Reddit mentions of J-Tech Digital 4K 60HZ HDMI Audio Extractor Converter SPDIF + 3.5MM Output Supports HDMI 2.0, 18Gpbs Bandwidth, HDCP 2.2, Dolby Digital/DTS Passthrough CEC, HDR10 [JTD18G-H5CH]

I am playing them on the ultrawide and using this to output the sound to the SPDIF input on the usb sound card

For connecting soundbar to projector this is what I have and works perfectly/voices in sync.

https://www.amazon.com/gp/aw/d/B074HHSJVN?psc=1&ref=ppx_pop_mob_b_asin_title

Soundbar works perfect for my casual use, if it sounds good to you that's all that matters, can always upgrade later on

What you need is a "HDMI Audio Extractor":

1080p support: https://www.amazon.com/J-Tech-Digital-Premium-Extractor-Converter/dp/B00BIQER0E/

4K support: https://www.amazon.com/J-Tech-Digital-Extractor-Converter-Passthrough/dp/B074HHSJVN/

Probably get an HDMI splitter with audio out. That's what I would do in your case since I already own one.

You can probably get this one:

https://www.amazon.com/J-Tech-Digital-Extractor-Converter-Passthrough/dp/B074HHSJVN/ref=sr_1_5?keywords=hdmi+audio+extractor&qid=1550100863&s=gateway&sr=8-5

https://www.amazon.com/J-Tech-Digital-Extractor-Converter-Support/dp/B074HHSJVN

That is the closest you can get. It can pass Dolby Digital or DTS from the HDMI chain to S/PDIF, but it can't convert other formats to the more basics one. Essentially it only decodes, not encodes.

https://www.amazon.com/Luzan-Digital-Decoder-Converter-Optical/dp/B01MS0973G

This might be closer to what you want, it takes a DTS, Dolby Digital, or PCM signal and gives you 5.1 analogue pre-outs.

You could simply buy a used receiver with HDMI that could handle this task for you. It would cost the same as either of these devices.

DD+ Atmos is supported by the TV and Amazon over ARC however your receiver if its quite old may have trouble with this format. On paper the receiver should ignore the Atmos metadata and simply play a Dolby Digital Plus stream as is.

Optical does not support DD+ Atmos which is why it works, it's DD, DTS and PCM stereo.

Check for any firmware updates to the Denon, check the manual or try contacting them and asking if the DD+ support can be disabled on the AVR.

As to work rounds, there are HDMI-ARC audio extractors you can buy, these may or may not support DD+ so you can filter that format out effectively.

Get a FireTV stick and plug in into the receiver directly in the hopes it outputs either PCM 5.1 or DD 5.1.

Unfortunately LG do not offer anything other than ARC, pass-through (eARC) and PCM (stereo), you cannot disable DD+ on the TV as far as I'm aware.

Does your monitor have an audio out by any chance? I don't know how likely it is since it doesn't have speakers, but it's worth checking. If it does, you could just run a cable from your monitor to your speakers.

If not, your best best is to get an HDMI audio splitter like this one.

It’s been a while since I booted up my PS4, but I believe it only allows output to a single device at once. I would suggest not using headphones on the controller. If you’re not using the mic on the headset, you can use something like this:

https://www.amazon.com/J-Tech-Digital-Extractor-Passthrough-JTD18G-H5CH/dp/B074HHSJVN/ref=mp_s_a_1_3?keywords=J-Tech+Digital+4K+60HZ+HDMI+Audio+Extractor+Converter&qid=1565959889&s=gateway&sr=8-3

This is what I use for mine, but I don’t use any kind of team chat on the PS4. This allows me to hear all audio from the PS4 without the lag associated with listening to the audio from the OBS stream.

