i installed an aftermarket stereo in my ls400 but i lost my sub (factory) how can i regain the sub..... thanks in advance !

 

Well the sub adds 5 chs to the equation.

So the only way to utilize the factory sub is to install a small mono amplifier.


this would entail running power and rca's from the front to the rear.

and a ground in the rear.

After all is said and done you might as well add an after market sub.



Goodluck,

There are ghetto ways to do it but you dont want to do them.

 

The sub amp needs a low level signal to work-- as well as a remote turn-on wired in -- you should actually be able to just connect the head unit's remote wire to the original remote lead in the harness to turn the amp on--

You removed it's head unit that supplied the sub amp a preamp level crossed over signal and you need to send the sub amp that signal once again--

It would be MUCHO helpful if your head unit you installed happened to have a subwoofer output with a built in xover-- if so -- man are you in luck-- you just need to run rca level from the sub output back to the sub amp wherever it is and set the xover to about 90 hz -- 80hz is fine too-

If you don't have this with your new head unit, and you still want to retain your stock sub and sub amp, you can still send your amp low level signal, but it will need to be crossed over-- so you can do one of two things-- buy a speaker level passive crossover for about $20 and run it inline with the speaker wires to the sub to cross it over, or run an electronic crossover b/t teh head unit and the sub amp--

The cheapest way is of course the passive xover if you in fact don't have the built in subwoofer output and built in xover in the head unit you installed--

I don't know why on earth this would be considered ghetto either-- I can show you $3000 tower speakers that use a combination of several passive xovers in them to route the proper frequencies to each respective driver-- It's just another way to do it--

What would sound the best???

An aftermarket sub in an enclosure with an aftermarket amp-- with new power wires ran to the amp and of course rca's to the amp as well-- not to mention you'll need the turn on lead (remote) from either the factory sub amp or your power antenna-- (either are somewhere in the trunk most likely) --

If you like the stock sub and amp for it's sound -- then keep it -- It can in fact sound even better if sent clean low level signal--

If keeping stock speakers is ghetto, then my car is pretty ghetto-- I've got a stock h/u and stock front speakers with awesome results -- the fronts are handling 70w x 2 with no problems whatsoever-- even though they're 16 years old -- I'm impressed with the level of quality engineered into the stock audio systems back in the late 80's early 90's -- separate amps, head units with xovers, factory subs in the rear deck, it's all pretty good stuff--

 

thank you both very much for the responses i understand sort of now.... the only reason why i said sort of is, i dont really understand the technical terms, but i want ot learn everything i can. thank you again for an exhaustive response. !

 

removing technical-- the factory amp needs signal to amplify-- which it will send to the sub--

you can send it signal from your new head unit -- there are a few ways to send that signal-- with or without a crossover (frequency filter) -- your sub only plays low frequencies-- so you want to send it only the right frequencies -- not full range--

this is the reason I was asking if your new head unit has a built in low pass crossover for a sub amp-- if it does it will make doing this very simple-- if not it's still simple, but will require more than one step to make it work--

Nothing complicated about it-- just routing signals where they need to go, and the proper signals at that--

 

i got this one

http://refurbdepot.com/productdetail...roduct_ID=4758

this is the one i have... i believe i read something in the description about crossovers...?? i apologize for the obvious noobness...

 

sweet-- your head unit DOES have a low pass filter for the subwoofer preamp output--

makes things much less complicated-