1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Rear sub?

Discussion in 'Subwoofers' started by petrolhead, Oct 20, 2002.

  1. petrolhead

    petrolhead
    Active Member

    Joined:
    Mar 29, 2002
    Messages:
    4,497
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    71
    Location:
    Newcastle
    Ratings:
    +83
    Having recently bought a Rel Strata III (Thanks Allan) to replace my PDR10. I have a question.

    Either I sell the PDR10 or how about I connect it to the rear surrond channel.

    Has anyone done this?

    Could I encounter any problems with the 2 subs fighting against each other?
     
  2. lynx

    lynx
    Well-known Member

    Joined:
    Jan 20, 2002
    Messages:
    4,633
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    It always rains.
    Ratings:
    +301
    Connecting to the rear surround is not the best of ideas as you want the signal from the lfe channel.Why not try a 'Y' splitter at the sub output and run a second cable to your rear sub?
     
  3. petrolhead

    petrolhead
    Active Member

    Joined:
    Mar 29, 2002
    Messages:
    4,497
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    71
    Location:
    Newcastle
    Ratings:
    +83
    I have now tried this. I am using a Denon 3802.

    I had to set the front L&R to large so that I could then set the surrouns to large, this was so I would get all the frequecy at the rear otherwise the sub did nothing.

    I also set the Sub to LFE. The choice is LFE or LFE + Main. My understanding is that set to LFE the lows still only go to the sub for the front L&R and if I set it to LFE + Main the lows go to the sub and the L&R. Not sure if this is correct, the manual does not realy clarify this, so if someone knows better?

    I then tested the opening to Toy story 2. To check it had worked I switched the front sub off so that I was sure the rear one was working and sure enough I get sub bass only when the rear effects work.

    Then I reconnected the front sub and did a further test and all seems fine.

    The best bit to check is when Buz getting blown into the sky when the robots blow up. Just as he lands the first piece of robot flies from left to right in the surround, what a difference, get this grate swoosh with a nice bit of bass as the piece fies left to right and then lands.

    I hope this makes sence.

    Lynx. The flaw in your idea is that I would get all the sub bass going to the rear sub which would defeat to object and would also sound a tad confusing.
     
  4. lynx

    lynx
    Well-known Member

    Joined:
    Jan 20, 2002
    Messages:
    4,633
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    It always rains.
    Ratings:
    +301
    Unless were at cross purposes you've lost me.The (lfe) signal at both subs will be the same and controlled by the recievers bass management. The 'Y' connector taking up at the reciever outlet,with a tail going to each sub. I accept that this will not be a surround bass channel if that is what you were looking to achieve. :)
     
  5. petrolhead

    petrolhead
    Active Member

    Joined:
    Mar 29, 2002
    Messages:
    4,497
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    71
    Location:
    Newcastle
    Ratings:
    +83
    You may be right and maybe I don't fully understand the Bass Channel.

    My thought was that I only wanted to enhance the rear channel with some base and thats why I connected the rear sub to the rear channel. I am probable doing something that should not be done as there is no rear sub in a cinema setup but I do detect an improvement to rear effects, they now have more weight.

    If I went the Y piece route I would get all the films bass at the back as well and that would confuse the rear effects.

    You probable think by now that I have gone mad :)
     
  6. Dom H

    Dom H
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    The thing you need to understand is bass is non-directional, ie you can't tell where it's coming from. That's why you only need the one sub. If the rears are set to 'small' then all their bass will be re-directed to the sub. It doesn't matter where the sub is as you can't, or rather shouldn't be able to pinpoint it anyway.

    In short, bass doesn't come from a particular direction, front, rear, side etc. it's merely everywhere!

    man thats deep :D
     
  7. The Nightfly

    The Nightfly
    Active Member

    Joined:
    Aug 31, 2002
    Messages:
    801
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    The New Frontier
    Ratings:
    +23
    Petrolhead,

    Just a thought. When I was running two subs with the rear sub connected to the rear speakers (ie high-level connection with rears set to 'large' at the amp) the rear speakers I was using seemed to handle the full range okay. The low frequency output from the rear speakers rolled off naturally and the sub's crossover was set to blend-in with the speaker roll-off.

    However, I guess with some really small rear speakers the full range signal might cause problems handling the cone excursions resulting in a limit in loudness from the rears before you start hearing distortion or 'cracking'.

    Some subs have both input and output speaker connections with the output having the low frequencies filtered out. If you have this facility on your PRD10 it might be worth using it. It will allow you to set the rears to large yet limit the bass being sent to the speakers themselves.

    Allan

    Edit: as to directionality, it is true that deep bass is non directional but above 50/60Hz directionality starts to set in. With very small speakers crossed over at say 100 or 120Hz then the upper output from the sub starts to become discernable.
     
  8. uncle eric

    uncle eric
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I have to disagree with you Dom. Even when crossing over low, although many of us cannot actually hear where the LF's are coming from we can feel where they are coming from.
    This is why I always advocate (when ever possible) that subs should be placed either side of the centre (or both sides when using a pair)
     
  9. petrolhead

    petrolhead
    Active Member

    Joined:
    Mar 29, 2002
    Messages:
    4,497
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    71
    Location:
    Newcastle
    Ratings:
    +83
    You are on my wavelength Allan. Thats exactly what I have done :)
     
  10. Dom H

    Dom H
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Got me there eric, I've never really considered feel to be an issue but having 'the wave' come from one side is actually rather distracting as you say
     

Share This Page

Loading...