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Loudness Issues

Discussion in 'Amps and Cabs [BG]' started by ReNmauZo, Mar 1, 2002.


  1. ReNmauZo

    ReNmauZo Guest

    Mar 1, 2002
    I have no clue why, but for some reason my amp (Warwick Pro Fet IV) isn't as loud as I believe 400W should be, even when running through a 115.
    The guitarist in my band seems to think that adding a 410 to my rig would make the difference, but I'd rather ask some experienced people first. Suggestions?
     
  2. warwickbass

    warwickbass

    Dec 8, 2001
    Minnesota
    at how many ohms does it put out 400watts and how many ohms is your cab?
     
  3. ReNmauZo

    ReNmauZo Guest

    Mar 1, 2002
    I think it puts out 400w @ 4 ohms and the cab is 8.
     
  4. warwickbass

    warwickbass

    Dec 8, 2001
    Minnesota
    ok heres your problem.... if it puts off 400 watts at 4 ohms it puts off less than 400watts with an 8 ohm cab connected to it, because your head is amp is also now running at 8 ohms, adding a 4x10 will make your rig louder, because it will lower the ohms that your head will run at. if you get another 8ohm cab your amp will run at 4 homs and put out the 400watts. if it runs at less than 4 ohms it will put more than 400 watts.
     
  5. yes, adding a 8-ohm 4x10 will increase your volume for two reasons. One, you'll now get the full 400 watts (as stated previously by Warwick), and Two, the increase speaker area will move a tone more air (40 inches vs. 15 before, a total of 55 in with the two cabs). Peavey makes a great 8-ohm 4x10 that's very affordable, if that helps.....
     
  6. chucko58

    chucko58

    Jan 17, 2002
    Silicon Valley, CA, USA
    I paid for all my gear myself. Well, me and MasterCard.
    Uh, Mark, your math is off, but the principle is right.

    It's not about speaker diameter, it's about surface area. A pair of 10s has about as much surface area as a single 15. So adding a 4x10 to a 15 will give you a total of 3 times the surface area. That translates directly into higher efficiency, which in turn means more volume!

    I hope someone will correct me if this is wrong, but I seem to recall that doubling the number of speakers (all the same size) increases the efficiency by 3 dB. So an 8x10 cab is going to be 9 dB more efficient than a single 10 by itself. If you started with 400 watts, you'd have to go to a 3200 watt amp to get the same increase in volume!
     
  7. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    Check your EQ.

    That amp must put out about 250 watts into your cabinet and that should be LOUD.

    If you are dialing out lots of mids and boosting lows you are wasting a lot of power on frequencies that are hard to hear. The more mids in your signal, the louder you will sound.