A friend of mine with a 98 GS300 (non-Nakamichi factory system with the trunk "free air" sub in the rear decklid) has a nice little 10-inch sub and box and a 200 watt amp ready to go into his trunk to add a bit of bass punch. The amp has speaker level inputs so we are thinking just disconnect speaker wires going to the rear decklid free air sub, feed those leads into the speaker level inputs on the amp and we're good to go....BUT, what about a remote turn-on lead for the amp? Can we just tap into a source that is "hot" only when the ignition is on (cigarette lighter maybe?) or is there an easier or better way?

Also, would it be worth it to totally remove the decklid free air sub to place the aftermarket subbox underneath it and maybe get a bit better sound transfer into the interior?

 

Do not run the factory amp outputs in to another amp. I doubt it would last very long. Try tapping the low level lines from the factory deck to the factory amp. Search for a diagram of the factory stereo. Yes, remove the factory 10. It's just dead weight compared to an aftermarket sub. I've used the cig lighter for a turn on source before. It worked fine.

 

it depends on how good the amp is. the high level input is usually a last resort. Using a high level to rca converter is usually recommended. But, you have to get the signal before it enters the factory amp. Otherwise you will fry your rca convertor.

Also, taking out the factory sub is recommended, but it takes a little bit of work. You have to remove the entire back seat.

 

The amp is a Clarion APX200.2 that is going to be run bridged (200 Watts RMS at 4ohms) driving a single 10inch sub.

I don't understand...if the Clarion has high-level inputs, why can't I just disconnect the speaker lines coming from the factory amp off the leads on the factory rear decklid sub and connect these speaker lines directly to the Clarion's high-level inputs?

 

Those high level inputs are not designed to handle an amplified signal. Don't let the name fool ya. High level inputs are better designed to be used with speaker lines from the head unit. More in the range of 20 to 40 watts. Not the 80+ watts (just a guesstimate) that goes from the factory amp to the sub. I'd definately tap the lines betwee the head unit and the amp. As koreanpers said, I'd do a high level to rca converter too.

 

hi, all you need to do is tap the wires that lead into the actual amp. Dont take the signal after the amp like Vegassc400 said, ur high level inputs are not designed to take a amplified signal in.

I fried a high level rca converter doing exactly what you are thinking of doing.

 

Gotcha...didn't realize "high level" inputs isn't exactly what the name implies!

Can I just literally splice leads into the lines going to the factory amp? We definitely want the factory amp to continue driving the factory speakers in the doors, etc.

 

Idiot's question - where do I find the factory amp? I know on the SC400 with the Nak system it's in the trunk under the floor liner by the wheel well, but what about on the 98 GS300 with the non-Nak system?

 

well, i have the nak system, and the amp is in the trunk on the right side wheel well. i am assumming it would be there for yours as well. and yes, u should be able to just splice. however, the speaker leads you splice from, will in turn reduce the volume of the in car speakers

 

OK looks like it is in the dash behind the CD changer. Is there a wiring diagram for the non-Nak system so I can see which wires to splice on the input harnesses to the amp?

http://www.carstereohelp.com/stereor...usGS300Amp.htm

 

Found an old post on here with the photos of the wiring diagram...from the looks of it, the factory amp has separate leads coming into it, one set for the CD changer left and right and another set for the radio left and right channels. I was hoping maybe the factory head unit did the "source selection" and only had left and right leads going into the factory amp but that does not appear to be the case from what I can tell....so do this mean I have to choose between CD "or" radio to splice the factory amp input leads to connect into the aftermarket amp running the sub , or is there any way to have the sub+amp working off both the CD and the radio?

 

you actually need a converter, and yeah i agree with everyone, do not connect with stock and after market amp, and take the stock 10' out to create a port hole for your aftermarket subs, it will sound much cleaner, if you are in southern california, just come by my shop, we will take care all that for you if you need help.

 

Barry,

Where did you find the HU/amp wiring diagram picture for the GS?

 

SAME HERE! I have a 10" Sony Subwoofer and a 180 Watt Apline amp...

Did you guys get it to work? How? Any pics would help me alot!