Multichannel System for Music - Standards, Setup, Thoughts, etc.

[ernestcarl]

I'm curious as to how JRiver or Foobar is creating the signal for the surround channels. Do they use one of the standard applications such as Dolby or DTS, or some other proprietary codec?

Mucking about with REW in my small MCH setup I was able to glean some interesting insight...

Here is the FR of my right LSR 305 with 120Hz LR 24dB/oct high pass crossover. The speaker is set right against a parallel wall so a lot of SBIR. No EQ other than xo and treble shelving to match the KH120.

The frequency response looks a bit "mangled" by JRiver's surround DSP when viewed "on its own". Overall volume is decreased (moreso for the low-mids and bass). Treble from being originally flat now waves up and down twice. However, this all becomes quite linear when coupled with its corresponding channel later.

KH120 same crossover filter as before but now with some 9 biquads generated in REW and applied via miniDSP's input stage 600Hz down -- what can I say, so I got lazy? Well, not really as all of this is based on several combined spatial average & vector average FR sweeps -- plus manually verifying with already flatter RTA averages. Yada yada yada... that's not what's interesting here.

Combined with the .1 bass channel now... there appears a somewhat ominous "V" notch around 100Hz -- didn't EQ this much to fix this time since it is not at all noticeable with music playing -- even with very intense concentration

But here's an interesting thing:

Combining that "mangled" looking rear channel response from the upmixing process earlier with its corresponding channel still yields a pretty linear FR outcome.

More interesting still: with all "pseudo" 5.1 channels played in a single sweep -- yes, ALL CHANNELS -- we get more SPL and a 6dB bass boost. Still pretty linear, even with the originally lumpy lows from the rears.

You can disregard the treble notch as that's just an artifact from the mono sweep. What's important here is... as long as you've got your bass management (xo, delays, volume matching, some room correction) and placement right, we essentially see no bass cancellation whatsoever.

I didn't even need to EQ those lumpy looking rear channel FR plots after all. The linearity from the mains seems to carry much, much more weight here in the MCH upmixing process. And with several channels running... you get less distortion too!

 

[ernestcarl]

View attachment 38772
The frequency response looks a bit "mangled" by JRiver's surround DSP when viewed "on its own".

JFYI: after doing subsequent measurements, I was unable to reproduce the wavy treble response for the sythesized/upmixed rear channels (from its original stereo source) -- it now looks quite linear. I'm not exactly sure how, but it may have been a measurement technique error on my part.

However, if you let JRiver upmix only a single channel (e.g. Left or Right only), surprisingly, it reproduces two separately distinct Rear Left and Right channel signals. The sound effect sounds rather strange when played on its own -- there's deinitely some kind of phase manipulation going on.

 

[ernestcarl]

I've been cobbling up some ideas for setting up a small MCH ACTIVE system -- that's somewhat easier to arrange/mount and move around -- based on my own research and some suggestions by others.

Furniture grade aesthetics are of no importance to me here. As for hiding and organizing the ugly cables, try using some zip ties, spiral cable wraps, and cable track covers etc.

Floor standers are also out of the question here as I want this system to be SMALL and easy to move around (plus securely mount) as much as possible.

For the speakers and stands/mounting stuff here's a list:

"ACTIVE" MCH SPEAKER IDEAS

Ideally, it would be preferable to use the same identical monitors. However, this is going to quickly ramp up your overall cost the more channels you add. But then, if you also think about it, there are some distinct advantages of using monitors with a coaxial design -- even if they may not be the "bestest" or most ideal one you had in mind.

The subwoofer(s) will be up to you to decide, but something with balanced inputs would be preferable.

Since I want this system to work for not just the most basic MCH formats, but also for the latest object-based surround formats e.g. Dolby Atmos & DTS:X, unfortunately, the most expensive part has to be our all-in-one home theater processor tasked to do all the DSP heavy-weight lifting.

7.2.4 home theater processor - Integra DRC-R1.3 (not yet released)

9.x.6 home theater processor - Emotiva XMC-2 (overkill 16 channels fully available today)

But if you absolutely believe that height speakers aren't simply going to be part of your setup, here's an alternative:

7.2 surround home theater processor - Outlaw Model 976

These are just suggestions of mine for future ideas. Feel free to add some of your own.

