Fi Car Audio DELTA 15

Code: FI-DELTA-15

The new 2019 Delta series is the largest and most powerful sub in our complete line of subwoofers


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The new Delta series is the largest and most powerful sub in our complete line of subwoofers. Sharing all the features of the Omega series like a 12.5” diameter split ferrite magnet design as the foundation allowing cooling air to flow through our massive 1/4” thick inductance ring. This inductance ring and the thermal mass it provides aids in reducing non-linearities in the coil as well as becomes the foundation for our new annular cooling system for the coil. The 4” voice coil and upper motor geometry allow extreme Xmax and linear throw. 4,5, or 6 spider suspension are offered as options(TS Params are based off of standard 5 spider). While the Omega is designed for ported and 6th order applications the Delta works well in 4th orders or smaller sub systems.

The new Hybrid+ lead system is standard with the stitched extreme lead and new attachment system. This allows for you to use any size speaker wire you would like for the ultimate in power transfer. The cones are available with epoxy impregnated option to the Kraft pulp/ fiber matrix and are stronger than ever before…. Offering power handling and features never before found on our subwoofers, it truly is the last word in brutality from Fi.

*****A note on power handling and use. The Delta series is not the sub for everyone or every application. The power rating of 4500W is a base rating that in testing were simply could not hurt it in any way. This is not to say that this is its “rating”. With the use of the Delta, power is 100% application dependent and in practical use can be much higher. The enlcosure, tuning, thermal/mechanical compression of the system will dictate how much more (if any) power can be used. The Delta series can be used in smaller single sub applications, lower pressure systems, or regular trunk setups while the Omega should not be. *****


Coils DUAL 1 | DUAL 2
FS 37.0 Hz | 36.4 Hz
RE 0.7|1.4 ohms
QMS 7.11 | 7.02
QES 0.25 | 0.36
QTS 0.25 | 0.35
MMS 434g | 436g
CMS 0.0 | 0.440
SD 810cm^2
VAS 39.1 l 40.4 l
SPL 90.8dB | 89.1dB
BL 19.53 | 27.6 Tm
XMAX 34mm (One Way)
RMS * Many Watts

Sealed box: NO | NO
Ported box: 3-5cuft | 3-5cuft
Sub OD: 15.625” | 15.625”
Cut ID: 14.125” | 14.125”
Mounting depth: 11.50” | 11.50”
Displacement: 0.25cuft | 0.25cuft

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
Hybrid+ lead system
FEA optimized motor
Split ferrite magnet design
4” diameter 4 layer coil
Single stack magnets
Progressive 10″ spiders
Unique motor profile
Machined, hand built / finished at Fi

*****A note on power handling and use. The Omega series is not the sub for everyone or every application. The power rating of 4500W is a base rating that in testing were simply could not hurt it in any way. This is not to say that this is its “rating”. With the use of the Omega, power is 100% application dependent and in practical use can be much higher. The enclosure, tuning, thermal/mechanical compression of the system will dictate how much more (if any) power can be used. This is not the sub for a single trunk setup because its the biggest thing we sell. Please save your money and purchase a Team or SP4 for better results. This is for big power, big number, music and SPL applications where you are chasing 163+ dB applications. If in doubt, ask… please do not buy it if you do not know you need it. We are trying to save you money and get you the right product*****

Custom Options Explained

makalah bahasa inggris 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 new Q series woofers in only a sealed enclosure. Low QTS: This option is for users who intend on using the new Q Series woofers in only ported enclosures.

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.

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).

“Fi Terms & Conditions”

These are not mass produced items. Each and every order is built from the ground up. This is not by using pre made parts and bolting/gluing them together, far from. They are machined to exact tolerance for your given application. There is no mass produced magnet sitting on the shelf, your woofer is made for you, when you order. Sure others can produce drivers faster but our manufacturing goes much deeper giving greater control during manufacturing resulting in a ultra high performance regardless of the footprint.

As a result build time is typically 10-14 days. With the distance from USA to the UK this can be anywhere from 14-28 days till you receive your Fi subwoofer.

