18″ Platform 4

Rated 5.00 out of 5 based on 2 customer ratings
(2 customer reviews)


  •  Performance Level


    Connection Type

    Dustcap Type

    Material Color

    Logo Type

    Logo Color

This product qualifies for a 10% discount on orders of 4-9, and a 15% discount on orders of 10+. The price will be updated in your shopping cart.

Platform 4

The Platform 4 series is a subwoofer that has been designed to deliver the ultimate in daily driving performance. The subwoofer boasts a huge 10″ diameter triple stacked magnet, 10″ diameter linear roll spiders, our huge tall roll high excursion surround, and our largest 3″ voice coil ever! These subwoofers are capable of incredibly high excursion, hair blowing low-frequency output and incredible accuracy. The subwoofers combine huge magnet strength, big xmax, high power handling, and PSI build quality to offer the ultimate high-end SQ subwoofer.

Power Handling Ratings:
Standard RMS Power Handling – 3000 watts
W/ Optional Hi Performance Addition- 3500 watts
Peak Power Handling – 6000 watts
SPL Burp Power – 8,000 watts

Standard version features include:
Massive triple stacked 10″ x 1″ magnets
Chrome top and bottom plates
FEA optimized motor assembly
  4/6 Spoke high excursion aluminum cast frame – Black
LARGE Chrome push terminals or 8ga XS-Flex OFC Direct Connect Wiring
Extended length 85mm aluminum flatwound voice coil
Dual 1 and Dual 2 ohm standard impedance
Triple 10″ linear roll poly-cotton spiders
.6″ spider spacing ring
Dual sewn 3mm heavy duty leadwire
Kevlar impregnated pulp cone body
1.5″ tall roll rubberized foam surround

 They are manufactured to the strictest standard, and guaranteed to last.
Hand built in the USA!


Our subwoofers are available in two different  performance configurations, Standard and High Performance. The High Performance option will modify the parts used to build the subwoofer to increase the overall power handling and output capability.

The following upgrades would be  applied to the subwoofer if the High Performance option is selected:
Power handling increase from 3000 Watts to 3500 Watts RMS
Quad stiff spider suspension
Triple stitched heavy gauge leadwires


 T/S Parameters for Platform 4 18″:
Revc = 3.81 ohms
Fs = 27.18 Hz
Zmax = 73.38
Qes = 0.37
Qms = 7.22
Qts = 0.35
Le = 4.98 mH
Sd = 1230 cm^2
Vas = 4.94 ft^3 / 139.98 L
BL = 29.56
Mms = 529.16 g
Cms = 64.80
Sensitivity = 90.6 dB @1W/1m
Sensitivity = 94.2 dB @2.83Vrms/1m
Xmax = 80mm total
Usable excursion = 3.9″ total

Enclosure Recommendations:
Sealed – 1.5-3.5 ft^3
Ported – 4.0-8.5 ft^3, tuned from 27-36hz

This product may also be used in Bandpass applications. Please contact us before purchasing this product for these installations to make sure that the standard parts will be compatible with your enclosure.

If you would like to customize this series of subwoofer with performance or cosmetic options that are not available in our online store, please submit a
Custom Subwoofer Request.


Physical Specifications for Platform 4 18″:
Rated Diameter 18″ / 460 mm
Overall Diameter 18.5″ / 470 mm
Bolt Hole Circle 17.375″” / 441mm
Cutout Diameter 16.75″ / 425mm
Mounting Depth 11.75″ / 298.5 mm
Magnet Diameter 9.85″ / 250 mm
Driver Displacement 0.41 ft.³ / 11.60 L
Shipping Weight 89.0 lb / 40.4kg

dimensionsti (Small)

 trPolypropylene Dome (Small) trCarbon Fiber Dome (Small)trFull Cone Cover (Small)

We offer connections to the subwoofer either via spring loaded terminals or direct connect wiring.

Push Terminals are chrome plated, and are marked with a red and black colors to designate the positive and negative terminals. They offer the simplest installation and provide a nice secure connection.

