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Anyone running two subs?

Discussion in 'Subwoofers' started by cmcg55, Jun 13, 2005.

  1. cmcg55

    cmcg55
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    I know this is going to sound really dumb, but... I've heard of some people using two subs at the same time. My question... well, I've got two of them:

    Firstly, for those who've done this, what benefit did it bring? Is it a noticable difference? I suppose I should also ask... WHY did you do it? Really big room, or... ?

    Secondly, how do you connect it? I know this has got to be obvious, and I'm feeling rather stupid to even ask, but... nearly all receivers have only one sub pre-amp output, so where does Sub #2 get it's signal from? Are there amps out there with two S/W pre-amp outputs, or is it some trick I'm missing?
     
  2. oconnpad

    oconnpad
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    I don't run 2 myself but there are so many opitons to adding a second sub you can have different 1's tuned for differnet freqs, 2 can give a much richer and depper sound. There's people here who run 4 and more subs so they might reply with a bit better info since they have the experience.

    I know it can be tricky to set-up and you could have a negative effect on your system.

    How you get 2 signals from the 1 output is using a Y adaptor on your receiver's single output.
     
  3. eviljohn2

    eviljohn2
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  4. cosaw

    cosaw
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    Well still building my two 60 litre ish sealed shivas. Gonna run them stereo taking speaker level inputs from my mains into active crossover filters with eq in the form of a linkwitz transform then into a seperate stereo power amp to feed the shivas. I'll tell you what it sounds like after they're finished and I've built the electronics - perhaps give us another 6 months! Its been fun and had other projects and am a bit of a perfectionist so these things do take time plus the fact that this is all learning to me as my first speaker project aside from refoaming my main's woofers. Oh and I'm trying to do this on a budget hence the diy route. Had one up and running without crossovers and it certainly sounds authoratative and at the same time musical. My brothers into Beethoven - the little test certainly prooved how much of Beethoven we'd been missing even though my sealed mains do have real good extension.

    Main benefit for me is keeping the size down by having 2 smallish sealed units while getting an spl boost of 6db from just having the extra sub. In tandem I should have plenty of reserve and not have to drive them as hard. The shivas are gonna want some extra wattage for the active eq so I'm gonna need a hefty amp anyway - therefore its nice to have an extra 6db by just utilising the second channel of a stereo amp especially when the use of active eq to extend your low bass can limit the amount of spls you can get higher up in the frequency range due to the fact that you're making your woofer excurse more in the lower end.

    Did quite a bit of reading before going this route - but could do with refreshing my memory also. I've read that there can be downsides as well. Gonna have a look at eviljohns threads to remind myself.

    Simon
     
  5. cosaw

    cosaw
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    Oh forgot to say they're also gonna be corner loaded to get some room gain (again saves on driving them at their limits) one left one right - so looking left to right at the end of my room:

    |Sub L, Main L,.............Main R, Sub R|

    The subs are in the corners - the mains are out of the corners - with my projection screen above when it gets hung - Its all work in progress!! All the speakers are sealed so gonna use the natural 12db/octave rolloff of my mains to cross over with 12db/octave filters to my subs.

    I'm gonna aim to get the subs flatish down to around 20Hz out of the corners and use some cut when they're corner loaded (so that they don't always have to rely on the corners if they get moved to a better position).

    The ideas I talked about are the main reason I decided to go for two over one.

    Simon
     

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