I bought a Harmon Kardon HTiB (HKTS 18) about two years ago. The subwoofer developed some problems, and it is going to be replaced. But, apparently they don't make this subwoofer for individual sale, so I am getting a whole replacement HTiB (and then for the warranty claim to be closed, I return a whole HTiB).

Because it is set up that way, the HK guy told me that I could replace whatever I wanted -- for cosmetic issues, whatever. As long as they get a complete set back, they don't care if it's comprised of old or new components.

So, should I replace all my speakers with the new ones? It's easy to do, so that's not an issue. The only reason I wouldn't is that I find electronics can be finicky sometimes, and so maybe as long as my other speakers are working, I should leave them be. On the other hand, they are 26 months old. Thoughts? (Besides the subwoofer, I haven't had any issues.)

Obviously, I can keep both old and new for a couple days before returning a set, but I find speaker problems normally don't show up that quickly.

I would certainly return everything and have new stuff. Plus, since it is all new, you should have a new warranty.

Ditto.

Replacement should be coming today. I'll be replacing all speakers, so thanks for your input.

Looks like you already did it but agree to upgrade to new stuff if you get the chance. Enjoy!