Article: The Value Proposition in Computer Audio: Entering Multichannel at the Ground Floor

[bluesman]

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[The Computer Audiophile]

Thanks so much for the thorough article @bluesman! I'm such a newbie when it comes to multichannel, but since Pearl Jam released its new album Gigaton in Dolby ATMOS, I'm close to finally jumping onboard. 

[bluesman]

49 minutes ago, The Computer Audiophile said:

Thanks so much for the thorough article @bluesman! I'm such a newbie when it comes to multichannel, but since Pearl Jam released its new album Gigaton in Dolby ATMOS, I'm close to finally jumping onboard. 

So I suppose now we have to stop dissing Muzak and thank it for the concept of ceiling speakers...... 😝 

[Bill Brown]

Great article @bluesman.  Well written, and it is clear you are enjoying yourself both playing with the hardware side and enjoying the music.

 

Every few months I get intrigued by MC and dive into research.  What I would want, though, is up-mixing of my extensive 2-channel material (not "ambience synthesis," but what I guess would still be called extraction).  I suppose I would buy some MC music, but it wouldn't be my main thing.  I wish I could read up to date stuff on up-mixing (I keep hoping KR will dip his toes into it, though I know in the past he wasn't impressed).

 

That leads to algorithms like Logic 7, DPL-II, Trinaural, Circle Surround, etc.

 

You seem to say that JRiver and Roon upsample stereo (v just passing through or decoding?).  If so, I wonder how it is done/what algorithm.

 

Since I don't need fancy video inputs/outputs, I end up looking at old surround processors- cheap!  Haven't pulled the trigger, though.

 

What I would like is plugins in a computer to process, then USB (or HDMI) to a multichannel DAC (or all of it in something like a Metric Halo interface).  There seem to be some plugins, but mostly for production/post-production.  I'll keep an eye out.

 

Thanks again for the article,

 

Bill

[bluesman]

21 minutes ago, Bill Brown said:

What I would like is plugins in a computer to process, then USB (or HDMI) to a multichannel DAC (or all of it in something like a Metric Halo interface).  There seem to be some plugins, but mostly for production/post-production.  I'll keep an eye out.

I don’t know exactly how the processing of 2 channel source material to MC output is done. But it’s done well by both proprietary programs like JRMC and Roon and by many open source players.  So you don’t have to look far or spend money to add this function to your computer.  You might want to review my article on front end audio software to find one for your computer -  here’s the summary table, which you can search for “MC” to find those that do it.  
 

I’m particularly pleased with HDMI for audio.  Driving good electronics, I believe it’s the equal of USB and coax for SQ.  Sadly, I don’t have a DAC that has HDMI plus USB - so I can only A/B the former against coax and optical into my Elite receiver. But from comparing it to USB into DACs and analog endpoints of the same spec and vintage, I think my belief is well founded.

 

Thanks a lot for your kind words!

 

David

[Bill Brown]

Wow.  I'd forgotten about that article, but now remember being impressed!

 

I am Mac only (got our first computer after residency!), and just haven't gone done the path that you have done in such depth.  Two of my sons went down that rabbit hole.  I am more interested in DIY with tubes, speakers, etc.

 

I used iTunes for Library management until "Music," have now given up.  Audirvana when on the "big rig"- ha!  Swinsian for casual (love it).

 

I will keep watching your adventures and maybe jump in the stream at some point. :)

 

Bill

[Skip Pack]

Superbly crafted article! It provides what I need to get going on MC music. I've been using RPi's for five years, and figured that pointers to successful configurations were what I needed, rather than plunging down successive rabbit holes. I have a room set up with 4.1 right now, with wiring for 5.1 centered on an old Yamaha RVX-375, which seems so sound nice.  It only has one spdif coax for digital input aside from HDMI. My RPi3+ with a spdif hat should drive that nicely. The octo sounds like a very reasonable alternative, so I suppose the issues will be the ease and accuracy timing out and balancing the channels, and the DAC quality. Thanks very much.

[bluesman]

23 hours ago, Skip Pack said:

Superbly crafted article! It provides what I need to get going on MC music. I've been using RPi's for five years, and figured that pointers to successful configurations were what I needed, rather than plunging down successive rabbit holes. I have a room set up with 4.1 right now, with wiring for 5.1 centered on an old Yamaha RVX-375, which seems so sound nice.  It only has one spdif coax for digital input aside from HDMI. My RPi3+ with a spdif hat should drive that nicely. The octo sounds like a very reasonable alternative, so I suppose the issues will be the ease and accuracy timing out and balancing the channels, and the DAC quality. Thanks very much.

Thanks!!  You don't need an Octo or an spdif HAT to play MC through your Yamaha receiver - HDMI from the Pi is fine.  As I recall, your Yamaha has the same (or similar) 24/192 DAC chips as my Pioneer and should sound fine through decent speakers.  The Octo is a nice device, but it sounds no better than my Elite receiver. Assuming you have MC source files at or below 24/192 and/or your player will reformat your 2 channel files to MC, you don't need to add any additional hardware or software.

