True, but if the HU doesn't have rear/sub and has just rear, you can use it, because its still the same signal the speakers are getting if you use a LOC. its sending all the bass through the rca's as if it were sending it to the normal speakers. I had that problem with my first vehicle before I had money to buy a nicer setup. I used rear output and used the crossover to tune out the mids/highs and it worked pretty good.

If your headunit doesn't have subwoofer outputs don't even bother it's such a waste of a sound system... The SQ is garbage and you can hear tons of filter issues even with crossovers and it's not even HALF as loud as a proper preout. Yes it works, yes it's an alternative but by no means does it work "good" or "pretty good" I've ran Line Outs to my subs before and it was complete GARBAGE.

I have a friend using an LOC and while it gets loud we had to max out his HU and amplifier just to get decent subwoofer movement and it sounds like garbage.

Well mine worked pretty good for me, never had it too loud tho because at the time the vehicle had stock mids/highs. And I hate LOC's. Id rather buy a new HU then use them. They do work tho.

When did I say it didn't work? You can use them if you wanna waste time/money, imo it's a stupid gimmick that should only be used for 4 channels if you have no preouts at all. I would never recommend it unless it was needed the guy did the smart thing and bought a new headunit which is what I woulda recommended.

Every LOC/Line Out subwoofer system I've heard sounded like total garbage idk how you can claim them to sound pretty good obviously you're unfamiliar with "pretty good" sounding systems :-p

I didn't say they sounded "pretty good". I was talking about when I used rear outs on a HU not a LOC. i'v never had a LOC.

Rear Outs and LOC are the same thing... an LOC is just worse imo because it actually robs power from your speakers. Both are sound terrible with terrible output like I said buy a new headunit or don't bother, imagine spending $500 on a system and then running a crappy headunit with line out doesn't that seem like a waste to you? half the loudness and terrible SQ? I guess I'm just that type of person I get what I need I don't just run things to get by with sub-par performance.

Read post #13. I said I'd rather buy a new HU than use them. At the time I was a 15 year old kid and was obviously broke. And I used rear out not LOC.

toggle switch looped from ingnition activated hot always works too

I have a toggle on my remote wire anyways lol. It goes from my HU, to a switch mounted in my dash, to my amps.