movement of air

Discussion in 'Amps and Cabs [BG]' started by Jon Burnet, Apr 26, 2002.

  1. Jon Burnet

    Jon Burnet

    Jan 21, 2001
    Memphis, TN
    Help me understand something. a 4x10 cab moves 40 inches of air correct? a 1x15=15? and a 1x12=12. well 2x12's would be only 24... afar cry from 40 from a 4x10. yet some people on this board say that the 12's crush the 10's. i love my peavey cab but the damn thing weighs about as much as a backstreet boy. so 2 1x12's sounds fun. hell i dunno. i play in a LOUD blues/r&b/jam band with a guitar player who runs 2 50 watt tube amps on 10 and a LOUD keyboard player. 4x10's cut it i was just wondering if 12's would.
  2. FalsehoodBass


    Jul 22, 2001
    Denver, CO
    a 4 10 has (4Pi times 25) square inches of surface area... a 15 has (Pi times 7.5 squared)

    Surface area goes by the radius squared. The number on a speaker is the diameter, which is twice the radius.

    there are also many other things to consider when considering how much volume you'll have.. not just surface area.
  3. Jon Burnet

    Jon Burnet

    Jan 21, 2001
    Memphis, TN
    such as sensitivity i know. real worl is a pair of 12's gonna be as loud as a 4x10. i want the aggies or the genz and i have a peavey 4x10.
  4. Nino Valenti

    Nino Valenti Supporting Member Commercial User

    Feb 2, 2001
    Staten Island NYC
    Builder: Valenti Basses
    It's not just speaker size. It's the design of the particular cabinet, the quality of the speaker, power handling og the speaker, ohmage of the cab, etc.

    Are you talking about a Hartke 410 transporter compared to an Aguilar 212?
  5. The amount of air displaced for each driver is the piston diameter (Sd) multiplied by the Xmax.

    A typical 10" driver piston is about 8.3" diameter.
  6. Kurt M.

    Kurt M.

    Dec 11, 2001
    Reading, PA

    I don't have much to offer in the way of a science lesson but I do have some thoughts.

    I play a Genz Benz 410XB. I've always played 4 tens. Anyhow recently I thought I'd move to a 15 and 2 tens. Easier to carry and I thought the 15 would help with the bottom as I now play a 5 string. I can tell you that I felt naked with just a 15. I felt the same way with the 2/12 (Bagend) that I tried. The punch and mid bass were gone. So, for me 2/12 cabs are not the answer.

    What I do wonder about is why some guys prefer a 15 or a 12 for the bottom. As far as cone area goes and all that stuff why couldn't you just use the appropriate amount of 10's to move the same amount of air as the 12 or the 15? But, yet I do hear *more* low end comming from the larger (12/15/18) drivers. So, there must be more to it than cone area and air movement. There must be something that makes a 12 or a 15 produce low frequencies better. Now what you could try is using two 2/10 enclosures. Say 2 SWR Golliath III's. Very punchy. Cuts the mix well assuming you have good power. Each box easier to carry than one 4/10 box.

    Just my thoughts.