Wow, I haven't logged on here in a long time! I didn't see any responses so I'll catch up, although I know I'm really late.
I am JUST NOW (more than a year later) trying my third attempt at installing the La Bella E string.. I have 2 of them now. One is my original string and I asked La Bella for a replacement after having problems but I had the same luck the second time. It sounded thumpy and dead with a super short sustain. Some people in other postings said that they had this problem so I assumed I had a problem with either 2 bad strings or my bass just didn't like that particular string for some reason. I switched to an Ernie Ball Group 3 flatwound E string (full scale) and I felt like I found a good match, but because the windings went around the post, the string's sound quality got worse over time. After a year, I realized I was back at square one with the dead thump without any note clarity.
Finally, I got tired of the thumpy dead string again so I decided to dig up my old La Bella E strings for one LAST attempt.. and magically, the string sounds amazing and balanced after my first try at installation. It's slightly zingy compared to my other worn in strings since I never used it, but it's very obviously matched and it's going to work for sure.
I suspect that I did, in fact, twist the string when I first installed it.. BOTH TIMES with TWO SEPARATE STRINGS! I realize now that this should be an extra careful process with flatwounds and a Mustang through-body especially. There's a high potential for getting a twist as the string gets extra bending points as it goes through the body. I am posting now so others who come across this problem in the future can see my experience and just try again before assuming it's a bad string or the bass. I will post again later if it doesn't sound so good anymore. My other La Bella strings (A, D and G) still all sing beautifully since I first installed them 2+ years ago.
I had the same issue with the Labella MUS, unbalanced thumpy low E, which was especially noticeable when using overdrive as the A, D and G strings would ring out nicely, but nothing on the low E.
I bet those NM4 pickups are nice! But I think you probably twisted the string while installing, just like I did my first two times. I didn't change anything else, but now everything sounds great! I'm still using the stock pickup in my Vintage Modified Squier (the one produced from 2011-2013) .. I'm SO glad I fixed this. I was about to buy a set of Thomastik flats (which some people say have a weird loose and unbalanced feel) or Chromes (which I liked for awhile, but they have kind of a metallic hollow sound) but now I'm going to leave these La Bellas on as long as I possibly can and try as hard as I can to never change anything. I feel super nerdy right now but I'm extremely happy that this finally worked out because this bass has a super special feel.
