[larry1960]

I installed the new pioneer 6.5 Armed Fiber components in the front and the same type in a coax the rear doors.I made a fiberglass box that replaced the BOSE-ZO subwoffer on top of the spair tire. Now I really have nice bass and no space taken up by a box.The amps I used were by directed electronics.The sub amp is a mono 700 watt amp driving a pioneer premiere 10' sub, 4'inches deep so it fits in the box.

I used the wiring in the rear for all my audio hook ups. I hooked up female RCA jacks to the factory wiring then pluged in regular RCA to the amps. The Bose outputs are in a gray shielded cable. The speaker wires are all twisted pairs.
I ran a 4guage wire to the rear and split it to 8 guage at a block.

I installed the crossovers in under the dash in the front.The tweeters are on the dash under the grill.

OK now all is working OK BUT I have some noise not wine but a BUZZ when the motor is on only. I tryed all the filters I have in stock and still have noise. O did say I have a audio store in Westchester NY I do, Any questions just E mail me.

So any ideas on this noise issue.

Thank You

 

[10413]

ground

Check your ground connections off your amps. Ground directly the the chassis with a 8 ga. wire, as short as possible. Use a dremel to polish off any paint from the area where you are attaching the grounds.

BTW -- still waiting to hear back from our email conversation regarding the sub box!

 

[jaak]

Noise? Yeah, you're running unbalanced audio outputs into a balanced audio input on the amp. You need a proper balanced to unbalanced line level converter and that's likely to eliminate your noise problem.

 

[10413]

Hmmmmmmm, jaak's reply made me re-read the original post a little more closely.

You said:

I hooked up female RCA jacks to the factory wiring then pluged in regular RCA to the amps.

Does that mean you cut the factory wires and spliced on a female RCA jack, then just ran that into an amp? Oh my... oh my my my... jaak is absolutely right.

You either need an amplifier with a proper high-level input circuit (and get rid of the rca plugs and just run the lines into the amp), or you need something like a PAC adapter or similar to convert the lines to low-level. I had assumed you were using a PAC or another high->low converter when I first read your post.

I don't mean to sound snide or rude, but you own an audio shop? That's a rather fundamental rule you violated there. One of your installers could have found that problem pretty quickly, I'm sure.

 

[jaak]

Noise? Yeah, you're running unbalanced audio outputs into a balanced audio input on the amp. You need a proper balanced to unbalanced line level converter and that's likely to eliminate your noise problem.

Must have been half asleep when I wrote that....

You're running Balanced audio Outputs into Unbalanced Inputs, is what I meant to say.

The audio lines from the Bose head unit to the Amp are balanced, so one wire carries the same information as the other, but inverted. On an unbalanced input, one side is grounded, and the other carries the audio.

So by connecting balanced directly to unbalanced, you are shorting out one side of the audio output to ground. Not good for the driving amplifier in the head unit.

Yes, get a Pac or equivalent balanced to unbalanced line level adapter.

 

[larry1960]

I removed the amp

Hmmmmmmm, jaak's reply made me re-read the original post a little more closely.

You said:



Does that mean you cut the factory wires and spliced on a female RCA jack, then just ran that into an amp? Oh my... oh my my my... jaak is absolutely right.

You either need an amplifier with a proper high-level input circuit (and get rid of the rca plugs and just run the lines into the amp), or you need something like a PAC adapter or similar to convert the lines to low-level. I had assumed you were using a PAC or another high->low converter when I first read your post.

I don't mean to sound snide or rude, but you own an audio shop? That's a rather fundamental rule you violated there. One of your installers could have found that problem pretty quickly, I'm sure.

The leads are the outputs of the bose radio that were going to the factory amp.Now they are going to the new amp Ths issue is a buzz and not a high to low device. The output is low already. It is bose is it really low?

 

[Tyler_Canada]

It's not a high level output from the head unit, it's a low level balanced output. The PAC converter that seems most popular (I've used it) also converts from high to low level, but that's not the problem here.

This is what you want:
http://www.pac-audio.com/oem1kits/aoemresults.cfm?aoemSearch=Nissan&Submit=Search+for+AOEM-1+kits

I got mine here:
OEM-1
ADD-NIS2
AMP-RCA

 

[10413]

Interesting... I wasn't aware the Bose system was set up this way. I assumed (incorrectly, apparently!) that the head unit fed high-level (speaker-level) signal into the Bose amp.

I stand corrected.

Just curious, where did you find this info? Is it in the service manual?

 

[Tyler_Canada]

Interesting... I wasn't aware the Bose system was set up this way. I assumed (incorrectly, apparently!) that the head unit fed high-level (speaker-level) signal into the Bose amp.

I stand corrected.

Just curious, where did you find this info? Is it in the service manual?

Probably from jaak.
Although I'm sure the info is in the S.M. too.

It would make sense though, that you would send high level signals to speakers, and low level signals to amps. This isn't always the case in aftermarket setups, but most factory setups follow this idea.

 

[10413]

Probably from jaak.
Although I'm sure the info is in the S.M. too.

It would make sense though, that you would send high level signals to speakers, and low level signals to amps. This isn't always the case in aftermarket setups, but most factory setups follow this idea.

That's interesting... I haven't run into that particular case before. I had (once again, incorrectly) assumed that the head unit for the Bose system was similar to the non-bose unit in that it sent a speaker-level signal out of the head unit (in this case, into the amp), and the amp handled the conversion. I've seen many setups like that.

I am curious if there's a test that one can do on the wires to see what type of signal it is...

 

[Tyler_Canada]

That's interesting... I haven't run into that particular case before. I had (once again, incorrectly) assumed that the head unit for the Bose system was similar to the non-bose unit in that it sent a speaker-level signal out of the head unit (in this case, into the amp), and the amp handled the conversion. I've seen many setups like that.

