Crossovers

[Panomaniac]

Yes, it's super hard to do crossover work at a distance. I've done it and had about a 50% success rate. Where the successes came was where there were good measurements.

Tho I have to say that I've had crossovers designed for me via long distance and it worked. But it took a lot longer than normal.

[vuki]

Basic measurement setup could be pretty cheap; panasonic's wm-61 microphone capsule, 3,5mm stereo jack, few feet of coax cable cost less than $10 and here is your measurement mic. For basic measurements (or even very professional ones) one can use ARTA demo software and PC soundcard's microphone input. That will do for RTA and even some MLS measurements. With additional small investment one can build microphone preamp and measuring jig and have full measuring functionality.
When doing loudspeaker project it is usually necessary to include your ears too because in-home measuring capabilities aren't enough to predict how loudspeaker will sound - there is always power response/ directionality/ acoustics relationship that can't be so easily measured and predicted.