A semi-profound simile used in two-channel audiophile reviewer circles posits: "Writing about music is like dancing about architecture." Said another way, English is a lousy language for describing how things sound. So how exactly do audio critics "describe" stereo sound? This article will provide some insight into the various sonic qualities that audiophiles want to hear from stereo systems and the various terms that audio reviewers use to describe sonic characteristics.
The frequency spectrum of human hearing covers low bass notes from 20 Hertz up to the highest audible frequencies around 20,000 Hertz (i.e. 20Hz to 20kHz). Audiophiles divide this spectrum into three ranges:
1) Treble sounds or highs;
In general, audio reviewers are like the seven dwarfs: six of them are never Happy. If a stereo system has bright, tinny, hard, brittle, or grainy sound, the result will always be a fatiguing sound that's more painful to listen to than Hilary Clinton after she's inhaled copious amounts of helium.
Stated succinctly, bad treble equals bad sound. If your stereo system makes a splash of cymbals sound like a 1977 Cadillac DeVille crashing through a half-dozen aluminum trash cans at 60mph, odds are, you've got issues within the high frequency registers.
A lot of different things can cause poor treble in stereo systems. Lousy tweeters, cheap cabling, shoddy digital components, starving / polluted A/C power supplies, and overly reflective room acoustics can all result in a myriad of fatiguing noise up in the highs. Overall, two-channel music reproduction systems seek to create natural high frequency sounds with air, openness, extension, and space; just as real instruments do.
The Midrange And Lower Midrange
The midrange is where music lives. Human hearing is far more sensitive to sonic anomalies within the mid-band than in the bass or treble registers. Male and female vocals in the midrange are particularly revealing of how musical and accurate a stereo is. If your favorite singer sounds like Kermit the frog with a sinus infection after a month-long weed bender, it's a safe bet that your audio system isn't accurately reproducing male and/or female voices.
Midrange distortions sound like someone's cupping their hands over their mouth while they're singing or speaking. If your loudspeakers fail to correctly reproduce recorded vocals, they'll stick out as prominently and annoyingly as a rally to make smoking legal again inside coffee shops and shopping malls.
Audio critics use pejorative words like honking, congested, nasal, thick, phlegm-coated, and boxed in to describe lousy midrange sonics. When you buy $100 ‘marine grade' speakers from K-Mart and wire them up with a Wal-Mart lamp cord, you'll hear all of these sonic discolorations. If vocals sound monotonous, tired, or colored, a speaker probably has unnatural peaks and dips within the mid-band.
Midrange drivers are especially prone to amplifying unchecked cabinet vibrations. Solo piano recordings are quite useful for revealing cabinet resonances. If the cabinetry in your speakers is more flexible than Oprah's yoga stretch pants, you'll be losing sound quality in the midrange quite fast.
Upper Bass, Mid-Bass, And Low Bass
Bass shouldn't sound like a freshly cut air-biscuit echoing around the inside of a porta-potty. Most of the music I listen to needs a copious amount of high quality low end to sound realistic. Audiophiles like to hear bass that's full, round, taut, muscular, incisive, correctly weighted, and tangible. The lower registers should be driven by rhythm, tone, texture, and *feel*; not deafening volume levels.
Audiophiles divide bass frequencies into three ranges: upper bass, mid bass, and lower bass. Audio critics want to hear all of the wondrous instruments within these lower frequency ranges reproduced with correct PRaT (Pace, Rhythm, and Timing), timbral accuracy, texture, weight, and a palpable *feel* that moves the soul.
The rhythm of music lives in the lows. Orchestral and symphonic music needs the impact, presence, and slam of articulate bass. The swing and groove of jazz needs eloquent and textured bass. The jungle-boogie rhythms of Latin, Caribbean, and Brazilian music must have good bass. The rampaging thunder, galloping rhythms, and explosive energy of speed metal, doom metal, NWoBHM rock, space rock, stoner rock, and black metal all need bass that's textured, articulate, and layered.
Good bass should move a listener's soul to wanna get up off of her couch, shake her God-given booty, and deliriously swing her hips around the room like a panda bear on roller skates on an five-day caffeine-fueled freak-out.
