Depends on the strings and the fretboard. One thing to keep in mind - buying the strings, or other gear, any particular player uses won't give you the sound any particular player gets. Good luck.

Yo Dylan,
Yeah Gar is right! Heck, I use to think the same thing! It is Not the Gear but, the Player, that makes the SOUND!
You see, when you get your Round Wound Bass Strings they are going to Sound the way You Play! You'll have to develop your Technique! Then you can try to get as close to JJ's Sound as you can! Just think of how Fun you will have doing that? :^D
Black Hawk

hehehehehe...I am laughing at the little emoticons in your message lol, not at the content of your message!

Yo Gar,
LMAO!! Maybe I shouldn't have used that one!! :^D
Black Hawk

Hey Hawk, what??? if I put Roto's on my jazz I won't play like Geddy???? Damn it!!! LOL! Dylan just playing around no harm intended. Don

No harm seen :). I know just throwing some new strings won't get my tone to be exactly like anyone else's (believe me, I've tried in the past), but a lot of my favorite players swear by them. I was mainly just worried about them tearing up my fretboard.

Can't hurt to try 'em! I love flats and I use them on my Geddy Lee Jazz and my Jaguar. However, I prefer roundwounds on my Mustang bass (which is a short-scale at 30 as opposed to the standard 34 inch neck).

Yo Don,
LOL!! That is what I'm trying to say!! :^D
Black Hawk

Playing fretless is the only instance where you'd need to worry about roundwounds eating up your fretboard. Also, nickel roundwounds will have less of an impact than steel.

I use Rotosounds roundwounds on my Tokai Rockinbetter and I must say the sound resembles to the sound I aim for...a bit agressive but deep and clear at the same time. But of course the strings only play a partial role in the whole process, there's the PU's, the bass itself and above all the tweaking of the amp you use...

Sean ;)