What is a woofer?
A woofer is a type of loudspeaker driver designed to reproduce low-frequency sounds. It is responsible for bass, weight, and the sense of scale in music and film soundtracks.
Definition: what a woofer does
A woofer is a loudspeaker driver that reproduces low frequencies, typically from around 20 Hz up to 500 Hz.
These frequencies include bass notes, kick drums, bass guitars, and the lower registers of many instruments.
Why woofers are large
Low frequencies require moving a large volume of air. To do this efficiently, a woofer needs a large diaphragm with enough surface area to push air at slower speeds.
Compared to tweeters, woofers move more air but move more slowly. Size and excursion matter more than speed.
How a woofer works
Most woofers are dynamic drivers. An electrical signal flows through a voice coil suspended in a magnetic field, causing the cone to move back and forth.
As the cone moves, it compresses and rarefies the air in front of it, creating low-frequency sound waves that you hear as bass.
Woofer cones and materials
Woofer cones must balance rigidity, mass, and damping. Different materials affect sound character and control.
- Paper / pulp: lightweight and well damped, often very natural sounding.
- Polypropylene: durable and consistent, sometimes less lively.
- Metal: stiff and precise, but requires careful control to avoid resonance.
- Composite materials: combine strength, damping, and low distortion.
The cabinet’s role in bass
A woofer does not work in isolation. The cabinet strongly affects how bass is produced, controlled, and perceived.
Sealed vs ported designs
- Sealed: tighter, more controlled bass with gentler roll-off.
- Ported: greater bass output and extension, but more sensitive to placement.
Woofer vs subwoofer
| Driver | Primary role | Typical frequency range |
|---|---|---|
| Woofer | Low-frequency reproduction within a speaker | ~20–500 Hz |
| Subwoofer | Dedicated deep bass reproduction | ~20–120 Hz |
What woofers contribute to sound quality
- Bass weight: the sense of power and impact.
- Rhythm: timing and drive in music.
- Scale: how large and realistic a system sounds.
- Balance: too much or too little bass affects the entire presentation.
Common questions
Does a bigger woofer always mean better bass?
Not necessarily. Cabinet design, tuning, room size, and placement all matter. A well-designed smaller woofer can outperform a poorly implemented larger one.
Can a woofer play midrange frequencies?
Some woofers can play into the midrange, especially in two-way speakers. In multi-way designs, a crossover limits the woofer to lower frequencies only.
Is a subwoofer better than large woofers?
Subwoofers offer deeper bass and flexibility, but integration is critical. Large woofers can provide excellent bass without the complexity of a separate sub.