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Thread: 7.1 Height Channels vs. Surround Back Channels - Which is Better?

  1. #1
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    Default 7.1 Height Channels vs. Surround Back Channels - Which is Better?

    I'm getting my new system in place (Onkyo TX-SR607)... right now, it's 5.1 and when I get the two other speakers in the coming days, it'll be 7.1.

    So my main question is this: which is better, having rear surround speakers or front height speakers? Note it isn't a huge room, maybe around 25-foot x 15-foot x 13-foot height (higher than usual). The main relax & watch area is probably only 15-foot x 15-foot, though.

    Another thing that might make a difference: what movies use the height channel? I read "We Were Soldiers" was one of the first back in 2002, but I don't know if many movies use this channel to make it worth-while. And if there are many movies that do, what do I look for... Dolby what? What are the Dolby options, good - better - best? (TrueHD vs. Pro Logic II)

    Lastly, in regards to the side surround speakers, I understand they should be about ear level when watching and equidistant from the viewer. But what if in this smallish room the speakers would be ear level, but 6-inches away from the ear... should the speakers go behind, or higher, or...?

    My layman thoughts would be to use front height speakers and put the surround sound speakers up and behind the viewer about 6-inches, hopefully creating more depth from behind.

    Thanks!
    Brian

    P.S. Dolby Laboratories is of great help, but of course they're going to brag about all their technologies. I'm not sure which is best, which to use, if TrueHD and Pro Logic IIz can be combined, etc.
    Last edited by kcsamerica; 12-03-2009 at 01:02 PM.

  2. #2
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    Quote Originally Posted by kcsamerica View Post
    I'm getting my new system in place (Onkyo TX-SR607)... right now, it's 5.1 and when I get the two other speakers in the coming days, it'll be 7.1.

    So my main question is this: which is better, having rear surround speakers or front height speakers? Note it isn't a huge room, maybe around 25-foot x 15-foot x 13-foot height (higher than usual). The main relax & watch area is probably only 15-foot x 15-foot, though.
    I've been playing around with the PLIIz height channels lately with an Onkyo HT-RC160 and if definitely can enhance the spaciousness of the front soundstage, but it's really a fairly subtle difference. If I recall, your seating placement is a little irregular, so I think 7.1 with rear/side surrounds might be a better option for you.

    Another thing that might make a difference: what movies use the height channel? I read "We Were Soldiers" was one of the first back in 2002, but I don't know if many movies use this channel to make it worth-while.
    Actually, right now, nothing has been encoded in Dolby PLIIz. Most likely games will be the first software to include a real encoded height channel. There are some movies or sections of movies that sound particularly nice with PLIIz decoding - the opening rain sequence in "Ratatouille," the dream sequence in "LOTR: The Two Towers" and a few others, but these are all simulations of height based on the content, they are not "real" encoded height channels.

    Keep in mind that movie theaters do not have height channels so to add a height channel to a home release of a movie on Blu-ray or DVD would create something entirely new, unlike the theatrical presentation. Of course, this doesn't mean it won't happen. It just means that the director/producer/mixer, etc. would need to make different choices for the home release than the theatrical one.

    And if there are many movies that do, what do I look for... Dolby what? What are the Dolby options, good - better - best? (TrueHD vs. Pro Logic II)
    Dolby TrueHD is the top of the line sound for Dolby right now. It's available mostly in 5.1, but also in 7.1 channel versions. If and when Dolby PLIIz encoding gets added to movies, it will be done as a matrixed (encoded) height channel, much the way the original Dolby Pro Logic encoding was done on 2-channel formats such as VHS. It will be entirely backwardly compatible so a new movie that may have a PLIIz height channel will sound perfectly fine on a non-PLIIz-enabled system. But as of now, you won't see the PLIIz logo on anything except receivers and preamp processors as there is no software encoded for it yet.

    Lastly, in regards to the side surround speakers, I understand they should be about ear level when watching and equidistant from the viewer. But what if in this smallish room the speakers would be ear level, but 6-inches away from the ear... should the speakers go behind, or higher, or...?
    Surround speakers (side and rear) actually shouldn't be too close to the ear and in fact normally sound best placed a little above listening height, not at it. In your situation, where you have a few different listening positions, I would put the side and rear speakers a bit above the listening axis and probably even aim them at the wall instead of aiming them directly at the listening so you can get a more diffuse surround soundfield. Also, when you get all the speakers in, make sure you do your Audyssey calibration from at least 2 or three of the different listening positions so if can average out the levels for the best overall effect for everyone.

