Delay Times and Distance

Discussion in 'Speakers' started by RobTauber, Jan 18, 2005.

  1. RobTauber

    RobTauber Agent

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    I have an Onkyo TX-DS989, and have a 7.1 setup. I have input the correct distances for my 7.1 setup, and have calibrated with a SPL meter. My question is this. My rear speakers are only 3.5 feet behind me, while my side surrounds are both 8.0 feet away. There is a relative delay setting on my receiver, should I consider adding delay to my rear speakers to compensate for the difference in distance between my side and rears, and if so, what would the formula be? My receiver adds -4 to +6 ms of delay. I have played around with the delay, but am not sure if I am on the right track. Any help would be great. My front speakers are all at 12 feet away. [​IMG]
     
  2. steve nn

    steve nn Cinematographer

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    Sure go ahead. Just be sure to calibrate after doing so. I find distance a help (timing) in calibrating a sub sometimes also.
     
  3. Adil M

    Adil M Supporting Actor

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    Rob, I have a 989 and you can set the speaker distance for each speaker. No reason to mess w/ delay unless you are getting lip synch issues. This is something I wish Avia had a pattern to test for.
     
  4. Leo Kerr

    Leo Kerr Screenwriter

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    One rule of thumb is to set the speakers to all the same 'distance' using the delay.

    Another rule of thumb (for conventional surround) is to set the rears to be at least 5ms 'behind' the mains.

    I'd guess that you'd generally want some delay between the sides and the rears, but I really don't know - I'm still in a 5.1 setting.

    So.

    If I remember my calculations correctly, sound moves at about .92'/ms, and is generally rounded to 1 foot per millisecond.

    By this guide, you'd probably want, say,

    20-25ms to the sides
    15-20ms on the rears.

    Perhaps the best thing to do is experiment.

    Leo
     
  5. RobTauber

    RobTauber Agent

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    The only reason I am messing with the delay is so that the receiver processes differently. I have set my speakers to the actual distance. I wish the manual explained the relative delay section better. As I understand it, the receiver processes the signal for the distances I have programmed, then adding delay, the receiver reconfigures the signal to recreate a different distance. So, what I have from scratch is 0 delay on each speaker. Since the Onkyo allows up to 10 feet (-4 to +6 mS) of delay, to compensate for irregular speaker configuration. I have set my rear R/L at +4.5 mS of delay, or 4.5 feet so that the receiver creates a soundfield where my F/C/Sub are 12 feet away, my surround R/L are 8 feet away, and my surround rear R/L are 8' away (even though the signal is based on an actual distance of 3.5 feet) I think this is how it works, and it seems to sound better. the problem I was having is that I did not have very good surround and rear surround seperation. What I was hoping for was that somebody could either confirm or set me straight as to what this setting does and if it works the way I read it.
    Onkyo has taken their usual 12-14 week response time.[​IMG]
     
  6. NhanT

    NhanT Auditioning

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    Rob,

    I was trying to determine this myself (I have the 898)...where does the delay setting come to play? Since you mentioned the manual, I decide to have another look at it. Here's an excerpt...

    "...Once the coarse adjustments--speaker level and distance adjustments--are made, the system is set up to provide a typical or broad surround environment. By adjusting the relative position of the speakers, we are able to alter the soundfield to be more spread out (deeper) or focused (shallower)."

    So basically, the delay is just for fine tuning the previous "coarse adjustments". Another consideration is if one can use it to create more or less "spatial" effect based upons one's preference.

    Thanks for bringing this up by the way. You helped me answer my own question. Oh, this is my first post to the HTF too... I've been lurking way too long.

    Nhan
     

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