Subwoofers

A subwoofer is the most misunderstood component in a domestic system. Most people buy one to make the bass louder. The reason to own one is almost the opposite: a correctly integrated subwoofer lets you use a smaller, better-placed main speaker, takes the hardest work away from your amplifier, and — because it can sit where the room wants it rather than where the furniture allows — fixes bass problems that no main speaker can solve from where it is standing.

When you actually need one

Your main speakers had to be small. This is the commonest and best reason. If the room, the decor or the wall meant standmounts or on-walls, a subwoofer restores the bottom two octaves that were traded away.
The room has a bass problem. Every room has peaks and nulls. A subwoofer that can be positioned independently of the main speakers can be placed to work with the room rather than against it — and with two subwoofers, the problems can be very substantially cancelled out.
You are building a cinema. Film soundtracks carry a dedicated low-frequency channel with dynamic demands no full-range speaker is designed to meet. A cinema without a subwoofer is not finished.

When you do not. If you have well-chosen floorstanders, in a room of the right size, positioned properly, for music only — a subwoofer is often a way of adding a problem. We will say so.

The rules that actually matter

Two small subwoofers beat one large one. Almost always, in almost every room. Two units in different positions average out the room’s peaks and nulls in a way one cannot, regardless of how much the one cost. If the budget stretches to one big subwoofer or two smaller ones, buy two.

Placement is worth more than money. Moving a subwoofer half a metre can change the in-room response more than doubling its price. This is free, and it is why we measure rather than guess.

Set the crossover to the speaker, not to a habit. The right crossover point depends on where your main speakers genuinely start to roll off in your room — not on the number in the manual, and not on 80 Hz because somebody on a forum said so.

Get the phase right or the whole thing is pointless. An out-of-phase subwoofer subtracts. The result is less bass than you started with, and it is the single most common fault we find in systems people have installed themselves.

Calibrate. Every serious installation we do ends with measurement. It is the difference between a subwoofer you notice and a subwoofer you only notice when it is switched off — which is what correct sounds like.

What we carry

Sealed, compact, for music in a smaller room — the Sonos Sub Mini around £429 and Sonos Sub around £799 for wireless whole-home systems, and the Bluesound PULSE SUB+ around £799 where the room runs on BluOS.

Room-corrected, for integration with an active system — the Lyngdorf BW series, around £1,099 to £1,299, designed to be corrected as part of the whole system rather than tuned by ear in isolation. See the BW-3 and BW-2.

Reference music subwoofers — the Grimm Audio SB1 motion-feedback subwoofer around £6,120 and the LS1s pair around £7,980. Motion feedback measures what the driver is actually doing and corrects it in real time; in a serious two-channel system the difference is in control rather than quantity.

In-wall, for rooms where nothing may be seen — the Wisdom Audio S55i, S57i and S90i in-wall subwoofers, specified as part of a complete Wisdom system and quoted per project.

Next steps

Tell us the room dimensions, what your main speakers are, and whether the system is for music, film or both. We will tell you whether you need one subwoofer, two, or none — and where they should go. See room acoustics, home cinema design and installation, or get in touch.

All prices shown include VAT, except Wisdom Audio systems which are quoted per project. Hidden Home Technology is a family-run, CEDIA Professional Member business based in Bath, working across Bath, Bristol, the Cotswolds, the wider South West, South Wales, London and the Home Counties.