Got these to augment my RTi's upfront. They are not too shabby. Good for 90-21Khz.
Soon I will have pairs of 6.5 incher's and 5.25 incher's up front for 2 channel mode.
That should cover the audio spectrum.
The caps are just about all that's worth upgrading on the XO considering their price.
Reinforcing the cabinet sides with 1x2 stringers and a cross-brace, centered behind the tweeter.
Will add to the sides; 2 patches of .25" foam and that should make em good for 20 years.
Caps are exact values as measured from OE's: Solon 9.1uf=LP, Dayton/Bennic 8.2 & 2.2uf=HP