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[Mitchco]

Hello,

My system uses the convolution engine to host a 3 way digital XO for a stereo system.

What I am not clear on is the rest of the DSP for a 5.1 movie and stereo playback. I look at the audio path, and get that. I also understand convolution, but lost on the 2 channels in a 5.1 container (and is that the right setting? Why not 5.1?). What is JRSS doing in this particular scenario? What is being low passed at 45 Hz to my 3 way stereo system? Or does any or all of it even apply in my 5.1 to stereo scenario?

Lol, I know these are my settings, but I arrived here from what others were doing. Now I am not really sure with 5.1 content what is being sent to my triamped stereo system. Looked through some threads, and wiki, but could not find the decoder ring or at least what I could understand. Any assistance appreciated.

Thanks,
Mitch

[mattkhan]

Firstly, I recommend measuring this to verify the behaviour is exactly as you expect - https://wiki.jriver.com/index.php/Verifying_DSP_Studio

but lost on the 2 channels in a 5.1 container (and is that the right setting? Why not 5.1?).

this is covered https://wiki.jriver.com/index.php/Output_Format#Understanding_the_Channel_Options

it's due to the way MC conflates the mix target with the number of physical output channels. 2 channels in a 5.1 container means "create a 6 channel output device, mix content to stereo" whereas 5.1 means "create a 6 channel output device, mix content to 5.1"

In your case, you have the correct option.

What is JRSS doing in this particular scenario?

jrss mixing means downmix 5.1 to stereo and pass stereo through as is except that you have...

What is being low passed at 45 Hz to my 3 way stereo system? Or does any or all of it even apply in my 5.1 to stereo scenario?

See https://wiki.jriver.com/index.php/Output_Format#Subwoofer

As far as I know, this is basically a double bass option. It will copy some portion of the main channels to create a .1 channel.

In your particular case, I have no idea what it will do. Some things I can imagine it doing....

* ignore the setting completely
* fold that content back into stereo mix (i.e. adding that option creates a 2.1 feed from stereo but the mix target is stereo so move that bass back into the mains)
* throw away that content (i.e. discarding LFE on downmix)

or it might do something completely broken like see 6 channel output and leave it on channel 4 (obviously a terrible thing in your case).

This is definitely a case where you should measure to see what it does.

Having said that, in your case, I think you should simply turn it off.

[Hendrik]

In your particular case, I have no idea what it will do. Some things I can imagine it doing....

* ignore the setting completely
* fold that content back into stereo mix (i.e. adding that option creates a 2.1 feed from stereo but the mix target is stereo so move that bass back into the mains)
* throw away that content (i.e. discarding LFE on downmix)

or it might do something completely broken like see 6 channel output and leave it on channel 4 (obviously a terrible thing in your case).

Its neither of those actually. If you have a mix target without a LFE channel, and the input has a LFE channel, then it'll low-pass the LFE channel before mixing it into the front mains (ie. left/right channel). This is done because some audio tracks of movies have unexpected high frequencies in their LFE channel, which are inaudible if you output it to a Subwoofer, but if you mix them into L/R they cause distortions.

If your input has no LFE, then nothing happens in this configuration.

[mattkhan]

Thanks for clarifying.

Do you mean that the jrss subwoofer setting controls whether the lfe is discarded or redistributed when downmixing an lfe channel?

[Hendrik]

That is correct. If you set it to silent, it'll discard it, otherwise it'll low-pass it with the specified frequency.

[mattkhan]

Right ok. So in this case and assuming you want the lfe content, you might want to take upto something like 120Hz from the lfe and then high pass the resulting W channels as necessary depending on the capability of the woofers.

[Mitchco]

Thanks Matt and Hendrik. Matt, I read those links before I posted and was still confused. I do verify everything is working fine by using my Hilo to loopback REW through JRiver's ASIO line input and working fine. But I don't think there is a way to simulate LFE content...

So if I am using 2 channels in a 5.1 container and using JRSS to downmix 5.1 content and if the content contains LFE effects, then JRSS will mix that in to the stereo mix? And I can set the low pass frequency? I have good low frequency capability with the subs I am using. So if yes, then the only change I need to make to the screen shot "actual signal.jpg" attached to the first post would be to play with the JRSS subwoofer low pass frequency?

Kind regards,
Mitch

[mattkhan]

But I don't think there is a way to simulate LFE content...

You can use the external sweep method if you edit the track so it is a 6 channel wav with the sweep in channel 4. Alternatively open a 6 channel asio line in and route rew to the 4th channel

So if I am using 2 channels in a 5.1 container and using JRSS to downmix 5.1 content and if the content contains LFE effects, then JRSS will mix that in to the stereo mix? And I can set the low pass frequency? I have good low frequency capability with the subs I am using. So if yes, then the only change I need to make to the screen shot "actual signal.jpg" attached to the first post would be to play with the JRSS subwoofer low pass frequency?

Yes

[Mitchco]

Thanks Matt!