This was not my original post, and was not my circuit. It was designed by 808Speed6 and the directions posted on another board. I just recently completed this mod, and i'm impressed.
All the parts can be had from Radioshack for $10-20, or less if you happen to have some sitting around. Difficulty: 3 (1 easy-10 impossible); Time: 2 hours; O-factor: 4 (1 eh - 10 OMGWTFBBQ); Tools: Soldering iron (optional) wire cutters/strippers, screw driver, 1/4 socket(10mm)
Heres what you need:
1 small Breadboard(solderless snap in style) or Perfboard(solder style) *
1 4.7k ohm 1/4 watt resistor *2
1 15k ohm 1/4 watt resistor
1 1uF capacitor >25volts
1 100uF capacitor >25 volts
1 LM741cn operational amplifier
some small pieces of wire (about 14-16 guage)
electrical tape
soldering iron/solder (optional)
*I highly recommend the breadboard, as that way if you do something incorrectly, it can be easily corrected
*2 A note on reading resistors: the colors on the resistor will tell you the resistance. In the pack I purchased from RadioShack (this one) there is actually a chart on the back that will help with deciphering them.
On to the instructions:
1) Remove your subwoofer amplifier. Disconnect the wire harness, and then there are 3 bolts connecing the plastic housing to the sub. Once that is removed, just pull the audio connections off the sub. There are 4 small screws holding the amp to the housing, remove those and pull the amp out of the casing.
2) assemble the circuit. The schematic is below. Here is a completed pic (stolen from ryceboi)
3) attach the circuit to the wires from the harness. Heres how this works:
Purple = Signal +; Cut it. Connect the side from the harness to the Signal+ wire on your circuit. Connect the side to the amplifier to the Signal Out wire on your circuit.
Yellow = Signal -; Tap this wire (strip a bit of insulation without cutting it) and connect your Signal - circuit wire.
Orange = +12V; Tap this wire (strip a bit of insulation without cutting it) and connect your +12v circuit wire.
Black = ground; Tap this wire (strip a bit of insulation without cutting it) and connect your ground circuit wire.
To connect these wires I recommend using solder. This will eliminate any chance of the wires coming apart and shorting out. Of course you will want to wrap the hell out of them in electrical tape at the very least.
4) Reverse the phase of the wires going to the subwoofer. These are the green and red wires running under the amp up to the sub. This can be done by either cutting and reattaching green-red or cutting the slides off and attaching new ones. Unfortunately Bose used a smaller connector for the - one, so we cant just switch them easily.
5) Reassemble, put it back in the car, test it out.
Some things to be aware of: You don't have a ton of room ontop of the amplifier, so be sure to keep the wires on the caps/resistors short, so they dont stick up and touch the bottom of the sub.
If your capacitor is marked with an arrow instead of a +/-, the arrow flows from pos to neg.
And just a word on how breadboards work. The two horizontal rows are connected, and each vertical row is connected. There is a drawing at the bottom of the schmatic (which was created by Ryceboi) to show this.
If your LM741 does not have a notch, the hole marks which pin is #1
Disclaimer: You are working with electical components here. There is of course the chance that you could fry fuses, your sub, your amp, yourself. Do this at your own risk.
All the parts can be had from Radioshack for $10-20, or less if you happen to have some sitting around. Difficulty: 3 (1 easy-10 impossible); Time: 2 hours; O-factor: 4 (1 eh - 10 OMGWTFBBQ); Tools: Soldering iron (optional) wire cutters/strippers, screw driver, 1/4 socket(10mm)
Heres what you need:
1 small Breadboard(solderless snap in style) or Perfboard(solder style) *
1 4.7k ohm 1/4 watt resistor *2
1 15k ohm 1/4 watt resistor
1 1uF capacitor >25volts
1 100uF capacitor >25 volts
1 LM741cn operational amplifier
some small pieces of wire (about 14-16 guage)
electrical tape
soldering iron/solder (optional)
*I highly recommend the breadboard, as that way if you do something incorrectly, it can be easily corrected
*2 A note on reading resistors: the colors on the resistor will tell you the resistance. In the pack I purchased from RadioShack (this one) there is actually a chart on the back that will help with deciphering them.
On to the instructions:
1) Remove your subwoofer amplifier. Disconnect the wire harness, and then there are 3 bolts connecing the plastic housing to the sub. Once that is removed, just pull the audio connections off the sub. There are 4 small screws holding the amp to the housing, remove those and pull the amp out of the casing.
2) assemble the circuit. The schematic is below. Here is a completed pic (stolen from ryceboi)
3) attach the circuit to the wires from the harness. Heres how this works:
Purple = Signal +; Cut it. Connect the side from the harness to the Signal+ wire on your circuit. Connect the side to the amplifier to the Signal Out wire on your circuit.
Yellow = Signal -; Tap this wire (strip a bit of insulation without cutting it) and connect your Signal - circuit wire.
Orange = +12V; Tap this wire (strip a bit of insulation without cutting it) and connect your +12v circuit wire.
Black = ground; Tap this wire (strip a bit of insulation without cutting it) and connect your ground circuit wire.
To connect these wires I recommend using solder. This will eliminate any chance of the wires coming apart and shorting out. Of course you will want to wrap the hell out of them in electrical tape at the very least.
4) Reverse the phase of the wires going to the subwoofer. These are the green and red wires running under the amp up to the sub. This can be done by either cutting and reattaching green-red or cutting the slides off and attaching new ones. Unfortunately Bose used a smaller connector for the - one, so we cant just switch them easily.
5) Reassemble, put it back in the car, test it out.
Some things to be aware of: You don't have a ton of room ontop of the amplifier, so be sure to keep the wires on the caps/resistors short, so they dont stick up and touch the bottom of the sub.
If your capacitor is marked with an arrow instead of a +/-, the arrow flows from pos to neg.
And just a word on how breadboards work. The two horizontal rows are connected, and each vertical row is connected. There is a drawing at the bottom of the schmatic (which was created by Ryceboi) to show this.
If your LM741 does not have a notch, the hole marks which pin is #1
Disclaimer: You are working with electical components here. There is of course the chance that you could fry fuses, your sub, your amp, yourself. Do this at your own risk.
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