The SP4 Series is the latest in the progression of Fi subwoofers geared towards thundering daily drivers. Starting with a monster 4" voicecoil for increase thermal capacity, we built the rest of the sub around that. With a proprietary US made steel machined in house on one of our CNC machines, there is no shortage of motor force in the FEA derived design. With a solid pole and the optional cooling systems, there is plenty of thermal capacity in the SP4. Two high grade magnets provide the Gauss while 5 Fi designed 10" progressive spiders keep things under mechanical control. Utilizing a special 144 tinsel count leadwire there are no losses with power transfer to the coil. The 2012 SP4 Series is designed for monster daily driving systems requiring high linearity and extreme power handling. The SP4 Series raises the bar for the industry...again.
Showing reviews 1-10 of 14 | Next
Posted by Deaf by Dishonor on 12th May 2013
This is my 2nd sp4 15", and let me tell Ya. These THINGS pound. Have previously own ALL kind of subs, but my personal favorite was the 04'/05' RE XXX's, until I got these "Trunk Molesters" These astronomical subs are so precise, and acturate with their linearity, and flat responce it just bring me back to the good old days of the xxx's. High performance linear subwoofer is what you need, then look no further!!!! Tears every part of my car apart with just a measly 4000 watts, & the subs just laugh, as they are tickled to death.....not even close to breaking then in....smh...I know I'm Waaaayyyy over doing it with 2 of these steroids of a sub, but Hey-what can i say.. :-D
Posted by derik posey on 26th Apr 2013
other then having to wait a month longer then expected and not getting stickers like promised i am more than satisfied with the product. even on only 1500w rms it gets way louder then i ever imagined. great product from a great company
Posted by DP on 14th Apr 2013
hey every one im waning to get 4 of these subs with 2 ns1 sundown amp but was wondering what ohm of subs would hafe to get?
Posted by Christian on 2nd Apr 2013
I hooked up the sp4 to a AQ 1200D as a temporary set up till I made the amp rack for the Aq (SQ) 3500 but man even on those 1200watts the sub WANGED! BROKE the rear view mirror and took of some glass of the windshield! Don't hesitate to purchase this one of a kind woofer
Posted by A.I. James on 6th Mar 2013
We have 4 of these in our shop demo truck, and have been through various woofers in the past. These are by far the best woofers as far as handling and linearity to date. great product here. Even had them delivered half way to us personally... Thanks again
Posted by ryan on 16th Jan 2013
i have one sp4 15 fullyloaded dual 1 on a kicker zx 1500 @2ohms an it is amazing deep bass everything shakes in the car amazing sub box is tuned at 38hz did a 140.6 on the dash on music loving the aub cant wait to get more power to it an get it sealed off in the trunk
Posted by Bryan aka Obibassoholic on 29th Nov 2012
VERY NICE sub! Have 4 of them walled in my Lincoln LS. Absolutely destroys everything it plays. On 8kw car does a 150@20hz, 153.7@25hz, and from 26-45hz stays inbetween a 154.3-8, and tappers off at 50hz with a 52.8...... all on music :D
Posted by blross91 on 24th Nov 2012
3000 watts!! is that for the older ones to or just the new ones
Posted by Fi-Foo on 12th Nov 2012
Sounds great I have one in an saz3500 and it slams. Great quality and overall a great driver. Thanks for an awesome product :)
Posted by Unknown on 23rd Oct 2012
Well worth the money. Takes what you give it and asks for more. Its a monster.
Showing reviews 1-10 of 14 | Next