Unless the amplifier was horribly under powering the subs than you likely won’t notice a SQ difference in terms of definition, but with more power you would get louder and have higher dynamic range, which means the bass volume between the softer sounds and the louder ones is greater. You need to more than double power though to notice it.
Ryan got I think 113 amps draw from the K1000 at 2 ohms, which is very good efficiency. I have mine on a shared 4 gauge power wire (upgrading soon to dedicated 4g) with my Pioneer 75x4 Amplifier with no issues on stock electrical and an AGM yellow top battery. I have zero eletrical issues and my voltage doesn’t even budge, even when I’m cranking it playing bass heavy music. This amplifier has near 1600 watts dynamic power so it should be happy driving your Alpines subs, provided you set the gain correctly. Also, with such a large ported box, your Alpine subwoofers probably don’t need the full amount of power they are rated for. If fact, that large box might be why they sound kind of muddy, depending on your tune and box construction. The right box makes a huge difference in the subwoofers SQ and even power handling.
I’ve swapped many different amplifiers of similar ratings and never notice any SQ difference. It’s only when I swap a more powerful one with a lesser one that I notice a difference. The last time that happened whe was when I swapped my 40wpc with over 100 wpc. Well, I actually did notice a big difference between a cheap NVX micro amplifier and a 25 year old Alpine amplifier that was supposedly rated for 40 watts less and strangely it was a large difference.
