You can connect your TV’s sound to a home theater receiver or soundbar without an HDMI cable by using the TV’s digital optical output (also called TOSLINK), a coaxial digital output, the red and white RCA outputs, the 3.5mm headphone jack, or Bluetooth. For most setups, optical is the best choice because it carries digital surround sound with no electrical noise. Below is how to tell which ports you have, how to hook up each type, and which settings to change so the sound actually comes out of your speakers.
Check which audio outputs your TV has
Look at the back or side panel of the TV. Most TVs label their audio outputs clearly. You are looking for one of these:
- Optical (digital audio out): a small square port, often with a dust flap. You may see a faint red light inside when the TV is on. It is usually labeled “Optical,” “Digital Audio Out” or “TOSLINK.”
- Coaxial digital: a single round RCA-style jack, often orange, labeled “Coaxial” or “Digital Out.” This is more common on older TVs.
- Analog RCA: a red and white pair labeled “Audio Out.”
- Headphone jack: a 3.5mm jack marked with a headphone symbol or “Audio Out.”
- Bluetooth: there is no port for this. You will find it in the TV’s sound menu, if the TV supports sending audio over Bluetooth.
Many newer TVs no longer have red and white RCA outputs. If you only find an optical port and a headphone jack, that is normal.
Check which inputs your receiver or soundbar has
Now look at the back of your receiver or soundbar. Optical inputs are labeled “Optical In,” “Opt” or “Digital In.” Coaxial inputs say “Coax.” Analog inputs are pairs of red and white jacks, often named after a source you may not even own anymore, such as “CD,” “Aux,” “DVD” or “Tape.” Any of these will work for TV audio.
You need one output on the TV and a matching input on the receiver. If they don’t match, an inexpensive adapter will usually solve it. We cover that further down.
Which connection should you use?
| Connection | What it carries | Good to know |
|---|---|---|
| Optical | Stereo and 5.1 surround (Dolby Digital, and DTS on TVs that pass it) | Best choice for most people. Cannot carry Dolby Atmos from streaming apps or lossless formats like Dolby TrueHD. |
| Coaxial digital | Same as optical | Use it if both devices have a coax jack. Sound quality is the same as optical. |
| Analog RCA or 3.5mm | Two-channel stereo | Fine for TV shows, news and sports. Your receiver can still spread stereo across all your speakers. |
| Bluetooth | Compressed stereo | Easiest to try with a soundbar, but you may notice the sound lagging behind the picture. |
How to connect with an optical cable
- Pull the small clear plastic caps off both ends of the cable. People miss these all the time, and the cable will not seat with them on.
- Plug one end into the TV’s optical output and the other into the receiver’s optical input. The plug only fits one way. Push until it clicks.
- Turn on both devices and set the receiver to the input that the optical jack belongs to. It is often called “TV,” “Opt” or “D.In.”
- In the TV’s sound settings, change the speaker output from “TV Speaker” to “Optical,” “External Speaker” or “Audio Out.”
- Find the digital audio output format setting. Choose “Bitstream” or “Auto” for surround sound. If you hear nothing, try “PCM,” which every receiver can decode.
When a show with 5.1 sound is playing, the receiver’s display should read “Dolby Digital.” If it reads “PCM” or “Stereo,” go back to step 5.
How to connect with RCA cables or a headphone jack
- If the TV has red and white outputs, use a standard stereo RCA cable. Connect red to red and white to white, then plug the other end into any analog input on the receiver.
- If the TV only has a headphone jack, use a 3.5mm to RCA cable. They are sold at any electronics store.
- In the TV menu, set the audio output to the headphone or line out. Some TVs let you set that jack to a fixed “line” level. Choose that if you can, so the volume stays steady and you control it from the receiver.
- Select the matching input on the receiver and play something to test it.
An analog connection carries stereo only. Most receivers have a mode such as Dolby Surround or “Multi-Channel Stereo” that sends that stereo signal to all of your speakers, which works well for everyday TV.
What if the ports don’t match?
- TV has optical, receiver only has analog inputs: use a small digital-to-analog converter. It takes optical in, puts RCA out, and runs on USB power.
- TV has optical, receiver only has a coaxial digital input: an optical-to-coax converter handles it.
- TV only offers HDMI ARC for sound: an HDMI ARC audio extractor pulls the sound off the TV and gives you optical or RCA outputs. You need one short HDMI cable from the TV to the extractor, but your receiver never needs an HDMI port.
Settings that fix the most common problems
- No sound at all: check the receiver input, make sure the TV is no longer set to its own speakers, confirm the optical caps are off, and switch the TV’s digital format to PCM as a test.
- Sound from both the TV and the receiver: turn off the TV’s built-in speakers in the sound menu.
- Voices out of sync with lips: adjust “Audio Delay” or “Digital Output Delay” on the TV, or “A/V Sync” on the receiver. Bluetooth is the most likely to drift.
- Only stereo when you expected surround: set the format to Bitstream or Auto. Some streaming apps only send stereo over optical, and some TVs do not pass DTS at all.
- The TV remote doesn’t change the volume: without HDMI there is no automatic control link between the TV and the receiver. Many soundbars and receivers can learn the volume buttons from your TV remote, or you can use a universal remote.
- A hum or buzz on an analog connection: this is usually a ground loop, often caused by a cable box on the same system. A ground loop isolator usually stops it. Switching to optical stops it for good because light carries no electrical noise.
If you are still deciding on room layout, speakers or calibration, our home theater installation tips cover those next steps.
When a professionally designed system makes sense
Optical and analog connections are good workarounds, and for a living room they may be all you need. They do have limits. You won’t get Dolby Atmos from your streaming apps, you will probably have two volume controls, and the pile of remotes tends to grow.
If you are finishing a basement, building a dedicated theater room, or you are simply tired of switching inputs, a designed system is worth a look. That usually means a current receiver or processor with HDMI eARC, in-wall or in-ceiling speakers placed for the room, and a control system such as Savant or Control4. One button turns on the TV, picks the source, sets the volume and dims the Lutron lights. The speakers are calibrated to the room, so dialogue stays clear without turning the volume up. You don’t need any of that to get better TV sound tonight, but it helps to know where the workarounds stop.
Common questions
Does an optical cable carry Dolby Atmos?
No. Optical tops out at compressed 5.1 surround (Dolby Digital or DTS). Streaming apps send Atmos inside Dolby Digital Plus, which needs an HDMI ARC or eARC connection. Blu-ray discs use Dolby TrueHD, which needs eARC or a direct HDMI connection from the player to the receiver.
Is a coaxial digital cable better than optical?
They carry the same audio. Pick whichever port both of your devices share.
Can I connect a smart TV to an older receiver?
Yes. Use optical if the receiver has an optical input. If it doesn’t, an RCA cable or a 3.5mm to RCA cable will work, or you can add a digital-to-analog converter.
Planning a home theater project?
We design and install home theaters across Greater Boston, the South Shore and Rhode Island, and our theater work earned a CE Pro 2026 Home of the Year Bronze award. Book a free consultation or read more about our custom home theater services.
Want help with your TV sound? Call or text us at (781) 333-8003 or start your project.