 

Timing and balance problems do not exist when cabling the Octo to analog endpoints.  The only such problems I encountered were with BT wireless MC.

[Kal Rubinson]

On 9/18/2020 at 2:18 PM, Bill Brown said:

(I keep hoping KR will dip his toes into it, though I know in the past he wasn't impressed).

Sorry.  I do not have any need for upmixing for anything more than ambiance recovery and, for that, I can use Auro2D or Auro3D.  

[thotdoc]

I am in way over my head in this, but: Though Roon can change 2 in to 4+ out, it still needs an 4+out dac? Or what am I missing? Thank you in advance.

[thotdoc]

43 minutes ago, thotdoc said:

I am in way over my head in this, but: Though Roon can change 2 in to 4+ out, it still needs an 4+out dac? Or what am I missing? Thank you in advance.

Ok. I reread it.  Got it. I'd gotten to thinking about using a v g DAC I had here and lost the thread.

 

[bluesman]

10 hours ago, thotdoc said:

Ok. I reread it.  Got it. I'd gotten to thinking about using a v g DAC I had here and lost the thread.

 

Just to clarify:  you need an analog output channel for each channel in your chosen audio output format.  A complete channel includes hardware conversion of the digital signal to analog, plus amplification and a speaker.  Conversion can occur in a DAC at the beginning of the chain or integrated into an amplification stage further downstream.
 

With traditional analog amplification, digital conversion to analog happens at line level (in the DAC) before input into the first analog stage.  If you use digital amplification, the conversion from digital to analog happens at or near the last stage in the hardware (the power output stage that drives the speaker).

 

So no matter how you shuffle the hardware deck, each audio output channel needs its own D-to-A conversion, amplification, and transduction.  A 2 channel DAC will only convert and deliver 2 channels of analog audio to the amplification stages.  The Octo card has 8 discrete DAC channels.  Digital audio interfaces have enough for their max output formats, so a 5.1 DAI has 6 channels and outputs.  Basic HT receivers are usually 7.1 .  If you input 4 channel source material, you’ll get 4 audio channels from 4 of the 8 outputs and nothing from the other 4.

[Bill Brown]

16 hours ago, Kal Rubinson said:

Sorry.  I do not have any need for upmixing for anything more than ambiance recovery and, for that, I can use Auro2D or Auro3D.  

 

Actually, this is exactly what I am talking about.  Thank you!  Ambience recovery for stereo to multichannel via plug-ins (they have AAX only at this point, but apparently working on the VST format).  Not interested in special effects, synthesis, etc., just ambience recovery, enhanced spaciousness with acoustic music.

 

If you have experience with Auro and like it, that would be a nice place for me to start (with your extensive experience listening to discrete multichannel).  There are several companies making plugins for professional work turning 2-channel to multiple MC options, but the algorithms used/how effective they may be aren't always clear.

 

I was interested in getting started with a center channel then going on from there.  SW player with plugins to MC DAC.

 

Thanks again,

 

Bill

 

 

[bluesman]

11 minutes ago, Bill Brown said:

I was interested in getting started with a center channel then going on from there.  SW player with plugins to MC DAC.

As I recall, the AuroMatic 2D plugin lists for $600 per the B&H website.  I was hoping to find a less costly way to try this, but I’ve not found one yet.  If you succeed, please post about what you found.  Thx!

[thotdoc]

3 hours ago, bluesman said:

Just to clarify:  you need an analog output channel for each channel in your chosen audio output format.  A complete channel includes hardware conversion of the digital signal to analog, plus amplification and a speaker.  Conversion can occur in a DAC at the beginning of the chain or integrated into an amplification stage further downstream.

Thank you

[Bill Brown]

Oy.  Now going back down the rabbit hole of processors and receivers....I just can't stand all the bells and whistles, love simplicity, buying maximal quality for the price on the features I need.  I have been so comfortable with my RME-ADI2, Benchmark amp system.  Maybe digital to them for the mains.

 

Sorry to stick all of this into your simple/inexpensive MC thread!  I am just now committed to keeping my system simple for family use.  No more isolated space, have given up on hours of solitary listening (though get some every now and then).  And reluctant to delve more into computers.

 

Bill

[ted_b]

On 9/18/2020 at 10:08 AM, The Computer Audiophile said:

Thanks so much for the thorough article @bluesman! I'm such a newbie when it comes to multichannel, but since Pearl Jam released its new album Gigaton in Dolby ATMOS, I'm close to finally jumping onboard. 

Now that I'm back to building the music room (and finishing the walk out lower level) I have prewired the ceiling for 5.1.4 for one particular reason....Abbey Road Atmos mix.  :)  I am soo looking forward to setting up the system in a room designed for mch (i.e wider than Ohio room, so equidistant rears are comfortably at about 100 degrees). 

