Saturday, February 27, 2010

Acoustic Music Is Dead

A few weeks back, I ranted about a godawful Minnesota Orchestra pops “concert’ I suffered. This week, I recorded an electric/acoustic act that had pretensions of acoustic-ness that they didn’t bother to live up to. I mean, they didn’t attempt an acoustic sound.

Years ago, my partner and I rented out our sound company to a couple seasons of bluegrass festivals. We had a very high fidelity sound system with plenty of power to provide audio to several thousand outdoor rock and rollers and enough stage monitoring to keep most lead guitarists and screaming metal-head vocalists happy. With that capacity, we always found ourselves short on the necessary acoustic power to satisfy solo banjo pickers and the rest of the characters who qualify as “entertainers” on the bluegrass circuit.

The sound of a banjo picker whacking on the vocal mic, saying, “Can you hear this out there? I can’t hear a damn thing” still haunts my memories of doing live sound in that venue. Led Zepplin has nothing on a bluegrass quartet, when it comes to stage volume. Their hearing defect is the core to the problem with acoustic music. Fragile egos, hearing impairment, or ordinary poor taste has convinced almost every musician that deafening stage volume is a necessary component of every performance. With that as a given, delicate and sophisticated tonal character is sacrificed for the God of Gain over Feedback. A microphone doesn’t have a chance in hell of picking up a usable tone from an acoustic instrument in the midst of that atonal racket.

The problem is that tone and volume do not co-exist. Sound companies have been proving that for more than 50 years and the evidence is better today than ever. Every musician makes a choice before every performance, “Do I want to sound good or do I want to be loud?” The answer to that question goes to the heart of a musician’s reason for selecting a particular instrument, for practicing and perfecting technique, and for being a musician. The answer, too often, is the one that drives guitarists to select a pickup over a microphone or performing without amplification.
That was 30 years ago. Today, acoustic music is dead. I miss it and I doubt that it is resting in peace.

I can’t remember the last time I saw a folk, classical, or jazz solo guitarist who didn’t bring more amplification to a small club than would be needed to thoroughly overwhelm a small auditorium. Not only do they carry this crap to every living room jam session, but they feel compelled to use it.

It’s one thing to be an electric guitarist who happens to like the feel of a full-bodied acoustic instrument. It’s another thing to pretend to be an acoustic guitarist while depending on a few hundred watts to blast every audience into submission. Sometimes I suspect the real reason musicians pick acoustic instruments is that it gives them an excuse to sit while they play. It sure isn’t because they like the way an acoustic guitar sounds because nothing coming out of an overpriced faux-hi-fi amplifier supplied with the signal provided by a Mickey Mouse rubber band “guitar” pickup.

When I try to position a microphone in front of an acoustic instrument, the claim I almost always get from a guitarist, violinist, or bassist sounds a lot like, “You don’t need a microphone, my pickup sounds great.”

I can think of one instance that I found that claim to be half-true. Otherwise, I think all acoustic instrument pickups belong in rock and roll bands where sound quality is the dead last show concern. They no more sound like acoustic guitars than does a Les Paul plugged directly into a console through a DI. That’s the nicest thing I can say about the lot. Most piezo pickups make an objectionable sound that only a deaf modern musician could love. Their magnetic cousins just turn an acoustic guitar into an oversized electric.

The sound of the acoustic guitar pickup is one that I’ve been trying to find a home for in the mix for 40 years. Usually, the best thing that can be done for that tone is to treat it like a jazz guitar and bury it in delays, chorus, and behind every other instrument in the mix. Otherwise, it just sounds like that miserable noise Al Di Meola has been making since Ovation purchased his soul.

This is coming from someone who loves acoustic guitars. A well-mic’d acoustic guitar is one of my favorite musical instruments. An acoustic guitar, left to its own devices, with no electronics between its output and my ears is up there with any musical sound made by any instrument or voice. Pickups and guitar amplifiers just don’t have anything resembling the nuance to reproduce the instrument. I hate what they do to my favorite instrument and don’t have a lot of love for musicians who can’t hear the difference.

