Out of stock

BTL Series – BTL-NEO15

$829.00 $619.00

Handmade in USADue to COVID-19 all orders can have upto 45 business days lead time

The 2017 BTL v3 is the culmination of a decades progression of the dominatingBTL Series.

SKU: BTL-NEO15 Categories:

The BTL v3 Series is the latest in the progression of Fi subwoofers geared towards thundering daily drivers. A very unique 6 column Neodymium magnet design using US steel cut on our water jet and finish machined on our CNCs. There is plenty of motor force in the FEA derived design for both daily and SPL use. Utilizing a solid pole and a new 3 channel venturi aided pole profile, the forced cooling keeps thermal temperatures under control. Six grade N52 Neodymium magnets provide the Gauss while 5 Fi designed 10″ heavy progressive spiders keep things under mechanical control. Utilizing a special 144 tinsel count leadwire that is double sewn to the spider pack, there are no losses in power transfer to the coil  (available in either standard stitched with terminals or the hybrid stitched/FOAD termination). The 2017 BTL Series is the culmination of years of testing and development in the BTL line.  Setting the new standard for what it means to be “Built To Last”.

  • Dual 1 and Dual 2 Ohm

  • Extra heavy aluminum basket

  • Wrap around gasket

  • Kraft pulp fiber reinforced cone

  • Dual layer wide foam surround

  • 144 tinsel count leads

  • Machined in house at Fi

  • FEA optimized motor

  • High Flux Neodymium design

  • 3” diameter 4 layer coil high Xmax coil

  • 6 N52 Neodymium magnets

  • 5 progressive 10″ spiders

  • Unique motor profile

  • Standard heavy duty stitched lead or Hybrid stitched FOAD system
Weight 55 lbs
Dimensions 16 × 16 × 14 in

Thiele-Small Parameters

  BTLv3 12 BTLv3 15 BTLv3 18
Coils DUAL 1 | DUAL 2 DUAL 1 | DUAL 2 DUAL 1 | DUAL 2
FS 33.9 Hz 32.8 Hz 32.4 Hz
RE 0.9 | 1.8 0.9|1.8 0.9 | 1.8
QMS 6.15 6.61 7.71
QES 0.26 0.30 0.36
QTS 0.25 0.29 0.34
MMS 279g 326g 393g
CMS 0.833 0.718 0.612
SD 480cm^2 810cm^2 1210cm^2
VAS 24.9 l 66.1 l 126.3 l
SPL 87.6dB 90.8dB 92.6dB
BL 20.1 N/A | 28.4N/A 20.1 N/A | 28.6 N/A 20.1 N/A | 28.6 N/A
XMAX 34mm (One Way) 34mm (One Way) 34mm (One Way)
RMS 2500W 2500W 2500W

Technical Specifications

  BTL12 BTL15 BTL18
Overall Diameter 12.500” 15.625” 18.500”
Cutout Diameter 11.125” 14.125” 16.750”
Mounting Depth 11.250” 11.250” 11.250”
Driver Displacement 0.19cuft 0.21cuft 0.26cuft
Sealed Box N/A N/A N/A
Ported Box 1.8-2.5 cuft 3-5 cuft 6-8 cuft

This is a complete list of options; not all options are available on all models.
See drop down selections for options available with each speaker model.

P Chamfer: This is a chamfer on the end of the pole, it helps to bring the air down around inside of the motor and helps cool the coil better. It also helps relieve the pressure underneath the dustcap. We recommend at the bare minimum to get this option if you choose this series of woofers.

Hyper Pole: This is an extended version of the standard P Chamfer. It has 1.250” more pole and chamfer resulting in an increased compression ratio for better cooling.

Cooling: Self explanatory, the cooling channels are machined into the inside of the sub to help cool the coil FAR better. But there are some things that you sacrifice. There is less metal inside of the motor so it is a little weaker. If you are looking for a fart/burp only scenario for SPL we suggest that you do NOT get this option. Stick with only the P chamfer. Now if you are looking for a daily sub to beat on and you have less then 2000 watts then this is the option for you. 2000+ watts you need to look into the BTL series.

Flatwind: The flatwire coil option simply helps the power handling of the sub. The coil has more surface area to dissipate heat and will take more power then the regular round wire coil that comes in the ‘stock’ version of the sub. This option will also make the sub tend to be more prone to ‘peaking’. If you are looking to do an SPL install we highly recommend that you use choose the flatwound coil option. In testing it is louder then the regular roundwire coil and takes the thermal abuse much better.

