What to do with this cab?

Discussion in 'Amps and Cabs [BG]' started by lowsideonacurve, Mar 21, 2011.


  1. lowsideonacurve

    lowsideonacurve

    Feb 24, 2011
    I've got this Sub woofer cab that I think might make a decent bass cab.

    It's an Optimus Pro SW14 with a 12" speaker, 8ohms, 100 watts.
    cab.jpg
    I hooked it up to the Ext. Spkr. line out on my Fender BXR 15w practice amp and was blown away by the bottom end coming out of this thing! This thing is loud, no mids or highs, but enough lows to upset the neighbors.


    It has some components under the connectors that I assume are the Low-Pass and High-Pass Crossovers.
    board.jpg
    I'm just curious if these can be bypassed or modified to make this into a functional extension cab.

    Inside cabinet dimensions are; 15"W x 16"H x 12"D, 3" port.
    Speaker and wiring suggestions would be appreciated.
     
  2. will33

    will33

    May 22, 2006
    austin,tx
    Well, just looking at it, I'd say because it's MDF construction with 45's in the corners...feet on the same side as the speaker (down firing), and a bunch of inductors.....it's a home stereo type subwoofer. As far as gig level stuff, it won't add really anything you could hear to your sound.

    As far as putting bottom under a bedroom practice amp....it'll definately do that.:D
     
  3. will33

    will33

    May 22, 2006
    austin,tx
    It's probably a low-passed sub with a "high-out" to chain to the rest of your system so you could run off of one amp.
     
  4. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    It's a hi-fi subwoofer, which will sound fair enough paired with a 15 watt combo, but won't last one set at gig levels.
     
  5. lowsideonacurve

    lowsideonacurve

    Feb 24, 2011
    Yeah, I knew it was a Hi-Fi Sub Woofer, (Optimus Pro SW14) and making a punchy little practice rig is pretty much what I had in mind because the 8" speaker in my little Fender BXR 15 farts out at 5+. The 15w line out makes plenty of deep low end with this sub woofer, but no mids or highs regardless of treble, and EQ settings.
    I was wondering if it were as simple as bypassing the cross overs and going direct to the speaker, or does it need some sort of circuit?
     
  6. You'll never get good useable bass at high volume out of this cab. It's internal volume is an estimated 1 cu. ft. which is just too small for any pro sound 12" bass speakers that I am aware of. If you can live with that and want a loud cab then an Eminence Kappalite 3012 HO with a 3 x 5 port will be plenty loud but not low. In a case like this you would just bypass the crossover.

    If you just want bedroom levels then you should keep the sub AS IS and connect a small cab to the high pass out of the sub to handle everything above 200hz. Typical subwoofer speaker drivers are not capable of any high frequency content even if the crossover is bypassed. This is the trade-off for getting low frequency extension.
     
  7. Robby Hoinsky

    Robby Hoinsky

    Dec 28, 2010
    New Haven, CT
    Art of Noise Audio, fEARful™ builder
    It is an interesting looking crossover because it looks like two identical 3rd order crossovers with both pairs of speaker leads going to the speaker, which doesn't quite make sense. Do all four of those wires go to the speaker?

    I'd use it as is paired up with a combo amp. It will add some nice lows. Or you could just bipass the crossover and try it full range, probably wouldn't sound that bad.

    Robby
     
  8. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    It does with a dual coil driver. It's not dual 3rd order, it's a pair of 1st order, low pass for the sub driver and high pass for external mains.
     
  9. lowsideonacurve

    lowsideonacurve

    Feb 24, 2011
    Thanks MuzikMan, just the kind of info I was hoping for. I tried connecting a KLH Center speaker, (100w 8ohm 2x4 with a small tweeter ) to the high pass out of the sub as suggested and it sounded much better, but the ultra low frequencies from the sub are still too much. I may play with bypassing the crossover yet, but I'm sure you're right, it would never produce a usable sound even with an appropriate speaker.
    Again, Thanks for the info.
     
  10. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
    Jul 24, 2021

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