Does anyone have experience with the Sennheiser XSW IEMs for bass? Looking online it says the response range is 45hz to 15khz which pretty much restricts anything from a low B (~31hz) up to even a Low F (~43hz) I called Sennheiser and they said it's a straight drop-off, not a taper so it just flat-out wouldn't reproduce B - > F on bass. This seems very strange and quite misguided by Sennheiser. Nearly AU$1000 for something a unit that just doesn't work for bass? Has anyone got a pair of these and used them with a 5 string? Does it work? Was the random person on the phone just wrong?