On the one hand, too much bass that overwhelms the midrange and highs is no good. An excess of bass is described by critics as being boomy, muddy, bloated, congested, loose, slow, and fat. On the other paw, too little extension, weight, texture, and/or presence in the low end is just as bad. Audio reviewers describe a lack of bass as sounding lean, thin, threadbare, over-damped, and/or lacking extension.
Getting the PRaT, dynamics, groove, and energy in the lower registers to sound like live music requires decent speed and articulation. If the bass is slower than a snail and lags behind the midrange and treble, all forms of music will lack rhythm and musical substance.
Once you've heard recorded music with acoustics that are so lifelike that it transports you to an actual concert hall, you'll immediately understand why audiophiles value soundstaging so much.
Instrumental images shouldn't overlap, blur into one another, or cancel each other out. Audio critics describe stellar imaging as being tight, focused, precisely located, and sharp. Poor imaging is described as being blurred, congested, opaque, confused, murky, overlapping, and/or lacking focus.
Studio recordings rarely achieve lifelike soundstaging or imaging. Audiophile recordings made at live venues or within real acoustical spaces using stereo microphone set-ups and a pure signal path are critical to achieving realistic soundstaging and imaging.
Audio critics also use differences in how well a stereo reproduces the size of instruments to determine how good (or bad) the imaging is. A recorded cello's sonic image signature should have the height, width, and depth of a real cello. If the cello's sizing is too large or too small, then the imaging isn't accurate.
Pace, Rhythm, and Timing (PRaT)
Errors in PRaT are caused by poor source components, lousy amplification, throw-away cabling, polluted A/C power, or room acoustics which suck worse than a 60 year old Hoovermatic. Get the PRaT wrong and the music has no chance of creating excitement or involving a listener.
Different volume levels convey different emotional messages. Just as in the way we communicate, softly whispering or angrily screaming often carries more emotional meaning than any of the actual words spoken.
There are two types of dynamics: macro dynamics; and micro dynamics. Macro dynamics refers to the music's overriding sense of impact and power. When a live 80 piece orchestra reaches a musical crescendo, it delivers a massive wallop of sound. The stronger the visceral sense of the *slam* that a two-channel stereo delivers, the better audio critics consider said system's macro dynamics to be.
Micro dynamics aren't about volume, impact, or slam. They do, however, carry an enormous amount of bearing on how *real* recorded music sounds. The resonance of a delicately braised cymbal's percussive accent is very subtle. It's not meant to shake the foundations of any jazz club. And yet, getting the timbral accuracy, speed, and harmonic textures contained within the dynamic structure of a cymbal's shimmering echo correct is critical towards achieving the sound of live music.
Just being able to play loud or soft doesn't innately mean that a stereo system has good dynamics. Some low-powered SET (Single Ended Triode) tube amplifiers can deliver a goosebump inducing sound quality when playing a single acoustic guitar. Ask that same SET amp to accurately reproduce the scale and building shaking volume of a live Anthrax album and, more than likely, said low-powered amp will be turning purple with exertion. With far too many amplifiers, as the volume increases soundstage width decreases, the size and location of individual instruments compresses, (or even disappears completely), and the whole 3-D soundstage collapses.
Detail / Smoothness
As with many aspects of high-end stereo sound, the trick is to find the right balance between: a), the amount of detail produced; and b), how smooth and musical the overall sound is. Only state of the art products are capable of successfully walking along this razor's edge of providing oodles of low-level sonic detail, while concurrently not inducing listening fatigue.
If the resolution is too low, the midrange and treble won't have enough detail to make instruments sound realistic. Much like listening to Alvin and the Chipmunks synced with an 18KHz white noise warble tone, too much detail will quickly cause migraine headaches. To audio critics, excessive detail is like a sadistic form of torture. You'll have an easier time raising sponsorship money for an adult film shoot at Kmart than getting audiophiles to tolerate bright and fatiguing stereo sound.
The bottom line is this: Two-channel / stereo playback systems should make you want to listen to more music. Regardless of the type of music you love, listening to music at home should be fun and enjoyable. Trying different source components, pre-amplifiers, pre/power combos, speakers, cables, and tweaks all make audio a fun hobby, but it's the music that matters the most. Try not to lose sight of that.
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