An HDMI audio extractor that separates high-fidelity audio from HDMI sources while preserving video. Home cinema owners and console gamers can route optical or 3.5mm sound to legacy receivers without losing 4K passthrough. Is the CMSTEDCD HDMI Audio Extractor the right way to add surround sound to an existing AV setup?
⚡ At a Glance
- • Audio Formats: Supports 2CH PCM, 5.1CH digital and DTS on SPDIF; does not support 7.1
- • Best for: Home cinema setups and console gamers wanting optical 5.1 passthrough alongside HDMI video
- • Not ideal for: Setups that rely on ARC or eARC, or where the TV is used as the HDMI source
HDMI input and output allow audio extraction to optical Toslink and 3.5mm stereo while passing video up to 4K@30Hz. Three EDID modes (Pass, 2CH, 5.1CH) let the source output stereo or surround as required.
Keep 4K video while extracting audio – Thanks to HDMI 1.4 passthrough
HDMI 1.4-based passthrough carries video signals up to 4K@30Hz while routing the audio stream separately to SPDIF or 3.5mm outputs. HDMI input and output maintain synchronous A/V transmission so picture and sound stay aligned.
Preserves full-resolution video to displays while sending audio to external speakers or headphones, ideal for matching older audio equipment with modern sources.
Flexible surround output – With optical SPDIF, 3.5mm stereo and selectable EDID modes
Optical Toslink SPDIF supports 2CH PCM, 5.1 digital and DTS, while the 3.5mm jack supplies 2CH PCM stereo. EDID settings (Pass, 2CH, 5.1CH) force the source to output the chosen audio format for reliable compatibility.
Easily connect legacy AV receivers or soundbars for genuine 5.1 surround or simple stereo, depending on the connected system and chosen EDID mode.
Quick installs and durable casing – With metal housing and USB bus power
Metal box construction provides stable signal transmission and a compact footprint for discreet installs. Low-power design draws 5V from a USB port so an additional power brick is typically unnecessary.
Plug-and-play setup suits tight media cabinets and temporary rigs; the robust case keeps connections secure for long-term use.
✨ The 4 Key Reasons for CMSTEDCD HDMI Audio Extractor
- 4K HDMI passthrough – Keeps original video quality while sending audio to external speakers
- Optical SPDIF 5.1 support – Enables Dolby/DTS surround through compatible receivers and soundbars
- Three EDID modes – Force stereo or surround depending on connected audio system needs
- USB bus-powered metal case – Stable connections with compact, durable build for discreet installs
📋 Technical Details at a Glance
- Category: HDMI audio extractor / splitter
- HDMI Version: HDMI 1.4
- Max Resolution: 4K x 2K @ 30Hz
- Supported Resolutions: 4K@30Hz, 1080p, 1080i, 720p, 576p, 576i, 480p, 480i
- Audio Outputs: Optical Toslink SPDIF, 3.5mm L/R stereo, HDMI output
❓ Frequently Asked Questions
Q: Can it pass 4K at 60Hz?
A: No, maximum supported resolution is 4K at 30Hz and the unit follows HDMI 1.4 specifications.
Q: Will I get 5.1 surround over the optical output?
A: Yes, SPDIF supports 5.1 digital and DTS, but when using 5.1CH digital audio the signal source must be set to PCM; if the source is set to 'linear PCM' the surround signal may be converted to stereo.
Q: Does it support ARC or eARC from a TV?
A: ARC and eARC are not supported. Use an ARC/eARC converter to convert the TV's ARC/eARC signal to optical or 3.5mm before connecting to speakers if required.
🏆 Our Verdict
Ideal for home cinema owners and console gamers who need to add optical or stereo outputs while preserving HDMI video. The combination of 4K HDMI passthrough, selectable EDID modes and optical 5.1 support makes it a flexible solution for mixing modern sources with older audio kit. Not aimed at setups that require ARC/eARC, but reliable passthrough and modest power needs give lasting practical value for many AV systems.
