Can a poor man own a pair of high-end monitor speakers? Yes, if he can spend $220 on drivers and crossover parts. I'll call this design "Poor Man's High-End Monitor." This design uses relatively inexpensive drive units but will not compromise performance. This is possible thanks to two low-cost, high-performance drivers Zaph recently tested: the SB Acoustics SB17NRXC35-8 and the Vifa DQ25SC16-04. I believe this system's distortion performance is nearly as good as some other, presumably, high-end 2-way designs that use more expensive drive units.
LR4 crossover at 1.9 kHz
You can order drive units from Madisound or Meniscus Audio. As for the crossover parts, I recommend ordering from Erse Audio (www.erseaudio.com). Their crossover components are of higher quality at lower prices than other retailers'. You'll save money for what you get even with shipping cost added. A BOM is attached to this post below.
Predicted system response and individual driver rolloffs
Plots of filter transfer functions and system impedance curve are also attached below.
Net internal volume:
For a vented option, 21 to 25 liters with 34 to 38 Hz port tuning.
Use 2" ID port tube cut to total 5.5" to 7.5". Enclosure can be either front- or rear-ported.
For a sealed option, 12 to 15 liters. This speaker in a sealed enclosure of a volume on a larger side (14 to 15 liters) may provide adequate bass in a small room, but a subwoofer or two will be needed for full range reproduction in a larger room.
8.5" to 9" wide. Baffle height does not matter though it will somewhat affect midrange tonal balance.
Driver layout on baffle:
Tweeter's center is 3" from the baffle's top edge with no horizontal offset.
Midwoofer's center is 4-7/8" (4.88") below the tweeter's center, which means 7-7/8" (7.88") below the baffle top.
Drivers should be mounted flush with the baffle in recessed cutouts.
Experiment with tweeter padding resistor values (see the schematic for a suggested range).
See a builder's review here.
Also find a couple of short listening impressions from builders of a preliminary version in this thread.