Can a center channel improve stereo music?

[theREALdotnet]

Yes, DSU and DTS upmixing both do a good job of extracting phantom center. The result is significantly clearer center vocals.

Why would they be clearer? Where is the extra information coming from?

 

[Jon AA]

OK, I understand but you must admit that is a specialist example. How many stereo recordings rely on psychoacoustic tricks that upmixing will uncover?

Tons (maybe most?) of them. Any recording of a live performance (or one meant to sound like one) will have tons of decorrelated content in it. And the same quality difference between hearing that from two speakers or from multiple speakers around the room displayed by the above examples applies to all of it--as can be heard when you switch back and forth from stereo to an upmixer that plays those sounds from real speakers in the room.

Even studio recordings that aren't meant to sound like live performances, in all but the very most dry ones, will have added reverb and ambiance (fake, but can be done well) and even just that will sound better with upmixers (in my opinion). But naturally, the more decorrelated information there is in the recording, the larger the improvement.

Besides, if you are mixing the stereo track specifically for upmixing, why not master in multi-channel in the first place?

For the most part, they do. Many artists for decades have released multi-channel DVD or SACD versions of their albums that are quite different from their stereo "radio mixes." Nobody is actually going to mix an instrument that's behind the audience--such that you'd want to hear quality direct sound--into the stereo mix that way knowing most will be listening on only two speakers. The quality is just too poor. Even the purists at 2L generally don't generally do that. In many of their albums/tracks when there's an instrument behind the audience, it will be behind the audience in the multi-channel and immersive tracks, but for the stereo mix they put it in front. It sounds much better on two speakers that way, but the soundstage is complete fiction--those with only two speakers will be missing out on how the performance really sounded.

Anyway, back to center channels....

So in conclusion: I will stick to stereo unless a center channel with an upmixer can significantly improve the sound and get rid of those HRTF cancellations.

Honestly, I would not get a center to get rid of the HRTF 2K dip. That's how stereo sounds, it always has and it always will, and we are used to it. It's fine--for one listener. It's the last caveat that I think is much more important. If you listen alone, you won't miss a center channel. The biggest reason for it still remains providing a better experience for multiple listeners. Even with only two people sitting side by side, the center will be a big improvement--with a single listener, not so much. Especially if you'll have difficulty fitting a really capable, quality speaker in the center (a common problem).

I have spent several months per year the last couple of years without a center (a fireplace thing.... ). I don't miss it at all. But the sound for my wife sucks. Luckily she doesn't really notice or care. But I couldn't stand sitting in her seat without the center installed.

 

[gnarly]

You could do it with software (Acourate, etc...) But I have always hated the thought of a Windows PC being the "heart" of the system. Q-Sys is way more elegant. Shame they are killing off their traditional I/O options and essentially forcing the consumer to buy networked amps or their under-performing I

yep. I've looked at Acourate, Audiolense, etc....but all the software that aims for the home-audio market, misses the mark imo, being overly complicated, often chasing immaterial levels of perfection, and becoming error prone.
Plus. like you I just can't trust my system control to a PC. I don't care how much faith i have in my limiter settings.

Tis truly a shame QSC has discontinued the card based I/O. That said, it has created some opportunities in the used marketplace.
I just nabbed my 2nd Core510i off ebay, full of I/O cards, Dante included, for about $1300. Crazy the deals that can be had with diligent shopping...
What kind of DIY nut needs two Core 510s ? haha

Of course. Total pipeline latency needs to be kept at a minimum at these things because of DJ beatmatching and tight audience proximity. Festivals are easy to get away with FIR because the audience can't hear the stage monitors/iem feeds. As long as there aren't so many taps used that it starts to visually become an issue (but nowadays, with the IMAG screens, the video operator can just delay the live feeds and fool 99% of the crowd since almost everyone watches the screens)

yep again. Hey, are there any simple (cheap) consumer video delays you know of.
I could use a couple of hundred ms .

I always wondered how the Marani "minimum phase" implementation works vs Linea. They both use the same marketing jargon so I was thinking Marani licensed it.

No experience with Marani, but looking at their site, their processor does look like a rebadged Linea.
Mine is a Danley SC-48. As you know doubt know, the LIR / MIR filters are essentially a linear phase LR 24.
Slickest implementation I've encountered to date....Linea ought to license it widely i think.

 

[benanders]

Here’s a slight veer:

If going with a center Ch,

AND

you could choose between:

(1) a wide dispersion vertical array identical to L / R Ch’s

OR

(2) a narrower dispersion vertical array with 2x driver SA (~115 Hz up) of the L / R Ch’s (other than dispersion, SA and sensitivity, same specs as L / R)

then

which would better suit a larger listening space? I know the answer must be as intuitive as it would seem, but…
you often don’t know what you don’t know until someone else tells ya.

Would / should that scenario be different for up-mixed stereo music vs. multi-Ch theater?

 

[Zensō]

Personally, I would never use a center channel in a system intended primarily for listening to music produced in stereo. Mixing and mastering engineers put a tremendous amount of effort and care into creating the stereo field; I see no reason to adulterate their work with an upmixer. Of course, movies, games, and music produced specifically for immersive formats are a different matter.

 

[theswede]

Imo it depends...

