Multi-digital input -> 5.1 system digitally controlled?

[br3nnabee]

Hey guys,

I'm a TOTAL newbie to sound stuff, especially hardware, so I apologize if my question might seem a little dumb. I'm mainly a software tinkerer, and do a lot of server stuff so I work quite a bit with systems. I'm soon going to be moving, and as a part of that, I wanted to see if I could delve into upgrading my sound system for my room with a 5.1 surround system, however my needs are kind of... finnicky?

I have a lot of selfhosted stuff, and some of it has to do with audio. This primarily comes down to jellyfin for music, a custom voice assistant, and some other miscellaneous things. The problem is, these are all on separate devices, with jellyfin on my tv box, the voice assistant + more on my raspberry pis, and of course my actual devices such as my phone occasionally, as well as PC and consoles. I'd like them all to be able to play sound through the same speakers without me manually having to change any input channels, but have something like an arduino or raspberry pi be able to control the different inputs, changing volumes, inputs, etc. according to different parameters. The biggest thing that comes to mind for me is having the voice assistant always take priority when awake and reduce the volume for anything else playing.

Would anybody know of how I could make this happen? Thanks in advance!

 

[staticV3]

That sounds extremely difficult to accomplish.

For a Multi-digital input -> 5.1 system, the Flex HT should be perfect.

It can be used as a hub for your TV box, console, computer, Raspberry Pi, and phone.

However, afaik, the Flex doesn't have any mixing capabilities.
So for example, if you play something on your console and activate your voice assistant, there's no way for it to play over the game audio and reduce its volume.

 

[br3nnabee]

However, afaik, the Flex doesn't have any mixing capabilities.

Hmmm, that's unfortunate, it's kind of the biggest thing for me
I've been doing a little bit of extra reading, and although I haven't found anything that matches my needs perfectly, I did learn that DSP boards can be bought seperately and controlled by Pis via I2C, or that raspberry Pis can actually be used as DSPs (kind of). They seem really patchy though and not something I would prefer to do, but it does give me hope that maybe there's something a little bit more developed? Mixing wouldn't seem too hard to implement so if there's like any easier solution I'd happily pay a premium lmao

 

[DVDdoug]

without me manually having to change any input channels,

Without pushing a button or using a remote control?

You'd need a mixer, but mixers are for analog (some have one USB input/output) and a mixer with lots if input channels and more than 2-channel stereo output is an expensive professional piece of equipment (and rather large).

Most 5.1 digital sources have to be decoded with an AVR or surround sound processor (usually more expensive than an AVR). Most stand-alone DACs are only 2-channel, and they can't decode the DVD or Blu-Ray surround formats.

An AVR will do most of what you want. It will have multiple digital and analog inputs (but you'd have to make sure they are the "right" digital inputs). And you'll have to use the remote control to switch between inputs. You'll get at least 5 channels of amplification and a line-leve subwoofer output with bass management for a powered sub.

Mixing wouldn't seem too hard to implement so if there's like any easier solution

Digital mixing is "easy". It's done with sample-by-sample summation. But the sample rates & bit depths have to match (if you are actually mixing) and you have to "get to" and "intercept" the uncompressed audio stream. (Digital volume control is also "easy". It's multiplication by a factor of more than 1 for amplification and a factor of less than one for attenuation.) ...I've never done any audio programming but I've done a fair amount of other programming and I know quite a bit about audio.

 

[br3nnabee]

An AVR will do most of what you want. It will have multiple digital and analog inputs (but you'd have to make sure they are the "right" digital inputs). And you'll have to use the remote control to switch between inputs. You'll get at least 5 channels of amplification and a line-leve subwoofer output with bass management for a powered sub.

This gave me an idea and I did a little digging, seems like I might not be the only one who's had some linked desires. Essentially, it boils down to using a raspberry pi itself as a digital mixer, then sending that to a dac. This post showed me that although there aren't many options, something like this Evolve II comes in at a decent cost and can actually do 7.1. So, what I think I might be able to do is send audio to the raspberry pi via network, have it take it (via pulseaudio or pipewire) and mix it according to my parameters, then output via HDMI, which the Evolve 2 should be able to extract and output to the speaker system?

Latency might be a little bit noticeable, but tbh aside from that I don't see any issues. What do you guys think, could this one work or am I missing something dumb?

 

[mkt]

Most 5.1 digital sources have to be decoded with an AVR or surround sound processor (usually more expensive than an AVR). Most stand-alone DACs are only 2-channel, and they can't decode the DVD or Blu-Ray surround formats.

That depends a lot on the source. Many (if not most) 5.1 sources don't need an AVR for decoding.