BP: “BP” option which was a machined aluminum compression plug to the pole which helps channel all of the air under the dustcap around the coil for better cooling. To aid with this increased airflow we also added 6 axial cooling channels in the top plate. Along with increased thermal capacity comes the addition of an extra spider and a changed spider pack. All of these features increase power handling from 200-500 Watts depending on the application.

High QTS: This option is for users who intend on using the subwoofer in only a sealed enclosure.

Low QTS: This option is for users who intend on using the subwoofer in only ported enclosures.

Extra Spider: This option adds an additional spider to the spider pack to help with mechanical power handling and keeping the moving assembly under control.

I Heat Ring: This option is a machined aluminum ring in the gap that lowers the inductance of the voice coil which allows it to play up a little higher in the frequency range and have better overall transient response. Please note that you can NOT select low Qts and the I Heat Ring options together.

Internal Lead: This option is for 8 lead coit per coil, increasing the current flow from coil to terminals.

Inner Heat Sink: Its a machined aluminum ring in the gap that lowers the voice coils inductance (allowing it to play up higher and have a little better overall transient response). It also reduces the volume inside the magnet gap of the motor increasing air speed with the cooling as well as allowing the coil to kick off heat to a more receptive thermal mass rather than magnets.

Daily or SPL: Simply put, if you plan on listening to any type of music you MUST choose the daily option. If it is strictly for a fart/burp scenario then choose the SPL option. The reason we have these options is the gap tolerances between the two are different. The gap in the SPL woofer is much tighter and FAR less forgiving in comparison to the Daily option. The Daily option simply gives the coil more wiggle room inside of the gap to deal with the non-linearity tendancys that you can get into when you are using a sub in a daily driving scenario. Typically SPL applications deal with 1 note and it does not change, therefore we can make the gap much tighter and get all of the motor strength that we can out of it.

Spider Spacer: Adding this feature mirrors the spider layers and in turn reduces rock ratio helping keep the voice in line at extreme excursion.

Universal: This option gives you the choice to later chance the impedance of your voice coils. You can change from dual 2s to dual 1s and vice versa by reconing them. If you do not choose this option your motor(s) will be optimized per the coil resistance that you have chosen. (Dual 2s will forever be a dual 2 motor, Dual 1 will forever be a Dual 1 motor).


Speaker Terminals

We have two terminal options on selected subwoofers.

Our Standard Push terminal using 144 strand count sewn tinsel leads Or our new Hybrid+ lead system with ring terminal attachment for high power systems.



We have 4 Dustcap options on selected subwoofers.

Our regular Dry Carbon composite dustcap and new Gloss Carbon. Both variants are available in 6″ and ‘Big’ 7″ diameters to further your customized experience with Fi.



We have a wide array of color options to choose from, with over 10 colors to choose from we’re sure you’ll find something to enhance the look of your Fi subwoofer.


Subwoofers & Recones are dispatched via FedEx Ground. Small goods such as sticker packs, various apparel items are shipped via USPS. Upon dispatch of your goods, order status will be updated from “test/pack” to “shipped” which is accompanied with tracking details.

General Information

All orders are custom made to your selected options.  Each order is machined from raw steel and hand made.  This normally takes 10-15 business days, but due to unforseen issues it can take longer. Fi will maintain reasonable communication should an item take longer than our normal 15 business days to make.  We also note for each item the current lead times (which can be longer than our normal 10-15 business days. Should an item take longer than normal, all refund policies still are in effect.

Delivery Location

Items offered on our website are only available for delivery to addresses in the US and Canada. We also accept orders from international customers who are shipping to addresses on an individual basis.  All items will ship direct from our Las Vegas, Nevada location.

Delivery Time

An estimated delivery time will be provided to you once your order is placed. Delivery times are estimates and commence from the date of shipping, rather than the date of order. Delivery times are to be used as a guide only and are subject to the acceptance and approval of your order.  Deliveries will be made through FedEx Ground unless otherwise noted.  Delivery times in the US generally take from 1 to 5 business days depending on how far you are from our facility in Las Vegas, Nevada

Unless there are exceptional circumstances, we make every effort to fulfill your order within [15] business days of the date of your order. Business day mean Monday to Friday, except holidays.

Date of delivery may vary due to carrier shipping practices, delivery location, method of delivery, and the items ordered. Products may also be delivered in separate shipments.

Delivery Instructions

We will only ship to the customers billing address.  No exceptions.  All orders are shipped with direct signature required.  We will not ship orders without direct signature, sorry if this causes any inconvenience.

Shipping Costs

Shipping costs are based on the weight of your order and the delivery method. To find out how much your order will cost, simple add the items you would like to purchase to your cart, and proceed to the checkout page. Once at the checkout screen, shipping charges will be displayed.