I’m no more fond of those abominations on violins, basses, or mandolins. They are just fine on banjos because there is no way to screw up the tone of that instrument. I guess it doesn’t matter, though. Musicians don’t have the ear, patience, or audience for acoustic music in almost every venue, so let’s just agree that acoustic music is dead and quit pretending that playing something with a hollow body is in any way similar to an acoustic instrument.

Sunday, February 21, 2010

Vinyl vs. Bits

For some reason, I've toted around about 100 pounds of vinyl and a last-generation direct drive Sony turntable for the last two decades. It hasn't been much of an effort for the last dozen years, since the whole pile has lived, boxed, and sealed in my basement. Last week a friend loaned me his new turntable-to-USB toy and I decided to convert some of my old records into a format I might listen to. The experience has been eye-opening. 

No, I haven't been converted to an analog fanatic. Just the opposite, in fact. 

The more I listen to the magical world of vinyl the easier it is to understand why records vanished so quickly. Another friend who loves all things old and expensive is convinced that my dislike of the classic "snap, crackle, and pop" sound of records is overly picky in a world of crappy live sound systems, digital television dropouts, and grossly over-compressed CDs and other audio media. I admit that I do like the dynamic range of a 1968 LP. However, the max s/n of a record was somewhere in the 50-60dB territory and CDs easily exceed that range. 

The fact that modern mastering standards generate non-musical products does not condemn the technology. There is a boatload of crazy vinyl philosophy on the web. One of my favorite nutty claims is "Vinyl was custom made for the human ear." Vinyl -- like CDs, MP3s, and tape -- was made to generate a pile of money for someone. Several someones, at best. There is absolutely nothing about the RIAA equalization curve that bears any relation to the best function of the human ear. The incapacity of records to tolerate the sorts of phase oddities that surround us every day is another example of how poorly vinyl records and reproduces acoustic activity. The lack of dynamic range and LF capacity and the phonograph records inability to store and reproduce distinctly different information on the left and right channels is even more data for the "vinyl sucks" argument. 

And, of course, "snap, crackle, and pop" were still everpresent. Clean them, lubricate them with expensive concoctions, put them in a vacuum chamber and records will still contribute their irritating "quality" to the listening experience. 

 But that's not the point of this rant. The real surprise for me was how often my old records had been mixed by crazy people. I'm not talking about the early "stereo" mixes that were just bastardizations of mixes that were intended for mono; like the early Beatles stereo records (instruments full left, vocals full right). No, I mean "modern" mixes intended for stereo records that are just nuts. At first I thought there was something wrong with the turntable. No one would be so careless with pan controls, would they? I was wrong. They would. A bunch of the Warner Brothers stuff I'd kept out of nostalgia is practically unlistenable because the mixer was clearly on crack. Guitars that swing from one side to the other, drums that vary their pan dimensions or are so obviously spaced mic recordings that are so radically spaced that half of the kit resides only in the left ear and the other half in the right. Of course the kick is buried in the limpid center and the bass mumbles around that same vicinity. 

The "obvious" advantage of records completely escapes me while listening to this mess. All this brings back nasty memories of my own record past. At Wirebender, we never found a mastering lab that did much more than not piss us off. When we had a budget for 3 or more mastering options, we selected the one that did the least damage to our master tapes. Never once did a record even approach the dynamic range, frequency response, or stereo image of the original final mixed tape. I remember the phrase, "I hate this one the least" as the closest thing to acceptance we ever managed. 

Finally, after all these years of lugging 100 pounds of vinyl around, I'm going to be able to clear out this section of the basement to make room for something useful. The next pile of junk I'm going to pare away is my collection of unstarted model motorcycle kits.

Saturday, February 20, 2010

Busting Bubbles

Harold, dude, you're breaking my heart. At least a little. 

