Useful tools
Cable calculator
Get the right cable for the run. Size speaker-wire gauge, check how far your HDMI signal will reach, and sort out long subwoofer runs, then shop the cables that fit.
Enter the one-way run length, the distance from the amp/receiver to the device, and how many runs you need. We'll size the cable and work out how much to buy.
One run per speaker — a 5.1 needs five, a 7.2.4 needs eleven. If your runs differ, size the gauge on the longest one and we’ll add slack to the total.
Most speakers are 8 Ω; check the back panel or the manual if unsure.
Continuous (RMS) watts per channel into this impedance. Sets the current the cable must carry and the power it loses.
Reference = high-output speakers such as Ascendo Cinema.
Pick the highest signal your source and display support (most 4K TVs/projectors are 4K60; newer gaming and 8K gear is 48 Gbps).
A subwoofer takes a single RCA (mono LFE) run from the receiver's SUB OUT. Long, unshielded runs can pick up hum.
Worked from standard copper resistance against a nominal 8 Ω load. In-wall runs need cable rated for the cavity, and long runs to low-impedance speakers may want a step up from what this suggests — worth a call before you buy a drum of it.