*If this is going to be centered on a desk for critical video editing/viewing, might I suggest: BenQ SW271 27" 16:9 4K HDR IPS Monitor. I'm already extremely happy with my NEC PA272W which is around 6 years old now -- up to 10-bit color and 99% Adobe RGB, but it's just not HDR ready. Let's not under utilize our expensive, oversized surround processor.

**Even better -- and more expensive -- professional monitor for video editing with Dolby Vision support is the ASUS ProArt PA32UCX (more details from Tom's Hardware: Asus ProArt PA32UCX Review: First Mini-LED Monitor Wows)

 

[ernestcarl]

Dolby and DTS sample clips/tracks can be found here (and a few are in 4k too):

https://thedigitaltheater.com/dolby-trailers/

https://thedigitaltheater.com/dts-trailers/

Enjoy!

 

[ernestcarl]

Dolby Home Theater Speaker Placement Guides/Example Plans (actually, more like a simple sketch only):

5.1.4

7.1.4

9.1.4

Mounting Accessories from Neumann: Monitor Accessories

And here's an idea for portable/moving location work:

It looks like they just clamped the speakers together to one stand. Ugly, but pretty nifty and efficient!

*Not sure what that attachment's model# is used on top the tripod speaker stands -- you'd have to ask/contact Neumann or those guys directly. It looks a little bit like the one used in Neumann's LH 65 stand:

 

[Sancus]

Huh, I live in a rental so physically mounting speakers to the ceiling is out, and I like that method of putting two speakers to a stand. It is ugly, but still less ugly than using a separate stand for each speaker!

Are they just using a clamp to hold the speaker in the middle part of the stand? Not quite sure what hardware was used there.

I also came to the same conclusion re: coaxial speakers being attractive for this, however, most of the coaxial speakers I've found are either large(Kali IN-8) or expensive(Genelecs), and as much as I might like to, there's no way I'm using $2000US 8331as for height channels, lol.

Are there small coaxials that measure well and don't cost a fortune? If not, KH80s do seem pretty ideal.

E: Kef Q150?

 

[Rja4000]

My venerable Yamaha DM1000 mixer is multi-channel (surround) capable. You even have kind of a Joystick to position source...
Nowadays, you may find one second hand for almost nothing.

 

[ernestcarl]

Huh, I live in a rental so physically mounting speakers to the ceiling is out, and I like that method of putting two speakers to a stand. It is ugly, but still less ugly than using a separate stand for each speaker!

Are they just using a clamp to hold the speaker in the middle part of the stand? Not quite sure what hardware was used there.

I also came to the same conclusion re: coaxial speakers being attractive for this, however, most of the coaxial speakers I've found are either large(Kali IN-8) or expensive(Genelecs), and as much as I might like to, there's no way I'm using $2000US 8331as for height channels, lol.

Are there small coaxials that measure well and don't cost a fortune? If not, KH80s do seem pretty ideal.

E: Kef Q150?

The video wasn't particularly clear but it must be similar to item #4 (genelec stand/pole clamp) in the following list (check link below):

"ACTIVE" MCH SPEAKER IDEAS

In the list you'll also find the Fluid Audio FX50. Cheap and easily mountable active coaxial speaker (not yet available, though -- so no measurements yet -- coming from Fluid Audio, they're probably good. But of course, not on par with Genelec, Geithain and the like). I'm only a little bit concerned with the fragile tweeter horn.

There's a myriad of professional mounting attachments not just from Neumann, but also from Genelec, K&M etc. The trouble is finding every single part needed to fit one's exact requirements. It's almost like a puzzle finding the right combination...

At least these monitors are all ready to mount, unlike the insane number of KEF LS50s used here: KEF LS50 for Dolby Atmos Speakers

 

[krabapple]

Thank you for this thread.

A question please:

Is it fair to say that up mixing stereo CDs is unlikely to be worth the trouble if the source is studio bound pop music but more likely useful if using well recorded classical (most of my music is 70s pop which is rarely available in multi channel format).

No, it is not fair to say that.

I upmix everything that isn't mixed in surround . I own tons of 'studio bound' pop music on CD (i.e., pan-potted, recorded as overdubs over basic tracks). The upmix virtually *always* sound better than plain old stereo. Sometimes the synthetic surround effects are truly startling.

