Speaker specifications: what the numbers tell you

Read each number with its conditions

A specification is an answer to a particular test or design question. Before comparing two speakers, circle the units, tolerance, distance, input and environment beside each number. If a condition is missing, record it as unknown rather than supplying a favorable assumption.

Here is a way to annotate the main fields. The examples illustrate reading a sheet, not choosing a product.

Frequency response and frequency range

Circle: lower and upper frequencies, allowed deviation and measurement environment. A ±3 dB response range and a −6 dB range are different descriptions. An in-room estimate is also distinct from another measurement environment.

For example, the R3 Meta specification sheet lists 58 Hz–28 kHz at ±3 dB and 38 Hz–50 kHz at −6 dB, alongside a separate in-room bass figure. Those entries should not be collapsed into a single “goes down to” number. They also do not establish how loudly the speaker can reproduce its lowest frequencies without excessive distortion.

Sensitivity

Circle: the input, distance and any test conditions. Sensitivity describes sound output for a stated input. The same sheet lists 87 dB at 2.83 V and 1 m. Preserve that voltage reference when copying the figure; do not silently turn it into 87 dB for 1 W at 1 m.

Klipsch's sensitivity explanation describes the one-watt convention and the 2.83 V relationship for an 8-ohm load. Sensitivity is different from maximum sound pressure level and from efficiency expressed as a percentage.

Impedance

Circle: nominal value, minimum value if given, and any further load information. A nominal rating does not mean that the speaker is a fixed resistor at every frequency. The example sheet lists 4 ohms nominal and 3.2 ohms minimum. Those figures serve different purposes; neither alone certifies a particular amplifier pairing.

Use the amplifier's instructions to establish supported loads. Speaker specifications guidance also distinguishes nominal impedance from its variation with frequency.

Power and maximum output

Circle: whether the entry is speaker power handling, a recommended amplifier range or maximum SPL. For power handling, retain the test method and duration where supplied. A speaker labelled 100 W does not draw 100 W continuously, and that label is not a loudness rating.

For maximum SPL, look for distance, bandwidth, duration and distortion conditions. Keep any distortion percentage attached to its test level and frequency range. The R5 Meta sheet, for example, gives separate maximum-SPL and level-qualified distortion fields. Missing test detail cannot be recovered from cabinet size.

Crossover and dimensions

Circle: the frequency-band transitions and the dimensions of the complete installation. Crossover frequencies indicate how driver duties meet; they are not abrupt on/off boundaries or a quality score. Driver count is not necessarily the number of frequency bands, or “ways.”

For dimensions, check whether terminals, grilles, stands or plinths are included and whether weights or measurements refer to one speaker or the pair. The bookshelf-versus-floorstanding guide shows why support dimensions matter.

Why 2.83 volts is not always one watt

For an ideal resistor, power is voltage squared divided by resistance: P = V²/R. Using 2.83 V RMS gives approximately:

• 8 ohms: 2.83² ÷ 8 = 1.00 W.
• 4 ohms: 2.83² ÷ 4 = 2.00 W.

The second case uses twice the power. That explains the trap when voltage sensitivity and one-watt sensitivity appear side by side. Real speaker impedance varies with frequency, so nominal impedance alone cannot always supply an exact correction to an unspecified sensitivity test.

Compare amplifier conditions too

An amplifier's wattage needs its own conditions. Denon's example specification gives 45 W per channel into 8 ohms over 20 Hz–20 kHz at 0.07% THD, and 70 W per channel into 4 ohms at 1 kHz and 0.7% THD, both with two channels driven. Load, bandwidth and distortion differ. These entries cannot establish ideal power doubling in an otherwise identical test.

Use the amplifier-demand worksheet for a qualified estimate after preserving these conditions.

Write down what the sheet leaves unanswered

Look for off-axis response, output and distortion across frequency, detailed electrical load and test environment. Your room response and personal preference remain separate questions. Missing data is not proof of poor performance; it is a reason to ask a precise question or seek a relevant measurement. Keep placement and any subwoofer requirement in the system plan.