From: Fi Subwoofer

BTL would be the BEST!! but the BL and Fi Q are pretty decent also. This being a home application, I don't so much think you'll want a BTL disturbing the neighbors every time you watch a movie.

BTL is the best at what?

If I need a sub to match my 500rms amp in a sealed box, would you suggest I get the BTL, no. So STFU. Each sub has its own duty and application.

OP- IB3 is a infinte baffle sub, if you don't know what that means, that isn't for you. Plus Fi discontinued the IB3 and it will be moving to their HT line, BluePrint.

Picking subs needs to be based on a few details of the install. Power,enclosure, and what your looking to get out of the setup.

Sealed enclosure, X, SSD, and Q are the options.

X- <400rms

SSD- <1000rms

Q- <1200rms.

Ported, all will fit.

X-<400rms

SSD-<1000rms

Q-<1200rms

BL(3inch)-<1500rms

BL(4inch)-<2000rms

BTL N2-<3000rms

BTL N3- is a SPL only sub.

Also the BTL N1 hasn't come out yet so I can't comment of it yet fully.

As far as Fs, I'm not sure which coil option specs are listed but the HiXmax coil BTL has great lowend.

Hope this helps. Also giving us more details of the install so we can better answer your questions.

i prefer proted subwoofer

are u sure BTL Will do Deep bass like FR 15hz lower for deep bass high output

i know if high Fs 51.1 Hz i think deep bass 15hz or 20hz low output that cannot high output so how