The Reference Companion

Loudspeaker sensitivity 87 dB, one watt at one metre, driven at 100 watts from three metres away: the estimated result is 87 + 20 − 9.5 ≈ 97.5 dB, before the room or compression have their say. That’s an actual worked example from inside this volume, not a marketing simplification — every calculation here states its assumptions, works through the units, and ends by naming exactly what it cannot tell you.

This is the terminal lookup layer for the entire thirteen-volume series: decibels, frequency, sampling and digital data rates; room modes, reflections and decay time; screen geometry, aspect ratios and HDR; connectors, formats and diagnostic decision trees; worked design worksheets; and an A–Z encyclopaedia that closes every entry with the exact volume and chapter where the full explanation actually lives.

It replaces none of the other twelve volumes’ arguments, methods or diagnoses — it exists to be entered wherever a specific question arises, then to send you back to whichever volume answers it properly. Calculate to narrow the possibilities. Measure to discover what the real room and equipment are actually doing. Listen and watch to decide whether the result actually serves the experience.