clarkemtp

The last four digits of the part number tell the tale. 7550. That's the Metra 7550 harness. Same one I used for my non-bose install. Ok, so on that, again, it's not what I'd recommend to do the install correctly but if you're actually ok with the volume and you're not getting a ton of hiss during normal listening, you can leave it if you want.


Take the pictures so we can see, but I'm sticking with my initial observation for now. I've installed mine and helped a couple people install there double-DIN head unit's since I did mine (and helped dozens here on 350Z over the internet) and without fail, everyone either re-drilled their mounting bracket to center/flush the headunit in the opening or wished they had.

Good Luck!

PS - You can, obviously, specify all you want. But when you let someone else do the work you just never know what you're getting. lol That's why, regardless of what it is, these days I pretty much do all my own wrench turning (within the limits of my skill-set, or skills I'm able to figure out). Whether it's stereo or whatever doesn't matter, I want it done right.

GeauxLadyZ

iTrader: (9)

Ok man i called crutchfield and they DO carry the 7551 but the guy said its not in their system yet under the 350z w/ bose system so it doesnt get pulled up when they look. So basically I want to fly up there and whoop some ***.

However...he did say that there shouldnt be any difference in SQ btw the 7550 and 7551 because both are virtually the same thing only the 7551 uses the RCAs that go in the amp preout in the HU and the 7550 just goes through the regular harness. The 7550 puts the output at 'speaker level' and the 7551puts the output at 'RCA level', however both are virtually the same and the bose amp handles both the same--and therefore the output from the bose amp is the same for both.

He also said the only reason why i should be hearing hissing, whining, volume problems, etc is if the black/white amp ground/equalizer wire is not properly grounded. Whatcha say clark??

jniddy

iTrader: (1)

Might be a stupid question, but what is this long pink wire that comes seperate with the d3? Reading through the guide i cant see where it applies...

Thanks

Edit: Is this the wire that you splice into the VSS wire? And the other end goes into the car speed signal input?

One more thing, if someone can fill me in on the purple/white seperate wire also, getting confused here electrical isnt my thing

GeauxLadyZ

iTrader: (9)

The extra pink wire should be for the VSS (your right) its just extra slack i believe. And the purple/white is (i think) extra wire for the car's reverse gear signal (which you wont use if you dont have a backup camera) IF YOU GO TO THE FIRST PAGE OF THIS THREAD IT WILL TELL YOU THESE THINGS

jniddy

iTrader: (1)

Thanks alot Castro, i must have missed it

jp, i appreciate it

GeauxLadyZ

iTrader: (9)

Clark--i took it back to installer and they cleaned up the install job real nice--perfectly in fact--i still dont know what im gonna do about the 7550...maybe nothing. thanks for the help though bro!

Deezflip

don't mean to burst your bubble on this...

the 7551 DOES NOT use rca's in place of speaker leads. the RCA plugs into the low level outputs from the aftermarket headunit....then from the harness it taps into the original low level wires(in the first place, no speaker leads are going to the bose amp, none, zilch, ZERO!). The factory headunit does not have an internal amp, therefore....no speaker leads, only LOW level outputs.

The rest of those wires on the 7551 harness are just power, ground, lummination, etc.

People with a hiss, noise crackles and pops, the noise if coming from somewhere else. Maybe the cheap wires going to the bose amp,

or MAYBE(I read this somewhere) it's the difference between the original balanced signals from the stock headunit and the unbalanced signals from the aftermarket headunit.

GeauxLadyZ

iTrader: (9)

DEEZFLIP ---

---So hey man, if i have the 7550 installed on my z w/ bose system--do i need to get the 7551 for better sound?? Or is this just basically the same as the 7550 only with RCAs that go low level RCA ouputs instead of those same speaker wires going into the HUs regular speaker outputs?? Is the SQ better with the speakers going into the low level RCA outputs??

I cant seem to get this answer (for sure) out of anyone!!

Deezflip

Looks like you'd be ok with what you have....from what you guys described, the difference between the 7550 and 7551 is the rca plugs.

That leads me to think that the 7550 speaker level outputs(non-bose headunits) and the 7551(bose headunits) low level outputs are all in the same position/grid/area on the connecting harness. As long as your not feeding it high level(speaker outputs), just make sure the RCA outputs on your aftermarket headunit is connected to this.

One thing to make sure or check on is...make sure that the negative and positive is not reverse on each one of the low level output. This will cause one or the other speakers to cancel out bass response.

Now for people with small hisses, another possible solution is to ground the negative part of the RCA's and make sure you or your installer did not feed it high speaker outputs.

Deezflip

GeauxLadyZ,

just further clarifying some details...

Non-bose headunits.....has high outputs(speaker level), NO low level outputs(RCAs)

Bose headunnits....has low outputs(RCA level,no actual RCA output plugs, just regular-looking wires often mistaken for speaker wires), NO high outputs(speaker level)

Aftermarket headunits.....usually has both high level and low level outputs(speakers and RCA's).

Hopefully for you GeauxLadyZ, your installer has connected the low level outputs(not the speaker outputs)from the aftermarket headunit to either the 7550 or the 7551 which will feed to your low-level-loving bose amp.

H3ll, for even more better understanding, you can feed the 7550 and the 7551 cable TV signals, connect it to a TV and watch cinemax all night. Bottom line is, as long as your feeding it low level, your bose amp should be happy. Hope this clears it up

GeauxLadyZ

iTrader: (9)

Ok, but are my low levels outs(coming from back of aftermrk HU) in RCA plug form OR do low levels feed into the main harness plug with the rest of the wires (or are those ONLY the speaker level outs?)

Damn bose system.

