Subwoofer Basics

Discussion in 'Archived Threads 2001-2004' started by Dave Schofield, Mar 14, 2002.

  1. Dave Schofield

    Dave Schofield Second Unit

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    I've never owned a subwoofer and I'm contemplating adding one to my system. I've currently got a Yamaha 495 driving a pair of Paradigm Monitor 7's with CC-350 and Mini-Monitors coming to round out the 5. part of 5.1 I'm looking at primarily the Paradigm PDR-12 to add in the near future. My receiver does have a Sub Out post (looks like RCA).
    My question is what do I need to add in order to be ready for the sub. I keep hearing people talk about amps or old receivers powering the subs and I get confused. Do some subs have the amp built in (and if so does the PDR-12?) Then, what is this about crossovers? Again, do some subs have them built in? (and again, does the PDR-12?).
    I feel stupid for asking such rudimentary questions, but I figure this is the place to do it... [​IMG]
    Thanks
     
  2. Troy Swope

    Troy Swope Stunt Coordinator

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    Dave;

    yes, powered subs have built in amplifiers. to hook them up, generally all you need is a 110 volt plug close by, and an rca to rca cable that runs from the sub out of your av recvr, to the line input on the sub.

    they do sell non powered subs, they require an amplifier to drive them. (generally you do not want to tax your main amplifier with the job of outputting deep bass)

    as for crossovers, some subs have these built in as well, and some are adjustable from the back of the sub.

    I checked a review of the PDR-12 and from what i have read, it is a powered sub, that is: it does have its own amp built into it. all you would need to do is what i stated above.

    hope this has helped, i have been into HT for while, and just found this site recently. (and yes, I am in the middle of selling my BOSE LS 35 and upgrading... thanks to the expert info out here in HTF land! you guys rock!!)

    (if i have mis guided here, please step in and correct guys!)

    -troy
     
  3. Dustin B

    Dustin B Producer

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    Nope everything you have said so far is correct.

    What kind of budget are you looking at Dave? The PDR12 is a decent sub, but unless you are getting one hell of a deal there are quite a few other subs out there that will offer a much greater cost/performance ratio.

    The Adire Rava at $399. The HSU VTF2 at $450. The SVS 25-31PCi at $550 and the Adire Dharman at $599 are amoung my top picks.
     
  4. Dave Schofield

    Dave Schofield Second Unit

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    Where might I check out the Adire subs? URL?
     
  5. Harry Lincoln

    Harry Lincoln Stunt Coordinator

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  6. Dustin B

    Dustin B Producer

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    I suppose I should mention. If you have tools and some wood working experience. Or know someone with the tools and experience who would be willing to help you. You may want to build your own. You'd be amazed at what can be done in the $250-$400 with DIY subs.

    Alternatively you can contact Kyle at Acoustic Visions. He'll do as much or as little of the DIY part as you want. He will sell you a fulling completed DIY design at a fair price, he will sell you a flat kit and the components that you can then assemble. Or he'll can just sell you the raw components and you can build the entire enclosure yourself.
     
  7. Ten_Smith

    Ten_Smith Stunt Coordinator

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    As another person who has never owned a sub and is considering getting one, I too have a basic question. Do you have to adjust the volume on the sub separately as you adjust the volume on the receiver, or does it Does the volumen on the sub somehow automatically match the receivers volume, or do you have to adjust it separately each time you adjust the receivers volume?

    How do you decide what level to set the sub at?

    PS. Depending on your budget you may also wish to consider the Sony WAMF20 (model number may not be quite right). Goes for ~$200 and I saw it mentioned here as 'best sub under $300.' I also wonder about the Acoustic Research AR-S112PS which I saw advertised for around $189.
     
  8. Tony Granatelli

    Tony Granatelli Stunt Coordinator

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    Hi Guys,
    Although I am no expert, this following statement, while correct, will be much more expensive than what I suggest:
    yes, powered subs have built in amplifiers. to hook them up, generally all you need is a 110 volt plug close by, and an rca to rca cable that runs from the sub out of your av recvr, to the line input on the sub
    If the sub is greater than 3 or 4 meters from your A/V unit, RCA to RCA will be very expensive. I went to Radio Shack and purchased 50 feet of RG6 as well as 2 cable to RCA male adapters. This arrangement works excellent, and cost only anbout $18.
    Tony
     
  9. Dustin B

    Dustin B Producer

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    The sub preout on the receiver is a variable output. As you increase the volume on your receiver the sub preouts output is increased. So no you don't have to adjust them seperately.

