Axiom Home Page Forums General Discussion Technical Questions 7.1 rear surounds no sound

new setup, new user.
Should the rear surround speakers always provide sound in a 7.1 setup? They work fine but no sound comes from them except if I simulate 7.1.

Denon 3310CI
Oppo BDP83
M22s
VP150
Ep350
4xQS8

Yeah, that's normal.

There really isn't much 7.1 content, with the exception of Blu-Ray. Anything else, your processor has to be told to make it up.

Yep, I would recommend using Dolby Digital + PLIIx mode, that gives me the best results.

Yup, sirquack is right, though I find for music I sometimes prefer Neo6 if your processor has it - seems to put less emphasis on the center channel.

For an awesome 7.1 discrete soundtrack, check out Chris Botti in Boston

Cheers,

Oh yeah Dan, I was mainly talking about movies. For music I still listen to a lot of 2 channel stuff, but have experimented with PLIIx Music, Neo6, and even 7 channel stereo modes.

NB, welcome. Of course the rear surrounds can't produce sound if no signal is sent to them. There's still very little actual discrete 7.1 material and so, yes, to use all your speakers you should apply processing such as DPLIIx with both 2-channel and 5.1 material to put them to work. "Simulate" perhaps isn't the best description of the process, since only the natural rear ambience mixed into the front channels or side surround channels is extracted and sent to the back surrounds where it belongs. Nothing artificial is added, but what's already there is reproduced a little more realistically.

Lions Gate Productions have some 7.1 ch material. If you are worried about them not working just flip it over to 7ch stereo for a sec or two.

Later
Phil

I found this great site you will have to check it out to find out all your 7.1CH BR movies.

Blu Ray stats...filter page

later
Phil

Thanks Phil, someone had posted that earlier but I had deleted the link in an overzealous cleaning of my favorites.

Geez - that's a great link Phil. Thanks. 1st time I've seen it.

Ahh I finally feel like I contributed even though I do not own axioms yet LOL. Yeah that site can eat huge amounts of time just running filters and looking up nothing in particular.

Also in reguards to the OP I wonder if that Denon has what Yamaha calls Front Presence. It is like a 8 and 9th channel but shares the rear effect amp in the AVR and you can only select one the front or the rear. I never use this on my receiver but I have tried it, I did not like it for movies and for 7ch music my rear effects speakers are a step up or two from my paradigm inwalls I have for the presence ch so it sounds better as well. It does however give a much larger front sound stage.

later
Phil

Dolby Prologic (of any flavor up until IIz) has only used two channels for processing. So for 5.1 content, it only uses the surround channel to create the rear surround. It will have no effect on the mains or center at all.

Of course when fed stereo the only two channels available for processing are the left and right. It'll create the surrounds and center from there. When Prologic IIx Movie is processing stereo it will take any mono content (most of the time, the vocals in music) and place it firmly in the center channel, Music mode has a setting for center Width. It's adjustable from total removal of mono to the center, to not touching the center at all and leaving the mono content in the left and right (while still still performing ambiance extraction for the surrounds). By default the Width setting is somewhere in the middle leaving half the mono content in the mains, while routing the other half to the center.

Chris,
Thanks for the more detailed explanation. My music sources are only 2 channel, so that's what I was referring to. Your explanation helps me better understand what my Pio receiver is doing.

For me when listening to music, I like surround vs straight stereo usually, so when flipping between the surround modes I have often found that the Neo6 just blends the front sound stage better than the ProLogic Music mode which often makes my center stand out. Keep in mind I am talking about the 'pure' surround modes and not the jazz/dancehall/underwater/outerspace crazy settings! That width setting is a bit buried in the menus so i haven't played with it as much as I could have.

Now I have a new experiment for the weekend - fine tuning Neo6 music and ProLogic Music modes to see which I prefer/can make sound better to my ears!

On the Pioneer, the Center Width (along with Panorama and Dimension) settings are only avail when in PLIIx Music. But when playing in that mode, just hit the settings button and scroll down the list. NEO:6 has similar settings when it's mode is engaged.

