Is 8 analog outputs to multichannel PCM or even DD over HDMI in real time, possible?

[PHD]

Hi


A friend at work has a working Lexicon DC-2 which I can buy for $200. I want to connect my Bluesound node 2's SPDIF output to the DC-2 SPDIF input and set it to Logic-7 mode.

Now, my Denon X4800H doesn't have multichannel analog inputs.

So, I was thinking, is there a multichannel analog to digital on-the-fly converter/encoder device that can take 8 analog channels, encode them into a multichannel PCM, and output them via HDMI, which would support 8-channel PCM?

Perhaps it could be possible to do this using a PC with an 8-channel soundcard that can do l time encoding to even Dolby Digital or DTS?

Is this even worth the trouble? I'm very curious to test the logic-7 upmixing capabilities.

I'm even open to an offline solution (sound card with 8 channel analog inputs that can capture them at once as 8 different wave files which I could later encode as LPCM using an audio editor software)

Thanks

 

[krikboh]

Your Denon has Dolby Atmos, DTS:X, IMAX Enhanced, Auro 3D, Dolby Surround, and DTS Neural:X. Do you need Logic-7?

 

[PHD]

Your Denon has Dolby Atmos, DTS:X, IMAX Enhanced, Auro 3D, Dolby Surround, and DTS Neural:X. Do you need Logic-7?

I was always curious about Logic-7 as a 2.0 to 7.1 upmixer. Especially in the older Lexicon processors, where you have many ways to tweak the upmixing effect.

I really don't understand why the license to apply Logic-7 was never acquired by other brands if it is really that good as anyone who tried it claims...

 

[somebodyelse]

Perhaps it could be possible to do this using a PC with an 8-channel soundcard that can do l time encoding to even Dolby Digital or DTS?

That should work although there will be some latency. https://docs.pipewire.org/page_man_pipewire-pulse-modules_7.html has some info on supported compressed formats like DTS, but isn't entirely clear whether they're all capable of encode as well as decode.

 

[antcollinet]

So, I was thinking, is there a multichannel analog to digital on-the-fly converter/encoder device that can take 8 analog channels, encode them into a multichannel PCM, and output them via HDMI, which would support 8-channel PCM?

I doubt it. But even if there is it will be a royal pain in the ass to make it work properly, with decent quality.

On the other hand...

I was always curious about Logic-7 as a 2.0 to 7.1 upmixer.

Your Denon can also do this with a number of up-mixers, including Auro 3d - and I'd be surprised if the Lexicon - with its 25 year old tech - can do a better job of it.


My personal opinion - don't waste your time on this just to scratch a curiosity itch.

 

[dlaloum]

I was always curious about Logic-7 as a 2.0 to 7.1 upmixer. Especially in the older Lexicon processors, where you have many ways to tweak the upmixing effect.

I really don't understand why the license to apply Logic-7 was never acquired by other brands if it is really that good as anyone who tried it claims...

Lexicon, and then Harman, was busy using it as their special sales sauce....

And by the time it would have made sense to let go of the exclusivity, Fosgate had developed PLII and sold it to Dolby... and Dolby then as now dominates the market.

A missed opportunity.

 

[zdjh22]

Hi


A friend at work has a working Lexicon DC-2 which I can buy for $200. I want to connect my Bluesound node 2's SPDIF output to the DC-2 SPDIF input and set it to Logic-7 mode.

Now, my Denon X4800H doesn't have multichannel analog inputs.

So, I was thinking, is there a multichannel analog to digital on-the-fly converter/encoder device that can take 8 analog channels, encode them into a multichannel PCM, and output them via HDMI, which would support 8-channel PCM?

Perhaps it could be possible to do this using a PC with an 8-channel soundcard that can do l time encoding to even Dolby Digital or DTS?

Is this even worth the trouble? I'm very curious to test the logic-7 upmixing capabilities.

I'm even open to an offline solution (sound card with 8 channel analog inputs that can capture them at once as 8 different wave files which I could later encode as LPCM using an audio editor software)

Thanks

In case you are still looking, yes, you can build a small DIY device to do this.

Raspberry Pi 5 + HiFiBerry DAC8x + HiFiBerry ADC8x. Connect the analog inputs to the ADC8x, and use one of the two HDMI outputs of the RPI5 to connect to your AVR. The “alsaloop” program moves the data (your choice of sample size and sample rate) from the ADC8x to the HDMI out, with buffering and automatic clock adjustment to avoid over- and under-runs. By default this is PCM.

I’ve made one of these and use it to convert the 6 analog output channels of my Surround Master to HDMI to feed to my Denon 3600. I have a pretty extensive HOWTO document if you are interested in building your own.

For some reason (maximizing profits, I suppose) the DAC8x is required, even though I’m not using it. HiFiBerry indicated that they would be willing to produce a standalone ADC8x for an OEM, minimum order 50.

 

[phofman]

For some reason (maximizing profits, I suppose) the DAC8x is required, even though I’m not using it. HiFiBerry indicated that they would be willing to produce a standalone ADC8x for an OEM, minimum order 50.

IIUC the requirement is only because of the different header on the ADC board. The ADC uses just power supply and I2S clocks + the 4 I2S input data lines. It can be connected to the RPi header with wires. Also the driver is standard simple-card configuration and enables only the I2S interface, there is no I2C or SPI control of the chips used. Any device tree overlay which enables the multichannel I2S input as master would do (e.g. https://github.com/raspberrypi/linux/issues/6022 fixed for i2s_clk_producer, as described in that thread).

 

[Chrispy]

Lexicon, and then Harman, was busy using it as their special sales sauce....

And by the time it would have made sense to let go of the exclusivity, Fosgate had developed PLII and sold it to Dolby... and Dolby then as now dominates the market.

Hadn't heard PLII wasn't a Dolby product before....interesting.

 

[dlaloum]

Hadn't heard PLII wasn't a Dolby product before....interesting.

Sadly, the fosgate deal required Dolby to pay him (later his estate) a licencing fee for each licence... so after they developed the Dolby Surround as currently used, they stopped including PLII....
which is a shame as it was an excellent system for stereo and for extraction of additional channels.... but it is effectively dead now.

 

[MCH]

I think a regular usb interface (for the adc) to a raspberry pi (no need to be the new 5, the 4b should work) then 8 channel lpcm out of the hdmi port of the raspberry pi. Only problem might be channel swapping on the hdmi if they have not fixed it yet.

 

[Chrispy]

Sadly, the fosgate deal required Dolby to pay him (later his estate) a licencing fee for each licence... so after they developed the Dolby Surround as currently used, they stopped including PLII....
which is a shame as it was an excellent system for stereo and for extraction of additional channels.... but it is effectively dead now.

I had wondered why PLII disappeared so thoroughly!