Significant audio lag when using Roku to HDMI

Hey guys - decided to take work’s Nebula Mars II home for a little Halloween movies on my giant wall. I happen to have a huge light colored wall in my living room that is perfect for projectors.

Anyway, I noticed the terrible built in Netflix App didn’t do HD (seriously how is this even allowed on the Nebula??? It’s an HD projector!), so I decided to plug up my Roku to it instead.

However I noticed a significant 1 or 2 second lag in the audio which makes it not viewable of course.

I am sending to a bluetooth speaker (my sound bar plugged into a small BT receiver) however that’s not the issue as:

a.) When using the built in Netflix app + BT speaker the audio doesn’t lag at all.

b.) When using the built in speaker + Roku into HDMI the audio lags.

So it’s not the BT causing the lag. It’s the HDMI in.

Any idea how to fix this? Thanks!

Try changing the audio on the Roku to stereo instead of surround.

You could also try sideloading another version of Netflix onto the nebula that will hopefully play in HD.

One other thing that you could try is going to the Netflix website and making sure you have the highest video quality selected in settings.


Thanks for the reply! Unfortunately changing audio/video settings to the very basic on Roku didn’t work.

I also plugged in my computer to the HDMI to see if the lag still persisted. It did.

So it appears that any source coming into the HDMI on the Nebula has severe audio lag?

Is my unit just busted because obviously that would be unacceptable for any sort of use other than powerpoint projection.

I’ve also noticed that I can’t get my Nebula Connect app to see the projector at all. Both phone and Nebula are connected to the same WiFi and paired via Bluetooth. But nada.

Last thing I’ve done is change the Netflix app to a sideloaded version but it STILL only plays SD.

I’m guessing the app automatically gimps itself to 480p if it detects it’s on the Nebula? And thus non-certified by Netflix?

This projector had so much promise but has way too many crippling features.

I have had no issues with my Nebula playing HD content. I also do not experience any audio lag when using HDMI connections, we have used one of my Roku devices, my nether stream box and our laptop to connect to it without issues.

Thanks for the reply. So using the built in Netflix app shows HD content? It absolutely does not for us and we can’t figure out why. It’s so frustrating!

I’m guessing the HDMI delay is just because of a busted unit then. Maybe I’ll return it and see what’s going on. It even happens when using the Roku plus the built in speaker on the Nebula (so it excludes it being a BT issue).

the netflix app that was installed had to be updated right away, afterwards the whole unit had a firmware update and after that netflix again updated and has worked since. maybe check to see if there is a firmware update for your nebula and then try again

It’s all up to date :frowning:

Sounds like it busted unit. Reach out to for a warranty replacement.

@Zach_Prichard I understand that you want the Mars II to play HD with Netfilx App but please know that it is Netflix app itself doesn’t support HD. Meanwhile please note that it is a normal situation to see the Mars II has 1-2 seconds audio lags as the audio is transfer to the Mars II via HDMI cable. Please don’t hesitate to contact us @ if you have any further concern.

HUH? HD projector and you can’t use the Netflix app in HD? A 1-2 second delay in audio performance is expected??? Both of these make the projector unusable in my opinion.

Came to say how frustrated I am that it’s expected that audio lags via HDMI.