Your shrill comment is odd to me but to be fair I've realized that you need to consider the amp w h en describing PUs. I stI'll play a 1994 5150 head and that amp tends to be bright so much so that HFS PUs sound brittle and harsh. I can't get that PU to soften up on my amp unless it's detuned to D or lower. I've played an HFS on other amps and was pleasantly surprised. You are correct though, 5909 on my amp does get brighter with the volume rolled down but I can't say shrill or harsh. What kind of amp are you using?