Quick Answer / Summary: Plan five items: amplifier location (heat and access), speaker positions, cable route with real measurements, gauge per run (length and impedance), and connector types at both ends. Add 2 m of slack per end, keep power and speaker cable separated where they run parallel, and specify in-wall rated jacket for concealed runs. Buy all runs at once from the same batch to keep gauge and jacket consistent.
Most amplifier and speaker problems are decided before anything is powered: the route, the distance and the connector plan. Planning the run on paper costs an hour and prevents the mid-install discovery that the cable is 6 m short.
Amplifier Placement
The amplifier needs ventilation, access and short cable runs. Rack-mount near the speakers reduces copper; a distant cupboard increases length and gauge cost. Heat: class AB amplifiers dissipate 30-50% of their input as heat and need clearance above and below; class D dissipates far less but still needs airflow. Access: terminations are made at the back, so leave service space. Power: a dedicated circuit avoids sharing with dimmers and kitchen equipment, which is also the cheapest hum prevention available.
Distance or Convenience
Every metre of run costs gauge. Putting the amplifier near the speakers usually beats a tidy cupboard 30 m away.
Heat Clearance
Class AB in a closed cabinet overheats. One rack unit of clearance above and below is the minimum.
Route and Measurement
Measure the route with a tape, not the room’s length: cable goes around door frames, along skirting, through conduit and up walls. Add 2 m of slack at each end for termination and future service. Keep speaker cable away from mains where runs are parallel – a metre or more of separation, with perpendicular crossings where unavoidable. For concealed runs, specify CL2/CL3 jacket; for plenum spaces, CL3P. Photograph the route before the walls close – the next installer will need it.
Real Route, Real Length
Room dimensions underestimate by 20-40%. Measuring the path is the difference between a comfortable run and a stretched one.
Separation From Mains
Parallel runs couple hum. Cross at right angles where paths must meet.
Specification and Purchase
Build the schedule: run number, from, to, length, gauge, jacket, connector both ends. Then buy from one batch – jacket colour and gauge consistency matter when a run is serviced in five years. Connectors: speakON above 100 W, banana or binding post below, terminal blocks for 100 V lines. Test on arrival: continuity per run, polarity marked, and labels fitted at both ends before the cable goes into the wall.
One Batch, One Spec
Mixed batches vary in jacket and flexibility. Buy the schedule in one order so a future repair matches.
Label Before Install
Labels applied at the bench survive; labels applied after the cable is pulled rarely get applied at all.
Run Schedule Template
| Field | Example | Note |
|---|---|---|
| Run | L1 | Unique ID |
| Length | 17 m route + 4 m slack | Measured path |
| Gauge | 14 AWG | By length and load |
| Jacket | CL2 in-wall | Concealed runs |
| Connectors | speakON to binding post | Both ends stated |
| Label | L1 at both ends | Bench-applied |
Real-World Application Scenarios
A living-room install schedules three runs: 12 m and 14 m to the fronts, 9 m to the centre, all 14 AWG CL2, labelled at the bench. A bar’s four zones are planned from a rack position with a 22 m longest run, 12 AWG for the 4 ohm subs. A church photographs the route through the ceiling void before the tiles go back.
Recommended Internal Resources
(1) Product cluster – https://zh-zong.com/productlist/ (anchor: in-wall and surface speaker cable); (2) FAQ – https://zh-zong.com/faq/ (anchor: routing and rating questions); (3) Contact – https://zh-zong.com/contact/ (anchor: send a run schedule for quoting).
Related Reading in This Series
- Home Amplifier and Speakers: In-Wall Cable Done Once
- Amplifier for TV Speakers: ARC, Optical and the Speaker Run
- Amplifier for Sound System: Rack Wiring and Cable Discipline
Frequently Asked Questions (FAQ)
Q: How much slack should I allow?
A: About 2 m at each end for termination and service. Measure the real route, not the room’s dimensions.
Q: Can speaker cable run beside mains cable?
A: Keep them separated where parallel – a metre or more – and cross at right angles. Long parallel runs couple hum.
Q: What jacket rating for in-wall runs?
A: CL2 or CL3 for concealed runs, CL3P in plenum spaces. The rating is a code requirement, not an upgrade.