XMC-1 All Stereo Mode - What the heck is it doing?

[bluescale]

I've been trying to figure out how the XMC-1's All Stereo mode works, and it's left me scratching my head. Here's what the manual states:

All Stereo Mode
All Stereo Mode provides a full complement of processing and control options - with a stereo
output. In addition, the left signal is routed to all left side speakers and the right signal is routed to
all right side speakers for a “room filling” experience. In All Stereo Mode:
• The output is always TWO CHANNEL STEREO - routed to all speakers.
The left channel is routed to all left side speakers; the right channel to all right side speakers.
• Bass management IS available and the subwoofer IS active.
• Loudness Control, the Tone Controls, and the Tone Trims are active.
• Dirac Live and the manual parametric EQ Presets are active.
• Level Trims are active.
• Speaker Distance adjustments are available for both analog and digital inputs.
• Stereo analog signals are converted to digital audio and routed through the processor.
Stereo digital input signals are routed through the processor.
Surround sound digital signals are decoded, mixed down to stereo, and converted to analog
(the Center Channel and LFE signals, if present, are mixed into the stereo output).
• After all processing is completed, the left signal is routed to ALL left side speakers and the
right signal is routed to ALL right side speakers.
• If an LFE signal is present, and one or two subwoofers are also present, the LFE content will be
routed to the subs along with low-frequency content from the main channels (as determined
by the bass management settings).

If I'm reading that correctly, it should convert everything to a pure 2.0 signal, and then copy the right side information to all right side speakers, and the left side information to all left side speakers. The sub will get all the usua bass management goodies, and the center gets a little bit of everything. If you've been following the unofficial bug list, you'll know I've been poking at this a bit to see if I can figure out what going on. At this point, I'm simply perplexed. It was pointed out to me over on AVS that to understand what All Stereo is doing, I can't simply measure the Front Left speaker and the Sub, and understand its behavior. I need to see how each channel reacts when a signal is sent from the source to a front speaker, the center speaker and a rear speaker. With that in mind, using REW, I did the following:

• Sent a PCM signal over HDMI 1 (the left front channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them
• Sent a PCM signal over HDMI 3 (the center channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them
• Sent a PCM signal over HDMI 6 (the right surround channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them

The results were very strange. Before posting graphs, here are some observations:

• In general, the rear channels are were louder than the front channels.
• When sending the signal over HDMI 3 (center), L/R/C all behave similarly. LS is about 3-4dB hotter. RS is a whopping 13dB hotter. I re-ran this test a number of times because the numbers are just plain weird, but it always came out the same.
• The subwoofer level and curve is different depending on which channel your sending the signal to, which doesn't make sense. Keep in mind, this is not LFE data, but redirected bass from other channels. Regardless, the subwoofer is always hotter than the other channels.
• Of channels that received a signal, the center was always the quietest (although it was but a minuscule amount when the signal was sent to HDMI 3)

Despite how the mode description makes it sound, my guess is that All Stereo is made with the supposition that there will be no discrete data going to the rear channels, and therefore boosts the signal there more than it does to the L+R. Additionally, since the center gets data sent to it from all channels, it's always a little bit lower than the others. The sub level I'm not sure about. It's almost as if All Stereo doesn't know how to behave if it gets a non-stereo signal, so it goes a bit nuts.

Anyway, here are the testing results:

Signal sent over HDMI 1 (Left Channel):


Signal sent over HDMI 3 (Center Channel):


Signal sent over HDMI 6 (Rear Surround Channel):


The three different sub signals (note, they are all the same color, since I color coded by channel - this is posted just to show the difference):


All measurements were done with the speakers set to small, crossed over at 80Hz. all distance, EQ and Level settings were zeroed out.

So, can anyone make heads or tails of what's going on? Is this just one of those throw-away modes no one should use? Is it a mode that's supposed to be a simply copy that's gone awry (and needs to be fixed)? Am I missing the big picture?

[bootman]

Excellent detective work.
You sir are now the official gamma tester.

[bolle]

Great work!

Looks like this needs some serious fixing...

[frenchyfranky]

Thanks Bluescale, you put on graphics with measurements what I previously reported. I really appreciated your works.

[moovtune]

To answer one of your questions - for me, All-Stereo has always been a mode that's a "throw-away mode that no one should use". And not just on the XMC-1, but any processor. But that's just my feeling about it ... along with Jazz Club modes and Stadium modes etc.

[KeithL]

1) I'm one of those people who never uses All Stereo.

2) However, it IS supposed to work like it says in the manual, so I've passed this along to engineering to look into.

3) We have run into a few really weird problems on the XMC-1 that were fixed by simply doing a Factory Reset, so you might want to try that.
(Remember that on the XMC-1 you can save your configuration before doing the Factory Reset and then restore it afterwards )

[cwt]

Was generally referred to as the ''party mode'' when everyone hears the music ; the cary 11a has a particularly high db count with it

[bluescale]

Sept 3, 2014 13:35:42 GMT -5 KeithL said:

2) However, it IS supposed to work like it says in the manual, so I've passed this along to engineering to look into.

Thanks for taking a look at this so quickly! There was some speculation at AVS (where some people have a really skewed perception of Emotiva) that you guys would refuse to even consider this as an issue. bootman and I were hopeful that you would either look into it if it looked like an issue, or explain what's going on. I look forward to hearing Engineering thoughts. Also, if my testing is flawed, please let me know. I'm happy to admit a mistake and try again .

