Speaker testing evaluates physical transducer performance across distinct acoustic domains:

• Stereo Channel Panning & Separation: Panning synthesized $1\text{ kHz}$ test tones or localized speech prompts ($100\%$ Left vs. $100\%$ Right) verifies that audio interfaces, DACs, and headphone cables maintain true stereo separation without crosstalk.
• Full-Range Logarithmic Sine Sweep ($20\text{ Hz}–20\text{ kHz}$): Synthesizes a pure sine wave ($y(t) = \sin(2\pi f(t) t)$) sweeping logarithmically across the human auditory spectrum:
• Sub-Bass (20–60 Hz): Tests subwoofer physical excursion and port rumble.
• Bass (60–250 Hz): Tests woofer clarity and room resonance / cabinet rattles.
• Mid-Range (250–4000 Hz): Evaluates vocal clarity and crossover balance.
• Treble (4–20 kHz): Tests tweeter extension and high-frequency sparkle.
• White Noise vs. Pink Noise:
• White Noise: Equal energy per frequency Hertz ($+3\text{ dB/octave}$), sounding like bright television static.
• Pink Noise: Equal energy per musical octave ($-3\text{ dB/octave}$ roll-off), matching human ear perceived loudness across all frequencies for studio acoustic calibration.
• Stereo Phase Polarity Test: Inverted out-of-phase signals ($180^\circ$) cancel out when summed to mono; proper in-phase signals sound tight and centered.