# How to read a speaker spec sheet

Every number on a spec sheet in plain language — and which ones actually matter.

Source: https://truescaleaudio.com/en/guides/how-to-read-a-speaker-spec-sheet

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](/compare), or [browse the whole catalog ordered by height](/ladder). If you want the full story on sizing, read [How big is that speaker, really?](/guides/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](/guides/speaker-sensitivity-and-impedance).

## 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.
- **Open baffle:** no enclosure at all — the drivers sit on a flat panel and radiate from both faces. Expect an uncoloured midrange, modest deep bass, and a speaker that must stand well clear of the wall behind it.

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](/compare4) to compare them directly.