Having trouble achieving clear 5.1 audio from your TCL 55C745 to the Bose Lifestyle T20
Having trouble achieving clear 5.1 audio from your TCL 55C745 to the Bose Lifestyle T20
Hey everyone, I just moved into my first flat and took over a Bose Lifestyle T20 (~8 years old) from my dad. I’m trying to set up a home cinema system on a budget. I purchased a TCL 55C745 TV, which runs Google TV (probably). It looks like a solid pick for gaming and streaming UHD/4K content from the NAS I’m planning to build. Still, I want to enjoy movies using the TV’s built-in apps.
My main challenge is getting true 5.1 surround sound from the TV to the T20. Here’s what I know about my current arrangement:
- The Bose T20 only supports TV audio over its optical port—no HDMI ARC.
- Linking the TV’s ARC port to an HDMI input on the Bose doesn’t work for sound.
- The T20 isn’t meant to act as a standard ARC controller; it’s built to manage the whole setup via the Bose remote.
- Audio works through the Toslink cable, but it’s just a fake 5.1 setup.
- When I connect my PC directly to the T20 and use the pass-through HDMI port, I get 720p/1080p/1080i.
- I can switch between Dolby Atmos and DTS Virtual:X on the TV, but I want real 5.1 sound.
- The Toslink connection passes through to the TV, which then outputs a limited version.
What’s likely happening is that the TV can’t deliver Dolby Surround or DTS because it uses newer formats (like Dolby Atmos) that the T20 can’t handle.
What I’ve tried:
- Bought an HDMI ARC extractor to send TV audio to the T20 via optical.
- Still only get stereo output, even after checking connections and settings.
- When using the TV’s sound mode, I have options for Dolby Atmos 7.1 or DTS Virtual:X.
- I can pass through audio from TV HDMI inputs to the sound output, but only at lower resolutions.
Possible fixes I’m considering:
1. Try a different HDMI ARC extractor or adjust settings, but it might not be worth the cost.
2. Check if the TV’s specs are hidden behind an expert panel—maybe only certain modes work.
3. See if updating the Google TV firmware helps, or if it’s a hardware issue.
4. If nothing works, maybe the Acustimass subwoofer from the T20 can’t connect to newer systems, and I’d need a different amplifier.
Details I have:
- Inputs: top (T20), middle (PC via 15m HDMI 4k/60Hz), bottom (ARC/eARC to Acustimass).
- Connections: HDMI for control, optical/Toslink for audio.
- Notes: I’ve attached some images for reference. If you need more info, feel free to ask.
Any tips would be greatly appreciated. I’m eager to get this working and can share updates as I go. Thanks!
The problem is that the present Bose setup doesn't allow eARC. eARC enables audio input and output over a single HDMI link. To use an HDMI connection with Bose, you'd need to run one HDMI cable into the TV and another out of the TV back into the Bose device, creating a loop for transmission. Verify your cable box has multiple HDMI ports available. Certain boxes support both incoming and outgoing HDMI connections, which are useful for audio systems and DVR add-ons.
Tanks for the answer. I’m not sure what you mean by the "loop." I just want to begin with connecting only TV to Bose. I’ve already tried using an HDMI cable to the Bose HDMI input (second photo). Bose can handle audio over HDMI, but I can’t set the HDMI port to play sound only, so it didn’t work and no tone came through. Also, shouldn’t it be possible to send 5.1 audio over a TOSLINK cable?
EARC transmits and receives audio via a single HDMI cable. Without that feature, you can achieve 5.1 sound using a Toslink connection. The loop concept involves routing HDMI from your Bose system into the TV, then connecting one end out and the other back to Bose. This would require two HDMI cables, creating a loop that supports both sending and receiving audio. This setup works with TV sources that support multiple HDMI inputs or outputs, such as a cable box.
I don't rely on TV inputs except my desktop PC connected via HDMI over the TV. I only use the "SmartTV" applications. A loop between Bose and the TV has already been attempted without success. I don't believe the TV has additional HDMI outputs beyond the arc/eARC ports.
Review the instructions for both the television and the Bose device. The Toslink system does not allow Dolby Atmos playback.