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Author Topic: JRSS upmixing problem (from the v17 board)  (Read 1431 times)

Mikkel

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JRSS upmixing problem (from the v17 board)
« on: March 03, 2013, 04:09:07 pm »

(I wrote the following at the v17 board before I realised it wasn't the v18 board. Original thread: http://yabb.jriver.com/interact/index.php?topic=69060.0)


Hi Matt,

I take the liberty to bump this thread again to try and persuade you to change the jriver upmixing method. As hulkss states, regular stereo ofte has/creates a phantom center, which is problematic sound quality wise due to the influence of 1st order reflections from both front speakers. With discrete center channels only the 1st order reflections of that single speaker is involved in influencing the sound at the listening position.

Now, when retaining the full original left/right channel output it is practically the same as before only doubled (I think): now you have a phantom images between both left and center as well as center and right, which means a whole lot more reflections causing colouration etc. of the sound image - which as a counter productive byproduct also narrows down the size of the optimum listening spot to preserve the localization of sound.

This clearly cannot be an audible improvement, hence I hope you will reconsider the current method.

My inspiration for posting this was reading page 121 in:
Toole, F. E. (2008). Sound Reproduction. Loudspears and Rooms. Focal Press: Oxford.

Feel free to direct my attention to any misunderstandings of above. I shall gladly stand corrected if I in any way misinterpreted Toole's findings.

I do follow the argument on the quality of the front left/right speakers but acoustically in the interaction with and dependence of the listening room phantom images are just not ideal and since the center speaker was invented to releive the listening environment from this problem I think it should be used as such.

I hope you take my arguments constructively since it was certainly not my intention to criticize unproductively. JRiver is by far the best media center I know sonically.

[EDIT] I originally wrote (and later deleted) that because I (and others) often routes bass content to the subwoofer the similarity between all front speakers is very precise. What I should probably add is that major differences are probably only present if using full-range left/right speakers and a "regular" center speaker. With bookshelf speakers (or smaller) there is (my guess is) no difference at all. Normally, center speakers are very well designed because it delivers a very high percentage of the audio content compared to the other speakers. In my setup (a Swedish brand called "Audio Pro") undoubtedly the center speaker is the absolute best speaker in the setup.

If you do not want to modify the jrss upmixing, would you perhaps consider to make it optional whether the front left/right speakers should maintain their full, original signal?

Once again, JRiver is *the* best audio/videophile media center, and the support and interest in user's ideas is in a league of its own. So above is by no mean ment in disrespect, only as constructive criticism.


Best regards,
Mikkel
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JimH

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Re: JRSS upmixing problem (from the v17 board)
« Reply #1 on: March 03, 2013, 04:15:39 pm »

Matt is on vacation for a few days.
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Mikkel

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Re: JRSS upmixing problem (from the v17 board)
« Reply #2 on: March 04, 2013, 04:08:12 am »

Matt is on vacation for a few days.

Alright, thanks for the heads up. Hope he enjoys his vacation  :). I'll bump this one again in a few days, then.


Best regards,
Mikkel
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Mikkel

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Re: JRSS upmixing problem (from the v17 board)
« Reply #3 on: March 07, 2013, 01:45:40 am »

I noticed Matt is back from vacation, so *bump* (again)  ;D
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Matt

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Re: JRSS upmixing problem (from the v17 board)
« Reply #4 on: March 07, 2013, 09:22:02 am »

I think someday we may make a toolbox to offer more control over JRSS mixing.
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Matt Ashland, JRiver Media Center

Mikkel

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Re: JRSS upmixing problem (from the v17 board)
« Reply #5 on: March 07, 2013, 02:29:23 pm »

I think someday we may make a toolbox to offer more control over JRSS mixing.

Sounds great :)
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6233638

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Re: JRSS upmixing problem (from the v17 board)
« Reply #6 on: March 07, 2013, 03:36:44 pm »

That would be great - I'd love to have controls over the downmixing matrix. (I want to include LFE)
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Matt

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Re: JRSS upmixing problem (from the v17 board)
« Reply #7 on: March 07, 2013, 03:40:29 pm »

I want to include LFE

Maybe I'm not understanding, but downmixing does include the LFE.  It uses the correct levels as you would hear on a calibrated system.
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Matt Ashland, JRiver Media Center
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