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[AGAWA]

Can you look at the following:
I'm using JRSS Mixing;
Have 4 speakers, therefore I downmix with JRSS form 5.1 to 4.0.
Just measured levels (using  internal calibration test). Fantom Center is produced at +3 dB.

Center signal level should be lowered to 0,707 before injection to FL and FR, thus creating 0 dB Fantom Center.

My suspicion is that it is not lowered.

[AGAWA]

to be clear, I'm asking for verification of JRSS mixing algorithm;
my suspicion is that Center voltage level is not multiplied by 0.707 before injection to FL and FR.

+3dB is a result of mixing 100% of Center voltage into FL and FR

[Matt]

I'm looking, but the code looks right to me:

// mix center into main sides
m_aryMix[0][2] += HALF_POWER_MULTIPLIER;
m_aryMix[1][2] += HALF_POWER_MULTIPLIER;

// factor in the center volume
m_aryMix[0][2] *= CDecibels::GetMultiplierFromDecibels(nCenterLevel);
m_aryMix[1][2] *= CDecibels::GetMultiplierFromDecibels(nCenterLevel);

Could the way you're measuring be at fault?  Or some other explanation?

Thanks.

[AGAWA]

Tools -> Advanced -> Audio Calibration
There is 5.1 test

I'm using Radio Shack digital meter, set to 70 dB range;

Close to my head in my regular listening position; and FL and FR are 3 dB below Fantom Center
It should read about the same, +/- 1 dB.

Straightforward measurement

(equations: L'=L+0.707*C,R'=R+0.707*C,LS'=LS,RS'=LS.)

cheers

[Matt]

I'm testing the 5.1 volume calibration clips outputting as 4.0.

My volume in DSP Studio > Analyzer is about -35.0 dB when playing the center.  It's about -35.0 dB when I play the left or right as well.

So that seems like it's working.

[mwillems]

Maybe an obvious question but worth ruling out a configuration issue: In the output format block of DSP Studio, have you checked that you have the "Center:" entry set to 0dB and not +3dB (it used to be a checkbox, but now it's a drop down menu)?

Sorry for the obvious question, but I once was briefly perplexed that my phantom center was measuring 3dB high and then noticed that setting.

[AGAWA]

to be precise, measurements and trial on:
MC ver 24 for Mac

[Matt]

Please make sure you're running the latest MC.

[AGAWA]

I would like to, but get no help from JRiver.

I installed MC27 latest on Mac , did several parameters changes and did not know how to reset everything back to initial state. Similarly to Windows install I removed totally MC from Mac, and that was it.
After reinstall I was given option of extending trial by 45 days, received code and nothing. This does not work in Mac OS.

Eventually I found MC 24 installed and hence my test on  MC 24.

In my another topic I learned that I will get no help , asked for resetting my counter so I could test MC 27. No help so far.

Now, I wonder if Center problem has been corrected from MC 24 or is present all the way through.

If I can get help from you to test everything  in MC 27 then we can investigate together.

But my feeling is that Center in the mix problem has been thare all the time.

[AGAWA]

to your obvious question:
I was searching for this entry  in DSP on MAC MC24 but it is not there.
Now checked under Windows in MC27 and  it is there.

And I knew I saw it in Windows install.

Can you tell me if MC24 did not have this entry and it was added later?

Windows PC is stationary and I will not move it to test NC27. Moreover , I will use Mac with Apogee Duet, Windows is far behind Mac OS in this regard,

Hope that setting Center at 0 dB will solve the problem.
 But I need to see the window to do that.

[AGAWA]

can you confirm that MC27 Mac has the same window to set level of Center as MC27 Windows ver?
thanks