Additional shipping charges may apply to remote areas or for large or heavy items. You will be advised of any charges on the checkout page.

Damaged Items in Transport

If there is any damage to the packaging on delivery, contact us immediately.  A claim will need to be filed with Fedex.  In contacting us please have your order number (it has been emailed to you and is on the shipping label) and your tracking number (emailed to you and on the shipping label) ready to expedite the claims policy.


If you have any questions about the delivery and shipment or your order, please contact us.


    Who knew a 15 could sound this perfect? I currently have about 3500w going to a single 15 and it’s amazing. I’ve been an Fi fan since 08 and plan to be in the future.


    I purchased two 15s to replace my spl system which was five zvx 12’s on a 12k in my daily, I needed my third row back but didn’t want to sacrifice my bass I seen the needed enclosure size for these and the weight savings I got them after five weeks of impatiently waiting on my part, but I have these installed and they r great my box may need some tuning but for the price u cannot get a handmade suit custom built to order for even double this price the quality is great only drawback is the wait if u order these lean yoga or something to settle yr mind, but guys r great at fi and definitely worth the wait I have a us made subwoofer made for me u can’t really get that anywhere ekse


    Ok where do I start, little about my previous subs in the last 3 years kenwood 12,alpine type r, jbl stadium 12, soundqubed hds12, skar evl12, sundown e12, american bass xfl12, sundown sa12, Orion hcca12 black coil, sundown zv4 12, EMF banhammer 15,sundown zv5 15 and now Fi btl neo15, I know I like to try them all 😁😂😂🤣but I have to ask why am I not seeing reviews of Fi god they make the best sub in my book quality is super they hit hard I heard a few more Fi before, i actually demo a aa mayhem 12 sounds super clean n low heard it like a block away the guy approach the gas station I had to check it out n ask what he was running that led me to fi. Now there packaging is the best too second to them is Orion but Fi packaging u can probably drop it out from a truck n won’t hurt the sub. The second best sub that come close to hit hard n sound ok it’s the zv5 but no way near the fi, the btl neo is taking apart my car in a 3.6cft box tuned at 33hz on a 2500 watts amp at 1 ohms n I know I need a bigger box,but my question is y not many ppl running Fi instead of other brand like sundown Fi little cheaper but better overall took a month to get to me but it was worth waiting it actually flew by now I’m a fi fan for life will never run nothing else not say other brand is not good but the sundown zv5 15 for eg shake my car lots of wind but I felt like I was missing some thumping bass those missing notes but the btl dis low n hit hard n cleaner than the zv5 ok. Ppl that say u can’t get in contact with Fi hello there is FB messenger Brian super helpful reply within minutes. tnks Fi for making me stop spending money on other sub,they didn’t match the output as yours even though I bought and built the enclosure to match their spec. plz don’t hesitate to buy Fi they take the Power better than others that ive run that start stink, even after using a tpi 440 oscilloscope to set all gain n output to clean signal and Fi made in da USA can’t beat that


    I bought 2 15″ BTL Neo’s Limited Black Edition and needless to say these are Monsters. I have each one wired to 1 ohm at 2500 watts RMS each and needless to say they pound. I’m still breaking them in so haven’t really pushed them yet but they definitely sound like they could handle more watts easily. These are definitely are what i wanted and worth every penny! Better yet selected normal dust caps and still received them with carbon fiber dust caps.

    *Construction looks and feels solid. *Materials used are definitely quality.
    *Sound quality is excellent, deep and crisp

    Don’t really have any negatives but with this level if sub it kind of surprised me.
    *Inputs do not fit 8awg wire.
    *Rubber gasket holes do not line up and off by an inch on both subs and excess epoxy in spots locked gasket in place making it difficult to move without damaging gasket.

    All in all these are excellent subs and i would buy again without hesitation. Only thing i would do different is select the hybrid leads instead of the stitched. These were DEFINITELY worth the 1 month wait time while they were being built!!

    On a side note i did notice that if you added stickers to your order when buying subs it charged $10 per set for shipping even though it says stickers ship for free.


    Wow! I am lost for words. I ordered a BTL 15 for my birthday and was blown away by the sound of this beast. I was a little upset that it took over a month to get, but IT WAS WORTH THE WAIT!!! When I saw the details put into the sub I instantly forgot about how long it took. The sub hits clean and low. I am more then satisfied with the sub. Don’t hesitate to buy this sub and trust me, be patient because it will take some time to build. You can’t rush perfection. Thank you Fi for such an awesome sub and a hell of a birthday gift! I was truly surprised!! Fully load!!

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