Mixing and matching cabs- ohms/ power ratings

Discussion in 'Amps and Cabs [BG]' started by BottomThumper, Jan 25, 2013.

  1. Well I made an effort to see if this has been addressed before, but I am not coming up with anything and keep getting sucked into reading unrelated threads just because they are interesting.

    So here's the set-up:

    I have an Eden Metro combo and would like to add another cab. The Metro has the equivalent of a 210 built in, rated for 350w at 8 ohms. There is an Eden 410T cabinet available nearby rated at 550w at 4 ohms.

    If I did the math right, running these parallel would leave me at around a 2.6 ohm load, which bumps the power up to around 600 watts. The back of the amp indicates it's capable of running with a 2 ohm load at 750w.

    Please correct me if any of these calculations are flawed, and what I'd really like to know is if it's worth getting into a set-up like this. Would I be better off searching out another 8 ohm cab? Is pushing my volume up until the combo's internal speakers start distorting going to be my new peak indicator?

    Thanks in advance-
  2. B-string

    B-string Supporting Member

    Yes to question in bold. I would expect a good amount of increase in actual sound pressure. IMO/IME
  3. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Electrically a 4Ω 4x10 and an 8Ω 2x10 would match with each driver getting around the same power. As Mr. B posted you will be able to get louder, more speakers and more power from the amp. How the two will sound together is a question of try it and see.
  4. RickenBoogie


    Jul 22, 2007
    Dallas, TX
    Agreed. In THIS case, you'll have a significant increase in volume, and all 6 spkrs will get balanced power. If you were to go with an 8 ohm cab, it should be another 2x10, to balance what's in the combo, but your current plan seems solid.
  5. Also a big plus because of one of the usually overlooked factors: efficiency. If you added a 410 Ampeg cab, for example, the difference in efficiency would be unworkable.
  6. That's an aspect I didn't even consider- double the speakers at half the impedance will create even power going to all 6 speakers, with the two in the combo only good for 350 watts, though, I imagine I'll be dialing the master back a little bit more. Man, I wish I had known all this stuff 30 years ago. It would have saved me a BUNCH of heartache- and money...

    And Paul, you reminded me of another question that bugged me when I was writing the original post: what's the key combination to get an ohm symbol? ;)

    Yeah- that's a really good point. I was looking at 115 and 212 cabs and got steered away from that for this reason.

    If all of this is indeed the case, looks like I fell into a good idea armed with half the facts (if that).
  7. B-string

    B-string Supporting Member

    Ya know, being an IBM compat user I wondered this also! :D Not using any CAD programs for a long time.
  8. Jaco who?

    Jaco who?

    May 20, 2008
    Hold down the ALT key with 234 at the same time......................................
  9. HA! Found it- option (alt) - Z gives you Ω which, now that I think of it, is the last letter of the classic greek alphabet - Omega - that's on a Mac