The Panorama setting is the opposite of Center Width. It takes the stereo content which is in the left and right, and copies it to the left and right surround to create more of a wrap-around effect. I believe its turned all the way down by default.

I'm not exactly sure how the Dimension setting makes it's change. But you can hear it as it is adjusted. It's like the front sound stage moves toward you. It's probably like Panorama, but instead of copying the stereo signal from the LR, it removes it to the surround. What ever it does, I don't like anything but the default. Setting it smaller crushes the front width, and larger sounds odd. But then again, all my speakers are within a half foot of the being exactly the same distance from my listening position. People who are nearer to farther from the mains vs. surrounds may get more from this.

Yeah, I'm gonna play with those some more. I did a bit of experimentation when I first hooked up my system. Need to go back. Part of the reason I haven't fiddled with it is that I did not program my Harmony remote to go in to the settings so easily. I'll break out the original remote or add some programming to the Harmony.

Cheers,

Chris, the Dimension setting affects only the amount of out-of-phase surround material mixed into the front channels which is sent to the surrounds, not the front channel material in its entirety.

For music I used DPLIIx with for 2 channel and 5.1. The music made me misty. Very happy with my new room and setup. Mmore work to do...

Not sure if anyone out there has purchased an Oppo BDP-83 OR has used the AIX Audio Calibration HD Music Sampler that ships with it. When I try to run the Channel Identification test at (96KHz/24-bit/7.1 Dolby True HD) It does not work; the audio voice over tells me that it's receiving Dolby Digital (Not Dolby True HD) and to hook up HDMI to my AV receiver. Now, the only connection from my BDP to Receiver is HDMI..? Denon 3310CI is True HD compatible, and I tried setting the Oppo to output Bitstream...same incorrect result from the calibration. So all that make me think I am not running Dolby TrueHD?

Denon 3310CI
Oppo BDP83
M22s
VP150
EP350
4xQS8

make sure you are using PLIIx M (music) mode, and not C (Cinema) or G (games).

Turn off secondary audio in the 83. It can't mix the lossless quality with a secondary stream, so it falls back to the lossy track. AIX played some tricks with that disc to make it obvious when you're using software mixing.

Though keep in mind, if you want to use the BluTV or commentaries/games on some BDs you'll have to re-enable the secondary in order to hear them.

That did it. Now THD is working.

OK, got a chance to play a bit on the weekend. Here's what I found with PLIIX Music:

Panorama - sounded neat (more hall like) but not as natural as I would like (varied with source material), so decided to leave it off

Dimension - I had the same observation as you Chris - seems to move the soundstage forward or backwards - I ended up leaving it at default as well.

Center Width - found a setting of 2 or 3 works in my room to blend the center with the L&R and not have the vocals shackled to the center channel alone.

Once these tweaks were made and similar tweaks to Neo6 Music, I found there was little to decide between the 2 modes. I now like PLIIX Music much better than I previously did.

On a side note - I realised I must remember to turn my center back down to its true calibration setting for music as it's normally bumped up a few dB for movies.

Cheers,

Neverbored - glad you got the configuration issue solved. I have taken note of that for any future BRD player I may deal with. Thanks for asking the question

The secondary audio mixing isn't a problem for the PS3; the PS3 Slim can even quickly switch to PCM from bitstreaming when called upon to mix. Hopefully in the future more players will have enough DSP power to perform the same.

Fully agreed Chris. That's part of the reason I have just remained with my PS3 doubling as BRD player. I have a hard time justifying why I would pay for another device that does what my PS3 already does. Lack of good upconversion & fan noise are my only reasons so far for not being 100% happy with the PS3, but then I primarily rent/buy blu-ray so upconversion becomes a very small issue.

Yes, Dan; I use DPLII Music for all sources with the settings you described. Panorama, which is sort of a half-way step toward all-channel stereo, since it adds some of the regular in-phase front channel material(intended to be reproduced from front speakers)to the surrounds, should be left off.