5.1 Home theatre on apple dongles for that sweet sweet audiophile gore

[Mister_magister]

Hello everyone, you might be terrorized (that's the goal) but if you read it i should convince you that it's reasonable.

I was constantly joking about doing 5.1 on apple dongles ever since I realised how easy splitting 6 channels between 3 devices would be. So one day I got convinced that the joke is actually NOT that dumb of an idea. @Weeb Labs was the one that convinced me. He also recommended me cheap 6 channel amp. I wanted 6 channels for future 7.1 setup.

So what's the setup. I got linux HTPC with camilladsp running room correction and mixing. Here's plot of pipeline

I use alsa for mixing output into 3 separate devices. For now i'm using 2 dongles and onboard audio because t5v wanted higher signal. About that…

Speaker setup is:

• LR - Adam t5v - had them on my desktop and decided they were wasting playing youtube
• C - Elac Uni-Fi 2.0 UC52
• Surrounds - wharfedale diamond 220
• LFE - Klipsch R-121SW

Cheap amp I mentioned ealier is WONDOM AA-AB34181 TDA7498. That is powered by 36V 16A PSU, gets 3 inputs from two apple dongles. T5V are connected to onboard because they needed more Volts on RCA. Path is basically USB A -> USB C -> apple dongle -> 3.5 TRS to 2xRCA female -> RCA male to male (interconnect) -> amp. or in case of t5v trs -> rca and in case of sub the sub goes directly to rca female.

So here are the gore pics. Enjoy

Split with overcurrent protection and plug with switch because PSU doesn't have any

Here's psu and amp, i'm printing nice stand for amp and psu is sitting in it's foam because why not (oh ye and they're on top of htpc)

Here are the dongles. Pic from before i switched to onboard. Bit of cable mess but what can you do

Dry setup

AMP + printed stand:

Hope you enjoyed xd Might sound cursed, and look cursed, but it sounds awesome and IS CHEAP AS HELL

 

[Weeb Labs]

What a lovely OSHA violation project! I am glad that some of my advice was of help.

 

[Mister_magister]

I forgot to mention @ItsMeAubey helped with the DRC stuff

 

[AdamG]

Send it to Amir and have it tested! Love Mad Scientist stuff.

 

[Mister_magister]

Send it to Amir and have it tested! Love Mad Scientist stuff.

That's too much stuff to send lol But I got umik lol

Already talked with @Weeb Labs on upgrade path and well upgrade path is dropping multiple dacs lol. But wanted to do 5.1 on dongles, so I did, PoC works great so if anyone wants to follow for REALLY cheap, i think dongles were collecitvely 25 usd, amp and psu are like 83,54 € for amp, 56.06€ for psu, you can have great 5.1 if you don't want giant and ugly and problematic avr's

 

[mdsimon2]

Have you checked the sync between the dongles? I am curious how good or bad it is. Does ALSA do any resampling like Mac OS in an attempt to sync the dongles?

Michael

 

[Mister_magister]

I don't have audio interface so i doubt i can check it to be honest

 

[kemmler3D]

If it's stupid and it works, it ain't stupid.

If it's ugly and it works, it's still ugly, but hey.

This is really awesome. Would love to see some measurements or something, the only thing more satisfying than a franken-setup working is it measuring well.

 

[Mister_magister]

Ye wish i could somehow measure that but i'm not sure i can. I mean we got the apple dongles measurements, the amp is fairly fine too, just the timing between them would be interesting

 

[Chrispy]

One of the most convoluted/ineffective setups I've ever seen! Congrats!

 

[Mister_magister]

One of the most convoluted/ineffective setups I've ever seen! Congrats!

How's this setup ineffective?

 

[Chrispy]

How's this setup ineffective?

How is it particularly effective?

 

[Mister_magister]

How is it particularly effective?

nono, no "guilty until proven innocent" please. You said it's ineffective, i want to know why

 

[Chrispy]

nono, no "guilty until proven innocent" please. You said it's ineffective, i want to know why

Start with the generally available alternatives, what are you trying/improving upon?

 

[Mister_magister]

Start with the generally available alternatives, what are you trying/improving upon?

"why not just get avr and be done with it"

1st: reason is that i hate sending audio through hdmi because entire setup likes to bug out because audio is lost when you change resolution or refresh rate
2nd: size.
3rd: upgradability

 

[Chrispy]

"why not just get avr and be done with it"

1st: reason is that i hate sending audio through hdmi because entire setup likes to bug out because audio is lost when you change resolution or refresh rate
2nd: size.
3rd: upgradability

Sounds like you have some odd ideas about how audio works....

 

[Weeb Labs]

Sounds like you have some odd ideas about how audio works....

He was referring to the issue of audio dropout via HDMI when the AVR is connected to a PC and the display resolution or refresh rate are changed.

 

[Chrispy]

He was referring to the issue of audio dropout via HDMI when the AVR is connected to a PC and the display resolution or refresh rate are changed.

Sounds like hardware or setup/use issues. I've never had such issues connecting my pc to my avrs. Is this something using odd bit depth or sampling frequency content or ?

 

[Weeb Labs]

Sounds like hardware or setup/use issues. I've never had such issues connecting my pc to my avrs. Is this something using odd bit depth or sampling frequency content or ?

It is not a connection issue but rather a consequence of the HDMI protocol, which interleaves the audio and video. When the output resolution or refresh rate is switched by the source device, audio output is necessarily interrupted during the process.

 

[igfarm]

Have you checked the sync between the dongles? I am curious how good or bad it is. Does ALSA do any resampling like Mac OS in an attempt to sync the dongles?

Michael

I tried separate USB 2-channel DACs some time ago on RPi and CamillaDSP while trying to integrate my sub. There was a random delay offset of +/- 5-30 msec between signals out of the DACs. I moved to a Motu M4 DAC for that reason. It might not be noticeable watching a movie on this very cool setup.