Ive ran roughly 4k to a BTL... Tinsels didnt hold up, and coils always smelled like crap after about 45 seconds, even with gains ALL the way down.
I know guys who run 6k per sub for strictly bassrace applications, and 30 seconds is about all youre going to get. Ive also messed with and helped people with their cars who have 4k+ a sub and it never works for daily. It just isnt playable.
What people dont get is that 1 sub can only move so much air. Yeah, an 18 with 6k will be loud for an 18, but the cone can physically only move so far, and can only displace so much air. On all these big SPL subs they are so stiff that you need to much power to get them moving that its just inefficient for a daily/musical application.
If you have a sub thats super stiff like a BTL that takes a good 2,500+rms to REALLY get some excursion, thats still 2,500rms youre running to a 3" coil that isnt excurding much, which means there isnt much cooling going on.
The best type of subs for daily are subs with 3" coils with loser suspensions, like Fi SSDs and Qs, and other subs that have a 3" coil, relatively soft suspension, and 750-1200rms power rating.
When it comes down to loudness playing music, its all about displacing air. While 2 18s with 6k each at full stroke can displace X amount of air, if you took that 12k watts and put it on say 24 12s with 500rms each, youre going to be moving a TON of air because your subs will be excurding like crazy and displacing a ton of air. They will have a flat response, play for hours on end full tilt, move nasty air, and meter like a mofo as well.
There are no pros to running a ton of power to a sub over splitting it up between a couple of subs in a daily situation. Going with cone area for a musical build is a win-win.
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