LARGE Push Terminals are made to accept a single 4ga or dual 8ga wires and use a heavy duty, extra-thick tab bolted to the push pin, to which the leadwires from the voice coil are soldered. large-terminals

Direct Connect wiring offers the very best connection directly from your amplifiers output wiring to the voice coil of your subwoofer. Our direct connect wiring is securely attached to our interwoven braided lead wire via high temperature solder, then covered with heavy duty heat shrink. You can make your connection to the wiring via the twist and tape method, large wire nuts, crimp connectors, or solder.


XS-Flex is the best of the best! A 100% Pure Oxygen Free Tinned Copper wire, with 735 Strand Count and Soft Touch PVC Casing. XS Flex Cable is True AWG cable. The high strand count and soft touch cable jacket allows the wire to be super flexible and easy to use in any installation. XS-Flex is available in BLUE and CLEAR.

XP Flex Cable is also a True AWG cable. It is made up of 10% Oxygen Free Copper(OFC) 90% Copper Clad Aluminum(CCA), with  735 Strand Count and Soft Touch PVC Casing. XP-Flex is available in BLUE, RED and BLACK.

PSI Flex Cable is made to the same exact standards as XP Flex, but is available in PINK only.


Products manufactured by PSI are covered by a 1 year warranty.

• Our warranty covers all workmanship and materials on any defective items.
• Defective items will be repaired or replaced at the discretion of PSI Car Audio.
• Return freight costs shall be paid by the customer.
• The warranty does not cover burnt voice coils, customer abuse, improper installations, accidental damage, or any custom modifications.
• Any warranty repairs must the authorized via the Warranty Request Form.

custom subwoofers

If our standard or high-performance options don’t suit your installation needs, feel free to send us a custom subwoofer request. This form will allow you to submit all of your install specifics to us. You can also include any special requests for colors, custom logos, or other options.

Your email address? Please double check it for accuracy.

Your full name?

What is your phone number?

How many subwoofers do you need?

What size do they need to be?

How much power does EACH subwoofer need to handle? (RMS power)

What impedance will you need (Per voice coil)?

The brand AND model of amplifier you'll use with it?

The type of enclosure that it needs to work in? (Sealed, ported? Tuning Frequency?)

The type of music that you'll listen to with it?

Will you be competing with it, or is it a daily usage subwoofer?

Is it for competitions only?

Would you like any special colors? If so, where?

Upgrades of any sort? Direct leads, carbon fiber dustcap, etc?

What is your budget for these products?

Where are you located? ZIP CODE PLEASE

Do not use this form for recones for other brands of subwoofers.

If you have any photo examples to include with your submission, please upload them here.

Any other special instructions or requests?

Type those letters into this box. 🙂

Please double check your email address before sending the request. We get many requests from people who supply a misspelled email address from we cannot contact. If you do not supply the correct email address, we can't get in touch with you.

Please make sure that you add info@PSICarAudio.com to your safe senders list.

2 reviews for 18″ Platform 4

  1. Rated 5 out of 5

    Drew Vogeler

    Upgraded from platform 2s to these and on the same power it played alot louder and lower. Can’t wait to add power and really wake these beasts up! Psi ftw!

  2. Rated 5 out of 5

    Charlie McDaniel

    Upgraded to this from a 15″ platform 2. Definitely worth it if you have the space 🙂 I drive a van and need lots of cone area to move that much air and this thing gets the job done where no other sub would, even pairs. It can play loud on a power budget like 2k RMS or if you have the watts to spare you can stuff it for a little bit at a time and it will sound great both ways! It loves those ground pounding low frequencies to make sure to tune 32 and under. I experimented with a 34 and it works, but I think it’s better to make this sub truly shine in around 30hz enclosures. I plan on getting a second one around tax time 🙂

Add a review

Your email address will not be published. Required fields are marked *

Time limit is exhausted. Please reload the CAPTCHA.