Downtuning My Bass (Possible Issues)

No, if it's in standard tuning it works perfectly. It's just when I downtuned that low string.

That's excatly what happens when the intonation is out.

Hmm, I'll go read up on it. Thanks, Adam.

No, if it's in standard tuning it works perfectly. It's just when I downtuned that low string.

Yep, that's your intonation. If you change tuning, you typically have to re-intonate.

When you play an harmonic on the 12'th fret and then play the 12'th fret normally, does it sound off? if it does sound off then it's more likely the bridge that needs adjusting i believe.

But my question still is: why is it fine in standard tuning but not when I downtune?

edit: nvm, you answered my question.

But the weird thing is, my other guitar is fine when I downtune...

But my question still is: why is it fine in standard tuning but not when I downtune?

Because essentially, you're changing the tension of the instrument, which makes the where note are move, as it were. Your bass is set up for standard tuning tension, so when you change that, it changes where notes are on the neck.

If that makes sense.

But my question still is: why is it fine in standard tuning but not when I downtune?

From the bridge to the nut the strings have a set of harmonics on them that are supposed to correspond to certain frets (i.e. 12'th fret harmonic to 12'th fret, 7'th/19'th fret harmonic to 19'th fret, etc.)
When you change the tension of the strings the harmonics shift, but the frets stay put. So you have to adjust it.

Adam explained it better.

Thanks, you guys.