One cab is 8 ohm, one is 4 ohm?

Discussion in 'Amps and Cabs [BG]' started by Black 'n Tan, Sep 15, 2005.

  1. What happens if you run a 2x12 (4 ohm) and a 2x10 (8 ohm) off an amp head?
  2. There's a few threads on this with very good technical info if you do a search.

    Quickly.... the total load will be under 4 ohms (I believe around 2.7 ohms).... therefore, if your amp cannot run safely below 4 ohm, you would be in trouble.
  3. My amp is Aguilar DB750. I think it can run at 2 ohms.

    Is this desirable or would I be better off with two 8 ohm cabinets?
  4. That 750 has so much power at 4ohms that I would think it would be better to match the ohmage of the two cabs (i.e., 8ohms each). If you go with a 4ohm and an 8ohm cab... the 4ohm cab will have more power delivered to it, possibly making the pair sound unbalanced. This would be OK if, for example, you had a 4ohm 410 and an 8ohm 210... since, theoretically, each of the 6 individual speakers would be getting the same wattage delivered to them.

    However, all things being equal, it's probably better to run the Aggie at 4ohms (any amp, IMO) versus 2ohms, and at 750 watts into a 4ohm load, I can't believe you will need the extra 100 watts or so that a 2.67 ohm load would give you.

  5. Fuzzbass

    Fuzzbass P5 with overdrive Supporting Member

    I believe the 4 ohm 2x12 will receive twice as much power as the 8 ohm 2x10. I don't see a problem with that, as the 2x12 will likely handle more power.

    I frequently run a 4-ohm 3x10 and an 8-ohm 1x15 from the same amp. The cabinets seem to match up just fine, volume-wise.
  6. Lalala


    Sep 15, 2005
    The Netherlands
    a 4 ohm cab and an 8 ohm cab can do two things:
    blow up your amp because it's not rated under 4 ohms (4+8 is indeed 2.7)
    OR send twice as much power to the 4 ohm cab

    Overall it's best to have your cabs matched
  7. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    I rewired my 4 ohm 2x10 to 16 so I can run it with an 8 and not go below 4 ohms. The 8 ohm cab is louder. I don't stack. In loud rooms, I spread the cabs out for better stage coverage. I give the louder cab to my guitarist and point it a bit towards the drummer and keep the quieter cab on a tilt back stand near me. I'm on the other side of the drummer so I get a bit of both. The other cab is on the floor so most of the db blows past the guitarists knees.

    Works OK. I just scored another 2x10 of the same design so I'll rewire that one to 16 and run the pair which will probably be better. I'm also creating an 8 ohm 2x12 that shouuld be pretty deep sounding to add in if I really need the extra oomph...

    Anyway if you amp can go to 2 ohm's, pairing the cab's is worth a try. Often when pairing cabs, the whole is less than the sum of the parts though. Some cab's just can't agree to get along. In some rooms the pair may work well and others may sound really bad given the various acoustic environments we deal with. All in all a matched set is really a better bet.