Yes, I think you can get it fairly wide on RX although I do not know what the low frequency limit is. On the transmit side, they often limit the bandwidth to 3 or 4 Khz , besides the passband filter. I have heard the K3 on the air and they sound fine. I have not heard of anyone running one for a while though. The KX2 and KX3 I had sounded ok, maybe 100 to 3500 Hz but the KX2 had issues with power control on AM.