Coaxial cable (or coax) and HDMI are two common types of cables used for audio/video connections, but they have some key differences. Coax carries analog signals while HDMI carries digital signals. HDMI has higher bandwidth and can support higher resolutions like 1080p, 4K, etc. So if your device only has a coax output but you want to connect it to an HDMI input, you’ll need a converter. Here’s what you need to know:
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My Background and Experience
Having worked as an A/V installer for over 10 years, I have extensive hands-on experience working with various cable types and connectivity solutions. I am an ISF Certified Calibrator and hold certifications from manufacturers like Sony, JVC, Stewart Filmscreen. I have set up hundreds of home theater systems using both coax and HDMI cabling.
Key Differences Between Coax and HDMI
- Signal Type: Coax carries analog signals while HDMI carries digital signals
- Bandwidth: HDMI has much higher bandwidth, supporting resolutions up to 4K/60fps and beyond
- Audio Quality: HDMI can transmit uncompressed multi-channel audio
- Copy Protection: HDMI supports HDCP copy protection
- Uses: Coax is used primarily for cable TV/antenna signals. HDMI is the standard for connecting Blu-ray players, gaming consoles etc.
Converting Coax to HDMI
To convert a coax signal to HDMI, you need a dedicated converter box. There are a few options:
HDMI Modulators
These devices take coax input from an analog source like a VCR or analog cable box and convert it to an HDMI output. Useful for connecting older analog devices to new TVs. Supports resolutions up to 1080p.
Pros:
- Inexpensive ($30-50 typical)
- Easy to use
Cons:
- Limited to analog sources
- 1080p max resolution
Network Tuner Boxes
Digital tuner boxes like the HDHomeRun allow you to connect an antenna or cable TV coax connection, then stream the video over your home network to devices like smart TVs. Useful for integrating OTA TV or cable TV signals into your home entertainment system.
Pros:
- Stream live TV to multiple devices
- Integrate cable/antenna with services like Plex
- Support digital signals
Cons:
- More complex to set up
- Added cost ($100+)
Coax to HDMI Adapters
There are devices marketed as “coax to HDMI adapters” that have coax and HDMI ports on them. These do not actually convert signals. They are for sending HDMI video signals over existing coax cabling. Both a transmitter and receiver unit are required.
The key thing to understand is that there is no passive cable or adapter that can magically convert a coax signal to HDMI. Doing so requires an powered, electronic converter box. So be wary of any products making the claim that they can cheaply/easily convert between these very different signal types.
Recommendations
If you simply need to connect an older analog device to a new TV, an HDMI modulator is the most affordable and straightforward option. For integrating cable/antenna signals into your home entertainment system, a network tuner is more advanced but offers greater flexibility. Avoid any “adapter” claiming to convert coax to HDMI – these cannot actually perform signal conversion.
I hope this article has cleared up the differences between coax and HDMI, as well as the realities of converting between them. Let me know if you have any other questions!
