DIY Infinity Kappa Perfect 12vq Subwoofers

 

Enter, The Beast(s)

For a long time I had thought that the bass produced by my Axiom M80's was sufficient for my needs. I should make clear that I do not like boomy bass, which was what I had at one time thought to be the sound of basically, All subwoofers. I was wrong.

After adding up the costs to buy a good subwoofer, and Ship it here I decided that the best thing to do would be to built it myself. Thanks to a couple of members on the Audioholics forums (Chris,"WmAx" and Andrew, "Avaserfi") the hard part was already done for me, The part selection and designing.

Here's a Link to the Original Thread with the design for the subwoofer

http://forums.audioholics.com/forums/showthread.php?t=45528

And here's a link to a Build thread for my pair of subwoofers that goes into far more detail about the construction and also has many more pictures of the build.

http://forums.audioholics.com/forums/showthread.php?t=45561

 

 

For this project I needed:

  • Two Infinity Kappa perfect 12vq drivers
  • Behringer DCX2496 Active Crossover and EQ
  • Two QSC RMX1450 Amplifiers
  • Binding Posts
  • 8lb Rock wool insulation or Owens Corning OC705
  • Two sheets 3/4" birch cabinet grade plywood

 

 

Both Slot Port and Cross bracing assembly's completed and visible areas's primed. Everything has been glued and nailed together with a brad nailer.

Bottom, Back and one Side panel attached

12 gauge speaker wire. I securely attached it to the inside of the sub to prevent any rattling or vibration. The binding posts are located in the middle of the port but the hole in the side for the wire is completely sealed off and everything tucked away in the port to prevent any noise.

All the panels attached and holes for the driver and slot port cutout. The front baffle is double thickness of 3/4" birch ply but as you can see in the driver hole there are three layers. This is due to the poor choice to try and use T nuts and because I already had holes there from the T nuts I needed to add something to screw to. I also rounded over the edges.

Cabinet's Bondo'd and primed

Rockwool insulation glued in. Afterwards It was covered with some black burlap fabric to prevent loose fibers coming out of the port.

Binding posts and spikes installed. I later broke one of the spikes moving one of the subs because of their substantial weight and decided to use rubber feet instead of the spikes.

Parts Express binding posts. The posts and the aluminum plate are sold seperatly.

The QSC RMX1450 power Amplifier. I am using One of these per subwoofer bridged. Rated at 1400 watts bridged into 4 ohms which is what the 12vq is rated for. I know I am not getting the full output of the amplifiers as my AC line voltage sags too much under heavy load.

Inside the RMX1450. Before getting the dual QSC's I had the Behringer Ep2500 power amp but because I was able to pick up the pair of QSC amps used locally I just decided to return the Behringer amp.

 

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