ggibbons

This cabinet has been used for practicing bass and so has been in may positions. With the ports on the back you want to leave about 6" between the back of the speaker and the wall so that there is no impedence to the flow out the ports. My recommendation for your application would be to try different placements and see what works out best.

You are correct. I mispoke above. The crossover point is 2k Hz.

How does it sound? Pretty fierce. The base response is solid and pretty tight for a 15". The horn seems to have a bit too much sensitivity and I may have to reduce its output with an L-Pad or resistor network. The next step is to buy a bass head.

Rear firing ports...

With the cover...

Here with the driver installed...

I like to brace horns so, if the box is dropped, they don't sheer off.

I used a Dayton 2 way crossover from Part Express. 3K with a jumper that allows for 4 ohm woofer.

Sometimes projects get delayed...I've finally finished this one off!

Great recommendation. I like it and it looks like it will fit.

Here it is assembled. I use 1/4-20 T-Nuts and black oxide hex bolts to hold the driver in place. I worked hard to get the Klipsch logo aligned correctly. I covered the inside with 1" fiber glass...again left over from that other project. How does it sound? Like it needs a tweeter :-) The cabinet does not buzz and is still to the touch when driven hard. I'm driving it with an old Yamaha 100w rack amp and it clips of course before you can get it too loud. I believe the K48 is a 4ohm 400watt driver. I am a bit surprised at how much mid-range it has. My method of checking for the tuned frequency is to sweep slowly thru the low frequencies, say from 20 hz to 60 hz, with a finger gently laid upon the edge of the cone. Resonance is where the cone seems to be still (at reasonance the tuned box requires the least energy and movement from the speaker). I was shocked that the cone was still at 40 hz. Good quality Thiele Smalls! Thanks. Left to do... Get my spectrum analyser hooked up and get a curve Select a tweeter that will fit in the top right corner. I'm liking this one: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=275-130 as it goes down to 1300 hz. Put on feet and handles Finish it

Glueing up the front baffle. This is the same technique used on the back. Lots of good glue and clamps. Hole cut with my other large hole router cutout jig. Those things are great.

Back view. Note: the ports are not all the way pushed in. They go flush to the back when seated properly. Snug friction fit. I will probably secure with a dab of some glue once fully tuned.

Here it is with the back glued on.

Here is the inside of the back. I doubled up the thickness around the ports...glued and screwed. I cut the holes with my hole jig for my router. Amazingly I had some left over ABS 3" ID pipe from another project ( http://audioheritage.org/vbulletin/showthread.php?t=7140 ) that was exactly the right amount to tune this box to 40 Hz. The 1/4" phone plug came with the speaker. The steel plate is something I had laying around. Again, the design criteria for this project is to use as much on-hand stuff as possible.