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Your Price:
$354.00 (You save $61.00)
57.00 LBS
Estimated build time of 10-15 business days
Calculated at checkout

Product Description

All US steel machined in house at Fi.

The Q Series of subwoofers is our sound quality reference line. Featuring a hefty high strength single magnet motor structure with a heavily bumped t-yoke, the 27mm of Xmax allows for incredibly detailed, tight, and powerful bass. Triple progressive spiders keep the incredible linear excursion of this sub under control, while the extra heavy lead wire feeds the giant voice coil. With technology pulled from the larger BTL line the new Q has more options than ever before. Hyper chamfer, full cooling, high or low Qts topologies, as well as the ability to add an inductance ring in the high Qts design, there is now even more flexibility within the Q platform. Working well in both small ported and sealed enclosures, you do not have to give up your trunk to have strong bottom octave foundation for the rest of your system. The Q series is the new bottom octave benchmark.


Dual 1 and Dual 2 Ohm
Cast basket
Wrap around gasket
Kraft pulp fiber reinforced cone
Single layer wide foam surround
Push terminals
Extra heavy lead wire
FEA optimized motor
3" diameter 4 layer coil
Single high grade magnet
Quad progressive spiders
High or low Qts motors
Optional Heli-cool system
And many other custom options


Fs: 32.4 Hz | 32.1 Hz
Re: 0.7 Ohms/coil | 1.4 Ohms/coil
Qms: 9.31 | 9.37
Qes: .48 | .48
Qts: .46 | .46
Mms: 341g | 347g
Cms: 0.73mm/N | 0.73mm/N
Sd: 1210cm^2 | 1210cm^2
Vas: 149.7 l | 149.7 l
Spl: 92.0dB 1W/1m | 91.9dB 1W/1m
Bl: 13.9 N/A | 19.65 N/A
Xmax: 28mm
Rms: 1500W
Sealed box: 4-8 cuft
Ported box: 6-10 cuft @ 28Hz
Sub OD: 18.500”
Cut ID: 16.750”
Mounting depth: 10.000”
Displacement: 0.24cuft

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Product Videos

Fi Q 18" Subwoofers 2000 Blazer 4dr (02:04)
Song: B-Legit - Stickem, Decaf version (if you cant read it in the video haha) Details: 12.5 cu ft. @33hz with 150 sq inches of port area. Subs: 2 Fi 18" Qs (2 slug versions) with BP optionAmp: Soundstream TX1.26002 runs of 1/0 wire and 0 gauge amp inputs with Kinetik HC1400 in back stock battery up front.Mechman 270 amp alternator with Big 3 upgrade.
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Product Reviews

  1. what? cant hear you. fi to loud 5 Star Review

    Posted by on 12th Mar 2014

    I got it in a temp 8 cube slot vent tuned to 28hz and it hurts. Powered off a hifonics 1600 at 1ohm. Every time I turn it up I get permasmile :) bone stock no options.

  2. Great sub for a good price! 5 Star Review

    Posted by on 18th Jan 2014

    I love this thing I've got it in a ext cab ranger being pushed by a crescendo amp and it slams but it also has a huge range for being such a big sub thinking about getting two very pleased don't think just buy it!!!

  3. Quality 5 Star Review

    Posted by on 18th Jul 2013

    I got mine a few weeks ago with all options but High QTS and Heat ring.
    It is running on 700wrms in a tiny 2cuft sealed box right now, and while it is being broken in I can still feel the lower HZ. Playing heavy black/grind metal the thing doesnt miss a note.
    Sounding better than any others I've heard in person so far.

  4. Great Lows 5 Star Review

    Posted by on 15th Feb 2013

    i got my q18 in between 10 n 11 cubes tuned to low 20 hz. I love this thing. Sounds great on low notes. Mine has everything but the high qts option and i heat ring option

  5. soud quality 5 Star Review

    Posted by on 3rd Dec 2012

    sound quality is amazing and it gets low while sounding clean and clear i love it.

  6. Sound 4 Star Review

    Posted by on 27th Nov 2012

    This sub is one of the loudest low hitting subs that I have heard I have it in a box tuned to 30hz and the lows make my trunk go crazy I love this