A speaker spec sheet looks like a wall of numbers, and manufacturers rarely explain what any of them mean for you. But most of it is simpler than it looks — and a few figures genuinely predict how a speaker will behave in your room and with your amplifier.
This guide walks through every line you'll find on a TrueScale page, in order, and tells you which numbers matter and which are mostly marketing.
Dimensions (and why the photo lies)
Height, width and depth in millimetres. Boring, but the single most useful set of numbers — because a product photo tells you nothing about real size. A 'bookshelf' can be 45 cm tall; a 'compact' floorstander can be a metre. Always check whether the figures include the plinth, feet or spikes, since those add height and width.
This is exactly the problem TrueScale was built to solve: see any two speakers side by side at their real size, or browse the whole catalog ordered by height. If you want the full story on sizing, read How big is that speaker, really?.
Frequency response — read the fine print
Usually written as a range, e.g. 45 Hz – 25 kHz. The low number hints at how deep the bass goes; the high number is almost always beyond human hearing (~20 kHz) and rarely matters. But the range is meaningless without its tolerance — the '± dB' figure.
- ±3 dB is the honest, useful spec: the speaker stays within a tight window across that range.
- −6 dB or −10 dB figures stretch the low end on paper — the bass is technically 'present' but already rolling off and quiet. A '35 Hz' spec at −6 dB is not the same speaker as one at ±3 dB.
Rule of thumb: compare frequency response only between speakers quoted at the same tolerance, and treat any bass number without a ± figure with suspicion.
Sensitivity and impedance — the amplifier match
Sensitivity (in dB) is how loud a speaker plays for a given input — higher means easier to drive. Impedance (in ohms) is the electrical load it presents; lower and more variable loads demand a beefier amplifier. Together they decide whether your amp can comfortably drive the speaker.
This pairing is worth understanding properly — it's the difference between a system that sings and one that strains. We cover it in depth in Sensitivity and impedance: what amplifier you need.
Drivers and 'ways'
The drivers are the cones and domes that make the sound: a tweeter for treble, a mid-bass or midrange for the middle, a woofer for bass. How the work is split defines the 'ways':
- 2-way: a tweeter and a mid-bass. Simple, coherent, the norm for bookshelves.
- 3-way: tweeter + a dedicated midrange + woofer(s). The midrange (usually voices) gets its own driver, often cleaner in bigger speakers.
Driver materials (aluminium, paper, Kevlar, beryllium, wood-fibre) get a lot of marketing attention. They shape the character, but a well-engineered paper cone beats a poorly implemented exotic one — treat material as flavour, not a score.
Enclosure and ports
- Sealed: a closed box. Tighter, more accurate bass that rolls off gently; usually needs more power for the same depth.
- Bass-reflex (ported): a tuned port adds output and depth, at the cost of a little tightness. The port's location — front, rear or down-firing — affects how close to a wall you can place it.
- Passive radiator: a port's job done by an undriven cone — deep bass from a compact sealed-feeling box.
A rear port is the main reason a speaker needs breathing room behind it; if your speakers must sit against a wall, favour a sealed or front-ported design.
Power handling and recommended amplification
Recommended amplifier power is a range (e.g. 25–150 W) — the sweet spot the maker suggests. Counter-intuitively, most speaker damage comes from too little clean power (a small amp clipping), not too much. Aim for the upper half of the range from a quality amp rather than the maximum from a weak one. Power handling (a maximum wattage) matters mainly at party volumes.
The bottom line
The numbers that actually predict your experience are dimensions (will it fit?), sensitivity and impedance (will your amp drive it?) and frequency response at ±3 dB (how deep, honestly?). The rest is context. On TrueScale, every page lays these out in plain language — and you can put up to four spec sheets side by side in TrueSpecs to compare them directly.