BOSE / MOST

I have the standard 03 TT BOSE MOST system and I'm considering options which I think are: 1. Buy a PCM2 from fleabay 2. Change the head unit, amp and probably speakers as they have a low ohm value. 3. Find an aftermarket that interfaces with MOST. So my questions are the PCM2s that come up on fleabay are mostly for the Cayenne, will these interface correctly? And has anyone found an aftermarket head unit which incorporates MOST? Apologies if this has been discussed before, I've had a search and cant find the answers on here.

1. you can buy a 5 year old mobile phone while you at it..........ie why bother? 2. Best option, not always necessary to change speakers, depends on amp used etc. yes you will bin the MOST amp too. Kenwood or Pioneer options are good. 3. Don't think this is an option. Even tho MOST was/ios heralded as as the next level of technology the after market doesn't seem to bother with it at all.

Good advice above. If you go for Kenwood you don't need to bin your speakers, just purchase two crossovers that allow you to drive several speakers from one source - just make sure you match the impedance. Ray :lol:

Ray, could you expand on the Kenwood and the xovers?

Hi, IMHO do not bother wasting money on PCM2, dated, no blue tooth, no ipod and out of date discs. There is no present after market product from my extensive research that incorporates the MOSTbus technology. However good products to consider are the Pioneer Avic systems such as the double din varieties or the hybrid 500BT. As I am not renewing my waranty I will be finally getting round to doing this. Please note that if you have the full warranty having any after market sat nav will void it. Subject is open to discussion but my local OPC confirmed this several months ago. Regards Alan.

A standard Porsche system like mine has 6 speakers, 4 at the front (2 bass in the doors) and midrange/tweeters in the dash and then two wide range in the rear. The kenwood can only drive four speakers plus a bass. So in a standard Porsche you wire two of the outputs directly to the rear speakers and then you install the other two outputs to matched crossovers. These crossovers then send the low frequency to the door bass speakers, the mid range to the dash speakers and the high frequency to the dash speakers. The existing dash crossovers need to be removed (just a couple of components in the speaker housing). This is just like a home hi-fi speaker system where the crossovers are installed in the speaker boxes. I don't know the Bose connections, or even physically where the speakers are mounted, but I assume that the four rear speakers would also require crossovers too but you'd need to remove them and find out what type they are. The Kenwood can deliver against a wide range of impedance, 2-8 ohms I seem to remember, but the crossover impedance must match the speaker impedance otherwise you will send the wrong frequency to each speaker and it will sound rubbish. cheers Ray :bye:

So the door & dash speakers become 1, full range "speaker" and the rears are full range already, then you added a sub? I have the Bose sub which has 2 x 2 ohm speakers wired to 1 ohm (parallel?) which could probably be flipped to series & hence 4 ohm. I need to find a manual for the kenwood online somewhere.

Got it in one. The Kenwood has both amplified and un-amplified outputs. I used the amplified outputs to keep costs down. I may have got it wrong but I understood that the Bose amp and hence Bose speakers speakers aren't on the MOST bus. If that is the case then you can connect any standard unamplified amp outputs to it and its therefore a straightforward job, you wont need crossovers! Let me know if I've got it wrong :? Ray

yep, the amp IS on the MOST buss, unfortunately I have not found a way of getting an analogue signal into the Bose amp, if only, it would simplify things somewhat! I did read of a solution that used a separate 5 channel Alpine amp, expensive option but neat. I also need to find out the ohm rating of the other installed speakers, preferably without taking them out. I gave scanned the PET to no avail. Did you say the Kenwood has some sort of adjustable output impedance?

I think the only way to find the speaker impedance is to get a comprehensive manual or look on the back of each speaker. The Kenwood amplified outputs can deliver against a range of impedances just like modern hifi amps.

I changed my stereo to an alpine head unit and sony Xplod amp driving the existing Bose speakers. The only downside is that the subwoofer isn't connected and would need a further dedicated amp ..... which I have been informed would be very expensive as the amp would be very specialised because of the low impedance of the Sub as you mention above. Are you aware of any amps/solution for less than £250 that would drive the Bose subwoofer?

not for £250..... The Alpine PDX5 will work and drive ALL your speakers, also down to 2 ohms for the sub channel I believe, sell you xplod amp and do the job for £250 net?....... http://www.online-caraudio.co.uk/shop/amplifiers/alpine/pdx-range/alpine-pdx-5-547020.html

just found out that the issue with my Bose Sub is that it is 0.5ohm (as adivised by my headunit installer who measured its impedance) and very specialist and thus expensive amps are needed to drive them (and they tend to be designed for multiple subs). it looks like there isn't a practical solution other than to install a new sub if you want to upgrade your head unit and still drive all the Bose speakers inc the sub. MOST and Bose isn't the easiest to work with if you want to upgrade your headunit. I would welcome any other possible solutions.

I thought the sub was a 2 ohm unit,?? ie 2 x 1 ohm speakers wired in series. If they were wired in parallel then I would expect 0.5ohm. Check this as you can easily change the sub to 2 ohms if you need to.

Aftermarket in-dash sat nav for MOSTbus Hi - are we concluding that as of September 2009 not one aftermarket manufacturer has produced an in-dash sat nav head unit that is compatible with the MOST bus?