Has anyone had problems with 6.1? (localization)

Discussion in 'Archived Threads 2001-2004' started by MoG, Apr 8, 2002.

  1. MoG

    MoG Stunt Coordinator

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    Hi,
    I'm planning out my first HT. It'll be relatively modest. I plan on going with 6.1. I'm wondering if anyone has had any issues with a single rear speaker?
    I know it is possible in theory for the localization of the sound from the single rear speaker to come from in front of the listener.
    I'm wondering how prevelant this is in "real-world" situations, and if there are any sure-fire tricks to avoid it?
    I ask because it would cost me an extra $500 to move to 7.1 (1 more speaker and either a 2-channel amp to split the single rear channel coming from the receivers center rear preout)...and I'd prefer to save the money. [​IMG]
    Thanks!
     
  2. SidH

    SidH Agent

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    Any 6.1 receiver worth its salt should have a variable delay for the rear center as well as a relative balance setting. Setting these correctly should eliminate the possibility of imaging in the wrong spot.

    You can also use a more diffuse-sounding (e.g. dipole) speaker for the rear center if you are worried about localization. How effective this will be will depend on your room and speaker configuration. In my own case, a 7.1 setup would be overkill because the room is fairly small.

    So save your money (or even better, spend it on something else!).
     
  3. MoG

    MoG Stunt Coordinator

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    Hi SidH,

    Thanks for the reply. Would you mind elaborating on:

    variable delay for the rear center (this is just the millisecond delay/distance from speaker setting, right?)

    and

    relative balance setting

    Thanks!
     
  4. SidH

    SidH Agent

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    You've got it right, it's similar to the front center channel delay and is calibrated the same way: add 1 ms of delay for each foot that the rear center is closer to the listening position than the surrounds.
    As for the balance setting, it is simply the volume level relative to the other speakers. You can use your receiver's test-tone generator and/or you can get a test CD or DVD (ideally to be used with a sound-level meter) to get this right.
    There are a lot of online resources with regard to speaker setup, here are some:
    http://www.soundandvisionmag.com/hot...cleID=3&page=1
    http://www.geocities.com/Heartland/P...urroundex.html
    http://www.members.accessus.net/~090/awh/htheater.html
    http://www.geocities.com/m_churches/place.htm
     
  5. Rich Malloy

    Rich Malloy Producer

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    You've got it, MoG. He's saying that any receiver worth purchasing will let you set delays/volumes for all speakers relative to your front L and R mains. So long as you're able to adjust the delay and output of your front-center, left-rear, right-rear, and center-rear speakers relative to these, you should have no localization problems.

    Real world example: I'm closer to my surrounds than my fronts, so I have to add a delay to my surrounds. Each of my surround speakers is equidistant from the prime listening position, so each delay is identical. However, if you're rear-center speaker is closer to the listening position than your left- or right-rear speaker(s), then you'll have to increase the delay to account for this. Likewise, one must adjust the volume output to be identical in all channels. If you're closer to your rear-center than your other rear speakers, then you'll likely need to dial back a DB or so on the relative volume. Other factors such as speaker type also play a role here. I'm presently using two dipoles for my left and right-rears and a monopole for my center-rear (all equidistant from the listening position). The left and right-rears are increased by +2DB relative to my front L and R mains, and the center-rear is increased by +3DB relative to the front mains in order to achieve an identical output from all channels.

    (I've never heard 7.1.)
     
  6. Brian Treinen

    Brian Treinen Stunt Coordinator

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    Mog,

    I've got a denon 3802 and have set up 7.1. However, any 6.1/7.1 capable receiver would be able to do the same thing that Sid is referring to. The delay is, as you said, the milisecond delay usually calc'd by measuring distance from listening position to speaker. The relative balance is basically system calibration - setting the volume level for each of the speakers. The only trouble with that that I've found is that VE and Avia only have pink noise for 5.1 - while the receiver does have pink noise for each of the channels the levels (for me anyway) result in different settings if I calibrate to reference via the reciever or via Avia. One way "around" this is using the THX audio setup routine which is pretty popular now on DVDs to check the rear surround setting once you've calibrated the 5.1 setup with Avia or VE.
     
  7. MoG

    MoG Stunt Coordinator

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    You all rock! Thanks for the great comments. So I've been reading the manual for the receiver I'm probably going to buy:
    Yamaha 5560 Manual in PDF format
    using the receivers test tones to calibrate all 6.1 channels: check! (pages 21-22)
    delay for both center and center rear: check! (page 43)
    What about delay for the side surrounds?
    hrmmm... I'm thinking page 50 means I can set a seperate delay for the side surrounds for every DSP mode. What would I want to do that? Wouldn't time delay for all surrounds (rear and centers) be a "set it and forget" setting? And I'm not sure from the wording on page 50 if they mean the delays for all 3 surrounds or just the 2 side surrounds?
    Thanks!
     
  8. Rich Malloy

    Rich Malloy Producer

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    Your delay settings will be different for DD-5.1/DTS vs. Dolby Pro-Logic. I don't know why, but there it is!

    And DSP modes futz around with volumes and delays to produce such annoying "echo-y" effects as "Hall" and "Stadium". You can change them around if you wish, but I generally just ignore them.
     
  9. SidH

    SidH Agent

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    The ability (for better or worse) to change the delay for each DSP program is indeed a quirk that seems to be peculiar to Yamaha (I myself have an RX-V3200).

