Another string volume question

Here's the situation.
Pretty much still consider myself a newbie bass player - on Bass for less than 1 year. I play finger style almost exclusively, but played more with a pick early on.
Rondo/SX J-bass.
Daddario Half Round Mediums (.105 - .050) strings
Pickups adjusted level relative to strings.
Typically play neck pickup full up, bridge on probably 7-8, tone full up too.
Bass definitely needs string height set right - nut slots cut way too high, so I haven't put too much effort into lowering strings from the bridge yet. But the strings aren't terribly uncomfortable.

The problem, as you go to higher strings, the output seems lower - the E string booms, the A less so, etc. (both open and fretted strings but the open E REALLY booms) Its quite noticeable to me. Nobody else has said anything, but I notice it, like I said. I also notice it when plucking and using a pick.

I'm trying to figure out why. Do SXes or J-basses just do this? Would you guess it's the gauge of the strings? Or the brand itself? I can adjust the E side of the pickup down, but then the A drops even more. Could string height be that big a factor? Could it be crappy technique on my part?

I'm open to pretty much any suggestion, including that I just learn to pluck higher strings harder.... I know its a possibility, but I think I already try to compensate for the loudness this way and its not working.

Any thoughts at all are welcome! Thanks!!

I'm just guessing, but I think maybe it's due to the smaller diameter strings having a smaller magnetic field.

Tim

1. flat pickups without staggered height pole pieces to match the neck radius mean a weak A&D.

2. hotter pickups with ceramic magnets ime - low end basses often - not always - have 'hot' pickups. hot pickups often have a big low mid's bump 100 to 200 hz range ... This is true of the Fender Standard MIM's and many others in the low end. They make small amps sound impressive. When you hear thenm in a more hifi/full range setting you see that the low mid's bump serves only to mask the true low end and upper mid range detail. This is why folks report that new pickups in a MIM can be like taking a blanket off their amp ... At the price point for the SX ... this could be part of the issue. That isn't a slam on SX - I think it's amazing they can deliver a neck for that money let alone a workable bass afterall!

3. ceramic pickups generally have a magnet bar on the bottom of the coil and iron slugs as pole pieces. Not a rule but in the low end it is often true... Better quality J pickups have magnetic pole pieces and are staggered to meat the FB radius. In general - they are more detailed and have better string to string balance.

On a vintage style J, staggered pole pieces are the order of the day. On one of the hyper modern, no radius FB's (Sadowsky style) it isn't as critical as a 16" radius FB doesn't present near the difference in height as a 7.5" radius ...