trouble w/ not having a variable subsonic filter

[C4W18 0]

Well my issue here is a i just picked up a fi btl n2 (came in today) and i'm going to start building the box for it soon. i recently found out to quite a bit of dissapointment, that my rockford fosgate t2500-1bdCP doesn't have a variable subsonic filter, but rather a cheesy switched one. I know i need to tune my amp 2-3 hertz below my enclsoures PTF, but what if my enclosure ends up being out of range or the amplifiers tuning controls?

Crossover Controls Low-Pass (LP): 35Hz-250Hz @ 24dB/octave Butterworth

Infrasonic: 12dB/octave Butterworth, -3dB @ 28Hz

any insight guys?

[Sir-Lancelot 216]

I dont see the problem. Were you going to tune really high?

If you tune to 33 or so, just switch it on.

[Fi Car Audio 64]

We like to see higher order filters than 12dB, but can work with that if you are tuned 2-4 Hz above its cut off. Playing below tuning the box unloads and allows the speaker to flop out of phase, with no control, and with little output given the extreme excursion.

We are working on a solution for all the don't have adjustable filters

Thanks,

Scott

[Notorious97200 339]

It seems that RF makes amplifiers for subs in low tuned box.

30-33hz is good for music. I like it like that !

It may not be the best for high db numbers.

[C4W18 0]

We like to see higher order filters than 12dB, but can work with that if you are tuned 2-4 Hz above its cut off. Playing below tuning the box unloads and allows the speaker to flop out of phase, with no control, and with little output given the extreme excursion.

We are working on a solution for all the don't have adjustable filters

Thanks,

Scott

haha thanks....are you guys looking for more of an 18 or a 24 db octave? i was hoping someone could suggest a external filter or something to that extent. by the way scott, thanks alot, the sub looks great....my friends shit bricks when they saw the design.

[Swaco 0]

We like to see higher order filters than 12dB, but can work with that if you are tuned 2-4 Hz above its cut off. Playing below tuning the box unloads and allows the speaker to flop out of phase, with no control, and with little output given the extreme excursion.

We are working on a solution for all the don't have adjustable filters

Thanks,

Scott

haha thanks....are you guys looking for more of an 18 or a 24 db octave? i was hoping someone could suggest a external filter or something to that extent. by the way scott, thanks alot, the sub looks great....my friends shit bricks when they saw the design.

my audiocontrol dqx has one