I decided for my latest creation to go as simple, and as cheap as possible. I have several 5 1/4" FR drivers I purchased from pe some time ago, closeout. The actual drivers I believe were slated for use in the rear-deck of certain GM sedans.
I'm still in the rough stage, only took a quick listen last night. I wasn't expecting much at all, honestly, just thought it would be a fun thing do one night while sluggin brews.
Parts used (so far)
2 x 2' by 2' pre-cut 1/2" plywood. $2.50 each
4 x 5 1/4" FR drivers from pe. $1.25 each
10 ft 16/2 lamp cord from Home Depot. $2.00
2 x spring clip terminals from pe. $.99 each
Total invested so far: $14
Driver specs, 4ohm, 15w continuous / 35max. Paper cone, center mounted whizzer cone, cloth surround. Freq response 80-18K.
I wired each side with 2 drivers, in series, for an avg 8ohm load. So far, they are quite impressive. The do vocals and strings like no tomorrow. I'm thoroughly pleased so far, they are actually listenable! The only 2 issues I've noticed so far is this bass is present, but thin (as expected with the specs and the IB design) and on dynamic passages, the highs seem to become a little edgy, sharp, harsh.
Next step, I'll throw some stain on, figure out how to make them stand up on their own, solder all the cord, and start looking at a Zobel network (to smooth the impedance curve - probably the cause of the harshness on certain passages).
More to come, as things progress. No, won't beat a $500 speaker, but it amazes me that they aren't THAT far off either.