .mp3 is better than the
actual master source, though I had the experience
of Scott Cossu's 'Oristano Sojourn' being reissued
on Windham Hill in a digital remaster and they
totally ruined the sound. I posted the youtube
of this song -- old and dated by now, but had
all the bells and whistles (and sleighbells and
monkey calls) that made it a good test of both
vinyl's compliance and digital's fidelity.
I found that youtube and I found 2 sources of
.mp3 download of the tune. The youtube has
2 versions -- the HD is actually an .mpeg which
seems to be around the same size as the decent
.mp3s found elsewhere. The .flv sounds pretty
good, so the newest technology of rendering
is impressive. Still, nothing is as good as the
original vinyl analog recording. It was full of
overlapping complex sounds and it rendered
much flatter in all subsequent iterations:
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