Upgrading speakers in base 10-speaker stereo

[FarmerFox]

Yes, a pair of PNW-4 speakers in the dash corners made a big improvement. Bought from Crutchfield along with the adapter cable. They sounded so good, I went crazy and replaced the center with open-box PNW-4s and cable from eBay [I didn't notice a difference]. To be perfect, the speakers should have a $6 audiophile grade 1Ω 20W resistor from Parts Express added in series but I skipped it.

https://audiocontrol.com/products/pnw-4-4-coaxial-speakers-50w-rms