i am just starting to experiment with omnis. i typically use an ORTF pair as a main stereo pair, and plan to use a piar of omnis as flanking mics for medium sized ensembles, and also as close mics on acoustic instruments in a studio setting. the 183s are diffuse field mics, and may be too bright as close mics in the studio. the km130s are also diffuse field, while the km131s are flat in the free field. if i need mics that can do reasonably well in both the diffuse and free field applications, which mic is the best choice? are there attachments available for any of those mics that would allow me to adjust their sensitivity for both free and diffuse fields? thanks.