Adding aftermarket amp/sub

[BIRDMAN]

I don't think so. Look at your sub, its dual voice coil. Each coil is 1.5ohm... wired in series will give you a 3ohm resistance.

Parrallel would drop it to .75 ohm, almost a dead short.

Running them dual channel is just 1.5 ohm per channel.. thats pretty heavy for most car amps isnt it?

i'm talking about the Alpine Type R I posted. It says Dual 4ohm voice coil. correct me if I'm wrong but series adds the total resistance and parallel cuts it in half. 2ohm load on a quality amp is fine in my experience, i have run crappy amps 1ohm without issue before. i won't be turning it up all the way anyway.

 

[jdowens1]

series ckt total ckt resistance is the sum of all resistors added together for total resistance.

parallel ckt total resistance is the sum of all resistors then dividing by how many sissistors your have. Also in parallel ckt the total resistance will always lower than your lowest resistor.

 

[pirate air]

2, 4 ohm resistors in parallel have a resistance equivalence of 2 ohm's. You can take the resistance/load amount of one branch (in this case, 4ohms) and dived by the number of resistors/loads (in this case 2) to get the value. BUT the only time this method works is when the resistive values in each branch are the same. You could not do this if one branch was 1.5 ohms and the other was 4 ohms. This would give you 2.75 ohms which is wrong. The correct way to do this is by using the "reciprocal method" (you can also "product over sum" but its pointless). Recip method [(1/Rt= (1/R1) + (1/R2)] looks like this: (1/1.5)+(1/4)= circuit conductance in Siemens = .916 S or 916 mS now take 1 and dived by .916; 1/.916= 1.09 ohms, the correct resistance equivalent for 4 ohm and 1.5 ohm in parallel.

 

[jdowens1]

I haven't done a lot of stereo systems lately but everyone I have ever done I have never seen any remote wire with less then 12v. It might be 5v now with newer systems. I've also heard of people wiring relays for the remote wire to handle the current although I've never done it. This is my oppinion I would never wire in to any 5v ref that a module gives because if that amp or something fails and they find that to be the problem it will void warranty. The remote wire could also backfeed and cause issues that can make it hard to diagnoise and lead to a lot of frustration between the owner and technician. You would prob be alright if you wire in low current fuse inline to blow before any backfeeding could be done. Just my two cents I have seen problems like this before and they suck trying to find sometimes.

 

[Geno]

so if a have the basic factory system (no sub or nav), what is the best converter for rca outputs that will mount behind the factory deck?

 

[BIRDMAN]

so if a have the basic factory system (no sub or nav), what is the best converter for rca outputs that will mount behind the factory deck?

you can still do an rca conversion on your rear speaker leads.

 

[BIRDMAN]

that's great news. i didn't really have a problem with my last install where i used the rear speaker leads but i knew it wasn't to full potential. i had 2 massive 10's and 800w rms going to a vent tuned box so it was still more than enough, ear shattering even at times. since i will probably only do 300-400w rms and 1 sub under my rear seat i want to make sure i get it right. thanks for your help.

found an old video of my setup. i built that box it was vent tuned to the interior of my FJ Cruiser...then i had it rhino lined for durability and sound proofing.