Deezflip

well, your installer either chopped off your RCA plugs coming from your headunit where he spliced and connected it to the 7550 that you have OR ....he took your 7550 and attached some RCA plugs to it to attach to the RCA's of the headunit....don't really know how else to describe the situation.

If you need me to, I can draw and post a diagram, which is my interpretation of the whole deal...i'll try to show the different ways possible, including the scosche and pac users.

Khjhb

iTrader: (1)

Thanks for the great how to article. I'm a new 350z owner and this really made my base model alot nicer than it already was. Installation was perfect!

clarkemtp

Thanks for the clarification for everyone else, but just so we're clear you're not, umm, "bursting my bubble" in any respect. Yes I should've been clearer. In the interest of not confusing the issue for anyone not "into" car audio, I termed them "speaker leads" and that was/is not technically correct. I should've used "signal leads", but I tried to simplify for easy understanding, perhaps I shouldn't have?

That being said, I stand by my assertion the the Metra 7551 is NOT the best solution. As I said, will it work? Yes. Is it ideal? No.

The Bose HU, as equipped stock, feeds a low level (signal level) signal to the Bose amp. Both designed to work together. Now, feed another low level signal from (insert head unit here) to the Bose amp and will it work together optimally? Maybe. Yes. No. Depends on everything. Signal level the Bose amp expects? Depends on the output level of the (insert head unit here). If they just randomly happen to be a good match? Good results with the 7551. If they're not? Bad signal level match, bad sound.

A good Line output convertor allows you, during installation, to vary/match the output level of the headunit to the input of the stock Bose amp. So, whether you happened upon a HU that has "whatever" for an output level, you are allowed the flexibility to deliver an input signal to the stock amp that will optomize the best of a compromised situation (Aftermarket HeadUnit/stock bose amp).

So, in conclusion, I stand by my original assertion that, well.. instead of repeating it, for clarities sake let me quote just so we're all clear on what I said:

Again, I was in error by using "speaker lead" when I should've just called a spade, a spade, "signal lead". I was just trying to name a wire so the new people would understand. But that's no reason to take a condescending tone with "I hate to burst your bubble". If that wasn't your intention, I apologize in advance. I hope we're all clear now. Just to reiterate, I'm only after the best available method to level match an aftermarket HU with a stock amp. If level matching wasn't useful, the hardware to do it wouldn't sell.

Regards,
Clark


PS -


Or perhaps it's resulting from a less-than-optimal input level from the (insert-aftermarket-headunit-here)? See the problem? Using a line output convertor which allows level matching, just helps eliminate one more possible variable AND make the best of the compromise install.

Deezflip

Hey i agree with you that you can tweak and adjust the low level signals with a converter and I'm not trying to start an argument. I was just in the impression from what you have said that if anyone uses the 7551, it will blow up the whole car.

Stock headunit is dishing out about 2v on it's low outputs(at least for the G35 bose headunits, should be fairly close or the same as the 350z), Avic-D3 has a max on it's low level output at 1.7v...it's a good enough match.

Yes you can tweak that with a converter but i wouldn't say that 7551 is "definitely making a boo-boo" or is the cause of the hiss, clicks, pops, etc. IMO, people get noises from feeding the 7551 with high level signals accidently from their aftermarket HU. Especially people with the 7550 with no RCA plugs, thinking a wire to a speaker wire connection. Again, IMO this is where some people makes the mistake.

A converter would be powered with a + and - wires, with the (-) minus wire being grounded which will ground the RCAs automatically once attached to it. If people go with the 7551, they can run an extra wire to negative/minus part of the RCA and ground it.

There's two ways...
High signal>converter>low signal>bose amp>high signal>speakers
or
low signal>bose amp>high signal>speakers

Either way, the were no intentions to offend you in anything i've said. I'm just here for people that needed help or advice.

GeauxLadyZ

iTrader: (9)

Honestly im starting to think that my installer installed the wires correctly, albeit using the 7550. I can tell you this...i def get more lows out of my speakers than highs, i def have to increase the highs on my EQ menu to match that of the lows--I use the fac setting "Powerful" on preset EQ only i bring the lows down to 6db, and i turn the "loud" option totally off, but im still tryiong to learn the terms and meanings of the special tweeking options in the custom eq.

My system, tho, after the install is REALLY loud. For instance in the nav menu where you set the volume for the voice guided nav and the buttons "ding" volume--on the voice i have it only like a quarter of the way up and its still almost unbearibly loud, so i dunno.

Thanks to both u guys tho for addressing this 7550-7551 or Pac Audio thing. You guys have helped clearify alot!!

clarkemtp

Agreed, and it's all good brotha. I'm here for the same reason. Help where I can, learn what I don't know.

clarkemtp

Glad everyone could help. I mean, I can't speak for anyone else... but I know at least in my case and probably there's too, if it weren't fun hanging out and helping, we wouldn't be here.

That said, glad it's working for ya. Like I said earlier in respect to the way your installer wired it, if you were happy with the sound, I wouldn't screw with it. If your installer got the "cosmetic" aspect of it squared away to your liking, there's only one thing left to do:

Enjoy!

jniddy

iTrader: (1)

One last question....does the blue/white "Amp Turn On" wire just not connect to anything??

Edit: looks like im all set....i bought the kit off a guy on this site, and the bypass was already done, looks like all three grounds are tapped into the main ground already. Well see tomorrow

Kuro350z

Hi guys I'm new to these forums. I will be putting this deck in my 05' touring (Bose w/o Nav) as soon as I purchase the harness and dash kit. I will be following this guide for the most part. Anyone have some pointers for me? This is only the 3rd nav install i have ever done. If there is an interest I wouldn't mind doing a DIY guide for '05 Bose w/o nav. Let me know I'll be more than happy to take pics as i go along with the install. Thanks in advance!