Subwoofer in OTA ATSC 1.0?

[CEG3]

I was thinking about how I can get good surround sound watching Youtube videos, but never a signal for my sub. (a call to high audio shop and was told this works in his exp with Apple TV streamers) This caused me to notice this is the case with OTA TV through my HDH tuner also. Just wanted to double check that I shouldn't expect to get 5.1 audio OTA. Is this right? Thanks!

[Ken.F]

I get 5.1 audio from HDHomeRun tuners on ATSC 1.0 OTA if the program has it. Not sure about NTSC OTA. I thought that was phased out.

[CEG3]

Looks like I made a mistake in the title which has been corrected.

Just to be certain, are you saying you get subwoofer signals over the air? Your sub plays LFE sounds when you watch TV?

[Ken.F]

Yes.

[Cabal]

The OSD for my Denon receiver confirms that most broadcasts I receive are in AC-3 (DD) 5.1, other than those sub-channels coming in at DD 2.0.

Note that a lot of broadcast audio has been de-tuned to not do much with the LFE channel, even for movie content. I would need to turn the audio up pretty loud to get my subwoofer to kick on from, say, a news broadcast. Big hits in football will do it, though.

[rikd]

Looks like I made a mistake in the title which has been corrected.

Just to be certain, are you saying you get subwoofer signals over the air? Your sub plays LFE sounds when you watch TV?

Yes
Not every program is 5.1 - sometimes is AC3 2.0
but even then the subwoofer is active as the soundbars/AVRs in the house have the crossover set to ensure low frequency is pushed to the subwoofer.
Same with YT.

If your subwoofer is not activating - could be a configuration issue on the soundbar/AVR
If your soundbar/AVR is not receiving an LFE signal then could be configuration of your TV, playback device, or app (you have set up the HDHomeRun App to use 5.1 surround sound and not stereo speakers?)

[foxbat121]

Subwoofer signal is passed from your AVR or soundbar which may have many different modes of sound processing. Make sure you are not using Pure or Direct mode which turns off audio processing. A properly configured AVR (with speaker size set to small) or soundbar can output subwoofer signal regardless of input audio format, even if you only get 2.0 audio.

[CEG3]

Made some progress! After years of being convinced I can't get sub out watching youtube videos I have it now. Interestingly, my processor for my surround system now indicates DD Prologic with red flag instead of DD. I changed the audio setting in my Shield from manual format choices to auto play formats capable of and changed my TV audio to passthrough. I may have changed something else, but I'll have to play with it. Just to double check I realized the HDH tuner is now playing the sub. I think I changed it to passthrough but it keeps changing back to 5.1, so of course I'll leave it right there. The most interesting thing to me is the change to digital prologic which is probably due to changing Shield to auto select formats. I guess I got it! Thanks!

Soooo, I moved on to my fireTV Cube and with it I can now have no digital Prologic and a sub with passthrough as the audio setting in the Cube. If I change that setting in the Cube to 5.1, DD with red flag plays but I'm back to no sub. Oh boy! Passthrough setting in Cube audio setting does give me now HDH with DD and sub, so it looks like I can now have sub with HDH on my Shield and my Cube, but if I want sub and DD on watching youtube I'll have to stick with my Shield.

Optical out on TV is how I connect to my processor. This is a 25 year old Rotel system that pre-dates HDMI.

[rikd]

Made some progress! After years of being convinced I can't get sub out watching youtube videos I have it now. Interestingly, my processor for my surround system now indicates DD Prologic with red flag instead of DD. I changed the audio setting in my Shield from manual format choices to auto play formats capable of and changed my TV audio to passthrough. I may have changed something else, but I'll have to play with it. Just to double check I realized the HDH tuner is now playing the sub. I think I changed it to passthrough but it keeps changing back to 5.1, so of course I'll leave it right there. The most interesting thing to me is the change to digital prologic which is probably due to changing Shield to auto select formats. I guess I got it! Thanks!

Soooo, I moved on to my fireTV Cube and with it I can now have no digital Prologic and a sub with passthrough as the audio setting in the Cube. If I change that setting in the Cube to 5.1, DD with red flag plays but I'm back to no sub. Oh boy!

How are you connecting the fireTV or Shield to your audio system?
Is it via the TV?

[rikd]

Optical out on TV is how I connect to my processor.

This is likely the root cause of your subwoofer woes
What's the make and model of the TV?

[CEG3]

It's just a cheap Toshiba fireTV edition TV, (50C350KU, 2021 Model)

I'm feeling a little silly, because I've had this system so long and I haven't messed with setup for years. I am just now discovering/rediscovering with TV and Shield audio settings adjusted I can use my remote to switch between digital prologic and get sub audio on youtube and switch back to DD and the sub goes away. I have to wonder if I ever knew I could do this and just forgot. I bought this Rotel system new. The good news is you guys gave me some good tips and I know now that yes, one way or another I can get sub out watching youtube and HDH OTA broadcasts. Glad I didn't try to go down this rabbit hole late last night when I first wondered about it.

[rikd]

It's just a cheap Toshiba fireTV edition TV, (50C350KU, 2021 Model)

Open the menu on the TV and select Sound.
Check what you have for Advanced Settings -> Digital Audio Out

Also worth checking the Speakers menu too (under the same Sound menu).
Older Toshiba TVs used to have a feature where you can set the Subwoofer to be the TV - make sure that is NOT selected.

Have you tried the HDHR app on the fireTV in the Toshiba?
If the Digtal Audio Out is set correctly (Dolby Digital, bitstream, or similar), and the HDHR App set to digital passthrough it should work.

[jasonl]

If the HDHomeRun app isn't set to passthrough, you definitely aren't getting 5.1 sound, because S/PDIF is limited to stereo when carrying PCM. And if you're getting stereo, anything in the LFE channel will not be present as the LFE channel is not included in a stereo downmix (Dolby sets the downmixing parameters). In theory, a proper 5.1 mix should still have bass down to 20Hz in the 5 main channels then just use the LFE channel for extra on the thumps and booms and such, but most TV doesn't have a proper 5.1 mix, it's just stereo upmixed to 5.1 using a fancy processor, and that may include using a crossover to pull out everything below a particular frequency and stuffing it in LFE, leaving the main channels without any bass. If it then gets downmixed without LFE, no bass at all.

[CEG3]

It's looking like enabling passthrough on the TV and HDH app is making it work, though either on the fireTV HDH app or the Shield version the app keeps changing to 5.1 on its own. I really haven't used my surround with the HDH app very much and I recently discovered there was no sub. I don't even remember seeing passthrough as an option in the app. In the past it just seemed to work if I were watching a ballgame or something and honestly can't remember if the sub was working.

In the end watching OTA on HDH app I'm getting a sub now. I didn't even realize all stations didn't broadcast DD, because I'm seeing now my processor switching automatically between DD and digital prologic as I change stations and amazingly I'm getting sub in either mode. Watching Youtube I seem to have a choice of DD without sub or switching to digital prologic and getting sub, which is fine. I decided years ago that I would never have sub on youtube and I live in youtube. I gave up Netflix years ago and don't watch my HDH DVR shows too often and would be happy enough if I only have youtube and now I can listen to music in digital prologic with sub!