We can offer a faster service with additional freight charge to express. Typically 7 days. Please contact us about this before ordering.

Refunds, If your custom-built-item has not yet begun to be manufactured you will be charged a 5% processing fee for refunding your payment. If your speaker has begun to be manufactured, or is finished, but has not shipped, you will be charged a 30% refund fee. If the speaker has already shipped, you will be charged the 30% refund fee plus all applicable return shipping costs.

By reading these terms and conditions, you agree to wait upto the allotted 28 day period. If your order exceeds this due to manufacturing delay or part shortage you will be notified in good time and automatically will receive a free T-shirt.

If you have anymore questions do not hesitate in contacting us.


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Additional information

Weight 55 kg
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UK Delivery

All items ordered before 14.00pm are shipped the same day unless otherwise stated at the time of ordering. Orders placed after 14.00pm on a Friday will be shipped the following Monday (excluding bank holidays, in which case it will be the next working day). If the item is out of stock for whatever reason you will be emailed within 24hrs to inform you of this. Our site manages stock inventory so if it says ‘IN STOCK’ that means goods are available for immediate dispatch.

  • Shipping will be calculated at the checkout.
  • Free shipping available for customers in the UK mainland ONLY when orders are over £50.
  • We use Interlink Express for all UK next day deliveries (aswell as for orders over £50 if the weight exceeds 2kg) and Royal Mail Recorded Post for orders under 2kg.

Make sure you supply us with a mobile number when you order, then we can give you full tracking information & updates on your order throughout the process.

Clicking on the above image, will also allow you to track your order online. If you have any questions or queries, contact our helpful office team on

Free Delivery

Free delivery is available to UK mainland addresses ONLY and excludes addresses in the Scottish Highlands & Islands and Northern Ireland. Free delivery is applicable to orders over £50.00 (inc vat) ONLY. This offer doesn’t necessarily mean your goods will be sent on a courier next day service. However assuming the weight exceeds 2kg your goods are usually sent via courier (Interlink Express).

Guranteed 24 Hour

  • Next Day Delivery – Over £50 Inc. VAT – Any weight – Free!
  • Next Day Delivery – 2-5KG – £8.00
  • Next Day Delivery – 5-20KG – £9.99
  • Next Day Delivery – 20-30KG – £11.99
  • Next Day Delivery – 30-40KG – £15.00
  • Next Day Delivery – 45KG+ – £50.00


  • Royal Mail 1st Class Recorded 1-3 working days – Upto 1KG – £4.45
  • Royal Mail 1st Class Recorded 1-3 working days – Upto 1-2KG – £6.90
  • Royal Mail 2nd Class Recorded 2-5 working days – 0-2KG – £3.95


  • Royal Mail Special Delivery Saturday – Upto 2KG – £14.00
  • Courier Saturday – Upto 5KG – £15.95
  • Courier Saturday – 5-20KG – £19.95
  • Courier Saturday – 20-25KG – £22.95

Orders MUST be made before 2pm Friday

Back Order

Items that are listed with ‘Back order’ usually means there is around a 5-10 working day delay for the item to be back in stock. Some items are listed in this way as they are a low volume product and are considered special order with our suppliers.

European & International Delivery

Blade ICE ships internationally to many countries in Europe. Based on the weight of your order shipping will be calculated at the checkout.

Blade ICE reserves the right to charge the full shipping fee applicable to resend if the item is returned to us as the customer was unable to take delivery of the parcel for any reason. Courier returned items will be added back into our stock and your account credited with the order total, minus the fee the courier charges us to deliver the item back to us. You will have to re-place the order to have the item reshipped. If a customer inputs any incorrect details on their order, which causes the parcel to be delivered incorrectly, we will not hold any responsibility for this parcel.

Finally we advise you to check the contents of the order with the inventory sent with the goods. In the rare instance that goods are missing, please contact us within 24 hours and we will happily send out the missing goods at no extra cost to you. If goods are damaged or faulty please inform us within 3 working days of receiving your order.

Please refer to our Terms and Conditions for more information.