Phantom Center Mode

My old processor had a Phantom Center mode that would make the center channel mode come from the two front speakers. If I try to do this with the 950, I don't get any good surround modes. For example give this a try.

Disable your center channel, put in a DTS DVD and tell me what modes you can listen in.

My question is: If you disable the center channel are you suppose to have all of the other DTS modes? Will you be able to listen to LF/RF/RSB/LSB/LFE?


Thanks

[This message has been edited by MeanGene (edited October 22, 2002).]

Gene:

I am not positive,but I think I found the same thing. That is another reason I am still using my Sony processor, as you can disable the center channel and still have full functionality.

Anyone for some more MIPS?

What's MIPS?

Gene, Million Instructions Per Second. As in measuring the processing power of a computer chip. Can't the 950 be set up (in the Speaker Config menu) without a centre speaker? If so, then can't you play any discrete 5.1 sources, either DD or DTS? Mind you, I'm not talking about a phantom centre mode but a 'no centre' configuration.

Best,
Sanjay

[This message has been edited by sdurani (edited October 24, 2002).]

I knew what MIPS meant, but I am still not sure what it means in this thread, Oh well.

From what I have seen so far, if you remove the center channel from the config menu you will get no Digital sound, only stereo and with no subwoofer. Try it and tell me if your results are any different.


[This message has been edited by MeanGene (edited November 03, 2002).]

My center is down for maintenance, but everything else works as it should. I barely miss the center; the sub works as normal. If by the reference to MIPS, you mean there isn't enough horsepower to process without a center, thats clearly wrong. I drop into this forum once in a while, but less frequently now.
It seems the only folks posting are those who are looking for something to gripe about, and then usually are wrong anyway. My 950 is far and away the best value of any product I have had in years. I had a Kinergetics Chiro system before, which was Stereophool recommended. The 950 blows it away in the various processing modes, and for music is about its equal.
Mike

Either there isn't enough processing power (bandwidth), or else Outlaw (or Cirrus) simply chose not to include that capability.

You are not using the center speaker, but have you gone into the Configuration Menu of the 950 and selected "None" for the center channel? If you have and you are able to play all different modes, then there is something wrong with my 950. I am only able to 2.0 with the center channel disabled.

I would think that if your center channel was not hooked up you would be missing a large part of the DTS signal. I don't think the 950 automatically senses that it's not connected and sends the center channel signals to the LF/RF.

I am just trying to emulate 4.1 which the 950 cannot do.

________________________________

i beg your pardon, young man...i am certainly not a griper and i most definitely agree with your comments on the 950.

when i was young(er), i did some studio work and heard the playback from the master tape through 2 huge JBL 2-way monitors (this was around 1972). ever since then, i quietly dreamed of hearing that sort of playback in my own home. SACD and the 950 made that possible, as i will never buy a multi-kilo-bucks preamp. read any of my posts. ZERO complaints. and....it was good to read your post.

Yes, when I took the center speaker down, I changed the settings to "none" for center. Didn't miss a beat. I'll have it back up soon, and will actively listen for differences.

Hmm, for MIPS, as far as processing a 48kHz signal, to produce a phantom center would be at most 96,000 integer "add" operations per second, on top of what ever else was going on at the same time. A phantom center requires adding half the center signal to the left and right signals. Halving the center signal is just a bit-shift operation, which on most CPUs is extremely little work. Even if it requires a full "operation," that's still only 144,000 opertions per second, hardly a drop in the bucket when you're talking Millions of OPS.

So I don't think not supporting a phantom center in some modes is a matter of MIPS, I think it's a software oversight. Either someone didn't think to include it, or somebody didn't want to write the code to do it.

