New head unit/Replacement speakers

I currently have factory door speakers with the component tweeter in upper doors, an aftermarket Kenwood head unit, and two budget 10" subwoofers/amp behind the rear seat. I'm fine with the amp and subs for now, but I want to upgrade my radio and door speakers. My question is can I mix and match brands and it still sound ok? For example, I want to get the Kicker KS tweeter with adapter harness, but then use Focal or RF 6x9s in the doors. Any recommendations on quality head units would be appreciated too. Thanks!

 

Yes, you can mix and match. Your rear fill isn't very important. Get a decent setup up front. I personally use Hybrid Audio Unity 6.5 components up front with passive crossovers. I'm not a fan of 6x9 with extra tweeters.

 

what matters really isn't the brand so much, but the specific speaker sensitivity of the model series of the brand. ie, if you got all kicker KS gear, it's going to match in output because it's all manufactured the same.

mixing/matching speakers really comes down to paying attention to either the sensitivity specifications of each model you're interested in selecting, or building up your audio system to have adjustment within it to compensate for different sensitivity between speakers.

for an example:
the kicker ks tweeters have a 94 db sensitivity.
the focal access 690ac has a 91.3db sensitivity.

that means the the focal's are going to be slightly quieter than the kicker tweeters. depending on your audio tastes, this could be a good or bad thing. sometimes it doesn't need any work, or sometimes this can be tuned out with a simple eq adjustment, and sometimes it needs more work like individually amplifying the different pairs of speakers so one can adjust the amp gains for each set of speakers separately to make the blend better.

otherwise, the only true reason in my book to run all the same brand of gear is only when the company that makes it is paying you to install it.