On all my basses I have noticed that when playing the open e string, I hear more of the harmonic overtones, and find it hard to pick out the fundamental (both acoustically and plugged in). I ignored it for a few years. Recently it started to bug me, so I read up about the experiences of others on this matter and it all seemed to have to do with setting up the bass right. I didn't think I had been doing anything wrong all this while, but decided just to check anyway. No immediate solution was found, but I discovered that when I tuned the string sharp, the problem disappeared. Just now, I decided to listen to some songs which had a low e in their bassline, taking particular note of them. Only then did I realise I couldn't hear them too well either. I wonder how I had lived through so many years without ever noticing this. The way I was distinguishing the e was that it sounded lower than the f. I was unable to assign it a pitch, if you get my gist. So I concluded that my ears perhaps aren't that good with hearing notes below f. I don't suppose there is a way to remedy this, but it has given me some relief in knowing that my basses are all fine, unless somebody proves to me otherwise.