I've spent some time on this in practise and I'd say generally, if all of your channels are sonically equal and you are able to adjust the spread over the LCR channels to mimic the 2 channel soundstage as well as the width of the surround channels not to make the surround effects excessive you can make it sound as if you are listening to a stereo track but with more power, dynamics, clarity and immersiveness.
Technically you will have more speakers and amps sharing the effort of reproducing the music, particularly if you like it a bit louder and ofc better control/definition on non direct sound like surround effects in modern music or if you prefer ambiance in more traditional/live stereo recordings.

The caveats though are that all channels are typically not equal and even if they were you also need to have the timing right between all the speakers otherwise you won't be able to get the holistic balance right which will make some of the channels stand out or take over/tip the soundstage thus messing up the experience for those of us that grow up with stereo as the reference.

 

[MattHooper]

I listen to a lot of music upmixed to surround using my home theater system.

I've found various advantages (and disadvantages) to the center channel. One of the main advantages for me is it increases the sense of density to the presentation - another actual speaker in the middle of the soundstage can sound more solid than the wispier presentation of only phantom centered images. Further, throwing more boxes and drivers at the sound increases the sense of scale and heft.

Another thing I find interesting is it can increase, for me, the sense of timbral variation - that is the sense that each sound source, a trumpet, drums, piano, voice, clarinet - has a very individual character and timbre. And since I find most stereo playback (most sound reproduction in general) to homogonize the sound, this is quite welcome.

But I note, at least in my system, it makes this contribution best without using the room correction settings. So for instance, if I choose the "flat" setting, where all speakers are equalized to sound as indistinguishable as possible, the sound is more..."flat" and homogonized across the soundstage. Good for coherence and integration, but less so for the effect I'm mentioning. It's my speculation that without room correction, there's just enough idiosyncrasies in the sound coming from each speaker - due to different positions in the room etc - that they then each contribute their own slightly distinct sound. It makes for a bit more room boom, a bit less coherence, but more "suprisingness" and variation in instrumental timbre through the presentation, to my ears.

As to imaging, or maintaining the stereo imaging, I find some settings better than others, but most maintain the imaging quite well when I switch between stereo and 3 channel, or more channels. One of the best is actually a "multichannel stereo" setting on my Denon AVR, which tries to keep the general impression of stereo but spread to all the speakers, and it can sound just amazing for lots of stuff, orchestral especially.

Since my 2 channel tower speakers comprise a different sound system I just go to two channel when listening to lots of music, vinyl in particular. But I have nonetheless tried introducing my center channel too - running my L/R stereo speakers and the center through my AVR. It does add some density to the sound which is quite fun. Ultimately though I prefer the overall coherence, especially in terms of imaging and soundstagine precision, just using my two channel speakers.

 

[Gringoaudio1]

My centre channel sounds tonally different than my mains despite being from a matching 5.1 set. Okay for surround in movies only. Stereo is great with two speakers.

 

[just1n]

Personally, I would never use a center channel in a system intended primarily for listening to music produced in stereo. Mixing and mastering engineers put a tremendous amount of effort and care into creating the stereo field; I see no reason to adulterate their work with an upmixer. Of course, movies, games, and music produced specifically for immersive formats are a different matter.

Respectfully disagree. I use room correction and Auro3D 100% of the time listening to music. You say adulterate, I say enhance.

The mixing and mastering engineers may have done everything to perfect the music, but listeners are using everything from single channel Bluetooth/smart speakers to cars with over a dozen speakers to headphones to dedicated stereo and home theater systems. Does this means they are adulterating it too? You could argue that if anyone does not match their listening setup identically then they are adulterating it, too. Yours included.

Everyone listens to music in their own way. Let them enjoy it.

 

[Gringoaudio1]

Respectfully disagree. I use room correction and Auro3D 100% of the time listening to music. You say adulterate, I say enhance.

The mixing and mastering engineers may have done everything to perfect the music, but listeners are using everything from single channel Bluetooth/smart speakers to cars with over a dozen speakers to headphones to dedicated stereo and home theater systems. Does this means they are adulterating it too? You could argue that if anyone does not match their listening setup identically then they are adulterating it, too. Yours included.

Everyone listens to music in their own way. Let them enjoy it.

He didn’t say anything about using room correction/EQ which you appear to be talking about. He said ’upmixing’ which is about deriving a fake Center channel from stereo source material.
I too love that we can EQ so readily now. I use Equalizer APO. Unfortunately this means that my PC is now my source. My lovely CD player goes unused.

 

[keks8430]

Why would they be clearer? Where is the extra information coming from?

Generally, from source decorrelation, see DSP algorithms solving the cocktail party problem.
Specifically, here we have dialogs mixed with other sounds.
Separating the dialogs from the other sounds, playing them in distinct places, will help you to focus on what is important.
Dialog is generally mixed close to mono and thus can be separated by rather simple algorithms. Once separated, you are able to amplify dialogs in the center channel.

 

[keks8430]

With the newer AVR, only a few can have the center spread adjusted: the latest Onkyo have it.

On the NR7100, I can choose between the Dolby Center Spread option and the Vocal sound control (need to set Center Spread to off).
Vocal key on the remote looks like a mid-frequency equalizer, but it is about amplifying(?) the center signal.
For dialogs and Vocal set to 2, they are almost identical.
Different story for music. Center Spread much better preserves stage and sound. Vocal overall is blurring things.