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Discussion Starter · #1 ·
It can be done easily if you throw some money at the problem. Nav-tv has a converter box to allow integration of an aftermarket head unit with the Bose MOST (fiber optic system). It costs $649.00. Just ordered mine. Will inform on ease of installation - gonna do it myself.
 

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Let us know how that works out and if there's limitations on what heads it will work with. Even at the price it should come off much less than a PCM 2 install.
 

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It can be done easily if you throw some money at the problem. Nav-tv has a converter box to allow integration of an aftermarket head unit with the Bose MOST (fiber optic system). It costs $649.00. Just ordered mine. Will inform on ease of installation - gonna do it myself.
Which particular Nav-tv product are you looking at? I'd be interested in this rather than buying a new amplifier, if it's any good.
thanks
 

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Discussion Starter · #4 ·
At NAV-TV.com it's called MOST HUR. Tell them you saw it for $649.00. Easy install. The only things that don't transfer are no front to rear fader & the text does not show up on the speedo.
 

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At NAV-TV.com it's called MOST HUR. Tell them you saw it for $649.00. Easy install. The only things that don't transfer are no front to rear fader & the text does not show up on the speedo.
Thanks Rockhouse.
Do you know if it would work with a Kenwood DNX5220? does anything else not work?
I'm trying to decide whether to buy a JL 6 channel amp or to do this...

BTW, Only place I've seen this advertised is @ installer.com for $699, and they don't ship outside US.
 

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Discussion Starter · #6 ·
It will work with any head unit. Nav-tv has them pre-programmed for pioneer & Kenwood IR (steering wheel controls). The unit is user programmable. I had to raise the amp volume on mine. simple task. Even comes with the cable. Bought mine from Nav-tv. Saw it for sale for $649. They wanted 699. Got them to match the price.

Don't know about shipping across the pond. If you get in a bind I could ship it for you.
good luck
 

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thank you.

will do a bit more research and then decide. tbh, $700 plus shipping to uk is pricey and makes me wonder whether to just buy a JL G6600 and get my soldering iron out
 

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Discussion Starter · #8 ·
in addition to an aftermarket amp there may be an issue with the impedence of the Bose speakers. That's what made me go with the nav-tv interface. Also you don't have to give up precious storage space to mount the amp.
 

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IIRC the Bose speakers are on the order of 2 ohms. As long as the replacement amp is stable into this kind of load that shouldn't be an issue. There's a thread on that here.

The part that may make a bigger difference is the last I knew Bose equalized their setups for a given cars environment. Removing this and running the speakers full range could give strange results. Something to consider as you may need an equalizer for each channel in addition to the amp.

As to mounting space why not use the spot vacated by the Bose amp?
 

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I did a search on this unit and it appears that the head unit you select will need a 1/8" fiber optic output on the back. Several of the Kenwoods I looked at have this as standard.

I'd almost given up hope of ever having a decent BT connection for my car.

The next item will be if my Motorola Droid will work with any of the head units having the fiber optic output.
 

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I did a search on this unit and it appears that the head unit you select will need a 1/8" fiber optic output on the back. Several of the Kenwoods I looked at have this as standard.

I'd almost given up hope of ever having a decent BT connection for my car.

The next item will be if my Motorola Droid will work with any of the head units having the fiber optic output.
Checked, and my dnx5220 has fibre optic output!!
 

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Discussion Starter · #14 ·
Putting the replacement amp in the spot vacated by the OEM one might work if your amp will fit. The amps I was looking at did not.
 

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I spoke with Russell @ Installer.com,Houston Tex and the signal is converted
from the standard output of the new head unit to fiber optic on the MOST HUR converter then on to the factory amps. If you would like to hear directly
from the supplier tech people they can be reached in Boca Raton Florida at
866 477-3336. I will be trying this myself as soon as I receive my unit
 

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Discussion Starter · #17 ·
The Na-tv unit adapts the Bose fiber optic signal to a conventional electrical signal. If your OEM radio is Bose with fiber optic MOST system you need to either change out the amp & possibly the speakers (or adapt them) or install the Nav-tv system.

As far as aftermarket head units with fiber optic inputs I have no information on compatibility.
 

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they are 0.5 ohms; not 2.
0.5 Ohms would be very impractical. I would be surprised if they were as low as 2 ohm. I bet if you really tested them properly, you'd find that they are somewhere between 4-6 ohms.

0.5 Ohms sounds like their DC resistance, not their Impedance. If you take a VOM and measure the resistance of the speaker, you are measuring DC resistance. This is not an accurate way to measure a speakers impedance.

A loudspeaker has several electrical properties including resistance, inductance and capacitance. Impedance is basically the working resistance when all of those properties are combined and an AC voltage source is applied. Impedance will vary with frequency.

To properly measure a speakers impedance, you need to use two VOMs and a white noise source. You need to measure voltage with one VOM, current with the other. You can then calculate Impedance by dividing Voltage by Current. (You could use one VOM and take two separate measurements, but two would be most accurate).

I can almost guarantee that our Bose speakers do not have an impedance of 0.5 Ohms. That would be incredibly impractical. A speaker of that impedance would require 10 gauge speaker wires and an extremely high current amplifier. Making a two channel amplifier that is 1 Ohm stable and reliable is a real accomplishment and very expensive. Making one that is 0.5 Ohm stable and nine channel just wouldn't happen.

This is my companies best 4 channel amplifier:



This is a class AB competition amplifier. It's 4 channels and it's 2 Ohm stable. Drop it down to 1, it will work for a while then overheat. Drop it down to 0.5 and you will let the smoke out.

This amplifier is very expensive. It contains hand wound transformers and very high quality output transistors. It's made to be abused. But it couldn't handle a 0.5 Ohm speaker, and neither can that sorry excuse of an amplifier that's in our cars.
 

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Just to throw another "option" in the mix...

Cant you just use the amp built into the head unit, bypass the Bose amp and add resistors to the speakers to bring their impedance up?

I mean, lets get real here...These cars are REALLY noisy to begin with and the inside of a car is NOT the best venue for listening to music anyway...If you think spending an extra $649.00 will make any difference, go for it.

I truly think you'd never notice the difference when you are driving. Id bet $$$ that doing an A-B test, you couldn't hear the difference while you are driving any Porsche. Now, if you had a full sized Lexus, that's a different story.

IMHO, take it for what its worth

Steve (who used to be a recording engineer)
 

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No arguement at all about the listening environment. For me anyway the Bose is adequate for the task. This thread has my interest in that I'm considering changing out the CDR-24 for a unit with Nav and preferably Bluetooth. Thus the MOST-HUR becomes quite interesting. Even at the cost, it plus a good head unit is still cheaper than the PCM unit plus Dension. The downside is I'd lose my CD changer though iPod support would mitigate that one somewhat.

I think you'd find that the amps built into most head units are pretty marginal and probably wouldn't have the ability to equalize the individual speakers to match the enviroment. While the Bose isn't that great, taking it and making it sound like the base Cayman radio wouldn't be much of an improvement.
 
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