An old friend thought I was being too hard on Townshend and Friends for their Souper Bowl sellout. He tried to drag me into the sad, pitiful world of R&R reality by telling me that anyone in music can be bought for a corporate affair of some rich asshole's birthday party. Ok, it doesn't surprise me or disturb me that a washed up George Michael or John Mellencamp, Vegas divas Christina Aguilera or Elton John or Rod Stewart or Tom Jones, or even the crazy spending Rolling Stones can be bought for a few million for a night's work. If they'll play the "lost rock hero" club circuit, they're hard up enough to play for Arab princes, trust fund brats, and corporate brain-drain parties. 

Let's face it none of those acts can fill a mid-sized arena these days and they are probably supporting a collection of rock star bad habits. His claim that Dylan, Springstein, and anyone else you can name would tumble into the arms of any rich scumbag you can think of left me feeling somewhere between disgusted and depressed. If there was ever evidence that the top tax bracket is living far beyond their cultural value and that our tax system is totally screwed up, this is it. The idea that these giant douchebags are taking tax deductions for renting out rock stars for the entertainment of their royal elite is beyond disgusting. Obviously, there was good reason to "hope I die before I get old."

Technologically Stuck

I'm on my way to 62. I have most of the toys I want to own and more computers than I need. It's pretty easy for me to imagine that my current stock of computerized toys will suffice for the rest of my life; however long that may be. I'm not being depressive, although I have that talent. I, honestly, have all the tools I need to do the jobs I want to do. So, why would I buy new technology? 

 Two reasons: 1) The technology allows me to do something I suddenly need to do that I didn't need to do before or 2) the technology develops manners. 

The first reason is insanely unlikely. I have software and hardware that has produced music and video/movie material that is so far above the level at which I work that it is impossible to imagine that I will be able to reap the maximum benefits of the software/hardware I own. If that's true, adding new capacity to my already underutilized capacity is foolish. 

Honestly, I think the second reason is even more unlikely. I approach hate for the software I commonly use. The overriding impulse for programmers is to complete the task the programmer decided is most important, rather than apply a little hardware to observing what the user wants to be doing. Every time a piece of software takes off on some unimportant task, in total disregard for the signals I'm giving the software through the keyboard and mouse, I want to find that geek and push his head through a monitor. 

Manners are a vanishing commodity in today's technological society. People interrupt live conversations to check their phones for email, texts, or just to look at their Facebook page. Commercials blast over the top of program audio in an attempt to catch the viewers' attention, but mostly succeeding in pissing off potential customers. We drive in rage, interrupt each other without thought, and occasionally freakout and gun down our friends, family, and coworkers. Why would the concept of good manners find its way into software? 

No reason. It probably won't. 

Without either, or both, of those advantages, I have no reason in the world to buy a new computer or to spend significant money on new software. Apple, of course, banished guys like me to history with the move from PPC processors to Intel. I like my G5. It works and it's more than fast enough. Apple is done with the PPC generation, none of their current software will work on my machine. So, I'm done with Apple, at least as long as my G5 is working. Most likely, when it dies I'll just find another used G5 and carry on. 

Microsoft wasted a lot of good will and energy with Vista, but that left me with WinXP for an extra three years and a total of 9 years on one operating system. After all that familiarity, why would I want to move just because Win7 has "Snap?" Win7 is bigger, slower, and requires new hardware. My hardware works fine. XP works fine. It's rude, but so is OS X. 

 I used to think there was an advantage in "staying up with the times," but now I'm uncertain. I know a couple of guys who are still using their OS 9 Macs and are doing perfectly well on that historic equipment. A couple of years back, I met a few folks who make a living recording live shows and they are all solidly WinXP & Nuendo v2.0 users. Steinberg has a list of reasons why those guys ought to "upgrade" to Win7 and Nuendo 4.2, but there is one overriding reason for the recordists to ignore Steinberg: reliability. The system they use works and has worked since 2003 and "new" means new bugs and troubleshooting. 

 I'm wondering if Moore's Law (data density doubles approximately every 18 months) will have less effect on consumer spending in the future? When the software doesn't provide any actual functional advantage, what's the point in buying it? For me, I think the answer is "it's pointless."

Monday, February 8, 2010

What's the Matter with the Who?

