Used set...which is top hat?

[uncle duncan]

Bottom hat would be the heavier of the two.

[ludvista29]

typically the heavier cymbal of the pair goes on the bottom. Feel for which one is lighter and throw that on top. Most of the time you will be able to know fairly easily which one is heavier.

[Aeolian]

It's also likely that the hole for the top is worn more than the bottom. If you can't tell the difference in weight it probably won't make much difference but usually the stiffer cymbal goes on the bottom. Usually a higher tick sound when hit lightly but a deeper overall tone.

I have a pair of K-Custom Darks which are really similar in weight although the bottom is obviously deeper sounding. I also have a set of New Beats where the bottom is nearly twice as heavy as the top. The more differential, the more pronounced the closing "chick" sound is.

[fnargh]

Whichever one sounds better!

[NoPro]

Found the heavier one.. Thanks for taking a sec to reply to this post all of you

[toolskid]

the heavier will usually be higher in pitch