Define sounds horrible. The entire audible spectrum, more midrange, more on the high side, more on the lows. You may only have some high resistance solder connections.
One thing I would be leery of is those large value 400uf non polar 'lytics you got, on the large value keep the originals unless you know for a fact they have gone way south. I've had bunches of high uf value (200uf+)Bennic, Erse, and I forget what was printend on the other ones I tried. From madisound, parts express and erse. They all are about as usefull as thousand year old elephant dung. The 150's and below were more consistent, but anything over that was crazy bad. ESR all over the place, going as high as .05 , and that is at the high freq my meter uses, not at the lower frequencies the high value non polars see in the crossover. At those frequencies it would be much much much worse. The capacatance of them was also all over the place, pretty damn random as far off as +/- 30 percent. One "bad" original 150uf cap in my rs 4.5's caused a 5db drop out in the mids and a much duller sound, it's capacitance was fine, my meter showed it's ESR at .04 when all the other original lytics in the crossover showed .02. It took me 25 Bennic 150's to find consistent ones to use to replace the 6 150's and two 300's between the pair of speakers. I ordered that many since they were cheap and I already had reason to suspect horrific quality control on them from other comments I read, I literally ended up with 2 that I didn't use that were ok, the rest in the garbage.