    My layman thoughts would be to use front height speakers and put the surround sound speakers up and behind the viewer about 6-inches, hopefully creating more depth from behind.
    Unless I'm remembering your room incorrectly, I think you may get better results with rear, rather than height. But if you're willing to experiment a bit, you can try both. Unfortunately the TX-SR607 doesn't support doing both concurrently (9.1) - only the really expenive receivers support that right now - but you can switch back and forth between 7.1 height and 7.1 rear in the menus. I think you may even be able to hook up all 9.1 speakers at a time, though only the rears or the heights will be active t any one time. The problem with hooking up both is that you need to go through the calibration separately for each configuration if you want to get the best results. And I don't think the 607 can store a different calibration for height and for rears as two esparate profiles (though I may be mistaken on that - you'd have to play with it to see).

    P.S. Dolby Laboratories is of great help, but of course they're going to brag about all their technologies. I'm not sure which is best, which to use, if TrueHD and Pro Logic IIz can be combined, etc.
    They can be combined. Dolby ProLogic IIz decoding can be applied to any 5.1 or 7.1 source whether it's Dolby or DTS or PCM. You can even engage it on a 2-channel source but I'm not sure how successful or effective that would be.

    For now, IMHO, Dolby PLIIz is a "nice to have" but not entirely essential. If/when software comes out with actual height channel-encoding then this may change, and that's why it's good to have in your receiver for future-proofing.

    -CB
    Chris Boylan
    Editor in Chief
    Big Picture Big Sound

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    Thanks as always, Chris! I'm impressed you remember the picture layout I posted for my room!

    If I did the side and rear surround speakers, they'd all be the distance of the couch, plus a foot or two. To the left of the couch was a wall/doorway to another room; to the right was the main walkway through the room. So that makes it (guessing) about 8 feet to spread out all four surround speakers.

    Would it make sense to wall-attach the side surrounds behind the viewer about a foot (there's a radiator between the wall and the couch, forcing the couch away from the wall), about 6-inches above ear level, and aiming straight out instead of at the viewer... then wall-attached the back surrounds also about a foot behind the viewer, about 5-feet above ear level, and aiming straight out instead of the viewer? Or would it make better sense to get speaker stands so they are aimed at viewer -- for side and/or back surrounds? And should I consider putting all the Right speakers an additional (about) 8-feet away from the viewer to attach to walls, add floor space, whatever... or will that definitely distort the experience?

    Oh, and you mentioned Ratatouille! I own that, but on DVD. Do DVDs give the same experience, or all these 5.1 and 7.1 options only available on Blu-Ray?

    Thanks again!
    Brian

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    Here is a description of my 7.1 system: my left and right surrounds are In-Wall, 12 and 10 feet above the floor respectively. The left surround is facing at an oblique angle to the front, (remember it's 12 feet above the floor), but the Audessy system of my Denon 3808 nicely compensates for this. Also, the left surround is about 15 feet to my left above the staircase which makes for a very wide soundstage filling the whole room with sound.
    My rear left and right channels are Bose speakers placed on the floor behind me. I use the Definitive Tech Supercube II, subwoofer in the right front corner of the room. My left and right speakers are Definitive tech BP10's powered with a McIntosh 270 Watt per channel power amp, and a Definitive tech CLR for center channel; all surrounds and center channel powered with the Denon 3808.
    Most 5.1 and 7.1 discs completely envelope me in sound. Especially 3:10 to Yuma where my Wife is trying to duck the completely surrounding gunfire during the gunfights! Bullets/shots come from ALL directions.
    Terminator Salvation Blu-ray taught this system some new and exciting tricks:.....the sound was AWESOME!
    Bottom line: I am very happy with the setup described with both high and low surrounds and I don't need 9.1!
    Should have mentioned that I have a 21 foot Cathedral ceiling with the highest point to the rear above my seating position.
    My thought from experience is that left and right surround channels DO NOT have to be at ear level.
    When I was in the movie industry installing Dolby/DTS surround systems, Surround speakers were NEVER placed at ear level, they were always at some height above ear level and mounted on the side and rear walls no matter the size of the theater.
    Last edited by Daylightdon; 12-05-2009 at 09:12 AM.

