Rock Music for System Evaluation?

Back when I was a relatively clueless audiophile (some would say I still am), I read something in one of the few high-end mags that really over-torqued my lug nuts. The "reviewer" was making a case that rock music was an unsuitable reference/evaluation source for high-end audio systems. He went on and on about how rock music has no dynamic range and that only symphonic music could be used as a reference because of its superior dynamic range. Being the non-housebroken audiopuppy I was, I believed the guy. After all, he was writing for a magazine, he ought to know what he’s talking about, right?

Well, it just so happens that the old reviewer had his head up his woofer port. He was describing "average sound-pressure level" and calling it "dynamic range" -- an unforgivable error and an incorrect conclusion about what is, without a doubt, the world's most popular and widely enjoyed musical style. You see, average sound-pressure level means just what it says -- you take some segment of music, however long, and average the sound-pressure level for that segment. Dynamic range is nothing more than the "spread" in decibels between the loudest sound on a recording and the least-loud sound. You must search the entire recording to find these points, and they will need to be measured because your ear just isn’t the right instrument to find the precise instants of least loud and most loud. You can identify where to look, but finding the exact point is a job for instrumentation.

A well-recorded rock album can have as large or larger dynamic range than any classical recording. When a guitar hero wails on an open G string, there are thousands of possible frequencies the guitar could produce that are not being produced. Those sounds that are not being produced or which are at very low levels in the mix define the lower end of the dynamic-range measurement. So even though the music may be loud, there are plenty of frequencies at essentially "zero" that define the bottom of the dynamic-range floor. The loud volume level may mask the bottom end of the sound-pressure level, but it’s still there, especially if you use a spectrum analyzer to look at what’s going on.

When you’ve had a chance to listen to many systems in many environments, you begin to notice that not all systems are created equal. I’ve heard systems assembled by lovers of classical music that sound glorious when playing classical music, even big, bold symphonic-blockbuster stuff. But put on some Springsteen, Dire Straits, Eurythmics, B-52s, Smashing Pumpkins or Kid Rock and the sound you get is pathetic. How can that be? The snoot-in-the-air high-enders think rock music is inferior because it isn’t "live," isn’t acoustic, isn’t recorded in "a real space," and it’s all the same volume. Rock music, then, ought to be simple to reproduce for any system that can make beautiful classical music.

BUZZT! Wrong conclusion! Rock is very demanding. It pushes systems to their limits and beyond. It pushes loudspeakers into their discomfort zones and pushes power supplies in amplifiers up against the wall. Rock music drives a broad-spectrum, complex musical signal down the wires and through the components. Many of the transients and combinations of sounds that are commonplace in rock do not exist in symphonic music. Rock music puts a system in a completely different light. I know people who own two audio systems because they can’t get one system to reproduce all kinds of music the way they want it done. They use one system for classical, folk, and acoustic jazz. The second system is for rock, high-energy electric jazz, reggae, and anything else that cooks.

If you love rock music and you know that an important percentage of the music you will play on your system will be rock or other high-energy forms, the worst thing you can do is audition new systems or components with only classical, acoustic folk or acoustic jazz. You could easily spend $20,000 on a system in a fancy high-end store, get it home and have it sound very disappointing when you hit it with some Wilco or Pink Floyd. You can go the other way too -- auditioning only with rock and other high-energy music can lead to systems that just don’t sound right when playing classical or acoustic jazz. You really need to have a cross-section of the music you love with you when you listen to systems, and you have to insist that the sales people show you equipment that makes your favorite music sound good as well as making reference-quality CDs sound good. It can be done! If Professor Longhair is unlistenable on a system, then I don’t want to listen to that system -- period.

Don’t let the hi-fi snobs (people or stores!) make you feel "inferior" for enjoying rock music -- you’re not inferior. The fact that you enjoy rock and classical and other types of music makes you the superior life form. If they are stuck on classical and jazz and can’t abide other genres, that’s their problem. If you get any attitude when you want to listen to your "poor recordings," make sure they know that you’re too hip for the room (as currently configured) and that unless the room gets a lot hipper, you and your presidents are walking. If they can’t put together a system that sounds great on all types of music, you’re shopping in the wrong place. I promise, you can have one system that will do rock, classical and any other type of music wonderfully if that’s your goal.

The bottom line is, yes, rock music is not only legitimate for system evaluation, it is necessary if you are to acquire a system that can "do" rock with aplomb. Classical music presents another dimension that will undo rock-only systems. In between, there are lots of sub-types of music that you probably ought to sample also. Pedal-steel guitar has interesting, closely spaced overtones that can reveal things about a system you can’t hear in most other recordings. Folk, bluegrass, Celtic, big band, solo piano and harp tell things about sound systems you can’t easily notice without them. I know one guy who made a CD from his own DAT recordings of sounds he knows by heart -- his garage door opening, his key ring jangling, his dog, his wife’s voice, his car starting and idling recorded from the driver’s seat. It’s a hell of a thing, but worthless for anyone else. Don’t be afraid to make your own auditioning tools -- just be sure they are relevant.

Everything you throw at a system reveals something else about the system you may not notice just listening to one or two different types of music. I guess I’m assuming that most high-end audio enthusiasts are musical omnivores not limited to enjoying just one or two types of music. If you really are into only a narrow spectrum of music, you can probably get away with only using those types of music as your reference. Everyone else, start thinking about what should be in your evaluation arsenal.

...Doug Blackburn
db@soundstage.com

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