Mathematicians come here!

Discussion in 'Amps and Cabs [BG]' started by Stanley Design, Mar 17, 2005.

  1. I bought a 610 cab not knowing what the heck it was, I finally opened up the back, it's a yamaha. Now the speakers are all 8 ohms and say 30w on them. The cab is 4 ohms. What is the power handling for this? And could you show me how the equation works so I can do it myself in the future? I know it isn't rated at 180w because I've been running it at 350 no problem.
  2. According to my calculations it IS a 180 watt cab. I also believe it is impossible that it is a 4 ohm cab with six 8 ohm speakers in it. It is more than likely in the range of 5 to 6 ohms, not that that matters much.

    FWIW, I used to run 900 watts into a 200 watt cab and didn't blow it up. Obviously I didn't have to turn all the way up.
  3. I have cranked this up though without a problem, wierd. I'm selling this now, I dont want a big stinky cab that's heavy with low power rating.
  4. I wouldn't. That cab is a pretty good match for a 350 watt head actually.
  5. bigbeefdog

    bigbeefdog Who let the dogs in?

    Jul 7, 2003
    Mandeville, LA
    It's *probably* wired like my 6x10 Traynor. Three 8-ohm *pairs* wired in series, making the equivalent of three 16-ohm drivers; then the three pairs wired in parallel, for a total cab impedance of 16/3, or 5.33 ohms. And all drivers receiving equal power, so a rating of 30Wx6 = 180W.

    But as long as your amp is clean, you can go considerably past 180W.
  6. Petebass


    Dec 22, 2002
    QLD Australia
    Your 350w head isn't producing 350 watts all the time. It probably uses less that 100W in normal playing conditions and uses the rest as headroom. Provided you're cautious, you should be ok running 350W into a 180w cab.

    And I agree that it 5.33 Ohms, so it's arguable that the amp isn't capable of the full 350 watts anyway. My estimate is it is now only capable of roughly 300w.

    But in practice, you may as well pretend it's 4 when trying to determine if you can run extra speakers.
  7. I know this might be nit-picky, but while you can fairly safely use an amp capable of producing more than 180W to power this cabinet you can't actually put more than that into the cab without strong risk of damage. The reason you can get away with using amps more powerful than a cab's rating is because the average power an amp puts out is way less than maximum output power even if you see the clip lights on loud passages, because of dynamics ( like Pete said). Heat is what damages voice coils and the time-averaged power dissipated by the speaker is what's important, in terms of thermal damage.
  8. danman


    May 18, 2004
    Philadelphia, PA
    The rms watt rating on the speaker is only part of the equation.
    You should also consider box size and airflow.

    A low wattage speaker can handle more power as the box gets smaller.
    The airspace actually limits excursion (xmax).

    You cannot look at the rating of the speaker alone and get an accurate rating.

  9. TheChariot


    Jul 6, 2004
    Boston, MA
    If I were you, I'd replace the speakers with some Eminence speakers. Kind of a "Make-Your-Own" Avatar, if you will :)

    Figure out what impedance you'd need, and try to set it up correctly.You could even put Neo's in that thing. If you dont have the money for 6 new ones, then get 4, and leave the remaining 2 unhooked till you can get 2 more. :p

    Just a suggestion.... it all depends on if you enjoy screwing around with stuff like that. Personally, I'd go ahead and start replacing and rewiring, and all kindsa interesting stuff.
  10. If this is done you will have two passive radiators. It isn't likely they would tune the cab very well.