BIO-4-COX // 80 Watts RMS 4 Inch Car Coaxial Speakers, Pair
BIO-4-COX // 80 Watts RMS 4 Inch Car Coaxial Speakers, Pair
BIO-4-COX // 80 Watts RMS 4 Inch Car Coaxial Speakers, Pair
BIO-4-COX // 80 Watts RMS 4 Inch Car Coaxial Speakers, Pair
BIO-4-COX // 80 Watts RMS 4 Inch Car Coaxial Speakers, Pair
BIO-4-COX // 80 Watts RMS 4 Inch Car Coaxial Speakers, Pair

BIO-4-COX // 80 Watts RMS 4 Inch Car Coaxial Speakers, Pair

Regular price 30% OFF Before: $42.99 Sale pricePrice: $29.99

The CT Sounds BIO-4-COX 4” 2-way coaxial car speakers are the perfect upgrade for your factory car speakers and are extremely versatile with the ability to be powered by your factory head unit, an aftermarket head unit, or a multichannel amplifier. The speakers are sold as a pair and include (2) 4” signature CT Sounds speaker grilles, (2) premium speaker wires with pre-crimped female spade connectors, (8) 1” mounting screws, (8) mounting clips, and (1) product manual with wiring diagrams for easy installation. 

Quick Facts:
RMS Power: 80 Watts (Pair)
MAX Power: 160 Watts (Pair)
Speaker Type: 4" 2-Way Coaxial
Voice Coil Configuration: Single 4-Ohm

The name “BIO” derives from the Biosphere, Earth’s lowest atmospheric layer. And just like the name suggests, these 4-inch speakers come closer to earth delivering a nicely balanced tonal range at a price that won’t send you into space. The silk-dome tweeter combined with the polypropylene woofer delivers sound that is rich and full with tight bass and mids. Don’t just hear sound. Travel to the future and experience it. 

General Specifications:
Speaker Size: 4"
Speaker Type: 2-Way Coaxial Speaker Set
Impedance Per Speaker: Single 4-Ohm
Power Per Speaker: 40W (RMS) | 80W (MAX)
Total System Power: 80W (RMS) | 160W (MAX)
Voice Coil Size: 1.00"
Voice Coil Wire Material: CCAW
Voice Coil Bobbin Material: KSV
Magnet Diameter: 70 mm
Magnet Height: 10 mm
Magnet Weight: 5.27 Oz
Magnet Type: Y30
Cone Material: Black Vacuum Polypropylene
Surround Material: Nitrile Butadiene
Basket Type: Stamp Steel
Terminal Type: Steel Plate (Big Plate = Positive)
Woofer Specifications:
Output SPL (@1w/1m): 85 dB
QTS: 1.2
Frequency Response (@SPL -10dB): 105 Hz - 20 kHz
Resonant Frequency: 120 Hz
Sweep Voltage: 10 V
Crossover Point: 4 kHz
Tweeter Specifications:
Tweeter Size: 13 mm
Tweeter Type: Silk-Dome
Tweeter Voice Coil Material: KSV
Magnet Type: NdFeB
Output SPL (@1w/1m): 91 dB
Frequency Response (@SPL -10dB): 1500 Hz ~ 20 kHz
Sweep Voltage: 2.8 V
Crossover Specifications:
Crossover Circuit: 4.7 μF / 50 V
Filter For Tweeter: 6 dB/Oct
mounting info
Mounting Specifications:
Overall Diameter: 3.96"
Cut-out Diameter: 3.60"
Magnet Diameter: 2.76"
Magnet Height: 0.39"
Mounting Depth: 1.70"
Overall Height: 1.87"

Customer Reviews

Based on 6 reviews

Please understand this is still a price dependent item it's only 30.00 dollars, and I got 10% off that and free delivery. At that price, I was not expecting much. Honestly, as a stock speaker replacement added to a newphews first car, these are great. For his hip hop style music, they do a great job. Just be sure to use xovers or bass blockers. (They are only 4 inches after all.) I have used other 4 inch budget speakers and put them in many family members first rides before but CT Sounds is now my go to for all the kids in the extended family. Clean sound, especially for the price!

Berry M. (Casper, WY)
Nice little units

Perfect for a variety of applications. Nice packaging good shipping. I’m putting them on a pillars and running them as midrange

Julius (Youngtown, AZ)
Slapping little 4 inches

These were a huge upgrade for my Toyota pickup.


Haven’t installed them yet but I know they will sound great

Mike (Stonington, CT)
Big sound.

Got 4 of these 4" to go with my meso full range 6.5. The 4" in the dash and rear doors, meso full ranges in the front doors, in my 1992 Mercedes 300te.
Sounds perfect. I was worried about them popping or distorting because I have never really had good luck with cheaper highs, but these things don't have a issue. Way cleaner and louder than what was in there. Car has weird speaker sizes and the doors really don't enclose the speaker all that well even stock, but they still do their job and I'm super happy with the way it came out.
The dash takes a 5" and I know a 5.25 wasn't gonna fit and clear the stock cover, so I downsized and the 4" actually fit pretty well with only a minimal gap to fill.
Car has a single 12 sub and a 2k watt amp, it's absolutely perfect. Couldn't be happier.
I have CT sounds products in multiple cars and they are all awesome.