I want to add some kind of content, so I will try to do the best I can without good pictures, graphs and measurements.

I have recently been very interested in more exotic speaker configurations.  Such as line arrays,front loaded horns, back loaded horns, tapped horns (my favorite), transmissions lines, other quarter-wave designs, open baffle, and point source or single driver speakers.  Most of my future posts will pertain to these types of designs.  One of my more recent builds was an extremely narrow-profiled two way.  It is an MTM configuration with two Dayton ND105-4, and one ND20FA-6.  The woofers are in series with each other to provide an easy 8 ohm load to the amplifier.  The cabinet is a tapered, mass loaded transmission line that is tuned VERY low.  These 4 inch drivers can deliver usable output well into the 30hz range.  The crossover is at 4khz, and includes a significant amount of baffle step correction.  I will add pictures of the speakers, the crossover schematic, and the dimensions for the cabinet later when I get home.  Also, the speakers are actually too narrow, a base would be a very worthy addition to an already excellent speaker.  I can post the parts list now, but it is nearly unusable without the schematics and cabinet dimensions.

4x ND105-4

2x 2 1/2" x 8 1/2" port tube

2x ND20FA-6
1x Acoustic Foam 1-1/2" 24"x18"
2x 0.90mH 20 AWG inductor
2x 0.40mH 20 AWG Inductor
2x 0.30mH 20 AWG Inductor
2x 9.1 Ohm 10W Resistor
2x 5.6 Ohm 10W Resistor
2x 3.7 Ohm 10W Resistor
2x 2.0 Ohm 10W Resistor

2x Red Binding Post

2x Black Binding Post

6x 0.22uF Film Capacitor

2x 18uF Capacitor

2x 4uF Capacitor

2x 3uF Capacitor

(optional) feet for the speakers

Capacitors should be whatever you find suitable for audio.  I prefer polypropelene or film and foil, but electrolytics will work as well.  Be sure, if using electrolytic capacitors that they can handle the voltages involved in the output of a power amplifier.

Resistors should optimally be non-inductive and/or audio grade

All of these can be purchased at http://www.parts-express.com/

Better information coming Tomorrow... or monday, depending on the amount of homework I have, also, that picture is the actual driver. Which is on sale currently.