Stereo up-mixing into multi channel

[ziv1]

Hello friends,

I'm new in here.
I signed up because I'm interested in purchasing Emotiva XMC-1.


I plan to run songs from files, by using computer or Streamer or any other means.
Probably most of the songs will be in two-channel format and I wanted to know whether Dirac and Emotiva knows how to synchronize stereo information into multi-channel speakers.


More specifically:

1. Does the XMC-1 knows how to correct phase difference between speakers?

2. Does XMC-1 correct distance differences between speakers and the main listening position?
Can it calculate mutual compensation between two speakers transmitting the same information?
Does XCM-1 knows hows how to measure, calculate and compensate mutual interference between speakers, which transmits the same information?

I saw that Dirac doing some alignments at the time domain.
Does it coordinate each speaker relative to the other speakers?

3. what is it the "All Stereo Mode" in XMC-1?
Does it makes up-mixing from stereo to few channels for each side of the stereo information?

4. Does XCM1 knows how to make Short Pass Filter for the speakers and Long Pass Filter for Sub/Subs?
Does it allows to choose the slop of these filters?

5. How does the XMC-1's bass management compared to ddrc-88bm?


Thanks in advance for any help or advise!
Ziv

[KeithL]

1, 2 -
Phase and time are different aspects of the same thing.
The basic distance setting on all home theater pre/pros corrects for differences in arrival times between multiple speakers.
Dirac Live corrects for more specific anomalies caused by interactions between the speakers and the room (including frequency response and phase).
Each speaker is calibrated "individually and absolutely" (once each is properly adjusted individually, you shouldn't have to worry about interactions between them).

3 -
All Stereo just duplicates the same signal to all left speakers and all right speakers.
To "upmix" stereo into synthesized surround sound you would use Dolby Pro Logic II or DTS ES Matrix (the XMC-1 has both of those).

4 -
The bass management in the XMC-1 has separate high-pass filters for each set of channels.... and you can set different frequencies for each (you cannot set the slope).
You can set the low-pass slope on the sub to either 12 / 24 dB/octave.

5 -
The ddrc-88bm offers a lot more options - and a lot more detailed control - especially if you're using more than two subs.
(Of course it's a separate $1000 black box that ONLY does Dirac room correction and bass management.)

Note that, if you use the ddrc-88bm, your audio signal is subjected to two more conversions; A/D going in; and D/A coming out - in addition to the DACs in your pre/pro/
Of course, there is also the question of whether you have use for, or would benefit from, the extra options.

Oct 30, 2017 11:41:15 GMT -5 ziv1 said:

Hello friends,

I'm new in here.
I signed up because I'm interested in purchasing Emotiva XMC-1.


I plan to run songs from files, by using computer or Streamer or any other means.
Probably most of the songs will be in two-channel format and I wanted to know whether Dirac and Emotiva knows how to synchronize stereo information into multi-channel speakers.


More specifically:

1. Does the XMC-1 knows how to correct phase difference between speakers?

2. Does XMC-1 correct distance differences between speakers and the main listening position?
Can it calculate mutual compensation between two speakers transmitting the same information?
Does XCM-1 knows hows how to measure, calculate and compensate mutual interference between speakers, which transmits the same information?

I saw that Dirac doing some alignments at the time domain.
Does it coordinate each speaker relative to the other speakers?

3. what is it the "All Stereo Mode" in XMC-1?
Does it makes up-mixing from stereo to few channels for each side of the stereo information?

4. Does XCM1 knows how to make Short Pass Filter for the speakers and Long Pass Filter for Sub/Subs?
Does it allows to choose the slop of these filters?

5. How does the XMC-1's bass management compared to ddrc-88bm?


Thanks in advance for any help or advise!
Ziv

[ziv1]

Oct 30, 2017 13:30:12 GMT -5 KeithL said:

1, 2 -
Phase and time are different aspects of the same thing.
The basic distance setting on all home theater pre/pros corrects for differences in arrival times between multiple speakers.
Dirac Live corrects for more specific anomalies caused by interactions between the speakers and the room (including frequency response and phase).
Each speaker is calibrated "individually and absolutely" (once each is properly adjusted individually, you shouldn't have to worry about interactions between them).

