Nissan 370Z Forum - What to know about Bose

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Quote:

Originally Posted by theflyest1 (Post 1441480)

Hey Guys,

I just wanted to add my :twocents: to Matt's write up so it's part of this thread for people that may be thinking about upgrading the factory bose setup with navigation. I had a slightly bumpy road, but ultimately was able to upgrade successfully - and want to share how I got there.

I was part of Matt's "California Builds" recently - and wanted better quality audio all around, while retaining my factory nav/head unit. I quickly found out that I didn't have any options w/ swapping the head unit for reasons noted above.

So I opted for an MTX LOC which was reasonably priced (MTX RE-Q5) as the interface between my Bose head unit and new amplifier (Alpine PDX-5). We bypassed the factory amp and went straight to the RE-Q5 and then to the Alpine. We DID encounter problems w/ the MTX unit (faulty harness) - so I had to get another one mid-install. Definitely not fun scrambling to find one locally, but I was able to. The alpine amp was powering Image Dynamics components (door speakers/tweeters), and an Image Dynamics Sub.

This is where the problems began - alternator/engine whine. If you've never had to deal w/ this - it's a gnarly constant whine that persists whether the stereo is on or off...and amplifies as you accelerate. It can quickly drive you up the wall!

Matt double checked all grounds, but that was not the problem. Upon research, we found that many MTX RE-Q5 users experienced the same thing. Whether a higher end unit (JBL MS-8; Rockford Fosgate Three-60) would have avoided the whine - I can't say for sure. I would, however, recommend one of those higher end units as they would be MUCH easier to tune the system...but more on that later.

So finally, I had to use trial and error to find/resolve the source of the engine whine. I initially tried an inline power noise filter at the battery terminal (the MTX was fed directly from the battery). That didn't work. Next, I tried an inline power noise filter near the MTX; along with a ground loop isolator. I also separated any power and audio cabling w/ simple ducting. VOILA - engine whine gone!

I was happy at that point, but still a little unsettled w/ the overall tuning of the system (didn't feel the bump in the sub and front speakers were too loud relatively). I increased gains at the amp, played with the crossover frequencies and gains on the RE-Q5, and fine tuned w/ the factory audio controls - and FINALLY, I felt very happy w/ the result. As mentioned earlier, a higher-end LOC would have probably made the final audio adjustments easier (MTX has simple/cheap knobs you adjust w/ a screwdriver). That said, I have a hunch I would have still had to deal w/ eliminating engine noise which stems from having to amplify the factory Bose levels, which as Matt mentioned, are output at odd levels.

Matt and I ventured into this knowing we were entering uncharted waters...but I'm thrilled to finally have an upgraded system w/ the factory nav/Bose system. Significantly better clarity, imaging and bump :tup:. Hope this helps anyone looking to upgrade...

-Lohit

Lohit just a few things to add, not everyone may encounter engine noise it may or many not be there when you upgrade using the bose head unit as your base. Also higher end units have a lot more cleaning power so they would probably not be effected as badly as the MTX did. And man that was not fun trying to figure out why neither req would boot, all because of a bad harness.:shakes head:

Quote:

Originally Posted by jpritche (Post 1441486)

I have also upgraded my factory nav with bose. I did not have near the problems you did thank goodness. I just used a simple LOC and it works great. I used the wires that were going into the factory sub and hooked the LOC there and then ran my RCA from there to my amp. It has worked great for around a year now.

Currently I have a JL 12w3 in a Zenclosure box :)

By the way congrats on the new audio build.

Ya using a LOC to go to a new sub would not be effected by the wining noise as its higher pitched and usually comes from tweeters.

Quote:

Originally Posted by bigaudiofanat (Post 1441595)

Ya using a LOC to go to a new sub would not be effected by the wining noise as its higher pitched and usually comes from tweeters.

ohhhhhh, ok! makes sense lol

Quote:

Originally Posted by krUnizZLE (Post 1437628)

Nice... This Cleared a Couple Things Up But Im Still Stuck... :(

I Want Navi But I Dont Want Bose So i Guess When i Do Add Speakerz, Subs, Ampz, ETC. (Im A Audiophile) Ill Just Use The JBL MS8..

Also, What Is The BEST LOC (Price Is Not A Problem) You Can Get That Will Make The Bose Sound Like A AfterMarket?

