I own an Eastwood Classic 4 semihollow bass (which is a reduced 30" scale) and I love it except for the fact that the lowest string sounds flubbery. I have D'addario flatwounds on at the moment so I understand I have a couple factors working against me here but I'm wondering if a pickup change or string gauge change will help me out. I'd like to stick with flatwounds.
Thanks in advance.
Sorry, this isn't a pickup or a string gauge issue.

This is, quite honestly, a scale and a flatwounds issue.
It may also be an amp issue.

Think of a short scale bass as a spinet piano and a longer scale bass as a grand piano. Play the bottom four notes on a spinet piano and they'll sound pretty much the same, one to the other. Do the same with a grand and they'll ring out with definition and clarity.

It gets worse if you have an amp that can't reproduce the low E. Two reasons that might be the case; one is that the speaker and cabinet itself can't handle it, and the second is that you don't have enough power to reproduce it. So what you get is a jumble of harmonics that do their best to direct your brain into thinking that you're reproducing the actual note, but you're not.
I never thought that it may be the amp. I assumed it was because of the short scale but didn't think about the amp. Now that I look back it makes sense. I made a recording using a direct in and it sounded pretty good.
I'll try it through my friends Aguilar/Hartke head/combo and see if that makes a difference.
Thanks dspellman.
Try muting the low open E string by placing 3rd 4th and pinky fingers lightly touching the string while the index is essentially fingering the string on the opposite side of the nut...imagine it is playing a low Eb which actually doesn't exist. This will support the flappy open string and give it gusto!!! And while you're doin it, don't forget to groove..