JakeG37

Thanks for the info! I finally found a guy to do my install that knows what the hell he is talking about. Was frustrated talking to two different shops about how to integrate my stock HU into my desired setup. I had a guy argue with me repeatedly that it was not possible without keeping the stock Bose amp installed. I also will be installing a Alpine PXA-H800 and RUX-800 remote into my setup. I have decided to go with the JL HD 900/5 amplifier but I am still unsure as to which component speakers I will go with. The installer I am using highly recommends the Hertz line of speakers and based on my primary music preference pointed to a model that is in the $500 range. I am trying to research a little more before I make that decision. Also will be installing a battery to ensure clean, consistent power to my audio system. He said the battery I would need is small and is much better than going the capacitor route. I am buying my amp kit and speaker wire from Knukonceptz. I just got my CLD tiles to do some deadening and may look into getting some MLV (mass loaded vinyl) and melamine foam once I see how the system sounds. I plan to install some of the CLD tiles prior to the install and will have more to install if needed afterwards.

JakeG37

Oh I forgot to ask, do you have any hissing or other issues with your setup with the stock HU? The installer told me there will be problems to some degree because I will be using the stock HU. Depending on how bad it is, I may look at replacing the stock HU in the future. I have started to look into how to do that while maintaining control over my AC and other critical systems.

JakeG37

Now that I will be using a DSP which has crossover capability, do I need to hookup the crossover that comes with the component speakers?

charliekwin

Noise/hiss shouldn't be a problem with a properly-installed system. If done right, a ground loop isolator -- if anything -- is all you should need. Replacing the head unit is basically a non-starter; best option is to add another source that's totally outside of the stock system.

If your amp has the channels to drive each speaker, then no, you don't need the crossovers. The 900/5, for instance, could drive a pair of woofers and tweeters + sub without using passive crossovers.

RA081224

Running 2 Ohm speakers is not really an issue for any quality aftermarket amp, its more a question of adio balance, fidelity and frequency response than ability to drive the speaker. The Bose system is so interdependant on amps, equalization and speaker that replacing only half of it will not yield acceptable results.

RA081224

If your ok with half assed fidelity, you can mix and match. If your looking for sound quality, rip it all out. The Bose system is interdependent on each component and any partial changes compormise the interdependancy.

I tried the mix and match but in the end, I wound up blowing most of the OEM speakers by overpowering them with aftermarket amps and expecting them to operate at frequencies they were not desiged to operate at. Do yourself a favor, plan a three or four stage upgrade that in the end will gut the entire Bose system.

RA081224

LOC are not needed when tapping signals from the stock head unit. You only need to keep the Bose amp if yuor going to keep the Bose subwoofer amp as the signals are passed through the Bose amp. Take a look at the wiring schematics for your model/year and this will become apparent.

JakeG37

Might not have been clear in my earlier posts. I am not going to be using any of the Bose amps or speakers. I will replace the woofers in the doors with 6.5" and replace the tweeters. I will not be using the other 3" Bose in the doors. I will replace the 6x9's in the back and will not be using the rear mids. Since I am only going with one amp for now (JL HD 900/5) I will have to use the crossovers for the components up front.

RA081224

Be careful here. LOC's are more about signal level than frequency range. Most shops run variable LOC's because its safer and levels can be adjusted during a tuning phase. Without LOC's the customer may be more likely to blow stock speakers if the system is not tuned once aftermarket amps or speakers are installed.

Additionally, the signal from the head unit is relatively unprocessed save for some slight volume leveling. Therefore, frequecy correction is minimal, however, frequency divison is absolutely required given the various sizes and locations of the speakers in the car.

Unfortunately, its been my experience that supplimenting the Bose system is often more difficult to pull off successfully than replacing as frequency matching a subwoofer to an established Bose system requires some skill

RA081224

If your're going to replace all those drivers, using the Bose amps will be a waste of effort. The Bose amps are not going to drive speakers effectively above 2 ohms impedance and the Bose speakers are frequency matched with the Bose amps. By all means, replace the drivers and amps seperately to save the cash outlay but in the end, you will need to replace both the amplification and the speakers to get a balanced system.

The Bose amplification system is composed of two amplifiers. The Bose amp drives the door mids, tweeters and woofer as well as the rear mids to the left and right of the rear seats (coups only). The subwooer amp drives the speakers in the package shelf (coup). If you are replacing the Bose amp, LOC's are not required as your pulling signals off the head unit. If your replacing the subwoofer amp LOC's are not needed as your pulling line level signals from the Bose amp. The only reason to leave the Bose amp in place is if your using it to drive the door woofer, mids and tweeters

Never draw signals from the Bose amp to drive aftermarket amps as the signals from the Bose amp are heavily processed for the Bose system.

JakeG37

Ok I posted this next question in another thread that is really old so I will ask it here too. I have a system installed and was doing some tweaking and needed to confirm something. Here is my system layout:

Factory HU
Alpine DSP
Audison AV 5.1k amp
Hertz Mille 280.3 Legend tweeters
Hertz HV165XL mids
Hertz HX250D sub

The installers tapped into the preamps from the HU and put them into the DSP. I havent confirmed exactly which lines, but I think they are the Front left +/- (B41 35&36) , Front right (B41 33&34), Rear left +/- (B41 22&23), Rear Right +/- (B41 25&26). Since I am only running with components up front and am only concerned with stereo sound, i should only need to be concerned with the Front L/R HU preamp outs, right?