rossman66

Anyone,

I have a 93' SC300 and would like to replace the stock speakers. I have the basic Pioneer package. I have read many threads in this fourm and have been really amazed by the knowledge. I have installed many car stereo and speakers, but im a novice compared to what i've read here.

anyway, here's my question. I read a wonderful thread on here about replacing the stock sub with the JL Audio IB4 series. So I went to buy an 8" and the auto shop guy told me that since its an 8 Ohm sub and the stock speaker is 2 Ohms if i repalce it without a new amp it will sound worse that what i have. Is this true? I never tend to believe auto shop guys, but I'm at a loss when it comes to Ohms and impedence etc....

is the guy right? so i need a 2 Ohm sub? will the JL IB48 sound like crap without an aftermarket amp?

i have a 2 channel amp that i could install, but they wanted $90 to do it and i know i can probably do it myself...any suggestions?

thanks for the imput.....

Mark Ross
mark@markross.net

pcmw

That sounds correct.

MW

BabaBooey

It wouldn't sound "worse", but it would only be getting about 1/4th the power a 2 ohm speaker would be getting. Considering that the stock speaker, along with being 2 ohms, is probably pretty efficient, you're hardly going to get any output from the IB4 and would probably clip the amp trying to get decent bass out of it. In that case, yes it will sound like crap. Definitely use your aftermarket amp.

rossman66

Im sure its been written many times within the forums, but if you or anyone had any specific articles that detialed how to bypass the factory sub amp, that would be very helpful. I assume i can keep the factory head unit?

thanks for the quick responses BabaBooey and pcmw!!

Mark Ross
mark@markross.net

pcmw

Mark,

Someone wrote a website on all the connections... http://209.125.175.29/lexusstereo.html ... he is a member here.

All the wires you need can be found on the amp that is mounted next to the sub. You can see the silver casing from the trunk. If you have installed any stereos in the past...you should not have a problem doing this install.

1) pull rear deck off (instructions are in a thread here somewhere)
2) unplug the harness going to the factory sub amp.
3) look up the connector diagram on the site ( http://209.125.175.29/lexusstereo.html ) .
4) Run a separate 8ga power wire from the battery, thru the little empty grommet on the side of the brake master, down the dash, down drivers side of car, into trunk.
5) ground a screw to the metal in the trunk...preferably within 12" of the mounting location and into two pieces of metal that overlapped.
6) tap the two inputs from the factory deck into two RCA cables by splicing a pair of RCA's open and tapping the (-) wire to the shielding and (+) to the center wire. plug into amp...
7) i would suggest mounting the amp (if not too big) upside down where the factory unit was located. Use a piece of particle board to screw into and then screw down into the wood from the top.

That should do it. Takes about 30mins

MW

rossman66

My system does not have a stock CD Changer and therefore does not have a seperate amp for the sub. I pulled out the rear seats and rear deck and there is no amp So is it still possible to run an aftermarket amp? where can i pull the inputs from?

pcmw

That doesn't sound right.

The sub has to be amplified by something!!!

The amp is a tiny silver box...like a sardine can...

If you cannot find it...then trace the subwoofer speaker leads. They have to point somewhere.... subwoofers won't work from cosmic energy

If you are still having trouble...then get an aftermarket amp...use the current subwoofer wires as your "high level" input.

MW

PERRYinLA

Wow MW, you da MAN! That's about how long it took me to do just step one (removing the rear deck panel). That's because I was not able to remove it unless I removed the side panel first (the one that surrounds the rear windows). And that does not come off until the bottom side panel is off.

And I'm still not finished running my 4ga power wire from the battery into the trunk.

As for mounting the amp, that's another couple of hours, if you have to fabricate and fit a proper mounting bracket (see the following thread):

https://www.clublexus.com/forums/sho...threadid=34734

pcmw

Perry,

You let me down.... For such a respected authority on all things audio.... I would expect better, faster, and easier.



That mounting is nice...but a little much just to mount an amp. Amps have heatsinks that like more air space around the sinks... Merely flipping the amp over would do equal +/- here or there a couple of degrees the same efficiency to mounting a bracket right over the top. I mounted both of my amps upside down to 1/2 mdf with no issues. I really think it is better, faster, easier, more accessible, and sturdy.

On pulling the back deck...that has been covered a dozen times. Your back deck must be made of pure titanium for you to need to pull the sides off. I pulled the rear deck again last week to run a bass gain **** and it took less than 5 mins to pull the seats and deck out. Granted I was an installer for 5+ years and have worked on cars all my life...but come on... 3 screws and two plastic clips!!! Yawners...