3 -
All Stereo just duplicates the same signal to all left speakers and all right speakers.
To "upmix" stereo into synthesized surround sound you would use Dolby Pro Logic II or DTS ES Matrix (the XMC-1 has both of those).

4 -
The bass management in the XMC-1 has separate high-pass filters for each set of channels.... and you can set different frequencies for each (you cannot set the slope).
You can set the low-pass slope on the sub to either 12 / 24 dB/octave.

5 -
The ddrc-88bm offers a lot more options - and a lot more detailed control - especially if you're using more than two subs.
(Of course it's a separate $1000 black box that ONLY does Dirac room correction and bass management.)

Note that, if you use the ddrc-88bm, your audio signal is subjected to two more conversions; A/D going in; and D/A coming out - in addition to the DACs in your pre/pro/
Of course, there is also the question of whether you have use for, or would benefit from, the extra options.

Hello Keith,

Thanks for the quick reply!

1. Sound waves are doing interference.
Therefor, due to interference, I can't really understand how separate channels calibration can give the same results as simultansly calibration.

3- It seems that the feature "All Stereo Mode" in XMC-1, was designed to address the topic of this thread.

Does the "Dolby Pro Logic II or DTS ES Matrix" are enabled in old versions of the XMC-1?
If I purchas a second hand XMC-1, how can I know if it contains these formats/features?
*I am thinking to purchase old one because I don't need any new video format.

5- I am not goint to use three or more subs.
Do you familiar with other extra features that the DDRC-88-A/BM contains? 
Does the accuracy at the lower end of the spectrum is the same as the XMC-1?

*I have an old version of JL-F112 sub, and I am counting on Dirac to do the low frequencies calibration.
BTW, Thanks for your comment regarding the long way that the signal is going through, while using DDRC-99-A/BM

6. What is the output power in each XMC-1's channels, if I am using them all?

*I use two pairs of scansonic MB1, which is 6 Ohms and around +-86db sensitivity.
Should I add a power amplifier to the XMC-1, if I use such speakers?


Thanks,

Ziv

[bootman]

Minidsp would be your best source for info about any DDRC products and their capabilities.

[audiophill]

No output power on the xmc-1 per channel. It's a pre amp not a receiver. You need a multi channel amplifier.

[ziv1]

Oct 30, 2017 18:42:45 GMT -5 audiophill said:

No output power on the xmc-1 per channel. It's a pre amp not a receiver. You need a multi channel amplifier.

Thanks! I did not know that.
Do you have any recommendation regarding multi channel amplifier.?

Oct 30, 2017 17:31:37 GMT -5 bootman said:

Minidsp would be your best source for info about any DDRC products and their capabilities.

Makes sense

[bootman]

Oct 31, 2017 7:09:04 GMT -5 ziv1 said:

Oct 30, 2017 18:42:45 GMT -5 audiophill said:

No output power on the xmc-1 per channel. It's a pre amp not a receiver. You need a multi channel amplifier.

Thanks! I did not know that.
Do you have any recommendation regarding multi channel amplifier.?

Might as well look at the Emotiva offerings while you are here.
Just click on the link at the top of the page.

Oct 30, 2017 17:31:37 GMT -5 bootman said:

Minidsp would be your best source for info about any DDRC products and their capabilities.

My first thought was "This is like going to a Lexus dealer and then asking about a Nissan. Not sure what the response will be..."