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Matthew J. Hill
matt@idsi.net

MeanGene-- I believe AZRyan, who posts here occasionally, has always operated with a phanton center-- and in fact had a whole thread going on the subject. I'm sure if there was a problem, he would have mentioned it long ago. Anyway, I did a check on my 950 by going to Speaker Configuration and selecting- Center: NONE and played both DD and DTS in 5.1(LOTR and Gladiator) with NO problems. Surrounds were active- working "as normal". I am not sure why yours is not working. Many, if not most, movies start in 2.0 DD for the intro credits and selection menu and don't switch to multi-channel until the thing starts.


Matthew, does your 950 not operate with a phantom center selected? Have you tried?
I would think being able to select "NO" for a center channel is pretty much a stock option in anybody's surround processor- I really doubt they would leave this option out.

Now with your center channel disabled go into 5 channel stereo and play a DVDA or CD or what ever and listen to the rear speakers. Do ya hear anything?

Hello MeanGene---I don't believe 5 channel stereo was/is designed to "phanton" a center if you do not have one. I would recommend PLII-M if you want the surrounds to be active. You can probably change the dimension and panorama adjustments enough to approximate 5 chnnel stereo with 4 speakers (well, sort of). It will also allow a "phantom" center image.

I guess the question I am scratching my head over is: Is there Music Missing when you setup your system with no Center Channel? If so, what modes does this happen in? The sub woofer seems to stop getting a signal in certain modes when you don't have a center channel. What happens to the LFE? Does it get discarded or distributed? Same with the fronts does the signal get spread out or canceled out.

Hello Everyone,

Setting the center channel to "None" has no effect on the surround modes that are available. In modes where a center channel is typically involved (DD, DTS, PL II, etc), the Model 950 will automatically "down-mix" the center channel information to the front speakers. The "all channel" stereo modes simply operate with the number of channels that are activated.

If any one is concerned that their Model 950 is not functioning properly, we would encourage you to contact us directly first. Most of the time these issues are solved with simple configuration changes.

Yeah, but where's the fun in that?

I still have a problem with the center channel thing.

If you set the center channel to "none" and then watch TV through the 950 you will only get stereo. When you press the stereo button on the remote your only choices will be stereo. You will not have the choice of Stereo 5 or Stereo 7 mode. This means that you will not be able to hear the rear channels or the sub woofer. You have to turn on the center channel to be able to use anything more that 2 speakers in a non-DTS mode. I don't like this "feature". Please tell me if I am wrong.






[This message has been edited by MeanGene (edited November 14, 2002).]

Your 950 appears to be working as designed, MeanGene. I don't know why it works this way, but if you list the center or the surrounds as "none" you lose the 5/7 Stereo mode. (Losing it with no surrounds makes sense. Losing it with no center seems a little odd.) I tried it briefly using an analog stereo input this morning, and found that I still had the Pro Logic II and NEO6 modes available (including PLII with CES when I disabled the center channel). So if you have no center channel, you apparently cannot use the 5/7 Stereo mode. All other modes remain available, however.



You should still hear the subwoofer in Stereo mode, assuming that your mains are "small." And you aren't restricted to DTS only -- you are losing the 5/7 Stereo mode only. For TV viewing, I use PLII, which does support a phantom center.

Gotta head off to work now... Hope that helps some...

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

The thing should give a 4/6 Stereo mode when set to phantom center, I would think...

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Matthew J. Hill
matt@idsi.net

You would think. What I have found (I may be worng) is that when the center channel is set to NONE - and you are listening to a stereo signal - and you want that stereo signal to be heard in the other speakers - you only get sound out of the fronts. If you pick up the channel changer and press the stereo button you will only have one choice STEREO. You will not see STEREO 5, STEREO 7, or the missing STEREO 4 remember (QUAD STEREO). I hear you may be able to get around this by going into different modes like NEO6 or PLII.

[This message has been edited by MeanGene (edited November 15, 2002).]