A friend jumped on the Who's Super Bowl XLIV Concert, knowing that I'm a long-time fan. He reported that "Commentary coming in seems to lean towards 'worst Super Bowl show ever.'” Of course, he's getting his data from wingnut talk radio, which is like getting a restaurant review from a McDonald's fry cook. "Taste" is a personal thing, but folks who exhibit a distinct lack of intelligence or common sense in all areas of life should keep their opinions to themselves. That means you, Rush and the rest of the ClusterFox crowd.

As far as being the "worst ever," I don't know how the 1976 Up With People noise-pollution could ever be topped. Awful is way too weak a word. That might have been one of the worst moments in musical history, let alone Super Bowl history. How about 1989's Elvis impersonator: Elvis Presto? Coke gave us that tacky Vegas crap fest. The New Kids on the Block in 1991, with the 3500 kids and foam guitars? That was pretty bad, to express as mild an opinion as I can manage. Garth Brooks and Clint Black in 1993 and 1994 introduced the NASCAR crowd of hillbillies to the rest of us. Fortunately, I skipped out on those games and only saw painful bits of the performances on the tube post-game. U2 turned in a performance in 2002 that reminded us all of how good our local U2 cover bands can be; compared to the real thing. Janet and Justin took a lot of heat for their sex club act in 2004, but they were actually the class portion of a show that included chronic musical catastrophes P. Diddy and Kid Rock. 2006, 2006, 2007, and 2008 coughed up McCartney, the Stones, Prince, and Tom Petty. Nothing particularly adventurous or even lip-sync-free there. In a single concert, Prince caused a gayness outbreak that was worse than three generations of petrochemical pollution and phthalates. The evidence was obvious from all the butt-slapping that went on during the 2nd half of the game (Colts-Bears). Speaking of which, why is displaying a little boob "pornographic" while grabbing a 300 pound lineman's butt cheek barely gets noticed?

Honestly, I don't know why the Super Bowl halftime has turned into some sort of R&R Hall of Fame moment. The only show I can remember actually liking was the 1979 Fleetwood Mac half-time performance and that was only because of the USC Marching Band. I could care less about the Mac, but the USC band rocked. The sound sucked, though.

It is true that 65-year-old Daltry and 64-year-old Townshend were beyond their prime by a couple of decades. Hell, half of the band is dead. What part of that doesn't scream "obsolete?" The problem is who isn't? And of those who aren't, who wants to watch them? For that matter, among the suspicions that the Who's show was lip-synced was the obvious mediocre mix. If Daltry's voice was dubbed, why was the dubbing done after his voice was mostly gone? You'd think they would at least haul out a recording from when he could actually hit the notes. Townshend's guitar phased in and out of the mix through the whole show. I could not figure who who was singing the high harmony's, though. That bit was suspicious.

What about a pro football game would make fans want to watch a couple minutes of music, a fireworks show in the middle of the afternoon, and a whole lot of equipment rushed to and from a field? For all the hype, the whole concept is begging for ridicule and any band desperate enough to jump into that ring is bound to get hammered for the effort. Like working in Vegas, doing the Super Bowl is like conceding the point that your career is pretty much over and you're just in it for the money until that dries up.

Friday, February 5, 2010

Who Thought This Was A Good Idea?

All Rights Reserved © 2010 Thomas W. Day

It seemed like a clever idea, on paper and in the advertising: "The Music of Led Zeppelin & Queen with Members of the Minnesota Orchestra." The marketing puff for the concert claimed, "Bridging the gulf between rock n’ roll and classical music, conductor/arranger Brent Havens takes the podium to present The Music of Led Zeppelin & The Music of Queen, a program he scored to extend the listening experience of Led Zeppelin and Queen’s timeless tunes.

"Performed by members of the Minnesota Orchestra and amplified with a full rock band and screaming vocals by Randy Jackson, Havens and his ensemble capture Led Zeppelin’s 'sheer blast and power' riff for riff while cranking out new musical colors."

In reality, it was a painful excuse for a godawful sound company to blast the same old "musical colors" you can experience at any bar in any town in the country. What we got was the noise made by a mediocre garage band blasted at a moderate-sized audience through a PA designed in hell. It was another moment that painfully described why the audience for live music is shrinking so dramatically.

