phantom center channel

Ivyinvestor,

With my processor (as many others) you tell the unit the center is "phantom" and the information is routed to the L+R fronts (in mono, I would assume). Therefore, no information is lost.

It is not lost, per say, but it's certainly no longer anchored to the action occurring on screen.

Please recall that these audio standards were created to support large screen displays, at least initially. Thus, in a theater, either home or away, where all three primary channels are behind a perferated screen, their emplacement corresponds, if encoded/decoded correctly, to very near where the actions taking place on screen are located.

Forgive my assertion if you understand this. I very much appreciate the fundamentals behind stereo and multichannel setups. However, I often find that true stereophiles seem to agree that something that was spatially encoded can be moved around to support a non-HT standard. As a devout fan of several large orchestras, I have a good operating concept of where certain instruments are setup during performances: you likely do, of your favorite pieces/artists, as well. When some piece/artist is rearranged during a performance, or for a particular solo, I realize it: again, you likely do, as well.

If Lucasfilms specifically codes certain data to be in the "center", even the best processors do not make up for the physical lack of a transducer array in that position, regardless of price. There are too many spatial variables that are physically missing. Quite literally, the THXUltra 1&2 standards actually make an attempt, through re-equalization and time code adjustments, to account for a physical array. After all, the re-eq must deal with cabinet diffraction, reflections, and sub-modes created by nearby cabinets - even if wall mounted, behind a screen, & etc.

My thesis design project as a senior physics major was rooted in the beginnings of this thread. If you wish, I'd be happy to discuss further the variables that are neglected without a physical center channel - or the decoding requirements violated by matrixing the sound to either 1) the front L/R pair or 2) two center channel speakers (not really common anymore)...

Of course, what it all distills to is: do you appreciate your system as it stands? If so, who am I to tell you that physics and some rules from Dolby contend that you shouldn't?! ;)

Enjoy!

Speakers factor into this a lot. Often, people that have moved from stereo only setups to integrate a HT have much better L/R speakers than centre. That isn't to say they have poor centres, more to say that, compared to their other speakers, the centre isn't as good. In this case they could prefer no centre because the difference would be readily apparent.

This even happens with those building a HT from scratch. Many of us are programmed to believe we need great L/R and just passable rears and centre even though the majority of information comes from the centre for HT and surround music.

It's funny, I started out with 2 channel as a focus and have since moved to HT. I have now become a surround music convert due to my Citation 7.0's great 6-axis surround mode for 2 channel. But still, my centre was the lowest performance in the product line for matching centre's from Mirage.

Despite all this, I always seemed to think about upgrading my L/R speakers before anything else! It's just automatic for me. Finally I was able to convince myself the biggest improvement would be to upgrade my centre. I moved to the OM-C2 and couldn't be happier. I still try and fool myself into thinking I need better L/R but then I actually play something, get up and walk over to the L/R's and listen. Many may be surprized at how little information comes from these speakers compared to the centre in surround setups.

I know many of you already know this, but I thought I may drop it in because it's hadn't been directly mentioned yet. But it's a good exercise to put a movie or surround music on and walk over to your mains. You may be amazed at how little information comes from them compared to the centre. And then think about whether you have distributed your speaker budget accordingly.

Johnmcelfresh wrote: "With my processor (as many others) you tell the unit the center is "phantom" and the information is routed to the L+R fronts (in mono, I would assume). Therefore, no information is lost."

There are signals in the center which, due to the distance between the two sources, is somewhat out of phase electrically but which, if reproduced by the separate speakers, will sum/interact acoustically and give a correct signal at the ear of the listener. When these signals are combined electrically, as with your processor, the signals tend to cancel and cannot be recovered. Information is lost.

Kal

Kal-

Given the difficulty of properly setting up even a two channel system to get signals to sum and interact properly, and the fact that adding a center channel magnifies the set up problem in a non-linear fashion, I suspect the trade off still mitigates in favor of ditching the center channel. Besides, the concept of the center is to--as others have noted--anchor the sound for off-axis listeners anyway. Thus, the benefit of a center is for people who aren't going to enjoy the benefit of correctly summed/interacted signals anyway. I've run several iterations of HT systems, with and without center channels, and always preferred the phantom center mode.

But, I'm probably a bad person to ask. I got rid of everything except the L and R mains because I found DTS/DD didn't really enhance my viewing experience sufficiently to overcome the downside of having all that stuff...