Reference

The Absolute Sound of Bass
Before getting into the terminology describing LF imperfections, let's consider the characteristics of ideal ("perfect") bass reproduction. These are:

Balance: The amount of low-frequency output relative to the output through the rest of the audio spectrum.

Wide Range: Extending into the deep-bass region---and the deeper, the better. (Note here that a system will actually tend to sound as if it has greater LF range than its measurement would indicate.) Also called "Extension."

Smoothness: Freedom from audible dips and peaks in frequency response.

Impact: A quality of visceral pressure from impulsive LF sounds like those of kick drums or plucked bass strings. Also called "Sock."

Detail: The ability to delineate clearly the musical pitch of every LF fundamental.

Attack: The ability to track steep wavefronts, so that the fundamental of, say, a bass drum immediately follows its impact sound. Also called "Quickness," "Agility," "Speed," or "LF transient response" (a misnomer, but generally accepted usage).

Control: Freedom from audible lengthening (hangover) of brief LF tones. Also referred to as "tautness" or "critical damping."

These are the criteria of excellence; now to the real world of imperfections. Adjectives for describing these include:

Heavy: Producing apparent exaggeration of the entire LF range, like a broad peak starting in the upper bass, peaking out in the mid bass, and rolling off through the deep bass.

Warm: Like heavy, but less pronounced. (Can also refer to midrange character.)

Hungover: Having poor LF control; the system prolongs bass notes. Hangover is usually the result of a resonant peak, often due to inadequate system damping, or to standing waves in the listening room. (Damping is measured in terms of acoustical Q, analogous to the sharpness of resonance produced by a inductor/capacitor/resistor network. A resonant hump represents an underdamped condition.)

Boom: Exaggeration of, and hangover throughout, the midbass region.

Tubby: A "thuddy" quality, which tends to exaggerate the fundamental of bass drum. This sounds like a frequency-response peak through the low-bass region, even though it may not measure that way.

Woolly: Having very poor detail and control; ill-defined, lacking in pitch delineation.

Turgid: Bass-heavy and lacking in detail and impact.

Fat: Broadly peaked or exaggerated through the mid- and low-bass ranges.

Loose: Lacking in detail and tautness throughout the LF range. Often a symptom of inadequate woofer damping.

Monotonal: Tending towards marked exaggeration and prolongation of a very narrow range of LF frequencies. Also called "One-note bass."

Thin: Markedly deficient in output through the entire LF range.

Lean: Like thin, but not as severe. Characterized by a gradually diminishing output throughout the entire range. Leanness will appear to enhance detail and tautness. Also called "Sparseness."

Truncated: Deficient in deep-bass range, lacking in foundation. This is usually audible as poor reproduction of the characteristic ambience (the faint rumbling sound) of a performing hall, and of the deepest organ pedal notes.

Punchy: Having good impact; solid-sounding.

Gutsy: Having particularly good performance through the upper bass range. Also "Ballsy."

Controlled: Free from hangover.

Detailed: Exhibiting good pitch delineation.

Agile, Quick: Having the ability to respond rapidly to the sudden onset of a LF note. Also "Fast."

Taut: Having good LF control; free from hangover. Also "Tight."

Flaccid: Almost entirely devoid of control and detail. Also "Floppy," "Sloppy," "Soggy."