Audio experts...Can I replace just the factory head unit on the Bose system?

Just picked up my 02 cab. Bose system is okay. I'm an audio nut and there just isn't room to do what I want so I'm not going to bother. I've never owned a car with less than two twelves. Anyway, I have a sweet Alpine din and half head unit in my closet at home doing nothing. It's got no internal amplifier. Is it possible to get rid of the factory head unit and replace it with my alpine? I still need to be able to control the factory cd changer as well? Will it require a separate amplifer? I assumed that the Bose system speaker are not powered by the factory head unit? This alpine head unit plays MP3's and I'm dying to get at least that going again.

yeah sure get a separate amp and a harness adapter from becker and just use the factory speakers and dump the oem amp. Dunno if it's most but basically it's not an issue if you dump the deck and amp.

i'm probably wrong, but aren't the bose speakers individually amplified with amps on each of the speakers. i had a friend with a maxima and a corvette with the bose systems and they were both that way. i was hoping to not have to dump too much money into a system i know i'm going to be dissapointed with

Change the head unit, change the Amp and there is NO problem. The speakers are passive NOT active all the power comes from the factory Amp, Need any help just ask

any suggestions on the amp? how many channels will I need to do this right? I may change the stock speakers out someday for some BA's or MB's, so I'd prefer something that will accomodate my future needs and not just barely powerful enough to run the stocks. I don't need anything that will power a future sub though as my bass obsession will most certainly require a seperate amp for that when the time comes

one other thing...my head unit will control an alpine changer. is there a way to rig it so that i can control the factory changer with my alpine head unit?

i had the same setup in a previous car, and the installer was able to make my alpine head unit control the cd changer.

cool. that's good news. now, what kind of amp (channels, brand, with or without crossovers) do I need?

that is pretty cool about the changer control I haven't heard of that one- I know the cartridge is a sony so I wonder if the interface is as well that might help you. I am running a PPI 5440 5 channel with cdt audio separates in the front, focals rear, and a jl 10w0 in the back off a hk traffic pro, I am very happy with it.

how do you run the mids and highs? are they all amplified separately? what about crossovers? i know i've got mids and tweets in the dash with a mid bass in the door? what speakers are in the rear of an 02 cab? what is the best way to amplify and crossover this bose system?

anyone, anyone? how many channels do I need to run this setup properly? Are the midbass in the door and fronts considered one pair? What's in the rear? Will I need a crossover? Do the speakers get any power at all from the factory head unit or is it all from the amp?

Not sure I can help much since you have an '02, but I can give some info about the Bose system in the '04. The front and rear speakers consist of a 1-1/4" tweeter and a 3-1/2" mid/woofer. The door speakers are a 4" mid/woofer. Both are (IMHO) low quality. I haven't opened up the rear, so I'm not sure exactly what is there. The amp is 6 channel. Although I'm not sure, I _think_ that the door speakers and front speakers are on the same channel. The '03-04 amp is a 100watt switching amp with 5 25watt linear amps (although I'm sure what that really means) If I were in your situation, I would change out the speakers before doing anything, or change out the speakers at the same time that you do the head unit. I think the speakers are the weakest part of the system.

Docjackson: Could you give me the name of your intaller? My guy didn't think I could use the changer. I'd like to give your guy a call to see how he did it. What year was your 911 that they were able to do that? Acourvil: Where did you get that info on the bose system? I'd like to find out more about the amplifier. I don't know what the linear amp thing means either.

I am running everything off that ppi 5 channel amp. The separates came with cross overs for the mids and highs front. The rears are focal coaxials. My 5 channel amp has built in independent crossovers to boot for earch f, r, sub. I am using those aslo- my sub is hooked to the separate sub out on my hk traffic pro so I can tune it on the fly- very nice improvement! That's about it.

The info about the amp was from various official descriptions. Unfortuantely, Bose has a policy of not releasing technical info. I think I did see someone post here indicating that he designed the MOST amp used by Porsche, but I'm not sure what additional info he would be allowed to add. There is also a reference design available from the company that does the MOST system architecture, but I don't know how closely the Porsche/Bose amp follows that. The speaker info is from hands-on. I've pulled the front, rear and door speakers and replaced them with Infinity speakers. Although I just finished it and haven't had much time to evaluate, my initial impression is that merely replacing the speakers makes a major improvement to the sound. For about $150, the sound went from kind of painful at times to sounding pretty good (although part of the problem was a blown speaker in one of the doors).

there is no need to dump the amp on 02s, only 03s

cool, i'm assuming i just need to get some sort of adapter to hook my head unit (pre-amp only) to the amp? Moogle, do you know someone that did this? How did it sound with a diff head unit? i'm trying to spend as little money as possible so i'm trying not to replace anything i don't have to. anybody else able to find a way to control the porsche cd changer with an alpine head unit? my installer is scratching his head on this one.

