stcok SR5 audio upgrade

[nasdaqer]

I have a 2006 SR5 4Runner, with the stock stereo - it sucks. I don't want to put too much money into it, but am wondering if I would be better off starting by putting in new speakers or a new head uint? Which is the weakest link?

Thanks

 

[srpage]

Replace the head unit for the most bang for your buck.