I personally cant compare SQ from one high end unit to the next. They all sound excellent, but different brands have distinct sound characteristics. I found that Eclipse sounds more neutral, Alpine sounds more trebley. You have to figure out if you like brighter sound, and what tweeters you are running, as Alpine will have a crisper sound. That said, if you have something like Titanium tweets, and run it on Alpine, it could be an ear-bleeding combo. Both brands appear to have narrow tiny sound, some would call it more precise. Pioneers appear to have the most robust sound characteristics, but the sound may appear less sharp. But as I said, all high end gear will sound great.

I could be opening a can of worms for a massive debate, but that is not my intention. My experience.

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Direction > SQL
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Alpine 9887
Steg K2.03 > 1.2" CDT ES-010, 7.1" CDT ES-07, CDT 560i
Arc Audio KS1000.1 > 3 x 10" CSS SDX10's in 2.4 cubes sealed
Rockford Fosgate Riot Cables
Monster Cable 300 Series Speaker Wire
Focal Plain-Chants
Dynamat
Monster Cable 2-Farad Cap
Optima Yellow Top
180 amp Iraggi Amputator alt
Rockford Fosgate 0AWG "Big 3"


FOR SALE: Above subs with the custom wedged box and damping material on the inside. $450 No offers. Amazing stuff, mint, just too much weight for my lowered car.