If the radio uses the same filter for transmit as it does for receive, the audio will be restricted to 2.1kHz in bandwidth. Depending on your voice characteristics, this can make you sound really bad. I had the #702 filter in my FT-900, and EVERYBODY said my audio was horrible. We tried using the radio for Field Day, and one of the guys went back to his house to listen to that particular station to see why it wasn't getting any replies. The audio was very "constricted" sounding, and had no "punch" to it, even with the processor on. The '900 has a menu item to shift the transmit bandpass (only active when the processor is on), but it wouldn't shift far enough to make me sound decent. I've since learned that the '900 can be re-aligned to keep the sharp receive, but fatten up the transmit audio. I also had the same results with a pair of the filters in my FT-847. I swapped out the transmit filter, and the audio went back to normal. If you primarily run CW or Digital modes, go for it. Otherwise I'd be a little hesitant to recommend using them UNLESS you get the radio re-aligned. Of course, Your Mileage May Vary, but I was disappointed. They work amazingly well on receive, though, and the Inrad people are great to deal with. They even offered to buy back the filter, or exchange it for a wider one.