hispls 5,000+ posts
CarAudio.com Veteran
Build quality of Lanzar products in general is questionable. As much as the Skar is NOT = Nightshade and there's a lot of hate here, I'd trust them over lanzar subs. Opti amps seem pretty solid, but they have so many model numbers/names I don't know which is which. I'd stick to the more well known (reliable) 5K's , Atomic, Sundown 4500, RD D9, American Bass (and the dozen that are the same boards as these). They are proven performers and can be had used for 650-800$ range if you shop around, and a few variants can be had for not much more new if you wait for a sale or know somebody.See now that's a constructive comment... lol Could have said that the first time.. And yes I do have an SPL setup but to "MY EAR" it sounds good... Never said anything about competing against other sq setups because I clearly don't have one. You seem to actually know what the hell your talking about so would two opti 12s on a opti 5k be louder at 40hz. I'm going to sell the soundstreams but I want to see my numbers before then... I just want a direction to move towards either 2 15 skars or 2 12" optis. In this case in a civic 2 12's is looking better. And I never metered the skar yet. Estimating around 147 148 at 40hz. I did do a 141 on 900 rms with a single addictive audio V3 15" in a 3 cube box tuned to 42 ish 6 inch aero port. And it was done on termlab through MECA, Mic in passenger seat, driver door opened anywhere from 8 to 16 inches (best results)
You do realize that from 141 to 152 is a really huge jump. As you get up into high 140's you will very likely no longer gain 3db for doubling power and/or cone area. A friend of mine does @ 150 out of a trunk civic with 5K and a single 15 (db drag style sealed), he has done 52 and change with 10K but subs don't survive.... really subs don't survive 5K for long. His box is very solid and he has a lot of work into it.
If you want to break 150 you should also buy an SPL meter, some woodworking tools, and lumber. I don't believe that new subs are going to be the magic answer that will fix either your getting that much louder, or being able to play 25hz properly.