HELP! un-powered subwoofer!

Discussion in 'Archived Threads 2001-2004' started by CraigB, Sep 16, 2002.

  1. CraigB

    CraigB Auditioning

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    Hi, first post and new to HT, so please bear with me.

    We are undergoing a renovation/addition project and in the family room I coaxed the wife into letting me setup hometheater/entertainment center. I had custom install folks come out to the house but EVERYONE wanted to charge and arm and a leg above retail and would not give me what I wanted (it is a family room, not a dedicated hometheater). So, I ventured out on my own and purchased the equipment/speakers/etc and working with our electrician (who has experience in hometheater).

    The family room is an octagon and we decided to go with in wall speakers to save space and compliment the Sony PFM-50C1 Plasma that will be mounted on the wall. I went with the Niles HDLRS setup for front/center/rear and the in-wall PSW8 subwoofer (all run back to a dedicated A/V closet with a Sony STRDA2ES Receiver, Sony DVP-NS900V DVD player, etc...). PROBLEM: The sub is not powered and I didn't really take this into consideration prior to buying (looking for an in-wall sub that wouldn't break the bank). Sooooo, what impact will this have on our viewing experience and can anything be done (should anything be done?).

    Thanks in advance,
    Craig
     
  2. Jason Wilcox

    Jason Wilcox Supporting Actor

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    ...
     
  3. Ted Lee

    Ted Lee Lead Actor

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    you're looking for an in-wall sub?
    i'm not real familiar with those, but i suppose an unpowered sub is an unpowered sub.
    well, you're definitely going to have to buy an external amp. i suppose you can put the amp somewhere near your receiver then run the cable through the wall to the sub?
     
  4. CraigB

    CraigB Auditioning

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    I already have the in-wall sub (Niles PSW8) and it currently is set to be connected to the front L/R channels via a built-in crossover routed back to the receiver.

    With regards to how this may impact our viewing, specifically if the sub is unpowered and thus not connected as true 5:1...I guess it will be connected and low frequencies will be routed through the sub, but not a true 5:1. Will someone such as myself notice a major difference when watching movies . Will it be worth the hassle of grabbing an amp and directly connecting to my sub and receiver and pulling cable again (sheet rock is already up)?

    Thanks!

    Craig
     
  5. Ted Lee

    Ted Lee Lead Actor

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    just to confirm -

    you have the speaker wire routed like this:

    receiver --> sub --> speakers

    if that's the case and you are using the subwoofer's x-over and it's NOT powered, then i think you're going to "lose" all the LFE.

    essentially, you're telling the sub to "cut" all frequencies below the x-over point and only "send" the rest to your main speakers. however, the "cut" part won't have any power, so you'll never hear it.

    i'm not familiar with unpowered subs and how they utilize speaker level inputs, so someone please correct me if i'm wrong.
     
  6. Lew Crippen

    Lew Crippen Executive Producer

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    I am not familiar with the Sony receiver that you are using, nor the passive sub, but in general here is how to setup a passive sub:
    Connect as you have stated through the R/L front channels.
    On your receiver set your R/L front speakers to Large
    On your receiver set the center channel and the rear/surround speakers to Small
    On the receiver set the subwoofer to off or no, or none, or whatever is the appropriate labeling on your receiver.
    Your receiver may have a frequency setting that determines a cross-over for small speakers. This will send only frequencies above the setting to the small speakers. And all (above and below) frequencies to the front speakers. Set this cross-over to a setting in accordance with your center and surrounds. Probably this should be around 80–90Hz, but if you have very a small center and surrounds, you may want to set this higher (150Hz or 200Hz).
    There should be a crossover in your sub that passes frequencies above the setting to the R/L front speakers. If this is adjustable, set it in accordance with the characteristics of your front speakers.
    All of this taken together allow the sub to get all of the low frequencies (including the LFE, even though you don’t have the .1 of 5.1). However, the sub uses power from the two channels that, in most cases require the most power.
    Therefore you should follow Jason’s advice and buy a cheap amp to power your sub. Then run the sub from the sub output of your receiver, and set the front speakers to small.
     
  7. Will Orth

    Will Orth Stunt Coordinator

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    Yes do what "Jason Wilcox" Suggested! you can get a ready made built sub amp with a built in X-Over for under $200
    I use 2 of them in my system and very happy so far.


    Will
     

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