i have owned the sigma's and thought that the woofer did not make a smooth transaction into the mid bass driver, i always felt that the upper bass was lacking thus the reason i sold them, from the midrange up i thought that the sigmas sounded slightly better than the ren 90's probably because they used higher quality caps in them, i now have a pair of ren 90's and i actually like the sound of them better than the sigmas, i also have a pair of kappa 9's that i replaced all the old solen caps in the crossovers tweeter section with new solen caps and after the break in period, well let me say that the new solens sounded like crap and they are the same ones used in the ren 90, i called sonicraft and asked them which caps do they think would sound the best in my kappa 9's and they recommended the wonder dynamicaps over my preference the mondorf silver oils, the fellow i spoke with said that he would sell me either one but that i would be waisting my money if i went with the mondorfs, that the dynamicaps would match the kappa 9's much better, so i bought and installed the dynamicaps in all the crossovers tweeter sections in my kappa 9's, omg what a difference in the sound you hear everything, when i used to compare the kappa 9's to my ren 90's i always thought that the rens from about 5k to 10k sounded much better more dynamics than the kappa 9's, but not anymore, i used to like to listen to my rens but now when i compare them after having done the mod to the kappa 9's the rens sound like you have cotton balls in your ears and i just don't like to listen to them anymore, i wonder if you replaced the solen caps in the tweeters crossover section in the rens with the wonder dynamicaps how much better they will sound, has anyone tried replacing the caps in the rens crossovers tweeter section ? if so what where the results?.
greg
greg