How to Wire A TRS Audio Cable to a Mono Input

A TRS audio cable uses three conductors: tip, ring, and sleeve. In many audio systems, the tip carries the left audio signal, the ring carries the right audio signal, and the sleeve acts as ground or shield. If you need to feed a stereo TRS cable into a mono input, you may see instructions that say “tip and ring to positive.” This usually means the left and right audio signals are being combined into one mono feed.

• A mono input only plays one side of a stereo source
• Audio is missing because only the tip or ring is connected
• A stereo aux source needs to feed a mono amplifier input
• A paging or background music input needs a combined mono signal
• One speaker zone is missing part of the audio mix

• Tip/ring/sleeve are landed incorrectly
• The terminal block expects balanced mono, not unbalanced stereo
• The source output is too weak
• Bad or broken TRS cable

This method is generally used for line-level audio, such as headphone outputs, aux outputs, paging inputs, or audio interface inputs. It should not be used on speaker-level outputs unless the equipment manual specifically allows it.