it has come to my attention that the 2003 and up tt have cdr23 headunit which are fiber optic.

i guess i want to keep everyhting stock but switch out the rear subs, yet either keeping the stock bose enclosure or getting a box with very similar dimensions.

if i keep the box, what subs can i switch them out to?
are they 5" or 6" subs.
also what is the ohm rating.
can i run an extra amp to these "new" subs?, yet keeping everything else stock. i heard before that the bose system/amp is very wierd. you cant just switch out speakers due to the resistance of the speakers.

anyone with info regarding the stock system, which i can barely find any info about because it seem like all you guys only focus on is making your very fast gt700 cars even faster , will be highly appreciated...

 

I put in the caraudioinnovations.com stage 1 box. It sounds killer it is 3 jl 6.5 w0 speakers and I put an alpine amp. This fits in the stock location of the stock bose sub. Check it out. As far as the Stock subs you really can;t do anything with them. They are a differnet ohm 16ohm I beleive.

-Suman

 

suman, very helpful link. can you be abit more descriptive of how it sounds compared to the bose subs, and also do you have mids/highs upgraded speakers, or is everything else stock. also, what type of music do you mostly listen too.
thanks

 

hey i got a Cab...i got a 8'' factory in the passenger side floor...makes the car sound just nice... if you want add a sub to the trunk..and and an amp to the speakers in side...if you want to go NUTZ...then go McIntosh, Focal, and Diamond audio... Then you wont know what hit you.

 

sound is way tighter then the bose sub. Way more powerful and i'm still using the factory amp and main speakers. Honestly I'm not doing one mor ething becuase the imagining is perfect. The sub in the front foot well does not image as well as the sub in the back just an opinion again. Bt its worth the 6-700 dollars. I have an aftermarket headunit and my whole point to do this was so I would have a sub control. the bose you can't control seperately unless theres something I dont know about the stock unit cause I never had one. I put my amp for the sub where the stock cd changer goes. Alpines new 400 watt bridged amp worked perfectly looks and quality wise. good luck

-Suman

 

Nuber 23 I listen to all sorts regaee Blue Classic rock Rap trance ETC. all sounds great through this set up actually bassier disc sounds even tighter do to the recordings being electronic based and over produced. GL

-SM

 

suman..let me get this strait about your setup. Aftermarket headunit ---> stock factory amp---> stock interiour speakers for mids/highs alpine amp --->3 jl 6.5" subs in rear?

did you tap into the signal for the rear sub amp after the stock amp, or did you run it directly from the head unit? the way i see it, because of this fiber optical crap headunit i have, i cant just switch it out like you did. I want to know if i can tap into the signal wires that go to the rear subs (which are most likely crossed over Lowpass already) and amplify those wires right after the stock amp. That will give me a signal.
One thing my basic audio knowledge tells me is that if i tap into the signal wires intended for the stock bose subs, but amplify those wires with a differnt amp and run them into the new subs, that will pose a problem since the signal is still coming off the oem amp which is looking for a 16 ohm, or 8 ohm load. Unless thiers a way to wire the 3 jl subs to the load stock load.


In general, in all my previous cars, i had excellent sound systems, installed by myself and a buddy.. From MBQuart QSD series to focal, the Best JL amps and subs.
My point is i never go for such a half *** job, but right now im just looking for a bit improvement in the bass dept since the sound quality up front sounds descent. Comparing to my previous M3's the stock bose on my car is the best stock system ive ever had in terms of SQ, imaging and balance.

MEQUICKER, i rather not utilize the small trunk space. i want to put the subs in the rear, in the exact location that the stock bose sit. also dont forget since the subs in the back are in the cabin already, you do not need to run as much power as if say they were sealed in a trunk of a a door car. thats why i dont mind using 3 w0 6.5" subs...

 

Everything you said is correct. I always put a headunit in all my cars for the sub out specifically. I would not tap the bose sub line unless you DO NOT have a sub out. If you do then by Peripherals speaker-rca converter and then hook the amp up. I'm the same as you very picky about music in my car. the JL's kick @ss.

In response to this:
"That will give me a signal.One thing my basic audio knowledge tells me is that if i tap into the signal wires intended for the stock bose subs, but amplify those wires with a differnt amp and run them into the new subs, that will pose a problem since the signal is still coming off the oem amp which is looking for a 16 ohm, or 8 ohm load. Unless thiers a way to wire the 3 jl subs to the load stock load."

