is everything in the box needed for Installation?

Yes, with the accompanying Amp Kit. Its complete along with rubber insulation you gave to attach yourself. I would suggest electrical tape, wire strippers, and a pair of terminal/electrical pliers (I apologize if you are already aware.).

Has anyone added a second sub to their system?

Yes. I used RCA splitters and installed two in my Mitsubishi Montero. Sounds amazing and have been going strong for 3 years. I tried to split the remote control using a telephone line splitter but got weird feedback when I tried to do that, so I just went without the remote control.

How difficult is this to install?

It's easy to install if you understand stereo systems and how to run the wires. The hardest part is getting to your stereo. Not sure if you have experience or not installing systems. If you do, its easy.

If I got splitters for both the rca and remote control (telephone jack), can I install one sub under each of the front seat?

Yes. I split my rca signal and installed 2 of the speakers.

Rockville SS8P Bundle: 400-Watt 8 in Slim Under-Seat Active Powered Car/Truck Subwoofer, RWK10 10 Gauge Amp Installation Kit with ANL Fuse Holder and 100% Copper RCA Cable, 2-Items

Rockville SS8P Bundle: 400-Watt 8 in Slim Under-Seat Active Powered Car/Truck Subwoofer, RWK10 10 Gauge Amp Installation Kit with ANL Fuse Holder and 100% Copper RCA Cable, 2-Items

Product ID: 444708095

Details

Brand
Rockville
Speaker Maximum Output Power
400 Watts
Frequency Response
20 Hz
Connectivity Technology
RCA
Audio Output Mode
Stereo

📏2.8" slim profile

🔊400W peak power

🔌10-gauge copper wiring

ASIN	B079PSSD6N
Age Range Description	Adult
Antenna Location	Car
Audio Driver Size	8 Inches
Audio Driver Type	Dynamic Driver
Audio Output Mode	Stereo
Box Contents	1) Rockville SS8P 400 Watt Slim Under-Seat Active Powered Car/Truck Subwoofer Sub, 1) Rockville RWK10 10 Gauge Amp Installation Kit ANL Fuse Holder 100% Copper RCA
Brand	Rockville
Brand Name	Rockville
Colour	silver
Compatible Devices	Car Audio System, Truck Audio System
Compatible with Vehicle Type	Car, Truck
Connectivity Protocol	RCA
Connectivity Technology	RCA
Control Method	Remote
Controller Type	Remote Control
Customer Reviews	4.4 out of 5 stars 1,481 Reviews
Enclosure Material	Aluminum
Frequency Response	20 Hz
Impedance Unit of Measure	2 Ohms
Is Waterproof	false
Item Dimensions D x W x H	27.9D x 35.8W x 13.7H Centimeters
Item Weight Unit of Measure	11 Pounds
MP3 player	No
Manufacturer	Rockville
Model Name	SS8P
Model Number	SS8P+RWK10
Mounting Type	Tabletop Mount
Network Connectivity Technology	RCA
Number Of Circuits	1
Number of Audio Channels	2 1
Number of Items	1
Power Source	12-volt DC electrical system
Processor Count	1
Product Features	Protection
Signal-to-Noise Ratio	90 dB
Speaker Maximum Output Power	400 Watts
Speaker Size	8 Inches
Speaker Type	Subwoofer
Specific Uses For Product	Under-seat installation in cars or trucks
Subwoofer Connectivity Technology	Wired
Subwoofer Speaker Diameter Unit of Measure	8 Inches
Tweeter Driver Diameter	1 Inches
Water Resistance Level	Not Water Resistant
Wireless Technology Type	Bluetooth
Woofer Driver Diameter	8 Inches

Rockville SS8P Bundle: 400-Watt 8 in Slim Under-Seat Active Powered Car/Truck Subwoofer, RWK10 10 Gauge Amp Installation Kit with ANL Fuse Holder and 100% Copper RCA Cable, 2-Items

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