 

Great mch article Bluesman.  We need all the mch support we can get.  From Beck's Sea Change to Jared's great Budapest recordings.  :0

[bluesman]

1 hour ago, Bill Brown said:

I just can't stand all the bells and whistles, love simplicity, buying maximal quality for the price on the features I need.

I'm with you on that philosophy.  For my "off duty" listening, my music server is Roon ROCK on a NUC and my main players are Pi 4s with Bridge.  The living room Pi drives an SMSL SU-8 into a Prima Luna power amp and Focal 726 towers.  The den Pi drives an iFi DSD Nano into a pair of JBL 305LSRs or my AKG 701QJs.  Every other room has a Chromecast Audio driving inexpensive powered speakers via optical, except for the water-resistant JBL in my bathroom that only has an analog input. 

 

I also run JRiver Media Center on each Pi, on my Linux DAW/media box, and on my workhorse Win10 PC.  JRMC lets me listen to my music anywhere around the world over the internet, and it's the best player I've found for MC on the Octo.

 

The OctoPi is running 5.1 JRiver into 3 JBL 305s and a Stewart PA100B driving my Rogers LS3/5as.  I'm enjoying MC more and more, and this system is very listenable, great value, and simple as Pi (sorry, but I couldn't resist...).  I do plan to acquire an ESI Gigaport EX as soon as I can find one.  They were introduced at the 2020 NAMM show, but getting them into the hands of the public has obviously been problematic during the pandemic. Once I get that (and assuming SQ is significantly better than the Octo), I'll add another pair of JBLs and use my Yamaha sub for a matched 5.1 system that will also be for "off duty" use.

 

For me, most opinions without experience are worthless.  So I've always tried everything I could - hardware, software, methods, program sources, etc.  But quality, simplicity and value are the metrics I hold most dear and try to balance in daily life.

[Kal Rubinson]

5 hours ago, bluesman said:

As I recall, the AuroMatic 2D plugin lists for $600 per the B&H website.

It came "free" with my Marantz AV8805.

[bluesman]

1 hour ago, Kal Rubinson said:

It came "free" with my Marantz AV8805.

It’s all in your point of view, Kal.  You also got great electronics “free” in that Marantz - but the case and controls cost about $4500.

 

The AuroMatic 2D plugin is $669 right now at Dale Audio and €595 direct from Auro.  The 3D plugin is €1195 (~1400 USD) from Auro.  This is a bit rich for people with Raspberry Pi streamers 😗

[jrobbins50]

Hey, @Kal Rubinson.  What do you do with Auro, and is it also in my AV-8802A?

 

Have you tried the above referenced ESI Gigaport ex MCH DAC yet?  Just wondering if you think it sounds better than the old miniDSP u-DAC8, which I still have in service on my porch system. It certainly is inexpensive. For $161, I ordered one today just to try out. Thanks. JCR 

[Kal Rubinson]

1 hour ago, jrobbins50 said:

What do you do with Auro, and is it also in my AV-8802A?

I just switch it on for many stereo sources.  It is subtle but effective in opening up the soundstage and disassociating it from the L/R speakers.  There is an Auro upgrade for the  AV8802a: 

Auro-3D

This mode uses an Auro-3D decoder to create three-dimensional audio output using the Height Channel. It is ideal for playback of signals encoded as Auro-3D with a Height Channel. If signals not encoded as Auro-3D are input, an Upmixer called the Auro-Matic is used to create highly realistic three-dimensional audio output.  

 

1 hour ago, jrobbins50 said:

Have you tried the above referenced ESI Gigaport ex MCH DAC yet?

I have not.

[jrobbins50]

@Kal Rubinson, what do you use for a height channel and where do you place it?  And could you offer a track or album that you believe best demonstrates the effect you note. Thanks. JCR 

[Kal Rubinson]

7 hours ago, jrobbins50 said:

@Kal Rubinson, what do you use for a height channel and where do you place it?  And could you offer a track or album that you believe best demonstrates the effect you note. Thanks. JCR 

I do not at the moment.  Right now, I am using Auro2d since I have only the 5 base level speakers.  I did experiment with Auro3d when I had a 5.1.4 system temporarily.  At that time, I added 4 KEF R8a ATMOS speakers, one on top of each FL, FR,SL and SR speaker.

 

However, since my acquisition of a NAD M28, I have decided to reinstate that configuration but the is currently in progress. 

[jrobbins50]

So, Auro3d requires no further speakers or amps. Let me understand the arrangement, @Kal Rubinson.  In my main system stereo setup, Roon is my playback and Audiolense convolution engine, running through my Bel Canto streamer, which will do the second MQA unfold. Then, I run into the Marantz stereo input where Audyssey is shut off, but bass management is still active. (I have a 2.2 setup for stereo and I ran my Audiolense filter measurements with the Marantz bass management in place.) Can I turn Auro2d alone on for a single input of that sort?  Thanks. JCR