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Amp Upgrade Help

Discussion in 'Amps and Cabs [BG]' started by BassPlayerRH, Feb 24, 2003.

  1. Alright. I know next to nothing about amps. I have a Behringer 1200. 120 watts I think. My guitar player just got a Crate stack, and I think I might need to upgrade to keep up with him. So I was thinking about buying a cab. Is it possible to use this amp I already have as the head/preamp in a stack? If this is true, does the cab have to be the same ohm rating? Please help
  2. Petebass


    Dec 22, 2002
    QLD Australia
    Have a look at the back panel of your amp. Is there a plug labeled "extra speakers" or something similar? If not, you could be stuck. This usually means your amp has a certain minimum ohm rating (say 4 ohms)and the existing speaker is already running the amp at 4 ohms. Add another cab and the total ohms drops to below safe levels and the amp will fry.

    If it has a socket for "extra speaker", that's great. This means the speaker is probably 8 ohms, meaning you can add another 8 ohm cab to creats a total 4 ohm load. Speakers are happy, the amp is happy, you're louder so you're happy. The only one who's not happy is the guitarist coz he's not twice as loud as you any more.

    Best bet is to bring the combo to someone who knows about this stuff and have them check the specs. The numbers I used above were just examples.
  3. I've read in the manual about a few options. One of which is speaker, which I think is what I need. It says you "Use the Speaker jack to connect an external bass cabinet. External Bass Cabinets should have a sufficient power rating and preferably an imperdence of 4 ohms to avoid damage." What's "Sufficient power rating" mean? Say this cab has 300 watts of power, and the original amp has 120, does the setup work at 120 or 300 watts output?
  4. Petebass


    Dec 22, 2002
    QLD Australia
    Oh OK. "Use External speaker" is not the same as "extra speaker". Looks like it lets you run EITHER a seperate speaker OR the speaker in the combo, but not both. Like I thought it's a 4 ohm amp and it's loaded with a 4 ohm speaker.

    What they're saying is to run a 4 ohm load and an appropriate wattage. The wattage isn't as critical as the ohms. If the amps is, say, 120 watts, the cabinet should be roughly 120 watts in theory.... Most external cabs will be more than this but that's OK.

    The other option is to buy 2 external cabs, make them 8 ohms each and link them for a total load of 4 ohms. Once you get into this sort of setup, you'd be better off buying a seperate bass head to run it more efficiently and with more power. But we're suddenly looking at a lot of $ so only do it if you really need to.
  5. How many cabs are made with only 4ohms?
  6. Petebass


    Dec 22, 2002
    QLD Australia
    Plenty. Most commercially available cabs come in both 4 ohm and 8 ohm options. The general rule is buy the 4 ohm if you plan to use one speaker only. Buy the 8 ohm if you plan to extend to 2 cabs later on. They should sound identical.

    Here's another idea. Pull the existing speaker out of the combo and replace it with something similar but 8 ohms. Then go buy an 8 ohm cab. Then work out how to link them in paralell and BINGO - total 4 ohm load and both the cab and the combo's speaker will function. But now we're getting fancy.
  7. Pete, you rule!!
  8. So what your saying is if I just use my amp as the head I can get another cab to use as a speaker, but wouldn't be able to use the cab and original speaker at the same time. And that the cab would only have 120 watts of power.
  9. BigTopBruno

    BigTopBruno Supporting Member

    Sep 6, 2002
    NJ, USA
    ..sounds right to me. I had a Crate that had the same thing...internal speaker shuts off if you attach an external one..(what good is that?). I also found out that the internal speaker was 8 ohms and the amp 4 ohm...so it wasn't giving the stated wattage.

    Seems like if you want LOUDER, your best options here are to get a new amp (that's what I did) or run to a PA.


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