Another power / impedance / multiple cab question...

Discussion in 'Amps and Cabs [BG]' started by therealting, Jan 8, 2005.

  1. I have an amp that puts out 300w @ 4 ohms (so, probably about 200w @ 8 ohms).

    I have a 250w 8 ohm cab I quite like and am considering getting a second. The two cabs chained together, for 4 ohms, would allow my amp to give out its full 300w output to the cabs, or 150w each.

    I understand doubling the wattage increases loudness by about 3dB, which is very little... and in this case 50% more power is not a big factor, but the doubled surface area of having two cabs will make a huge difference. Correct?

    Now - if I were to then buy a second, identical amp and use it to power the second cab instead of chaining them together, I would be back to 200w a cab. This would not sound much louder than the chaines output (150w a cab) in theory, but I would benefit from extra headroom. Correct?

    Just checking if I am making sense here. I am considering purchasing a second cab, and am thinking further along the line to whether it would be better to upgrade my amp, or to buy a second identical amp for my rig (and hence giving me an automatic backup in the case of failure).

  2. Either way you hook them up each cab is getting 150w I am pretty sure, but if you run in stereo and not daisy chained they wont be taking such a heavy load (both will be run at 8ohms not 4ohms) which means if you wanted to run 4 cabs you could. But maybe I'm just retardedly crazy, I'm really overtired.
  3. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago're correct on all points.

    If you did run two amps, you could tailor the EQ to each cabinet. Rolling the lows off of one cabinet might allow you extra volume before the amp ran out of steam.

    If you really needed more power, instead of a second identical amp, you could buy a stereo power amp and run it off of the preamp output of the first and probably get a lot more power for the money...assuming that you need it.
  4. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Yeah but, why would you want to buy a second amp? Why not just get one amp with enough power? More gear is more gear, all that means is you'll be hauling more weight to your gigs. Sell the underpowered amp, and get one with enough power. You can still use it with just one speaker. :)
  5. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    getting a second speaker will help you the most. running two identical amps will hardly give you any extra headroom. you won't notice it. Get the 2nd 8 ohm cab. if you still feel you need more volume then you're looking at getting something like a more powerful mono head (try it next to your head with the same cabs to see if it really is louder), or a stereo power amp that can put at least 400 watts a side into 8 ohms, or one that will let you bridge it into 4 ohms with at least 800 watts if not more. My guess is just getting the 2nd speaker will be enough.