 

[krabapple]

Wilson's work is 75% remastering, 25% remixing. The reason his prof rock stuff sounds so good is that the master tapes, while by no means perfect, were good enough to be exploited by today's tech.

The Abbey Road remaster is OK, but it's FR is still constrained by what was on the master tapes... and my sense was that it was merely "good enough" for the era of Crossley turntables and transistor radios. So the potential for a modern remastering process to deliver the same kind of gains as Fragile, CTTE, etc. is much lower.

Abbey Road was recorded in 1969, on an 8-track deck at one of the premiere studios of its day; the tapes themselves have likely been conserved better than most prog rock multitracks. THe year 1969 was when the prog rock classic 'In The Court of the Crimson King' was also recorded, which has been remixed twice in surround, by Wilson. I would say whatever differences you hear in AR 5.1 are not due to its master tapes being merely 'good enough' (versus 'better') but more likely to choices made by the remix/mastering engineers involved in the surround mixes.

(To my extremely Yes-sensitive ears, Wilson made a disappointing job of Close to the Edge, an OK one with Fragile and Tales, a terrible botch of Relayer, and only hit a home run with The Yes Album. Eddy Offord's still the man.)

 

[Sancus]

The video wasn't particularly clear but it must be similar to item #4 (genelec stand/pole clamp) in the following list (check link below):

"ACTIVE" MCH SPEAKER IDEAS

Ahh, yeah, interesting stuff. So there are various clamps that will just go on a tube of certain diameter. Should be possible to figure out with some trial and error. That's an expensive clamp!

In the list you'll also find the Fluid Audio FX50. Cheap and easily mountable active coaxial speaker (not yet available, though -- so no measurements yet -- coming from Fluid Audio, they're probably good. But of course, not on par with Genelec, Geithain and the like). I'm only a little bit concerned with the fragile tweeter horn.

Interesting for sure. Measurements would help a lot. It's very reasonably priced. However, I took another look at the measurements of the KH80 and well... the vertical directivity is better than I thought. It seems "fine" out to 30 degrees. The Genelec 8331a, which are probably the "gold standard" for a coaxial are basically perfect out to 45 degrees in the horizontal and vertical. But that's at their price point, I don't have too much hope the FX50 can keep up.

It seems like KH80s on the heights would be perfect at the central listening position, and may be good enough for secondary listening positions, which of course do matter some(at least to me). It's probably worth testing both out, which should be doable(just do it 1 at a time, of course). The price difference between the two is significant, but not so much that I wouldn't want to pick the better performer.

At least these monitors are all ready to mount, unlike the insane number of KEF LS50s used here: KEF LS50 for Dolby Atmos Speakers

Haha. The LS50 is an okay speaker, especially at its current less than 50% of MSRP pricing, but it's a bit heavier and larger than I'd prefer for height mounting. The fact that it's not ready to mount properly definitely takes it completely off the table for me.

 

[ernestcarl]

Ahh, yeah, interesting stuff. So there are various clamps that will just go on a tube of certain diameter. Should be possible to figure out with some trial and error. That's an expensive clamp!



Interesting for sure. Measurements would help a lot. It's very reasonably priced. However, I took another look at the measurements of the KH80 and well... the vertical directivity is better than I thought. It seems "fine" out to 30 degrees. The Genelec 8331a, which are probably the "gold standard" for a coaxial are basically perfect out to 45 degrees in the horizontal and vertical. But that's at their price point, I don't have too much hope the FX50 can keep up.

It seems like KH80s on the heights would be perfect at the central listening position, and may be good enough for secondary listening positions, which of course do matter some(at least to me). It's probably worth testing both out, which should be doable(just do it 1 at a time, of course). The price difference between the two is significant, but not so much that I wouldn't want to pick the better performer.



Haha. The LS50 is an okay speaker, especially at its current less than 50% of MSRP pricing, but it's a bit heavier and larger than I'd prefer for height mounting. The fact that it's not ready to mount properly definitely takes it completely off the table for me.

Yeah, I was thinking KH80s for front heights. But the thing is, I already have LSR305 rears that work just fine. So I was thinking I may get the FX50s for rear heights instead. But that's just an idea yet to be realized.

