Re: The different between 300K pots and 500K pots
What Duncan models are those PU's?
You don't want 300K's for neck HB's. It'll kill any treble and you tend to get mud. But, I use two 250K's for almost all my bridge HB's and P-90's. On some I also use warm magnets. But I like a full, rich sounding bridge. Some guys get a similar sound by turning down their tone pot, but to me this doesn't work as well, the tone isn't the same. It loses something. I want my PU's so that they both sound great with their tone pots on '10', with the same amp EQ setting.
The neck slot is inherently full of mids and bass, and the bridge is naturally sharp and bright, mostly high end. This due to the amount of string vibration and energy. I just don't see the logic in always using 500K pots for both PU's, which is how most guitars are wired. Both will get 'pushed' in the same direction EQ-wise, and bridges don't need more treble, necks do. Likewise, 250/300K pots make both PU's warmer, and necks usually don't need that, especially in an LP.
Sometimes you can dial in both PU's tones with mag swaps; sometimes you can do it with pots; and sometimes you may need both. Depends on the wood and your tastes.