2017 non jbl system

Ok so hopefully someone can confirm my thinking. I have the original non jbl head unit, I have upgraded the non jbl amp to an alpine 445u, added a loc to a rockville 8" amolified sub under drivers seat. All works well and sounds way better than stock.
I have also just changed my side dash speakers and disconnected my center dash speaker.

Ok so now my question the original corner dash speakers were 6ohm each and the center a dual voice 8ohm speaker in parallel to each corner speaker. Which by my calculation be 3.5 ohms each channel?
because if 2 8ohm speakers in parallel are 4 ohms then an 8 and a 6 should be 3.5 right?

Reason being I put in a 4ohm in each corner dash and removed center speaker so should now just be 4ohm each channel which is fine?

Thanks Hopefully no too confusing

 

From Crutchfield (albeit not always perfectly accurate):

"Both the base and JBL systems include a 3-1/2” speaker in the center of the dash. The base system’s 8-ohm speaker is a dual voice coil design that’s powered by the receiver. Each coil is wired in parallel with one of the corner dash speakers. The 2-ohm JBL model, on the other hand, is powered by its own channel in the factory amp.

Whether you’re replacing the high-impedance base speaker or the low-impedance JBL speaker, pay close attention to the impedance of the aftermarket speaker(s) you’re considering. A standard 4-ohm speaker will produce lower volume levels than the low-impedance stock speakers. This is obviously not optimal, so shop accordingly.

Whether you have a base or a JBL factory stereo, you’ll also find 3-1/2” speakers in the dash corners. In both systems, these speakers are wired in parallel with the front door tweeters. Removal and replacement is mostly easy, but there are some nuances, depending on which system you’re working with.

As with the center dash speakers, pay attention to impedance, whether you’re dealing with the 6-ohm base speakers or the 1-ohm JBL models. There’s no wiring harness adapter that works in this location, either, so you’ll need to splice, solder, or use Posi-Products speaker connectors."

Long story short, 4 ohms in the dash corners will be fine impedance wise for the factory head unit. Worst thing that'll happen is your dash corners will be quieter.

 

ok thanks for the reply

 

Also, I can't remember off the top of my head how the dash is wired exactly, but Crutchfield mentions the dash corners being wired to the tweeters, which seems familiar from other posts I've read on here, as well as from 5 Star Car Stereo on Youtube. If I'm not mistaken, the 4 door woofers are powered off the factory (in your case aftermarket amp), whereas the center channel, 2 dash corners, and 4 tweeters are all powered off the head unit. If that's true, you might wanna check the impedance of the factory tweeters to make sure with the addition of 4 ohm dash corners, you're not dropping the impedance to 1 ohm or something that could potentially harm the head unit.