Hooking amp up to stock head unit?

im looking to hook up an amp powering two subs to my stock radio in my 99 saab 9-5, im going to buy a line out converter but I was wondering if there is any specific one I need to get, or are they all the same?Hooking amp up to stock head unit?
If you buy an amp with speaker level inputs then the LOC would not be required. If it doesn't then any LOC would work but an adjustable one would be ideal because of being able to fine tune the voltage out (RCA).Hooking amp up to stock head unit?
Even if your amp has line level in, don't use them. They are not clean. I speak from experience. A LOC is a must.



PAC makes a good piece called a SNI-35. That's what we typically use. They go for around $30. This is a simple 6 wire hookup (positive and negative for left and right channel, and a redundant chasis ground to cut out noise).



However, if you are going to tap directly of the rear speakers, try PAC's TRUNK-LOC. It has a current sensing remote trigger. NOTE: The trigger may appear to work, but can sometimes cut off at higher volumes, as the majority of factory radios begin to cut off or reduce low frequencies as you increase the volume over the 1/2 or 1/3 point. This unit is a little more complex as you have to hook up 3 more wires. Don't worry though, instructions are provided.



The hookup will vary depending on which audio system you have in the car. If it already has a factory sub, try and hook the line out adapter there first. If it doesn't work/doesn't have a sub, then use the rear speakers. If you plan on replacing the radio, run the RCA and Remote Wire up front, and hook the LOC (Line Out Converter) behind the deck. Otherwise, just tap off at the rear radio or sub.



Sorry if I confused you.