Moof-rumblerumble-moof-moof-rumblerumblerumble-moof . . .

And so it went for an hour or so, until my patience failed and Idecided to save what was left of my hearing. That's my best written description of the garbage that was emitted by the subwoofers. Somewhere in all the mud was a kick drum and an electric bass. Over the top of that, but equally distorted, was a screeching vocal, a honking electric guitar, a splatting snare drum, and an occasional moment of calm where one or two instruments of the 50-piece orchestra broke though. If I'd have brought a distortion meter, it would have registered well over 50% for every moment of the evening.

The Minnesota Orchestra is one of the most impressive orchestras in the nation, staffed with musicians from all over the country and capable off making even the most pedestrian classical music seem worthwhile. This evening wasn't up to the worst of their rehearsals. If I were to blame anyone for the terrible sound quality of the performance, it would have to be "Guest Conductor Brent Havens." He clearly never took the obvious step away from his conductor's podium and into the Target Center to see what kind of mess the idiot behind the sound board was making of his orchestra.

Or, Havens is deaf and thinks that skinny line array and ridiculous heap of subwoofers were capable of reinforcing something as full-range and powerful as an orchestra.

In the 1970's, Hartley Peavey and his band of hearing-impaired engineers assembled one of the worst combinations of horns and drivers into a product called the "SP1." Garage bands all over the country swept up the SP1 and linked it to another of Peavey's aural disasters, the CS800 power amplifier, to create sonic evil that was rarely equaled in professional audio until some deaf idiot decided to pawn off giant versions of Shure's 1960's Vocalmaster columns as clever engineering under the marketing gimic of "array." The two scroungy strings of miserably designed and aligned speakers arrayed over the heads of the Minnesota Orchestra couldn't have held a sonic candle to a quartet of Vocalmaster columns, but they were definitely much louder and produced as much pain and distortion as their aural grandparent, the Peavey SP1.

Even with the handicap of this shrill and distorted system, the orchestra's sound moron managed to make matters far worse. For starters, he mostly seemed to forget that there were 50-some orchestra members who deserved to be somewhere in his mix. Obviously, our goof-behind-the-faders had spent too many drunken nights mixing crappy garage bands doing mediocre covers of Led Zepplin crap and he is now left with such limited hearing that he can only hear 1-5kHz and feel 80Hz and below. Occasionally, a piccolo would pop through in odd bits of the midrange wall of noise, but the horns and strings were lost all but a few brief moments of the entire Queen portion of the show. The string bass players might was well stayed home and spent the evening entertaining themselves.

What wasn't lost was the giant muffled poofing sound of the kickdrum and the constant rumble of random electric bass. The subwoofer was so poorly setup that it failed to reinforce the kick and bass, but simply turned it into a constant LF industrial noise. Nobody who ever heard a decent recording of a kick and bass would mistake this system's indistinct LF noise for those musical instruments. Unfortunately, after submerging the Target Center's mediocre acoustic field with massive LF distortion, there was no headroom left for anything broadband. So, the sound idiot opted to tweek his already narrow band system until it delivered a piercing and painful midband shriek from every instrument he managed to poke into the mix.

In the PR bullshit, Havens claims that his Queen impersonator "Las Vegas star Brody Dolyn" was a perfect clone of Freddy Mercury; "inflections were spot-on and even the wailing rock sound had that Freddie resonance." Since it's obvious that Havens has severe hearing impairment, I can understand his confusion. However, I had the pleasure of hearing Freddy Mercury and Queen live and I can tell you Dolyn isn't Freddy Mercury and the garage band Havens assembled behind Dolyn isn't the rest of Queen, either. Dolyn is a decent vocalist, if a hambone of a performer, but it's hard to believe that a dozen or more local performers weren't up to his standard of musicality. On that note, I was disappointed to see that the Minnesota Orchestra went solidly East Coast for all of the rock musicians in this show. I know any one of those four (drums, bass, guitar, and keys) players could have been replaced with local musicians with equal or superior results. Part of the reason for supporting the Minnesota Orchestra is to support local talent. If the orchestra's administration is incapable of identifying local talent, they are doing the area a serious disservice.