The best I can figure is that the 5/7 Stereo modes are automatically disabled if certain speakers are set to none. If the surrounds are not present, you have nothing by stereo (no "3 stereo"), which makes sense. Oddly, if you have no center, there is also nothing but stereo (no "4/5/6 Stereo"), which may be related to the treatment of the "no surround" condition. Also, this is only limited to the 5/7 Stereo mode -- PL II and NEO6 still work fine with no center channel.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

Maybe something wrong with my 950 cal, but when I use the PLII or NEO6 the db is much lower when compared to any stereo mode. So much lower that I don't get, what was before, max volume at +10 db. I don't want to re-cal every time I play a two channel source through 4+ speakers.

I should say that under normal playing the system is calibrated such that I never get close to +10 db. I watch DVD DTS EX movies about -5db most of the time. With the center channel set to NONE and playing a stereo signal through PLII, I find that I have to crank up the db. Does this make sense?

[This message has been edited by MeanGene (edited November 16, 2002).]

Just saw this thread!

"I guess the question I am scratching my head over is: Is there Music Missing when you setup your system with no Center Channel?"

As others have mentioned I've always used the 950 w/ a phantom center (Newform Research speakers).
You lose no information (and I personally can name several points in favor of using a 'phantom center' over an acutal center. check out some of my comments on the SACD/DVD-A thread here if you're interested).

"I should say that under normal playing the system is calibrated such that I never get close to +10 db. I watch DVD DTS EX movies about -5db most of the time.-"

I watch at ~0-+3db for most DVD movies. I don't calibrate 0 to any reference db (most set it to 75 or 85db), but it's Very loud during the big peaks.

"-With the center channel set to NONE and playing a stereo signal through PLII, I find that I have to crank up the db. Does this make sense?"

Not really. I listen to most stereo CD's at about -12 to -7. This is all much louder than the average volume of the movies though because movies are SOOOO dynamic compared to CD's.

When I process stereo to DLPII-Music it is overall slightly quieter than the original stereo setting, but you seem to be describing a BIG diff. of maybe 10-20db though?

I find it to be more like ~3db. 5db tops, and I think this is basically due to a chunk of front info being routed to the back speakers.

In theory I'd think there shouldn't be any diff in SPL going from 2-chan to DLPII, but it does sound like it's a little lower.
No big deal... I just add ~4db of volume (though I don't really like DPLII that much. Kinda gimicky sounding on most CD's to me. I find while it's sometimes pretty cool sounding surround-wise the front end is also slightly degraded so I rarely use it. I think it's better than NEO6 though, but never compared to closely).

"The sub woofer seems to stop getting a signal in certain modes when you don't have a center channel. What happens to the LFE? Does it get discarded or distributed?"

That shouldn't happen. If you don't have a center chan. but you set the 950 to center -'small or large' then you'd of course lose information in a very critical and blatantly horrible way unless there's nothing recorded in the center chan, otherwise (like in my case) the sub x-over and LFE track are ALWAYS sent to my subs whether in Stereo, DD, DTS, DPLII, NEO6.

My system's 2.1 or 4.1 at all times.

Anway... as Gonk said you can't get 5 or 7 chan. stereo if you set the center to 'none'. Also as Gonk basically said.. this is dumb. My old Denon did it. No reason for the 950 not to.

Then again... I think 5 chan stereo's cheesy anyway so I never used it when I had the Denon.

"You will not see STEREO 5, STEREO 7, or the missing STEREO 4 remember (QUAD STEREO). I hear you may be able to get around this by going into different modes like NEO6 or PLII."

All you have to do is set the center to -small or large though and even if you don't have a center hooked up you'll be able to set it to 5 or 7 chan. stereo, and it'll be 4 or 6 chan stereo. Setting the 950 to DPLII or NEO6 doesn't really 'get around' Stereo 5/7. There totally different processing.
But much better, so I'd recommend you use either of the over 4/56/7 chan. stereo.

You do know what 5/7 chan .stereo is right? It sends the exact same main chan. signal to your rear speakers and a combo to a center chan. There's nothing audio qualtiy-wise going on there.

This is really only used by most people for party's to fill the joint with tunes, not for actual real sit down to listen to great music.