Thread: Easy powered subwoofer install in a 2005 Saab 9-3...

Hi Folks...I'm a newbie here. I found some good info here that helped me with a subwoofer install in my Saab 9-3, so I thought I'd post the details of what I did to return the favor. I'd highly recommend the Infinity Basslink powered sub because of it's features that enable easy installation (see below). You need 3 things to install a powered sub: 1) power, 2) signal, and 3) mounting location, so here's the details:

1) Power: There's a fuse panel in the left side of the trunk behind a compartment door. There's a 30 amp circuit for the existing audio amplifier (fuse slot 22), and on my car there were a few unused circuits. I choose to get power from the trailer circuit (fuse slot 8, 20 amps) since I don't intend to ever pull a trailer with this car. I used the Littelfuse Add-A-Circuit Mini-fuse kit (~$9 from Pep Boys). Note that the fuse panel uses mini-blade fuses, not the full-size ATO blade fuses. There are two Add-A-Circuit kits, one for mini-fuses and one for full-size ATO fuses, so make sure you get the mini-fuse size. The Add-A-Circuit kit is ideal IMO...it's a fuse-shaped adapter with two fuse slots and a power lead. You pull a fuse (if it's a circuilt already in use), plug the adapter into the fuse slot, plug the original fuse into slot A, then plug the fuse for the accessory into slot B, and connect the power wire for the accessory to the power lead on the Add-a-circuit. Cool deal. The only issue is that the Add-a-circuit is only rated for 10 amps. The Infinity Basslink has an onboard fuse for 25 amps...BUT...the reality is that unless you have everything absolutely cranked, it's highly doubtful the sub would ever pull 25 amps. In fact, with it cranked pretty good, the average draw is going to be about 10%, so about 2.5 amps with spikes up to probably 10-15 amps. I have the sub's volume set about 2/3 of the way up, so I doubt it'll ever pull more than a 10 amp spike...if it does I should safely be able to replace the 10 amp fuse in the Add-a-circuit with a 15 amp fuse without worrying about starting a fire or anything. The trailer circuit on the fuse panel is 20 amps, so there should be no issue there. This circuit is switched (AFAIK) by the ignition, but it and the audio circuit stay on for about 15 mins after the ignition is turned off...not sure why, but it does. So, don't be concerned if the power LED stays lit on the powered sub after you turn the car off...it'll go off in 15 mins or so.

I first used one of the simple fuse taps from Radio Shack to get power to the sub, but those are designed for the full-size ATO fuse slots, so I had to file the contact end down to a triangular shape to get it to fit in the mini-fuse slot. Also the original fuse didn't seat as securely as I would have liked with the fuse tap in place AND the fuse tap expands the contacts in the fuse slot, so I decided to just get the Add-a-circuit which is much "neater and tidier" AND has a fuse for the new circuit already in place. I'd highly recommend the Littelfuse (yes, the spelling is correct) Add-a-circuit deal over the Radio Shack copper fuse taps.

2) Signal: In my car, there are seperate tweeters and woofers installed in the rear deck that separates the back seat and the trunk. As I understand it, the woofers are already crossed-over by low-pass filters somewhere in the circuit (although I'm not positive about that...the Infinity Basslink has a built-in crossover that you can set between 50 and 180 Hz with a knob, so it's not a big deal either way). The Infinity Basslink allows you to use speaker-level inputs in addition to line-level inputs. Also, if you are using the speaker-level inputs, it will automatically power-on when it detects a signal and automatically power-off when the signal disappears...this worked out perfectly. I used Quick-splice connectors from Radio Shack (part# 64-037, 22-18 gauge, 2 packs since you'll need four) to tap into the audio signal going to the woofers on both sides of the trunk. You clamp quick-splice over each wire going to a woofer just below the connector that plugs into the woofer, press it closed with some pliers until it clicks shut, then you can plug the blade plug onto the quick-splice. Very neat and tidy. I'd suggest splicing into both rear woofers to get a left and right signal. The other end goes to the sub's harness wires for rear left and right speaker-level signal.

3) The best place I could find to mount the sub was to the back of the left rear seat. The seats fold down in two sections, so fold that seat down and mount it leaving enough wiring to fold the seat up and down without yanking any wires. Before you put too many screws in, check that there's still clearance to fold the seat up and down with the sub in place, and double-check where the screws will go to make sure there's material underneath the seat back for it to grab rather than just empty space. I had to turn the sub just a little clockwise (with the cooling fins position up).

Hope this makes it really easy for someone else in the future. Enjoy!

Gruuve