As irritating and aurally hazardous as this was during the Queen portion of the performance, it got much worse when Randy Jackson brought his impression of the worst voice in rock and roll history, Robert Plant, to the mix. After the third tune, I was flinching as if someone was poking my eardrums with a sharp pin every time Jackson squalled at the high end of his range.

I admit it, I do not like Led Zepplin. I haven't heard a thing worth noting from LZ since their first album. I loved Good Times, Bad Times and even covered that and Communication Breakdown in a few of my own garage band ventures (30 years ago), but ten thousand radio-plays of Stairway to Aural Hell and I never wanted to hear Plant's noise again. Like Zappa's early recordings, I'd probably appreciate LZ a lot more if I could hear their stuff before they overdubbed the vocals, but I don't have that luxury.

Put an impression of that awful voice through a sound system limited to 1-5kHz and you have a formula for sonic pain. My wife and I voted to escape before we had to be air-lifted out of the Target Center. My ears were ringing the next morning as though I'd spent a day in a sheet-metal factory. I should have had a hearing test on Thursday so that I could take another one Friday and sue the Minnesota Orchestra for the difference. There is no way that the SPL in the Target on the evening of February 4, 2010 was any where near OSHA approved levels. The sound was painful, harmful, and musically and morally objectionable. I doubt that I will ever trust the Minnesota Orchestra with my ears ever again.

Supposedly, this farce has been going on for 12 years. All I can say is "there is no accounting for taste."

MP3 Comparison Tests

All Rights Reserved © 2006 Thomas W. Day 

A while back, I read an editorial in Mix Magazine that claimed to “prove once and for all” that MP3 audio compression was low-fi. The author was a Mac user, so maybe he can’t be faulted for the many flaws in his test procedure, but be that as it may be, I read between his lines and found a few statements that I couldn’t believe. His procedure was incredibly flawed and rigged to make MP3 files test poorly, even if the file format and compression were perfect. His built-in bias was so strong that it was obvious how the test would turn out, even before the second sentence. This author claimed to hear a “robust difference signal,” proving that the MP3 format was defective and high distortion. 

I listen to MP3s, mostly in my car and I was suspicious of that “robust difference signal.” First, probably because of the limitations of his computer equipment and/or software, the author took an audio sample, inverted the phase of that sample, played the two (in-phase and out-of-phase together), and found that the resulting signal was the expected nothing. The result was a near-perfect cancellation, proving that the two samples were equal, with practically non-existent distortion. 

Here is where the example died a non-scientific death. The author converted the phase-inverted signal to an MP3 format and, because his software could only play AIFF wave files, converted the MP3 back to AIFF and ran the above test again. Back in my audio manufacturing employment history, I built an ABX test rig for my employer and did a ton of ABX testing on anyone I could con into submitting to the ABX protocol. Mostly, we learned what the audiologist discovered at the 1985 AES Convention in LA; that most people involved in professional audio are “functionally deaf” or, at least, “hearing impaired.” Instead of spending our time trying to figure out what subtle differences in equipment were audible, we discovered that drastic defects in the signal path went undetected by most of our listeners. I went so far as to install defective active components (ICs producing as much as 10% THD) into the signal path of otherwise identical pieces of equipment and found that an alarming number of audio professionals were unable to hear the difference in a reasonably good listening environment. On the other hand, one of my own employees was able to hear signal differences that my test equipment (which was Audio Precision’s finest of the time) barely identified as measurable (except for substantial very-low-frequency phase differences that I’m still hard-pressed to believe explained the listening test results). 