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    Thanks Daylightdon!

    I'm more of a layman and not sure if I do follow all of that... would you suggest left & right speakers being placed at an equal distance from a listener, or would the Audyssey calibration/system work with right speakers 8 feet further from the listener and creating more of a sound-filled room?

    Would it impair the experience if the left speakers were above ear level, but only 1 foot from listener? Would it be okay to have any of these speakers, especially the left, forward facing instead of angled in toward the center/viewer?

    And curious what potential DVD has for 7.1 (or its typical limitations) compared with Blu-Ray...? I hope I don't have to re-purchase tons of movies to get great sound (not just really good, but great).


    Thanks again all!
    Brian

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    The Audessy system will (at least mine does to my satisfaction), correct for most room anamolies. You do not have to be equi distant from the surround speakers. As I stated, my surround speakers do not face me. and my sound is room filling.
    The processor in most modern receivers will decode or derive 7.1 sound even if it was not recorded that way. The 3:10 to Yuma is a 5.1 disc but it sends sound to all my speakers.
    Last edited by Daylightdon; 12-11-2009 at 11:07 AM.

  7. #7
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    Quote Originally Posted by Daylightdon View Post
    The Audessy system will (at least mine does to my satisfaction), correct for most room anamolies. You do not have to be equi distant from the surround speakers. As I stated, my speakers do not face me. and my sound is room filling.
    The processor in most modern receivers will decode or derive 7.1 sound even if it was not recorded that way. The 3:10 to Yuma is a 5.1 disc but it sends sound to all my speakers.
    Actually "3:10 to Yuma" is 7.1 uncompressed PCM. But yes, if you have an HDMI-audio equipped receiver, you can get room-filling 7.1 sound from 5.1 meterial using Dolby PLIIx or similar processing.

    -CB
    Chris Boylan
    Editor in Chief
    Big Picture Big Sound

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    ...and here I thought the speakers needed to be relatively equidistant from the viewer and/or TV. Does this apply for the front left/right speakers too? Because the right speakers would fit much nicer 8 feet away whether it's front or surroud or rear-surround, and as you said, the sound would fill the room if they all can be that far away... but I've been ready to drill a hole in my floor to bring up speaker wires to have them equal thinking the listener would feel lopsided, only hearing the left of anything! Audyssey calibration will put it all back in sync? I'm sorry, I'm a layman, and I'm excited if this is true...

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    Quote Originally Posted by kcsamerica View Post
    ...and here I thought the speakers needed to be relatively equidistant from the viewer and/or TV. Does this apply for the front left/right speakers too? Because the right speakers would fit much nicer 8 feet away whether it's front or surroud or rear-surround, and as you said, the sound would fill the room if they all can be that far away... but I've been ready to drill a hole in my floor to bring up speaker wires to have them equal thinking the listener would feel lopsided, only hearing the left of anything! Audyssey calibration will put it all back in sync? I'm sorry, I'm a layman, and I'm excited if this is true...
    Audyssey and/or manual level calibration can adjust levels and delays to compensate for minor divergences from the ideal speaker placement, but you should really always try to position your speakers equidistant from the main "sweet spot" where possible. Attached would be by recommendation using your original diagram as a starting point. The front speakers would ideally be on floor stands on either side of the TV with the right channel pointing outward angled between the chair and the couch.

    I'd put the rear and side speaker up on the walls near the ceiling pointing outward angled just slightly down. The shaded area that looks like a big blood stain in my diagram is roughly the sweet spot. People on the far left of the couch are not going to get an ideal experience but it won't be too bad. The chair and right side of the couch will get the best overall blend of sound.

    I angled the TV stand toward the viewing area a little and moved the chair in slightly. BTW, FL=front left, FR=front right, LS=left side, RS=right side, LR=left rear, RR=right rear.

    Hope it helps.

    -CB
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    Chris Boylan
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    Big Picture Big Sound

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    Oh great, now I have blood stains on my floor!

    The drawing does help; I'm impressed! Although one catch... the chair is used only maybe 10% of the time. Most of the time it's the couch. Would you still suggest a similar layout?

    Thanks!
    Brian

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