4 channel line out converter

Has anyone ever used the 4 chnl line out converter from install edge?  I see that if you use it, you can tag the blue wire into the factory speaker output, and the blue wire on the rca side will act as a remote turn on wire.  How is it supposed to be hooked up?  I've never used it, and I want to start using it rather than tagging an accessory wire for remote turn on.  Thanks

There are other makes that use this principle.  The LOC will convert the voltage it picks up from the speaker output into a 12 volt source, which will allow turn-on.  I don't have experience with this type because I fear it might not pick up enough voltage as soon as the deck is turned on.  I wouldn't want to mess around with troubleshooting something like this, or hear a thump when the amp comes on...anything like that.  But IIRC, someone on this forum some months back said that he has used this type several times and never had a problem with turn on function.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.