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JL Indoor Subwoofer


The JL subs, with the rest of my audio setup

Phase 1 - The "Tower of Power":
Since the power requirements are much more demanding than the Kicker subwoofer project, three power supplies were purchased to run the amplifier

Each DynaPower DP-500 power supply is capable of delivering 36A at 12V. Once all three are wired in parallel, their combined output will push 108A at 12V

Each PSU is opened up, and the Molex connectors are cut off

All the unnecessary power wires are removed from the supplies. The green PWR ON wire, one red +5V wire, seven yellow +12V wires, and seven black GROUND wires are left connected inside each PSU

The supplies are laid out once all the extra wires are removed

Silicone caulk is used to seal the cut wires from shorts

First modification: Each group of wires is sleeved. The green POWER ON wire is tied to the black GROUND wires. This turns the PSU on whenever power is supplied to it

All of the power supplies are sleeved

The Tower of Power begins to take shape. Each of the PSU's are re-assembled and stuck together using double-sided tape

Second modification: The ground terminal is created. Each of the ground wire groups from the three supplies are joined together. They are sleeved and held in place with heat-shrink tubing. The wire ends are stripped, twisted together, and covered in solder to form a hard, metal plug. The +12V plug is made in a similar fashion. The ends of the three leftover +5V wires are tied together, covered in tape, and tucked away. Keeping the +5V wire allows the future addition of low-voltage devices (like LED lights) to the tower.

The Tower of Power is complete. The power supplies must be powered on simultaneously, so they are all plugged into the same power strip

The surge strip is switched on, and the terminals are tested for voltage. The Tower of Power delivers a solid 12.05V. I would like to thank Jonathan Fry (www.fryguy.ca) for the advice he gave me on wiring power supplies in parallel.

Phase 2 - The Amplifier:
A Memphis PRD1000.1 car amplifier is used to power the subs. It is capable of delivering 1000W to a 1 ohm load. Its maximum current draw can exceed 120A at 13.8V!

The amplifier adjustments are found on the side panel. These include input sensitivity, bass EQ gain, and crossover cutoff frequencies

In order to protect the power supplies, the four 40A fuses originally found on the amp are replaced with four 20A ones. This prevents the amp from pulling any current greater than 80A from the Tower of Power

The Tower of Power is wired to the amplifier

The blue remote wire is connected to the +12V terminal. This causes the amp to turn on whenever power is supplied to it

The shrink-wrapped power plugs fit snugly into the amplifier terminals and are screwed in place. Speaker wire is attached as well

Phase 3 - The Subwoofers:
Three JL Audio 10w3v2 subwoofers are prepped to be wired together

Each sub measures 10" in diameter and has dual 6 ohm voice coils. The voice coils are wired in parallel to present a 3 ohm load per speaker. The three 3 ohm speakers are then wired in parallel to present a 1 ohm load to the amp

The speakers are screwed down securely into the box

The finished box. I would like to thank my pal Evan Pritchard for the great deal he gave me on the used subs, amp, and box

Wiring the subs into my audio setup

A close up shot of the subwoofer rig

The complete setup. Testing the subs at ~75% volume was sufficient to drive a bass-line throughout my entire three-story dorm building. The subs are total overkill, but their effect is certainly impressive


Costs:

Power supplies (3x) $104.52
Subs, amp, box $275.00
Sleeving, heat shrink $5.00
Fuses $8.00
Caulk, solder $1.00
Speaker wire FREE

Total $393.51


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