1994 Geo Prizm LSi

Vehicle: 1994 Geo (Toyota) Prizm LSi (Corolla). 1.6L DOHC. 33MPG, FTW!

Electrical: Whopping 70amp alternator. Orbital yellowtop battery. Big3 in 4g (fused @ 150a). The battery is grounded straight to the alternator casing as well as the body of the car. 4g (fused @ 150a) running to a Monster block with 4g going to each amp.

HU: Alpine CDA-9855. I'm running it 3 way active. The only processing I'm using is the internal crossovers and Time/Correction (time delay). No EQ'ing (simply because I do not have access to an RTA). Internal power is turned off. Blackout mode is always used. Having time delay on each individual driver is the shiz-nit!

Power: Alpine PDX4.100 -bi-amplifying the front stage. Crunch P1500.1 on the sub stage (yea I know, 'Crunch', but I'm running it @ 2ohms for better damping, lower THD, and a longer lifespan) -1kW for $147 shipped :)

Speakers: Front stage: Alpine SPS-1015 3/4" silk dome tweeters -'50w' tweeters getting about 120w each. Silver Flute W14RC25 mids -'60w' mids getting about 120w each. Sub stage: Boston Acoustics G51044 in 1.5 cubic feet @ 26.7Hz.

Crossover points: As of now, the tweeters are getting 3.2kHz & up, the mids are getting from 3.2kHz down to 80Hz, & the sub is getting 80Hz & down. 24dB/octave at all points.

Bragging rights: I did 135.4dBs @ 36Hz legal on the Term Lab. Also, this is the best sounding system I've ever heard (of course LoL). -I live in a small town...

Possible upgrades: When/ if the Alpine tweeters go out, I would like to upgrade to the VR line of JL tweeters -only because David likes them LoL. I need to build another box for my sub -one that'll fit in this trunk a little better -and rearfire for a couple more tenths (at least LoL). Also, I need to upgrade the power wire to at least 2g.

Special thanks to: i am an idiot (for much technical support over the past couple of years. DYohn (David) (for recommending the Silver Flute mids -MANY thanks, they are BEAUTIFUL LoL). haemphyst (David aka: ham fists of fury) (for designing my box, helping with crossover points, and overall system design.

I will add some pics whenever I build a new, vehicle-specific subwoofer box.

Let me know what you think! Thanks!

2013 Kia Rio -90a alternator

DDX470HD GTO14001 GTO1014D (x3)

Big3 in 1/0G

1/0G to GTO14001

I know you are already running a HUGE alternator (same Amperage as mine), but don't be surprised if your voltage dips at high audio outputs, especially with lights on. 70A is barely 1kW at full output. And - at that power - it's better to ground the battery to the engine block (or starter) than the alternator itself - the starter motor is the biggest load you have.

oldspark wrote: I know you are already running a HUGE alternator (same Amperage as mine), but don't be surprised if your voltage dips at high audio outputs, especially with lights on. 70A is barely 1kW at full output. And - at that power - it's better to ground the battery to the engine block (or starter) than the alternator itself - the starter motor is the biggest load you have.

1. My voltage never dips below 13.9 -even with the stereo wide open in 100degree temperatures. I am very careful with my gains as well as other electronics in the car being 'on' while I have my stereo on.

2. I totally disagree with you here. The alternator is the source of power in the car, so therefore it is 'absolute ground' -where there is the least resistance from the power source to the battery. It would be defeating the purpose if I grounded the battery to the block or even worse, the starter. Sure, it'd be great to beef up the wires to the starter, but that's not what I'm concerned with LoL Plus I only use the starter for a second or two at most. :)

2013 Kia Rio -90a alternator

DDX470HD GTO14001 GTO1014D (x3)

Big3 in 1/0G

1/0G to GTO14001

Not discussing absolute ground. Suggesting it's bad having alternator to starter ground losses - or in extreme cases, welding/burning bolts etc. It has to do with taking a typical 200-400A from the battery. Real wow but obvious stuff.    But like all designs, it depends on what you want. You are allowing for that "high" resistance path but consider your amp supply (or alternator 70A output) to be more important. That's fine. I've done the same. But it's good seeing someone smart enough to use loads within the vehicles limits, else understand them. I see so many "I have a 1kW amp but only a 1kW alternator".... (what size cap do I need?).

I simply do not understand... Why, again, would I be interested in upgrading the starter to battery ground?

The starter is only used for maybe 2 seconds, twice a day. It's an OEM part that is connected with OEM wiring (again, sure, it would be better to upgrade them, but why?). The starter only uses battery power.

On the other hand, my audio system uses its' power from the alternator. I have got 180amps worth of fusing on a 70amp alternator. It only makes sense to upgrade the positive and negative wires going to it so it, in turn, generates less heat which extends its' lifespan. -It makes no sense for the ground return to have to go through the starter terminals and wiring.

2013 Kia Rio -90a alternator

DDX470HD GTO14001 GTO1014D (x3)

Big3 in 1/0G

1/0G to GTO14001

So you have the original ground wiring as well (chassis/body to block)?

Correct, all factory wiring was left intact.2013 Kia Rio -90a alternator

DDX470HD GTO14001 GTO1014D (x3)

Big3 in 1/0G

1/0G to GTO14001

No problems then.

I awoke to this one cold winter morning. It did read 15.1, but it dropped as I got out my camera.

The battery is grounded straight to the alternator.

The wires are both as short as possible, as they should be.

Both the Big3 charging wire and the amplifier power wires are fused @ 150a (they are 4g).

2013 Kia Rio -90a alternator

DDX470HD GTO14001 GTO1014D (x3)

Big3 in 1/0G

1/0G to GTO14001

Is that a 3-wire SIL alternator? And S goes to battery +?