Anyone use their cab as a subwoofer?

Discussion in 'Amps and Cabs [BG]' started by jive1, Jun 15, 2004.

  1. jive1

    jive1 Moderator Staff Member Supporting Member Commercial User

    Jan 16, 2003
    Owner/Retailer: Jive Sound
    It's a little off topic, but has anyone used one of their bass cabinets as a subwoofer for their PA?

    I am rethinking our sound system, and am considering some subs. When I look at the specs, and ratings I find that one or two of my bass cabinets could do the trick. I can't see why it would be dangerous, or ineffective, but I don't know everything. Just plug the cab into the subwoofer power amp, and make sure not to give it more bass than it can handle, and crossover at the right point.

    Anybody done this, or have any thoughts on how to do this? Or is it not as simple as it seems?
  2. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    Most PA subs I've seen are designed for long-throw of deep bass, and most bass cabs are designed for shorter-throw with more low-mids. Pushing a bass cab with extreme lows, and trying to get them to throw those lows far, far into a room might prove too stressful for them.
  3. GrapeBass


    Jun 10, 2004
    Graphic designer: Yorkville Sound
    I've always said my 15 was for the audience (LF) and my 210 was for the stage. So, in a pinch you could possibly get away with some bass cabs as a sub, but I'd probably go with a twin 15. A single 15 is pretty well optimized around 80 Hz. Please, hold the tuning laughter boys'n'girls... The fact is MI cabs usually don't have the tuning tweeted for PA, but MI... the MI cabs also contain speakers that are not PA speakers, they're made to not only reproduce a bass guitar but compliment it as well. Also, a true sub should be crossed over about 100 Hz. If you do lots of medium sized venues do you really need a sub? What type of LF info do you need to go through the sub? Bass drum? Toms? Any good PA cab should be able to deal with that. No if you're playing larger venues that require all the band to go through the PA then buy a real sub, don't try to compromise.

    Jus' mt 2 centavos...

  4. Ericman197


    Feb 23, 2004
    What's an MI cab? I probably know what it is, but I just can't think of the acronym...
  5. GrapeBass


    Jun 10, 2004
    Graphic designer: Yorkville Sound
    "What's an MI cab? I probably know what it is, but I just can't think of the acronym..."

    Musical Instrument
  6. In my last band, we used my Carvin 1 X 18" cabinet as a sub-woofer and it worked very well.
  7. Jerry J

    Jerry J Supporting Member

    Mar 27, 2000
    P-town, OR
    Oddly enough I was thinking this same thing the other day. :confused:
  8. BruceWane


    Oct 31, 2002
    Houston, TX
    There is no reason you couldn't use a bass guitar cab as a PA subwoofer, as long as the cab is intended to reproduce the frequencies you're going to be pushing through it. A lot of bass cabs roll off low end response starting around 50Hz, which isn't any worse than most of the cheaper PA subs. The average bass cab is not going to perform as well as a 2x18 JBL sub, though.

    As far as "throw" that is entirely a function of the cabinet design. Horn loaded cabinets, like the well-known Cerwin-Vega "Earthquake", are designed to be more directional, where the typical front loaded vented cab is less so. But even horn loaded designs are intended to be used in multiples to achieve any real directional sound. The biggest advantage of horn loaded subs is the boost you get in efficiency. The disadvantage is their size and weight.

    For a typical gig, front loaded cabs are fine. You have to get into a pretty big room, or outdoors, before you'll have any real need for directional bass. Most people expect it to be a little quieter at the back of the bar, so having an array of bass horns throwing low frequencies against the back wall probably isn't really desirable anyway.

    So yeah, sure, you could use your bass cabs for PA subs, just be careful about feeding them frequencies below their range, and of course watch the wattage.
  9. I used my 1x15+2x10 as a sub for a rather underpowered PA system that we quickly knocked up for a college 'cultural' evening.

    The PA system that a mate brought in was 100w per side, which was fine for filling the 900cap hall for just vocals, but for a fashion show they were putting on it couldn't handle the bass or provide the volume. As a result I offered up my amp which we connected to the sub out of the mixer using my amp's "Power Amp In" section, bypassing the pre-amp.

    It worked very, very well. The whole hall (which is pretty damn big, around 120ft square and 3 storeys high) was filled with bass, even the very low end drum 'n' bass music. We actually got some complaints from the audience that the bass was too deep.

    The general idea was to use the 1x15 as the sub and the 2x10 complimented the existing PA. I'd do it again, but only for smaller events like this, not larger shows.
  10. Petebass


    Dec 22, 2002
    QLD Australia
    I'm putting together a small PA for some Duo work I've got lined up. Think of it as a DJ rig playing mostly recordrd music, except for the bass guitar and vocals which will be live. I built 2 seperate 1x10+horn cabs for mids and highs, and I'm using my JBL 15" bass speaker for bottom end. The kick drum and bass guitar sound very nice. But I doubt I'd be able to use it as a band PA. I believe a miced up kick drum would blow that 15 speaker to smithereens...