Yeah, some of these branded attachment accessories can get pretty expensive. I know some people just buy stuff from cheaper 3rd party brands, or make their own attachments/brackets/stands themselves.

---

I've bought some new movies from the iTunes and Microsoft store as I wanted to test which of these streaming players support MCH (DD at least). I know Netflix already does. Movies from the Microsoft Store plays MCH fine, but it has to be streamed and not downloaded. In iTunes, it's just plain stereo -- not to mention their player is just soooo crappy and slow -- pure Garbage software experience made especially for Windows Users. They frequently have sales, though, so it's hard not to be tempted to buy content from them. *for purchsed Youtube content, you can only play stereo on a Windows PC. For Atmos support, you have to buy their hardware (e.g. Xbox & Apple TV 4k to an external home theater processor) to be able to play the format. Annoying as hell. I think I have content just about eveywhere. The fragmentation of my media is maddening.

In the end, honestly, I think I still prefer plain physical media and local media servers over streaming. I can often find super cheap (likely returned) BD discs from time to time -- and I can always borrow from the huge collection in our city library. At the moment, PowerDVD can't play Atmos and DTS:X (downmixed only), but in a year or two, it'll enevitably be supported. Otherwise, people would have no reason to buy their software. With PowerDVD, you only need an audio interface that can output eight channels or more. I believe one should be able to reroute side channels as a pair of heights (maybe... *we will have to see). **Actually, reading more about the hurdles that have to be overcome (software and hardware), this may take quite a long while longer than I originally anticipated.

The reason I'm interested in an exterenal home theater processor is because of all these streaming platforms making it difficult or impossible to play already available MCH & Atmos content natively in Windows. Moreover, some of these external streaming boxes don't even allow for conversion to PCM so one can use something like a miniDSP nanoAVR for room correction. At least most Blu-ray players can decode to PCM...

 

[krabapple]

Room treatment is to reduce, or at least change, the effect room boundaries have on the sound. IMO they are as important (or not) for multichannel as for stereo. Having additional sound sources arguably means more chance for room reflections to influence the sound for better or worse. E.g. now you have first reflections interacting from a multitude of speakers instead of two. Personally I favor letting the ambience in the mix shine through, since that is the benefit of multichannel, and minimize the impact my room has on it.

But, you'll probably get 11 opinions by asking 10 people.

The other perspective (which IIRC is Floyd Toole's) is that being surrounded by direct , on-axis sources tends to swamp reflected sounds, making them less of a factor than in two-channel systems.

 

[Kal Rubinson]

The other perspective (which IIRC is Floyd Toole's) is that being surrounded by direct , on-axis sources tends to swamp reflected sounds, making them less of a factor than in two-channel systems.

This has been my consistent observation since I started with multichannel. Of course, that does not mean that room treatment (and EQ) are not important.

 

[Sancus]

Yeah, some of these branded attachment accessories can get pretty expensive. I know some people just buy stuff from cheaper 3rd party brands, or make their own attachments/brackets/stands themselves.

So I think I figured out what you use to properly mount a KH80 to the top of a standard 1 3/8" speaker stand: KH80 + LH61(in your list) + LH28(goes on tube).

I haven't figured out what you use to clamp the lower speaker onto the pole. I don't think that Genelec truss clamp is right, it says it's for "a 50mm tube" and speaker stands are 35 or 38mm(1 3/8" and 1 1/2"). Maybe something like https://www.globaltruss.com/jr-snap-clamp ? Not sure how that connects to the speaker bracket or what size bolt you need...

Edit: I did end up finding something that would work. Powerwerks Standmate. This clamps a 1 3/8" pole to the middle of a stand, and you can put the rest of the hardware on that.

 

[JoachimStrobel]

Yeah, I was thinking KH80s for front heights. But the thing is, I already have LSR305 rears that work just fine. So I was thinking I may get the FX50s for rear heights instead. But that's just an idea yet to be realized.

Yeah, some of these branded attachment accessories can get pretty expensive. I know some people just buy stuff from cheaper 3rd party brands, or make their own attachments/brackets/stands themselves.

