phantom center channel

My entertainment center can not accommodate a center channel without substantial and costly modification. Does anyone have experience with the "phantom center channel" option? Does this drastically change the listening experience?
Yes, it can drastically change the experience - many times for the better. I often experiment turning it on and off to see which sounds better. DVD concerts are almost a no-brainer for turning it off.
Remember that a center channel's main purpose is to anchor the dialogue in the center for those who are off center. Depending on where your seating position is, it may not be a necessity.
For a long dissertation on not using a center, go to Richard Hardesty's Audio Perfectionist website.
Snofun3 is correct, for movies. If multichannel music is the objective the center front channel is the most important of all.
I agree with the above. I'm currently not using a center channel and it's working very well, and I don't have to physically have a speaker in between my mains. If it is for one or 2 people you can get away very well with a phantom center--and often times it's actually an improvement.
Depending on the quality of your main speakers and their ability to image, a phantom center can be a better alternative to an actual speaker. Although the dialog won't be as "anchored" for those on the sides, integrating a center channel speaker (for music) can be quite challenging (much like integrating subwoofers).

I used to have an actual center channel. I currently use a phantom center and find that the image is much more cohesive this way.
If you really want a center channel, what about a floor stand under your TV? I see some in virtual systems and they look sharp!

I ran a dynamic center channel for awhile with Magnepan fronts and found I preferred the phantom center channel - the voices were better integrated with the rest of the audio. But I recently added a Magnepan center channel to match the fronts and found I prefer this due to my seating arrangement for movies: the seats are along both sides.
It definitely anchored the dialog and made it more cohesive. If you're seating positions are centered, I'd suggest just using the phantom. But if they're not, I' d say use a center of the same brand and quality.
There's a very good roundtable discussion on this in one of last years Absolute Sounds. Don't rememenber which issue but I think it's included in the surround sound discussion.
EMM labs will mod their Switchman preamp for a phantom center by spliting the center channel info to the front right and left speakers.
Don't forget though, that in movies, the center channel passes over 60% of the sonic energy...The percentage used to be greater with Pro Logic setups (>70%), but, nonetheless, the majority of action is happening on your screen, or behind it, as the mounting case may be. The main L & R, and secondary L & R fronts, in some systems configured as such, are obviously important, as well, as are the surround channels. In my opinion, though, there is too great an amount dedicated to a driver array that would not be "there". Plus, if one is interested in running a spec system (be it THXU2, THXU1, THXSelect1/2, or just a great 5.1 configuration), one should at least run with the basics covered, at first, and make additions/deletions from there...

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?! ;)

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.


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...
Sammydog, I feel your pain! I'm currently using a center channel in my system, but I want to upgrade to a front projecter/screen setup and will lose the space to fit my current center speaker due to it's depth and the fact that I still want to be able to use my fireplace. There's definately going to be pros/cons and sonic benefits/compromises (isn't there always?!!).



I do not disagree with your philosophy. However, I only recommend using the number of speakers that correspond to the number of discrete channels in the source. Thus, for stereo, only two. For 3.0 (MLP and LS SACDs), 5.0 and 5.1, I find a center amp/speaker essential for coherent reproduction. I eschew DPL and other matrixing modes but DD/DTS sorta come along free with the full amp/speaker array. Or course, I am also talking about using a full-size center channel speaker identical to those used for the main L and R.

BTW, my experiments with the 3.0 SACDs were the most convincing of the necessity for a center channel but creating a phantom center with them was as unsatisfying as deriving the center signal from the stereo tracks. Several doubters have heard this advantage clearly in my main system.

Kr4...I beg to differ with you about the effectiveness of deriving a center channel from a 2-channel source. In many recordings where there is a soloist, he/she was originally recorded as a discrete channel, and was subsequently mixed equally into Left and Right. When you derive a center channel what you are doing is unmixing so as to restore what was there originally.

I have used a center speaker for almost forty years, and have used many different techniques to drive it. Some work better than others. Of course, a discrete recorded center channel, SACD or DVDA, is best, but with some recordings the derived method comes close.

We are on the same page. I was trying to emphasize that a real center channel source with a center channel speaker is superior to either a phantom center or a real one derived from a 2channel source.

As for recovering what 'should' have been the center channel signal, I have found only a few devices which will do this to my satisfaction. Merely feeding a sum signal or using DPL without lots of trim options don't cut it with me.

BTW, to get back to the OP's query: If he is mounting the center channel inside an 'entertainment center,' these subtleties may be irrelevant.

Having previously used an all Vandersteen setup with 3A's and a VCC-1. I have moved to Aktiv Tri-amped Linn Ninkas with Linn 5103 as preamp. Using phantom mode, I actually prefer the sound. I dont think I will be going back to a center speaker.