Not sure what you would use if you need the mic

I just ordered this gadget to help resolve my 5.1 digital problems:

https://www.amazon.com/gp/product/B074HHSJVN/

Hopefully it works. Right now my 5.1 digital output via TOSLink cable is only giving 2 channel stereo for everything. I can only assume that the Mi Box is reading whats on the other end of my HDMI cable which is my TV which only has two speakers (like most TV's do) so it's auto converting everything to stereo. Converting to stereo even through the TOSLink output.

It was either wait for Xiaomi to fix it which could be a long time.. maybe never...

or

Buy a new receiver that has HDMI processing built in. My receiver I have is older and has HDMI pass-through ports so it won't process anything.

For our installations, we typically use something like this (it passes 4k 60fps), note the switch for 5.1 or PCM. We use a lot of J-Tech stuff, all their stuff is good. https://www.amazon.com/gp/product/B074HHSJVN/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Your HDMI audio extractor is not 4k compatible.

EDIT: Look at this one, for example: https://www.amazon.com/J-Tech-Digital-Extractor-Converter-Passthrough/dp/B074HHSJVN/

Ok this seems to be a stubborn problem. Short of physically opening up the projector and removing the speakers, here is a nuclear option:

Buy an HDMI audio extractor, such as this one:

J-Tech Digital 4K 60HZ HDMI Audio Extractor Converter SPDIF + 3.5MM Output supports HDMI 2.0, 18Gpbs Bandwidth, HDCP 2.2, Dolby Digital/DTS Passthrough CEC, HDR10 https://www.amazon.com/dp/B074HHSJVN/ref=cm_sw_r_cp_api_i_EVi.AbQY2K1TN

Connect the audio out of the audio extractor to your sound bar. Connect the HDMI out of the audio extractor to your projector. Then mute the volume on the projector if needed.

Another option is HDMI audio extractor itself...

Takes HDMI in, and splits the video and audio

This would sit between the HDMI out of the receiver and the HDMI to the projector.

I bet the issue is the TV
Try skipping the TV altogether then it comes to audio and get the audio directly from your source
Get this or something similar J-Tech Digital 4K 60HZ HDMI Audio Extractor Converter SPDIF + 3.5MM Output Supports HDMI 2.0, 18Gpbs Bandwidth, HDCP 2.2, Dolby Digital/DTS Passthrough CEC, HDR10 [JTD18G-H5CH] https://www.amazon.com/dp/B074HHSJVN/ref=cm_sw_r_cp_api_i_CrFRDbYG2MVSAc

Dumb question: could I use something like this to connect my optical cable from my soundbar to the HDMI arc input in my tv?

https://www.amazon.com/J-Tech-Digital-Extractor-Application-Function/dp/B074HHSJVN/ref=nav_ya_signin?_encoding=UTF8&pd_rd_i=B00YHS5E6Q&pd_rd_r=30821704-7b44-4609-9942-24a107a8eea6&pd_rd_w=OFsAM&pd_rd_wg=CcDGy&pf_rd_p=21bbdc4d-873b-48c5-a88a-70e643377944&pf_rd_r=Q421NNMPRMF734SP5CGR&refRID=Q421NNMPRMF734SP5CGR&th=1

Looks like this is a problem that is tied to specific TV's?

Looks like the common solution seems to be installing one of these?

https://www.amazon.com/J-Tech-Digital-Premium-Extractor-Converter/dp/B074HHSJVN?th=1

An hdmi audio extractor should do the trick. Hdmi cable from PC to extractor, then hdmi cable from extractor to tv, and optical cable from extractor to soundbar.

HDMI extractor. It will pull the audio off the hdmi and send it to toslink or RCA. Just as an example

https://www.amazon.com/J-Tech-Digital-Extractor-Converter-Support/dp/B074HHSJVN/ref=sr_1_1_sspa?crid=3RWSD2KQNNRQN&keywords=hdmi%2Bextractor&qid=1558736180&s=gateway&sprefix=Hdmi%2Bextra%2Caps%2C235&sr=8-1-spons&smid=A2IX3RNQE846HA&th=1