Speaker Wiring for a London Self Build: Cables, Quiet Floors and the Rack

Speaker wiring in a new London home should be planned on paper before first fix: every speaker gets its own cable back to an equipment rack, and every ceiling speaker gets a back box so music stays in the room it is meant for. Do that and you can leave the choice of speakers and amplifiers until the house is weathertight. Skip it and you are left with wireless speakers on shelves or cutting into finished ceilings.

Building your own home in London rarely means a big open plot. More often it is a replacement house on a tight site, a new build on a backland plot, or a house with a basement dug to win back space. Those homes tend to be tall rather than wide, with bedrooms stacked over living rooms, and that shapes how the speaker wiring should be done.

Home runs to one rack

The simplest and most flexible way to wire for audio is a home run: one cable from each speaker position all the way back to a single rack, with nothing joined or looped on the way. In a London house the rack often sits in the basement plant room, a utility cupboard or under the stairs. Put it somewhere ventilated and reachable, because amplifiers give off heat and will need attention from time to time.

A home run to every speaker means the amplifiers can live together, any room can be brought onto the system later, and nothing in the house depends on a hidden cupboard on the second floor. If the plan is to start with only the kitchen and the living room, still run the cables to the bedrooms and bathrooms now and leave them coiled and labelled in the ceiling. Our first fix wiring guide for London self builders covers the data and control cables that run alongside them.

Keeping music out of the bedroom above

London self builds are often three or four storeys, so a ceiling speaker in the kitchen is usually directly under someone's bedroom. Requirement E2 of Approved Document E asks for reasonable resistance to sound through the internal floors of a new home, and through internal walls between a bedroom or a room with a WC and other rooms. Table 0.2 of the document sets a laboratory value of Rw 40 dB for those new internal walls and floors.

Every ceiling speaker is a hole cut in one of those floors. Our approach is to fit an enclosed back box behind each one, so the sound is projected into the room below instead of filling the void between the joists, and to keep the acoustic insulation in the rest of the bay undisturbed. Talk to your architect and building control about the floor build up early, and give them the speaker positions with the rest of the ceiling plan.

Cable sizes and runs

A tall London house has short horizontal runs but plenty of vertical ones, so measure from each speaker to the rack via the real route, not in a straight line. Sonos publishes a useful guide to speaker wire gauge, which steps up to a thicker cable as the run from speaker to amplifier gets longer. Most runs in a London home are short enough for the lightest size it lists, but a garden studio or a roof terrace at the far end of a tall house can need the next one up.

• Use proper speaker cable, not leftover mains flex.
• Keep speaker cable apart from mains where they run side by side.
• Label both ends with the floor, the room and the speaker number.
• Leave a generous tail at the rack and a comfortable one at each speaker.
• Photograph every ceiling before it is boarded.

Speaker wiring checklist for a London new build

Basements, roof terraces and the TV wall

A basement is the natural home for a cinema or media room in London, and it has the benefit of being away from the bedrooms. Plan its speakers with the screen, the seating and the ventilation, and route the cables up to the rack before the walls are lined. Our page on home cinema installation in London shows what goes into a dedicated room.

Roof terraces and small gardens are popular places for music, but sound carries in a terrace of houses. Fewer, well placed outdoor speakers at a modest volume work better than a pair turned up loud. Our outdoor audio page shows the kind of speakers that suit.

For the TV wall in the living room, run speaker cables to the left and right of the screen or to a soundbar position, plus a network cable and a route back to the rack for the video. Lighting keypads that also control music should be planned at the same time; our lighting design guide explains how.

Who does the work

We design the system, supply the speakers and amplifiers, and install and programme them. For the first fix we give your electrician drawings and a cable schedule showing every speaker, keypad and run, so the speaker wiring goes in the right place first time. Our founder, Kieran McGuire, is an electrician, so the drawings are written with the person pulling the cables in mind. See our survey and design process and our page on multi room audio in London. If you would like to talk it through, a design consultation is £360 plus VAT, as shown on our booking page.

Questions we are often asked

Do ceiling speakers affect the sound insulation between floors?

They can, because each one is an opening in the ceiling. An enclosed back box behind the speaker and an undisturbed floor build up around it help keep music in the room below.

Where should the audio rack go in a London house?

Somewhere ventilated and easy to reach: a basement plant room, a utility cupboard or under the stairs. Every speaker cable should run back to it.

What speaker cable do I need?

It depends on the length of each run. Measure the real route, then choose a thicker cable for longer runs, as the speaker maker recommends.

Can I wire now and choose speakers later?

Yes. Run and label the cables at first fix, and choose the speakers once the house is weathertight and the interiors are taking shape.

Is it worth wiring the bedrooms if we only want music downstairs?

Usually. A labelled cable left in the ceiling costs little now and saves cutting into a decorated room later.

Book a consultation or call our head office on 01344 937999 (London office 0208 064 0196).