87 and 89 are a tad low. I'd aim for 90 or higher for both but it seems as you get into the more expensive components they go for less and less sensitivity and never really give you the power handling to make up for it.
To the OP: One thing I'd really like to point out is that running full range in the rear deck isn't the greatest of ideas. It causes more harm than good.
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These would pump out some serious bass with a small amount of power (100 watts per speaker). If you're looking to keep your trunk space yet want to add some bass this would be a good alternative to massive subs.
You'll find you'll run into clipping very quickly using the HU for power so if you hear distortion, turn it down because you're only harming your gear and your ears.
Then all is well.![]()