    Although you should get an SPL meter and a calibration disc; and level match the sub and the other 5 channels. After this is done all you will ever have to change volume wise is the master volume level on the receiver.
     
  10. Ted Lee

    Ted Lee Lead Actor

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    another feature to look for is a "phase" switch (knob?).

    this will invert the phase of the woofer cone so that it "matches" the phase of your speaker.

    this comes in handy when (because of various room acoustics) the sub actually ends up being out-of-phase with your main speakers. so you end up having a cancellation effect, thereby weakening the sub.

    although i've never tried...they say a neat trick for sub placement is to put the sub wherever you will sit. then crawl around the room until where the sub sounds "best"...that should be the idea location for your sub.
     
  11. Dave Schofield

    Dave Schofield Second Unit

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    I auditioned the PDR-12 and PW-1000 today. Both sounded very nice, though I liked the PDR-12 more (it doesn't hurt that I like the look and the price is less too). The salesman that I spoke with didn't seem to know his stuff. I've seen a bunch of threads here that have indicated that bandpass subs are not good HT subs, but when I mentioned this he said it was quite the contrary and started talking about the total watts of the PS-1000. I'm looking at the PDR-12 seriously, though I have to see how my new home next year will deal with bass. I'm renting an old fixed up grainery next door to my landlords house (out in the country) and I'm worried that the bass will travel a bit too far [​IMG] Is there any cheap way I could 'dampen' the wall facing her house?
    If I was in the mood for a DIY project I'd look at some of the things you mentioned, Dustin, but I'm really not up for it.
    Thanks everyone!
     
  12. Dustin B

    Dustin B Producer

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    I just don't like bandpass subs in general (never heard one I liked). People usually talk about music vs hometheater subs. In my opinion a sub can either be excellent for both or excellent for niether. If it is an excellent home theater sub it will also be an excellent music sub. If it is an excellent music sub it will also be an excellent home theater sub. Both require tight defined bass that can extend to the last octave with authority.

    If a sub lacks low end and high output capabilities but has tight defined bass, it will make an acceptable sub for most music, not an excellent one. But it won't make a good home theater sub for action movies.

    If a sub is boomy (bandpass are almost invariably boomy), but has most of the low end and high output it will make a barely acceptable home theater sub, not a good one, and far from an excellent one. The PS1000 is in this category. A barely acceptable home theater sub and a very poor music sub.
     
  13. Dave Schofield

    Dave Schofield Second Unit

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    If I were to buy a PDR-12, for instance, would my receiver know that a) the sub was there, natively (like it does when I don't have a center channel, like right now) and route the LFE track to it and b) does it set the crossover to a 'preset' point, like 60hz?

    I guess what I'm really asking is this, am I completely missing the LFE track right now? When I do get the sub will I have then get the LFE track AND take f
     
  14. Dustin B

    Dustin B Producer

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    You'll have to look it up in your manual for the specifics. But in general for yamaha receivers you have to tell it whether there is a sub there or not. If you tell it there is a sub, the LFE channel is sent there. If you tell it you don't have a sub then the LFE channel is sent to the mains. It doesn't detect this, you have to set it up. I'm pretty sure it doesn't detect the center either, you have to tell it.

    Then you also have to tell the receiver if your speakers are large or small (bad choice of words by receiver manufactures). If you set a speaker channel to small, then anything below 90hz in that channel is sent to the sub, anything above 90hz is sent to the speaker. If you set a channel to large, then nothing is redirected to the sub from that channel. It is almost always best to set all your speakers to small and let the sub handle everything below 90hz (even with tower mains). As no tower speaker of any reasonable cost (you have to get up into the $8000-$100000 a pair range to get true full range towers) can do as well in the last two octaves as a sub.

    All yamaha receivers have the sub crossover fixed at 90hz. Onkyo is fixed at 80hz and Marantz is fixed at 100hz. Denon has some fixed at 80hz and a couple with variable (one is 80/100/120/ some more stupid high ones, and another is 40/60/80/100).
     

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