---

I've bought some new movies from the iTunes and Microsoft store as I wanted to test which of these streaming players support MCH (DD at least). I know Netflix already does. Movies from the Microsoft Store plays MCH fine, but it has to be streamed and not downloaded. In iTunes, it's just plain stereo -- not to mention their player is just soooo crappy and slow -- pure Garbage software experience made especially for Windows Users. They frequently have sales, though, so it's hard not to be tempted to buy content from them. *for purchsed Youtube content, you can only play stereo on a Windows PC. For Atmos support, you have to buy their hardware (e.g. Xbox & Apple TV 4k to an external home theater processor) to be able to play the format. Annoying as hell. I think I have content just about eveywhere. The fragmentation of my media is maddening.

View attachment 43612

In the end, honestly, I think I still prefer plain physical media and local media servers over streaming. I can often find super cheap (likely returned) BD discs from time to time -- and I can always borrow from the huge collection in our city library. At the moment, PowerDVD can't play Atmos and DTS:X (downmixed only), but in a year or two, it'll enevitably be supported. Otherwise, people would have no reason to buy their software. With PowerDVD, you only need an audio interface that can output eight channels or more. I believe one should be able to reroute side channels as a pair of heights (maybe... *we will have to see). **Actually, reading more about the hurdles that have to be overcome (software and hardware), this may take quite a long while longer than I originally anticipated.

The reason I'm interested in an exterenal home theater processor is because of all these streaming platforms making it difficult or impossible to play already available MCH & Atmos content natively in Windows. Moreover, some of these external streaming boxes don't even allow for conversion to PCM so one can use something like a miniDSP nanoAVR for room correction. At least most Blu-ray players can decode to PCM...

I see the same problem with MCh delivery. It seems to be caused by a convolute of copy protection and digital interface. Hdmi has audio embedded in the videostream which is encoded, and only 2channel can be de-embedded lossless. Powerdvd will not yield Mch digital out to anything but some rare pro equipment that they forgot about. MiniDSP seals their I2S Pins so nobody can access them easily. Only the Raspberry has open I2S headers that could offer a solution. But then their HDMI output is crap and it is either I2S Mch, meaning deep DIY, or nothing. The Mch music industry is bound not to repeat the RedBook (no DRM) mistake. A serious I2S attempt by a small company might help.

 

[Kal Rubinson]

Hdmi has audio embedded in the videostream which is encoded, and only 2channel can be de-embedded lossless.

HDMI, since v1.2, can support multichannel lossless DSD in addition to lossless multichannel PCM.

 

[JoachimStrobel]

HDMI, since v1.2, can support multichannel lossless DSD in addition to lossless multichannel PCM.

Kal, sure. but this is then encrypted and I know if no legal way to access this PCM stream without propper DHCP de-encoding. I only see De-embedder that can either extract the 2 channel as SPDIF or re-encode 5.1 to AC3.

 

[Kal Rubinson]

Kal, sure. but this is then encrypted and I know if no legal way to access this PCM stream without propper DHCP de-encoding. I only see De-embedder that can either extract the 2 channel as SPDIF or re-encode 5.1 to AC3.

My response was off-hand. I have not been following your issue but, it seems to me, that depends on what is doing the extracting/re-encoding. I have been extracting multichannel PCM up to 24/96 (24/192?) for a while now and re-encoding it into FLAC files but that's not via HDMI. For that, I just play them. What am I missing?

 

[JoachimStrobel]

My response was off-hand. I have not been following your issue but, it seems to me, that depends on what is doing the extracting/re-encoding. I have been extracting multichannel PCM up to 24/96 (24/192?) for a while now and re-encoding it into FLAC files but that's not via HDMI. For that, I just play them. What am I missing?

I think we are missing a proper way to transport Mch through a cable. Hdmi fore sure does not cut it. Audio is embedded in between the video stream. This increases jitter, but even worse, there can be no audio without a video. That alone renders HDMI useless for audio. I have little experience with Mch via USB, but believe that no encrypted DVD or Blu-ray will yield its Mch content to USB. There seems to exist some Mch USB interfaces where Powerdvd yields Mch to. I once had such thing from Maudio which worked under Powerdvd and WinXP, but then they got cold feet and dropped support. I am not sure about HDMI to USB converters with DHCP. There are some HDMI to SDI converters that drop DHCP arguing its for Pro cabling only, but once that becomes too public it will go too. We have no Mch Spdif or a working I2S standard. Things may be different for ripped SACDs or else, but those feed no musicians.