RCA Cable for Soundbar: Choosing the Right Input
Quick answer / TL;DR: Short answer: use HDMI ARC or eARC if both devices support it, then optical, then RCA analogue. RCA carries stereo only, so surround formats are lost. Use RCA when the television has no other output, and use a separate RCA lead for a subwoofer output rather than splitting the main audio pair.
Four audio lines: balanced XLR, TRS, unbalanced RCA, and speaker cable.A soundbar may offer RCA, optical and HDMI ARC inputs. RCA is the oldest and usually the least capable, but it is often the only input an older television provides.
Choosing correctly avoids a setup that works but never delivers surround or volume control from the TV remote.
Input Comparison
| Connection | Channels | Control | Best for |
|---|
| HDMI ARC | Up to 5.1 or more | TV remote via CEC | Modern televisions |
| Optical | Up to 5.1 compressed | Separate remote | TVs without ARC |
| RCA analogue | 2 | Separate remote | Legacy televisions |
| Coaxial digital | Up to 5.1 | Separate remote | Older AV equipment |
Only HDMI ARC gives volume control and power coordination from the television remote, which is why it is preferred whenever both ends support it.
Wiring Notes
- Red is right, white is left; a swap is audible but not obvious
- Keep analogue runs short and away from mains cables
- Do not split the main pair to feed a subwoofer
- Use a dedicated subwoofer output where one exists
Splitting the main pair to feed a subwoofer sends full-range audio to it, which usually sounds worse than no subwoofer at all.
Real-World Applications
An older television with only RCA output and a soundbar with RCA input is a straightforward two-cable job. A newer television with ARC and a soundbar that supports it should use ARC, and the RCA cable stays in the box as a spare.
Standards and Verification
| Reference | Relevance |
|---|
| HDMI 2.1 | eARC and CEC |
| IEC 60958 | Digital audio interface |
| Consumer line level | About -10 dBV |
Input capability for a specific soundbar is not provided in the knowledge base. Check the rear panel labelling.
Practical Notes
Set the television audio output to the connection you actually used. A TV left on internal speakers with an external soundbar connected produces an echo that sounds like a sync fault.
Related reading: optical audio cable — blogs/news/optical-audio-cable
Related reading: rca patch cables — blogs/news/rca-patch-cables
Frequently Asked Questions
Is RCA better than optical?
No. Optical carries more channels and isolates ground.
Can RCA carry surround?
No, stereo only.
Why does the remote not control volume?
Only HDMI ARC carries volume control between devices.
Sourcing cables for a project, a store, or a private-label line? Contact our B2B sales team for specifications, certification evidence, and volume terms – FOB and CIF options available. Request a quote or sample.