Becker makes and sells them- http://www.harmanbecker.us/

i didn't see that on thier website. i'll have to give them a call. thanks. anyone else have any info on using an aftermarket head unit to control the changer?

Have you or someone you know actually dumped their '03 MOST components and backfilled them with a standard analog radio and amp? I, like others here, thought the speakers in the Bose MOST system were self-powered in some fashion. Are we sure these speakers are only driven by the central amp located in the front of the car? I also heard that the stock speakers were 2 ohms or less devices. Are we talking about standard impedance units? 4 or 8 ohm? If merely replacing the head unit and amp with something else will get past the restrictions imposed on us by the MOST system, then I will do this in a flash. An inexpensive TrafficPro maintains the stock look, and many generally available amps can drive the speakers if they have reasonably normal impedance values. Any further clarification is welcome. Dwayne

Clarification based on physically examining the Bose speakers from a '04 C4S: the front, rear and door speakers are 2 ohm. The front and rear speakers consist of a 4 ohm 1-1/4" tweeter and a 4 ohm 3-1/2" mid/woofer, wired in parallel for a 2 ohm total for the speaker. The door speakers are 2 ohm, 4" mids. These speakers are NOT self powered. It's possible there are in-line amps somewhere between the main amp and the speakers, but I didn't see them and it seems unlikely. (note: I have not looked at the woofer/subwoofer on the back deck, so I can't say what that is). Speculation: you should be able to take out the head unit, amp and cd changer and replace them with a completely independent system. You would not have them tied into the OBC or the dash display, and it's possible that you might need some kind of reset for the OBC, but there's not reason a completely independent sound system wouldn't run; all you need is the tap into the power. What you can't do is mix and match non-MOST and MOST components (i.e., non-MOST head unit and MOST amp) At least, none seems to have figured out how to do it. The Bose head unit and amp sounds significantly better with higher quality speakers, IMHO.

The head unit in the bose system is just the standard becker that everyone get's in there porsches right? mine head unit dosn't say bose anywhere on it. So which is it? Can you use an aftermarket head unit with the bose amp?

Sorry, when I said the Bose head unit I meant the factory unit. I have the Becker PCM II (which I think has the equivalent of Becker CDR-23 integrated into it, but I'm not sure), and I think the other option is the stand-alone Becker CDR-23. For 2003-2004, my understanding is that the head unit, amp and cd changer are all tied in to the MOST bus and you cannot use an aftermarket head unit with the MOST amp or CD changer. This was confirmed by someone at Becker. However, I think if you have the 2002 or before, you can do pretty much what you want because they are not connected via the MOST bus.

Apparently I can't just change the head unit on my car, or at least with my alpine 7998. i talked to an installer today. the 02 bose system will only accept speaker level inputs. my head unit has no internal power, so no "just the head unit" upgrade for me. you would think there would be a way to hook my rca outs to whatever inputs the bose amp had. the installer told me that the bose amp actually amplifies the speaker level signal coming out of the head unit. Ughhh. What a pain. Now it's either buy a new head unit with internal power and lose my changer, put a whole new system in, or buy the becker monza and keep my changer. what a hassle to get some decent sound in a cabriolet.

Just stick in the deck and get an amp to power them and be done with it.

because of Bose funky 2ohm speakers, you can't do that apparently. Installer told me that it would be really hard to get it right and couldn't guarantee that the amp would work properly. Installer said that they may be able to get the amp to see 6ohms if they wired it in series, but couldn't be sure if the amp would remain stable and even if if did, the power from the amp would be cut in half. if is wired in parallel, the imedance would drop to 1ohm or lower and shut the amp down. looks like it is all or nothing with this **** bose system. what a dissapointment.

There are no line amplifiers; the MOST amplifier drives the cabin speakers directly via channels 1-6. The only exception is that the bass driver/subwoofer has its own internal amplifier; but again, this is driven from the amplifier's channel 7 output.