First the amp determines the ohmage that will be provided to the subs. All th eperipheral does is convert the speak line VOLTAGE to voltage that is ACCEPTABLE for the amp. A Peripheral converter will change the VOLTAGE to anywhere between .5-2.5 volts. Most sub out on car radios these days are between 2.5-5 volts. Ohmage issue is thus nulled.

I have tapped off bose subs in many of my cars and this will not Pose a problem at all. the signal for the sub does not really effect the peripheral unit becuase the peripheral has its own power and controls for voltage lessening and gaining. make sur eyou use the speaker to RCA converter by Peripheral only others are garbage. the unit is Green and has two indented volume controls for left and right. If you havr a great radio you should have mo prblem using a wiring harness and using the factory amp for the highs. I personally think the highs are excellent and like you only bass was missing. If your in CT/NY/NJ I would love to sho you the work that I did.

-Suman

 

suman. yes i would like to see what you did with your car. I will Pm you right now.

REMEMBER THIS. YOU HAVE PREAMP WIRES COMING OUT OF YOUR HEADUNIT. weather you had OEM or aftermarket (which is what you have), you have preamp wires and now in addition you have a sub out.
what im trying to say is that i dont have any preamp wires. just making sure we understand eachother. we are not dealing with exactly the same issue.
i have an optical connection between the head unit and the factory amp. No way possible to my knowledge to get a full range signal out of my headunit. Do you agree with me. Everything after the factory amp is crossed over for sure.
i did alittle messing around right now and took alook at the factory headunit and the amp and i am correct. no preamp wires at all. Only speaker wires i find are at the OUTPUT of the amp (these are the wires that have basically seen the built in crossovers and amplification of the factory amp).

I took the bose sub apart, and noticed a relatively thicker guage (relative to other factory speaker wire to mids/highs) beige, then beige/brown stripe wires going into the factory sub.

I do see these wires as well in the output section of the amp. so we have located the factory sub wires at the amps output.
My idea would be this... and let me know if im wrong. this is only theory.
connect a periphrial high/low converter that you mentioned to these two sub wires right after the factory amp, connect the new RCAs to the jl 300/2 amp(probably bridged). Then connect the amp back to the wires that lead to theJl 6.5's in the rear . obviuosly i will use all existing factory wiring (to save me the time from running extra wires).

from previous installs i would never ever amplify a signal that has alraedy undergone amplification let alone a crossover. Who knows what type of signal the factory amp is outputing. Im assuming they (bose/porsche)didnt want to send really low frequencies (so that it doesnt sound sloppy or blow) so instead of it being a lowpass signal of say 120 and lower, its more like a 50hz-130hz signal (just a guesstimate), to protect the subs and sound ok, because keep i mind, factory subs are 5.25 woofers that have an ok magnet, but the cone feels cheap and weak, so thier is room for improvement.

All my previous installs included changing everything out. If i kept some components and added a sub i would take a FULL RANGE SIGNAL from a preamp wire and use the built in adjustable crossovers of the amp i will be using.

Please confirm that we are on the same page, due to us having different equipment, and me not having a preamp signal.
the last thing i would ask, is lets say i do what i said i wanted to do above, wouldnt the factory amp be built to operate ideally under "the set load" of the bose subs... Hopefully you are right and the second amp will NULL the first amps resistance requirments for the subs.

needless to say, i still want to get this job done (although it wont be perfect) it will sound really good if i can get a bit more power.
i was just in the car with the factory sub disconnected, and surprisingly the system (with base at 0 or -2) sounds clean (i was listening to light music).

thanks for the help and let me know what you think.

 

btw to answer my above questino if anyone is interested for the record...

i spoke to the main guy at the caraudioinovations website that suman listed above. very helpful gentleman that confirmed that if use the sub out speaker wires going to the oem sub, and amplify them to the aftermarket subs, i will be fine. so suman you were right.
thanks.

 

Airjordan23 - "Sounds like" you have a great idea going on. I think I would like to do the same setup. Have you completed the work? I also have an '03 tt w/ Bose and have not been totally satisfied. If you are done I would love to hear your impression of the results (money vs sound ? was it good enough or just rip the Bose system out and start all over) AND the details of your work. Like did you use the Bose base box and what specific equipment, wires etc did you use- thanks for the thread !!!