[KeithL]

1 -
The short answer is that room correction does its best to correct for a wide variety of anomalies - and over a range of listening positions.
If you have a 5.1 system, each speaker can interact with five other speakers, which works out to something like 720 different combinations of ways in which they can interact - at each frequency.
And all of those corrections will technically only be right at one singe listening position.
Therefore ALL room correction is a series of compromises.
At bass frequencies, which have very long wavelengths, we assume that the outputs of the speakers will add more or less directly.
So, if you have two subs, and each is individually "in proper phase", then their outputs should add algebraically.
(They would only have a serious cancellation if they were NOT properly in phase.)
At higher frequencies, we can calibrate the output of each speaker, and how it interacts with the room in general, but we really cannot calibrate interactions between speakers.
The wavelength of sound at 10 kHz is about one inch.
So, if two speakers add when your head is at a certain position, they will cancel if you move your head 1/2 inch either way..... trying to compensate for the response at one of those positions is a losing battle.
Therefore, we assume that "the total energy released into the room at that frequency adds together" and ignore the tiny detailed cancellations and interactions.
In short, it simply isn't possible to effectively perform a multi-speaker calibration except under very limited circumstances (and nobody is really doing it).
When you get up into multiple subs, there are multiple solutions that produce a variety of similar but different compromise results - which is why there are so many different ways of "calibrating" multiple subs.

3 -
Errrrrr..... not really.
You get the best sound quality from a STEREO input signal if you pay it from two stereo speakers (some people would argue that a center channel can be worthwhile in some rooms).
The All Stereo feature was added for people "who are playing something in stereo but want sound coming from all of their speakers" (some manufacturers call it "party mode".
You can install the current XMC-1 firmware on any XMC-1 ever made - and it supports Dolby ProLogic II (and also DTS:Neo6 - which is the latest DTS matrix mode).
Something like ProLogic is generally preferred over All Stereo because, rather than just copy the two channels to all the other speakers, it actually synthesizes surround sound (each speaks is playing something different).

5 -
We license the Dirac software, so I don't have all the details about what specific calculations it performs.
I can tell you that it does indeed calibrate each channel, including each sub, separately (and the XMC-1 supports two subs).
In terms of additional features....
- the DDRC-99-A/BM can store and choose between four separate Dirac filters; the XMC-1 is designed to hold a single Dirac filter.
- the DDRC-99-A/BM seems to have some additional options in terms of being used as an active crossover
However, as far as the basic Dirac Live room correction capabilities, I don't see any significant differences.
(I assume that the corrections they perform, and the math they use to calculate them, are the same. As far as we know, the same Dirac software was "ported" to the miniDSP and the XMC-1.)

 6 -
You will need a power amp..... and we recommend our XPA-5 Gen3 or our BasX 5175.

Oct 30, 2017 16:03:40 GMT -5 ziv1 said:

Oct 30, 2017 13:30:12 GMT -5 KeithL said:

Hello Keith,

Thanks for the quick reply!

1. Sound waves are doing interference.
Therefor, due to interference, I can't really understand how separate channels calibration can give the same results as simultansly calibration.

3- It seems that the feature "All Stereo Mode" in XMC-1, was designed to address the topic of this thread.

Does the "Dolby Pro Logic II or DTS ES Matrix" are enabled in old versions of the XMC-1?
If I purchas a second hand XMC-1, how can I know if it contains these formats/features?
*I am thinking to purchase old one because I don't need any new video format.

5- I am not goint to use three or more subs.
Do you familiar with other extra features that the DDRC-88-A/BM contains? 
Does the accuracy at the lower end of the spectrum is the same as the XMC-1?

*I have an old version of JL-F112 sub, and I am counting on Dirac to do the low frequencies calibration.
BTW, Thanks for your comment regarding the long way that the signal is going through, while using DDRC-99-A/BM

6. What is the output power in each XMC-1's channels, if I am using them all?

*I use two pairs of scansonic MB1, which is 6 Ohms and around +-86db sensitivity.
Should I add a power amplifier to the XMC-1, if I use such speakers?


Thanks,

Ziv

[cwt]

Oct 30, 2017 16:03:40 GMT -5 ziv1 said:

Does the "Dolby Pro Logic II or DTS ES Matrix" are enabled in old versions of the XMC-1?
If I purchas a second hand XMC-1, how can I know if it contains these formats/features?
*I am thinking to purchase old one because I don't need any new video format.

6. What is the output power in each XMC-1's channels, if I am using them all?

Those dsp modes are current in all present and past XMC1's Ziv . To utilise those dsp modes[ pl2x and dts es matrix ] you need specifically a 7ch power amp as well to power some back surrounds as well as the other 5