Bio 8 Inch D4 (250W RMS) (Used - Working)

$44.99 Regular price $59.99 Sale price

You Save 25% ($15.00)


The item was tested and it is working. There may be cosmetic damage, small scratches, dents, and/or damage to the gift box. If for some reason the item is not working, you have 30 days from the date of purchase to notify us. We will ask you to return the item (with the packaging received) back to us. Once we verify it is the item and it is not working, we will issue you a store credit only. If we discover the item is working, we will not issue a refund and will offer to return the item to your address at your cost.

The Bio series, known as Badass, is our entry-level, no-frills, workhorse subwoofer. The drivers share high-grade components, perfect for the bass head on a budget. It has 250 watts RMS and 500 watts MAX power. It features a 4-layer copper Dual 4 Ohm voice coil and a polypropylene cone. It is CT’s most affordable series while still delivering excellent performance and deep low notes. The Bio is the perfect choice for its price and will not disappoint. You will stand out loud, and your friends will notice.


Whats in the box:

  • 1 x Bio 8" D4 Car Subwoofer (Dual 4 ohm)


  1. Dual 4Ω (ohm) resistive (voice coil) subwoofer
  2. 250W RMS car audio sub & can take up to 500W PEAK
  3. Dual connectivity terminals with 2" (diameter) voice coil make this product versatile irrespective of its size, dimensions and power consumption
  4. Incorporates Y30 graded ferrite magnet
  5. Strong & sturdy basket frame, capable of handling high diaphragm moves with maximum Xmax


Product Manual



Technical Specifications:

  1. Sub power: 250W (RMS) | 500W (MAX) 
  2. Subwoofer size: 8"
  3. Subwoofer type/ impedance: Dual 4 ohm
  4. Voice coil (dia): 2" (51mm)
  5. BL: 13.724
  6. FS: 44.956Hz
  7. QTS: 0.408
  8. QES: 0.426
  9. QMS: 9.601
  10. VAS: 9.587 liters
  11. SPL: 85 dB (@1w/1m)
  12. Xmax: 14.2mm (Peak to peak)

Box Specifications:

  1. Sealed: 0.3 ft3
  2. Ported: 0.40 ~ 0.75 ft3

Mounting / Installation Parameters:

  1. Cutout diameter: 183mm / 7.2"
  2. Overall diameter: 213mm / 8.4"
  3. Mounting depth: 114mm / 4.5"


Customer Reviews

Based on 1 review
Levi Neri
strong bottom of barral sub

i recomend this if you have a single cab or for under seat,this sub can be loud in a big box but if you are on a buget i recommend a tropo 8 if you have no buget but just want to get loud with an 8 get meso 8or crystal audio solutions 8