My new stereo is rated 50w P/C.

Can anyone tell me the rated power handling of the stock X300 speakers? (I have the standard setup, not premium. The speakers are Philips, but have noting on the back except for "4 Ohm" and a bunch of numbers. I tried the numbers in Google, but nothing)

I'm not going to be thrashing the stereo, so I'm just wondering if I'll be able to keep using the stock speakers for now.

I'd replace them. Stock is pretty much junk.

It's better to overdrive a speaker than to underdrive. If you play the music loud at all, and don't have adequate power for the speaker, you will send a square wave which will destroy them in short time. I can guarantee that your aftermarket head at 50W/channel sends out more than what the stock speakers are rated for, but generally speaking this is not a bad thing if you don't turn the power up past half or so. My 2 cents

For what it's worth I ran the stock ones for awhile with my Kenwood head. Replaced after a while with the Polk db series and a dedicated 400W amp. They fit great but dont offer much in terms of bass and don't sound too great unless played somewhat loud. They sound a bit thin otherwise and I'll prob switch to another speaker at some point

I agree Fenja! I had an extra pair of Bose that I didn't use in the Vette so I put them in the back doors as the originals were shot!

What a difference!

What about the little tweeters? Are their high pass filters sufficient to protect them against the extra power of a 50W aftermarket unit?

I am currently researching sound systems for my project and from what I have learned, the tweets are actually pretty good and should hold up well.