Man how did i over look this question!!!

The MS8 hands down is probably one of the best out there. It does so much to make your system sound it's best and it will be the one I will be using in my setup, even though I am going with a new head unit.

thanks for the write up Matt. damn Bose. sucks that we gotta go through all this to upgrade the speakers.

@theflyest1 i read ur build thread i love your car.

and that alternator whine is awful. i did an install on my maxima and had the same whine it drove me crazy. i got used to it after a long time but damn it made me wanna tear everything out and smash it all.

So if i get the JBL MS-8 can i still use all my factory controls?

Quote:

Originally Posted by pwrhsms (Post 1501797)

So if i get the JBL MS-8 can i still use all my factory controls?

Yes, as long as your keeping your stock head unit and your bos amp installed. Run the speaker outputs into the inputs of the MS8 and than out to your new amps than your new speakers.

Matt the Bose harness from crutchfield... do we use every wire? Some say for Subaru only and there are no Nissan specifics on the diagram. Trying to get everything wired up correctly the first time.

Quote:

Originally Posted by MattP725 (Post 1502298)

Matt the Bose harness from crutchfield... do we use every wire? Some say for Subaru only and there are no Nissan specifics on the diagram. Trying to get everything wired up correctly the first time.

The Subaru "black wire" is for grounding which the nissan does not have in its harness, you have to ground your new head unit to a piece of metal of your car.

If there is a dimmer one that says it as well do not use that as well.

Awesome I'll clip it. Thanks brotha!

Quote:

Originally Posted by bigaudiofanat (Post 1501803)

Yes, as long as your keeping your stock head unit and your bos amp installed. Run the speaker outputs into the inputs of the MS8 and than out to your new amps than your new speakers.

thanks for the quick response. MS8 on the way!!

I want to reiterate that you can not wire up new speakers directly to the bose system. I have been getting a lot of emails asking this. You need the fallowing:

LOC
New amp
New speakers
New speaker wire
Base system speaker brackets

Quote:

Originally Posted by bigaudiofanat (Post 1777725)

Out of curiosity why doesn't another manufacturer make compatible speakers?
Bose makes them so why doesn't someone else just make a superior product?
Seems crazy to have to put in all of the above. Is it not feasible from a design perspective
or is it some kind of industry protection thing? Just curious as I've read all your threads on this and don't recall the actual reason?

Thanks Bigaudiofanat :tiphat:

Quote:

Originally Posted by sparky (Post 1778411)

It is not only because of the different ohms rating, that can be matched. The second reason is the bose amp filters the sound before it ever gets to the speakers. So replacing the speakers is not going to help if the bose amp is set at a crazy crossover range.

You need a flat unmodified signal to start with than add amps than your new speakers.

To put it in other words, the bose by default omits a lot of frequency's a new pair of speakers can reproduce just fine. So you would not be getting the best sound from them if you were to just wire them up to the bose system, not to mention a change of under driving the speakers with the bose amp.

Quote:

Originally Posted by bigaudiofanat (Post 1777725)

Bold statement...yet not entirely correct.

Non-bose specific and or vehicle specific speakers can be installed but will unlikely yield the desired effect - namely improved sound quality to a degree that is satisfactory given the investment in the aftermarket speakers. The difference in efficiency, overall impedance and frequency response of the replacement speaker will likely give an undesirable effect but it is not absolute.

There are too many variables given the integrated design of the Bose system to really have an absolute idea how the aftermarket speakers will interact with the existing Bose amps. The Bose system integration include consideration for amplification and its' speaker specifications including placement. Something that without complete specifications, would be guess work when replace one component in the chain.

I agree in principle if one were to replace the speakers, the rest should to be discarded especially in the Z Bose system. There's a work around but that requires either disabling the dash speaker (if one were to use a 2-way at the door - for example or rewire/relocation) Component sets will require two separate cross-over to ensure proper frequency distribution and double check impedance responses given the x-overs plus knowing the output from the Bose amp...the list goes on. The bottom line is that it is much more difficult to make the Bose amp work well with aftermarket speakers than replace it all. That said, I've replaced a door speaker on a Bose system with a two way in the door in the past on a 240SX with no problems. Frequency response improvement was definitely noticeable.