    I think it has to do with their particular emphasis on DSP processing, which I used to play around with a lot (but I no longer have the time). IMHO their DSP programs are much more sophisticated than any other manufacturer's (save Lexicon's) and flexible as well. But if you don't care about such stuff, it is just an additional hassle (albeit a minor one).
     
  10. MoG

    MoG Stunt Coordinator

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    So am I correct in assuming the feature of changing the delay for every surround mode is basically a VERY customizable way to change the JOINT delay for the L/R surrounds? Sounds like (no pun intended) there is no ability with this receiver to set seperate L/R surround delays.

    I suspect the center delay is not affected by these values. More specifically, I imagine the center delay is simply added to these surround delays.

    I guess a joint L/R surround delay is acceptable... would've been nice to have had seperate delays for L and R surrounds.
     
  11. Rich Malloy

    Rich Malloy Producer

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    MoG, now that I think on it, I can't recall for sure whether my Outlaw 1050 has adjustable delays for the R and L rear surrounds (though I'm pretty sure it does). But so long as your listening position isn't off-axis (that is, so long as it's centered between your speakers), then it's not of great significance IMO. But it is important that you're able to adjust the delay on the rear-center channel independently, and also (IMO) that you can set the output level of each speaker independently. Room idiosyncracies can cause output level differences from the left to the right side that may need compensating for. Delay, however, shouldn't be effected by anything other than distance from the listening position.

    And I can tell you from experience that the proper setting of output levels on your speakers - using a Radio Shack analog meter (and if you don't have one, buy one!) - is the best and cheapest tweak you can undertake. In fact, it's so important in the attainment of good sound that I'm hardpressed to call it a "tweak" - it's simply a necessary step in setting up your system. (But you probably already know this!)
     
  12. StephenL

    StephenL Second Unit

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    I have an unusual room. The back of my living room/home theater has a railing overlooking a foyer and staircase. My surround back right speaker is mounted on the back wall of the foyer 7.5 feet from the center seat. My surround back left speaker is mounted on the back wall at the top of the stairs 5.5 feet from the center seat. Speaker distances and levels are properly calibrated. I tested the surround back channel using the "Tex II" THX-EX demo from the Kenwood Sovereign DVD. Tex flies around the room and in the surround back channel he can be heard sawing and hitting himself with a hammer ("ow!"). First I tried a pair of monopole speakers for the surround back channel. They provided the proper image for listeners in the center and right seats, but Tex sounded as if he was front and center to a listener in the left seat. Then I tried a pair of dipole speakers for the surround back channel. They provided the proper image for all seats. Best advice: experiment to determine what works best in your room.
     
  13. Rich Malloy

    Rich Malloy Producer

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    Very interesting, Stephen.

    I'm currently running two dipoles on the side and a monopole in the rear (happened to have a matching one handy), but am on the crux of an upgrade. I prefer the sound of dipole surrounds, generally, and so have been wondering whether I should stick with my current two dipoles and a monopole, or go all dipole for the surrounds.

    Sounds like the latter may be the way to go for me, too. Have you experienced any problems with the dipole rear-center? Is it too diffuse, or does it really seem to blend better?
     
  14. StephenL

    StephenL Second Unit

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    Rich, I prefer the sound of dipoles for the left and right surround channels too. I suspect that the distance between the listener and the surround back speaker(s) is an important factor in deciding which type of speaker use. I think that a pair of monopole speakers would work in my room if the surround back left speaker could be placed as far back as the surround back right. The main problem in my room is that the surround back speakers are not on the same plane. Using dipoles in my room may provide more diffusion than necessary for listeners in the center and right seats, but they provide proper imaging for a listener in the left seat. Try using your dipoles for the surround back channel and let us know what you think.
     
  15. Rich Malloy

    Rich Malloy Producer

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    Unfortunately, I've only got a pair of dipoles, but I could hook up some monopoles on the left- and right-rears and put a dipole (or pair of dipoles) in the center-rear. That won't let me know how all three would interact if they were all dipoles, but I guess it would give me some idea what a rear dipole might do. Hmmmm....
     
  16. StephenL

    StephenL Second Unit

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    For those interested in using one speaker for the back surround channel, Daniel Kumin of Sound & Vision reported that he's had great success using a single bipole speaker. Boston Acoustics makes one for that purpose:
    http://www.bostonacoustics.com/Produ...=1&SeriesID=35
     
  17. SidH

    SidH Agent

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    I am also in the process of upgrading my surrounds. My problem is that the listening position is a couch sitting right up against the rear wall. Also, the surrounds have to be mounted up at least 8 feet high.

    Because of that, I was afraid that I would lose too much detail using dipoles or bipoles firing across over my head. I spoke to a dealer about the problem but he seemed more interested in selling me a $1500 amp (has this ever happened to you?).

    I finally decided to go with monopoles, specifically (and coincidentally) Boston Acoustics Bravo speakers that were also reviewed by Daniel Kumin in S&V. These speakers are designed for corner mounting so they can go up where the rear wall meets the ceiling. Supposedly, this kind of placement gives a more diffuse effect that approaches bipoles.

    It's too bad that it is much more difficult to audition surround speakers in a meaningful way unless you actually bring them home. I should be getting the speakers in a week or so, I'm keeping my fingers crossed....

    Sid
     

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