Sept 3, 2014 13:35:42 GMT -5 KeithL said:

3) We have run into a few really weird problems on the XMC-1 that were fixed by simply doing a Factory Reset, so you might want to try that.
(Remember that on the XMC-1 you can save your configuration before doing the Factory Reset and then restore it afterwards )

Good point! I'll give that a try.

[tknice]

Sept 3, 2014 12:43:46 GMT -5 moovtune said:

To answer one of your questions - for me, All-Stereo has always been a mode that's a "throw-away mode that no one should use". And not just on the XMC-1, but any processor. But that's just my feeling about it ... along with Jazz Club modes and Stadium modes etc.

You know when it's good is for stuff like sports so that everyone can hear the commentary well. When we get a roomfull of people watching football, the chatter gets loud in there and it can be hard for some people to hear the annoucers and refs.

All-Stereo is great for this.

[moovtune]

That sounds reasonable. I can see it would work well in that situation.

[frenchyfranky]

Sept 3, 2014 13:35:42 GMT -5 KeithL said:

1) I'm one of those people who never uses All Stereo.

2) However, it IS supposed to work like it says in the manual, so I've passed this along to engineering to look into.

3) We have run into a few really weird problems on the XMC-1 that were fixed by simply doing a Factory Reset, so you might want to try that.
(Remember that on the XMC-1 you can save your configuration before doing the Factory Reset and then restore it afterwards )

I had tried the factory reset and nothing has changed after this.

[bluescale]

Sept 3, 2014 15:28:30 GMT -5 tknice said:

You know when it's good is for stuff like sports so that everyone can hear the commentary well. When we get a roomfull of people watching football, the chatter gets loud in there and it can be hard for some people to hear the annoucers and refs.

All-Stereo is great for this.

Most people I know that use such modes have multiple rows, and are listening to something non-critical (like a game).

[LCSeminole]

I'll admit I used to use the All Stereo type of listening mode for casual background music, but with the XMC-1 I've found my preferred listening mode for multi-channel music from a 2 channel source that I've become partial to DTS NEO:6 Music.

[aud]

This is where I'm going to miss my old Anthem AVM20. Their Anthem Music Logic was tremendous for multi channel music from a stereo source.

I have a confession to make:
The All Stereo Mode was a true stereo copy to the Surrounds and the Rears with the Anthem. I would trim them down to blend with the Fronts. I was always amazed at how good it would sound. On some recordings the soundstage would be wide open, but the good imaging would still be there.

[bluescale]

Sept 3, 2014 17:55:12 GMT -5 aud said:

The All Stereo Mode was a true stereo copy to the Surrounds and the Rears with the Anthem.

It sounds like this is the goal for the XMC-1 as well. Hopefully Emotiva can deliver the experience you're looking for.

[Gary Cook]

•Sent a PCM signal over HDMI 1 (the left front channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them
•Sent a PCM signal over HDMI 3 (the center channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them
•Sent a PCM signal over HDMI 6 (the right surround channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them

I'm not sure of the above methodology, did you not have the ability to send a discrete signal for each channel via the same HDMI connection?


Cheers
Gary

[kurthaudio]

Sept 3, 2014 20:26:41 GMT -5 Gary Cook said:

•Sent a PCM signal over HDMI 1 (the left front channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them
•Sent a PCM signal over HDMI 3 (the center channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them
•Sent a PCM signal over HDMI 6 (the right surround channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them

I'm not sure of the above methodology, did you not have the ability to send a discrete signal for each channel via the same HDMI connection?


Cheers
Gary

I'm with Gary here. Why use different HDMI inputs? I might be completely misunderstanding what it is you are doing. Why can't and or wouldn't you send your signals to individual speakers via the same input?

[bluescale]

Sept 3, 2014 20:26:41 GMT -5 Gary Cook said:

•Sent a PCM signal over HDMI 1 (the left front channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them
•Sent a PCM signal over HDMI 3 (the center channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them
•Sent a PCM signal over HDMI 6 (the right surround channel), and measured each of the 5.1 channels to see what signal the XMC-1 sent them

I'm not sure of the above methodology, did you not have the ability to send a discrete signal for each channel via the same HDMI connection?

Sorry that wasn't clear, Gary. I've been living in REW recently, and sometimes assume people are used to seeing what I'm seeing. When I say HDMI 3, I don't mean input 3 on the XMC-1. This is just how ASIO displays the discrete signal being sent to each channel over a signal HDMI cable. If you take a look at this article on the MiniDSP site, it breaks down the channels under the section for Test and Measure:

www.minidsp.com/applications/acoustic-measurements/umik-1-hdmi-on-windows

[Gary Cook]

Sept 3, 2014 20:52:14 GMT -5 bluescale said:

Sept 3, 2014 20:26:41 GMT -5 Gary Cook said:

I'm not sure of the above methodology, did you not have the ability to send a discrete signal for each channel via the same HDMI connection?

Sorry that wasn't clear, Gary. I've been living in REW recently, and sometimes assume people are used to seeing what I'm seeing. When I say HDMI 3, I don't mean input 3 on the XMC-1. This is just how ASIO displays the discrete signal being sent to each channel over a signal HDMI cable. If you take a look at this article on the MiniDSP site, it breaks down the channels under the section for Test and Measure:
www.minidsp.com/applications/acoustic-measurements/umik-1-hdmi-on-windows

OK, got it, that's what I thought you would be doing but I didn't read it that way.

Cheers
Gary

[springwright]

I've run into the "All Stereo Mode" volume issues as well (with HDMI and with optical). The factory reset doesn't seem to clear things up for me either. There's definitely something amiss here. Can you address this Keith?