With that history behind me, I decided to replicate the magazine test myself, using a Windows-based software (Adobe Audition) which doesn’t have the limitation of only being able to play one file format simultaneously. This eliminates the multiple conversion errors from the author’s test and makes the test more of an apple-to-apple test. I picked three MP3 formats, 128Kbps, 192Kbps, and 320Kbps, constant bitrate, with CRC checksums and a pair of 44kHz, 16-bit CD recordings (“Afternoon” from Pat Metheny Group, Speaking of Now, and L’Adoration de la Terre from Telarc’s Cleveland Orchestra recording of the Stravinsky The Rite of Spring) for the test. I, first, copied a section of the music and made an inverse-phase mono copy of that section. In Audition’s Multitrack View, I inserted the two sections into a pair of tracks and compared the resulting signal; or lack of signal. 

Figure 1

The two WAV copies exactly cancelled, both according to my ears and Audition’s metering system. Figure 1 (from the Afternoon recording) displays a section of the original signal from the recording that I will use to display the results of the signal-canceling comparison tests. Figure 1 (on right): The original signal, with peaks approaching 0dB. I tried both Windows’ Media Player v9.0 and dBpowerAMP Music Converter™ for the creation of my MP3 files (all made from the reversed-phase WAV file with an already established signal accuracy). I believe I saw a very slight reduction in distortion using the 320Kbps Music Converter™ version of the Media Player output, so I created the rest of my MP3 samples using that program. I inserted the 3 MP3 inverse-phase signals into a 5 channel Multitrack file and listened to the resulting output, comparing each MP3 to the original in-phase WAV file. 

Figure 2

The first problem you will discover in performing this test is that the MP3 converters both added a short leader (approximately 50mS) to the files. Ignoring this anomaly produces the “robust” distortion difference signal that started this investigation for me. Time-aligning my files took some time, but produced a much more believable result from the comparisons. Figure 2 (on right): 128Kbps distortion result waveform The 128Kbps compression produced a tinny output, with a little low end and a sound quality that was obviously distortion components. The resulting distortion component waveform is pictured in Figure 2. 

Figure 3
Figure 4

At this point in the original recording, the peaks are touching 0dB, so the peak distortion output was approximately 25dB below the peak recording signal level. Figure 3 (left) and 4 (right) picture the results of repeating this test with the 192Kbps and 320Kbps MP3 samples. The distortion components of the 320Kbps compression sample are 33-36dB below the original signal. Those residual signal values roughly translate to 5% THD for 128Kbps, 3% THD, for 192Kbps, and around 1% THD for 320Kbps MP3 samples. I’ll agree that these are substantial distortion values, but “robust” is not how I’d describe the resultant signal and I question the ability of most professionals to clearly hear the difference signal in an ABX environment. After all, I’ve simulated much worse distortion components that appeared to have been inaudible. 

Regardless of my test results, I recommend that you try a similar test with material of your own choosing and in a controlled listening environment. Personally, I discount the results of any listening test that doesn’t live up to the rigor of the ABX protocol. You can believe any fantasy you like, though. Part of what makes working in audio so entertaining is the delusions under which we labor and the resulting, sometimes silly, products produced to cater to those illusions. I do, however, intensely suspect the opinions of someone who claims that consumer cassettes were musical and that MP3 reproduction systems are deficient in comparison. Compared to FM radio, a high resolution MP3 is practically pristine. Pop recordings are often so distorted that the minimal harmonic addition low-fi 64Kbps compression introduces can do no more harm to what’s left of the musical content. If we’re not going to complain about these traditional high distortion delivery systems, where is our credibility regarding new technology? Most analog consoles don’t produce 40dB cancellation artifacts when one channel is beat against another in producing the side component in a Mid-Side microphone signal. Analog tape recording systems are far from capable of producing this level of signal uniformity. Dis’ing our customers’ sonic standards, because they are listening to a technology that has an economic impact on our industry, is dishonest, unbelievable and ineffective. They know the MP3 files they listen to are higher fidelity than past and current commercially delivered formats and once they suspect the industry is lying about quality, what else do we have to offer?

Wirebender Audio Rants

Over the dozen years I taught audio engineering at Musictech College and McNally Smith College of Music, I accumulated a lot of material that might be useful to all sorts of budding audio techs and musicians. This site will include comments and questions about professional audio standards, practices, and equipment. I will add occasional product reviews with as many objective and irrational opinions as possible.