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Can you add a cab onto a combo?

Discussion in 'Amps and Cabs [BG]' started by ReCkLeSsAbAnDoN, Jul 1, 2002.


  1. ReCkLeSsAbAnDoN

    ReCkLeSsAbAnDoN banned.

    Jun 13, 2002
    Hey, i was just wondering. I have a rogue 120w combo amp, and i was wondering if i could upgrade it. Ive read descritptions of other combos saying "enough power to power a 4x12" cab". So i was wondering, if i were to buy a cab....say 2x12" or something near, could i add it to my combo, or would i have to buy a whole seperate head? If i were able to, how would i go about doing this?

    Thanks

    Mike
     
  2. misterk73

    misterk73

    Apr 11, 2002
    Flagstaff, AZ
    Depends on the specific combo, I believe. Mine is 200W on its own and 350W with an extension cab, but it was designed that way.

    On you combo, what do you have in the way of in/out jacks? Anything labeled or look like it was designed for an extension cabinet?
     
  3. ReCkLeSsAbAnDoN

    ReCkLeSsAbAnDoN banned.

    Jun 13, 2002
    "features a line out, CD/Tape in for practice, headphone out, and an XLR direct out (pre EQ) with ground lift." If that helps any.....
     
  4. CS

    CS

    Dec 11, 1999
    UK
    Your amp doesn't have the facility for an extension cab. ok so you could wire in a socket but you'll have a problem.

    The existing speaker will be the wrong impedance to do it. This is how it works.

    The maker produces a combo that has a power amp capable of say 120w into 4 ohms. So they hook up a 4 ohm speaker and no extension socket (like your Rogue).

    Another maker produces a combo that produces say 120w into 4 ohms BUT they hook up an 8ohm speaker and an extension socket. This does 2 things 1 the player can 'upgrade' with another cab (must be 4ohm) 2 on its own the combo produces approx 80w (dont even think of correcting me-it's a guess). Losing this much power means a fairly significant reduction of volume/headroom and on a 120w amp this makes it close to unusable with a loud band.



    So you are going to need a new speaker to get a drop in volume then fork out for the cab. If you dont change the speaker you could blow the amp up if you add the ext. If you are unsatisfied with your amp 1 save for a new one 2 have a look at new speakers. Check the ohm and db ratings. Go for the same ohms and greater db.
     
  5. ReCkLeSsAbAnDoN

    ReCkLeSsAbAnDoN banned.

    Jun 13, 2002
    So what exactly would i look for in speakers. 8ohms? 4? and what would each allow me to do?
    Sorrie if im troubling you.

    by the way....im in a band, and well, we havent played any gigs yet. is the 120w good enuff...if say the guitar player has around 100w....for smaller gigs and gigs where i can run thru a pa? or should i look elsewhere?
     
  6. Ty McNeely

    Ty McNeely

    Mar 27, 2000
    TX

    You can't add an extension cab with what you have now. Your combo won't allow it.


    I would guess 120watts is enough, but it's a Rogue so you may have trouble with your tone if it get's too loud.
     
  7. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    To compete volume-wise, a bass needs about ten times the power of a guitar amp. This is because it takes much more energy to excite a speaker at bass frequencies. So for a band in which the guitarist plays a 100-watt head (which in guitar-land is a monster amp), you need nominally 1,000 watts and plenty of cabinet to compete. I'd say you could get away with a combo like the Eden Metro, which can produce 600 watts with an extension cab. Certainly, you'd want to have at least 300 or 400 watts to be real in any way.

    Seriously, a lot of guitarists use 40- or 60-watt heads on stage. I wouldn't want to be below 300 watts in that situation.
     
  8. CS

    CS

    Dec 11, 1999
    UK
    A 120w bass amp is going to struggle against a 100w guitar amp. If it's a valve one and the guitarist cranks it your amp will really struggle. As a rule of thumb I would use x4 not x10 (sorry Munji) which means a 400w amp. Assuming you don’t have disposable income of Eden or SWR proportions here's what I would do.

    In the band situation place the bass amp on a stand (chair/table) angled up a bit and facing sideways pointing at the drummer. Stand in the middle. Also try a little distance between you and the amp. So..

    Drummer you < amp

    Use your DI output to drive the PA and hope the sound desk attendant doesn’t ignore everything below 500hz.

    If you start gigging reguarly save for something in the 300w range. I used 140w for years until I could afford a 220w (valve and very loud) head and 4x10 which I use at the moment.
     
  9. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    I WAS going to say 20 times the power. Any way you look at it, you need many times the power of the guitar amp to be annihilated.