Subwoofer AMP

Discussion in 'Home Theater Projects' started by Richard=f, Jul 29, 2006.

  1. Richard=f

    Richard=f Auditioning

    Jun 21, 2006
    Likes Received:
    hello, I am looking from an amplifier to power the Titanik MKiii sub i built.

    I was first thinking of two different amps running about 500 RMS @ 4 OHMS

    But, recently I'v been hearing that the 500 watt amps may not drive it that well. Would if be worth it to bump up to the 1000 watt RMS amp?

    any help would be excellent.

    thank you.
  2. David_P

    David_P Stunt Coordinator

    Dec 12, 2003
    Likes Received:
    you need to model the sub in the type/volume/tuning of box you're going to use.

    Download Unibox (excel spreadsheet) ot WinISD Pro (free Beta) and check out the driver excursion in the box of your choice at the power input of the amp you want to use.

    Generally speaking, the smaller the box, and in the case of the vented box, the higher the tuning, the more power the driver can stand before being driven to overexcursion.

    IMHO, it is best to work with enclosure size/tuning and amp power hand in hand to come up with a design that allows the extension you want yet is power-limited rather than excursion-limited... e.g the amp will clip before the driver will bottom out.

    Example... I'm currently building a 13.5cu ft enclosure for 4 Tempest classics, sealed, using a 1200 watt amp. There will be an LT cct to provide greater extension. But if you model the drivers in that size of enclosure, you'll see that 1200 watts is incapable of driving them beyond Xmax. A deliberate design decision.


    Step 1: model driver in box, tune/size to get extension you want.
    Step 2: model that driver/box combo at various powers to see what power level drives driver near Xmax
    Step 3: buy amp with power level closest to but not exceeding power level in step 2


    Step 1: model driver at power level of amp you want to buy
    Step 2: play around with box size until xMax is not exceeded
    Step 3: add EQ (LT or parametric) to get extension back to where you want it.

    I used the second method, because I owned the amp prior to having the drivers. It worked out OK for me, as the 95+dBspl/1 watt/1 meter efficency of the 4 tempst drivers allows me a fair bit of headroom to use an LT cct for EQ. A single driver makes things far more difficult and you might run into excursion problems. The first method is probably best.

    Also look at getting a pro amp (Behringer 1500/2500) and a Behringer Feedback Destroyer for EQ... the combo is not much more expensive than a 1000 watt plate amp, and is FAR more flexible. The BFD can emulate the LT cct to a certain extent and also euqalize your room with ease.

    I happened to own the Adire ADA-1200, so that's what I'm using. Very full featured, including an on-board LT cct, but only two bands of parametric EQ... the BFD has several dozen, IIRC.

    Hope this helps


Share This Page