I am curious if there's a test that one can do on the wires to see what type of signal it is...

Why would you need to convert a speaker level signal to connect it to speakers?

The only case I've ever seen where you have high-level head units connected to an amp is when an amp was added to a system that didn't originally have one.

 

[Tyler_Canada]

Ok, I got really curious about how I found out that the head unit outputs are balanced. I couldn't find anything when I searched this forum, but then I remembered the forum jaak and I came from, freshalloy. I found this post from waaay back in the beginning:

http://forums.freshalloy.com/ubbthr...lposts&Main=67392701&Search=true#Post67392827

 

[10413]

Why would you need to convert a speaker level signal to connect it to speakers?

The only case I've ever seen where you have high-level head units connected to an amp is when an amp was added to a system that didn't originally have one.

Anytime you amplify a signal it should be low-level, so if it were speaker-level coming into the amp the amp would step it down before amplification to ensure it stayed clean... and I've seen OEM "premium audio system" amps do exactly that. The baseline system would drive speakers directly off the head unit, or on the "upgraded" premium audio systems they just add an amp in-line running off the same head unit signal and add/change speakers. In the case of the MO, since the head unit is different on the Bose and non-Bose systems, it makes sense that the signal on the wire is different.

I'm just saying that I have seen strange things with OEM audio systems, and I made my assumptions based on what I've seen in the past. In this case I was wrong. These companies like to do very strange things to lock you into thier proprietary system and make it difficult or impossible to upgrade with aftermarket parts, because you'd be altering their "precision engineered" system. *rolls eyes*

No one's arguing... just banter.

 

[Tyler_Canada]

What you say makes sense, when you think about it from the cost/flexibility perspective that the car manufacturers are looking from.

 

[jaak]

A quick glance shows that all audio output lines run from the head unit to the inputs of the integrated Bose amplifier. They are all balanced (+/- not referenced to ground) outputs and appear to be around +/- 1 volt, or 2 volts peak-peak. The single Bose amplifier feeds all the speakers, including the two used in the subwoofer. (Obviously the amp is more than one, contained in one box.)

The input connector looks like this:

|---|
.5 .6 .7 .8 .9 10 11 12 13 14 15 16
21 22 23 24 25 26 27 28 29 30 31 32

If this is a mess when you look at it, copy and paste into notepad or something, and select courier as the font and it should straighten it out.

Pin 31 - Amp on signal (G/W)

Pin 23 - Rear RH -ve (B/W)
Pin 24 - Rear RH +ve (L)
Pin 25 - Rear LH -ve (Y)
Pin 26 - Rear LH +ve (O)


The connector at the subwoofer appears to only contain 4 wires, even though it's a 6 pin connector. (This could just be me missing two of them in the schematic. Have a look and tell me, if there are 6 wires. I'd look, but I've got equipment on top of the cover right now!)

I only see pins 2, 3, 4, 6 used.

The connector shows the following configuration:
M
6 4 2
5 3 1

Locking tab is above pin 4

Left Woofer +ve is 2 (W), -ve is 3 (B)
Right Woofer +ve is 6 (B/P), -ve is 4 (O)

It should be pretty easy to figure out which way around the connector is.

Fuse is 15 Amps shared with head unit's "back up" power (for keeping the radio's memory intact). There is a Black wire on one corner of an 8 pin connector, that's ground. There's a yellow wire next to it, also on a corner, that's from the battery.

Hope this helps!

Since I wrote it on FA, I suppose it's OK for me to steal it off there as well...

Balanced outputs are more immune to noise (when fed into a balanced input, hint hint!) so it allows Nissan to use standard wiring instead of sheilded cable, which would be much more expensive to wire into the vehicle's harness.

I too, have seen "Booster" PA's where they take an existing speaker level and add another stage of amplification at the end of it, to bring up the power.

One of the advantages of having a lower level output is to get the power amp, it's associated bulk, power consumption and generated heat, out of the head unit and in a location that's not space and cooling sensitive.

 

[10413]

jaak -- i've mentioned this once or twice in other threads, but since you've done lots of digging into the innards of the Bose system -- according to the diagrams I've seen you post, there are 4 audio channels fed from the head unit into the Bose amp, and there are 6 output channels (2 for the sub). I assume there must be some sort of mixing/multiplexing going on inside the amp to create the channels for the subs, because no matter which way you adjust fade and/or balance, the sub always stays active, so it seems that it's not dependant on any particular channel(s). Can you shed some insight on that?

 

[larry1960]

I am getting a pac oem1

Since I wrote it on FA, I suppose it's OK for me to steal it off there as well...

Balanced outputs are more immune to noise (when fed into a balanced input, hint hint!) so it allows Nissan to use standard wiring instead of sheilded cable, which would be much more expensive to wire into the vehicle's harness.

I too, have seen "Booster" PA's where they take an existing speaker level and add another stage of amplification at the end of it, to bring up the power.

One of the advantages of having a lower level output is to get the power amp, it's associated bulk, power consumption and generated heat, out of the head unit and in a location that's not space and cooling sensitive.

They said that would help with this issue.I have noticed I lost stereo separation .Why?? I am installing this tomorrow

 

[jaak]

jaak -- i've mentioned this once or twice in other threads, but since you've done lots of digging into the innards of the Bose system -- according to the diagrams I've seen you post, there are 4 audio channels fed from the head unit into the Bose amp, and there are 6 output channels (2 for the sub). I assume there must be some sort of mixing/multiplexing going on inside the amp to create the channels for the subs, because no matter which way you adjust fade and/or balance, the sub always stays active, so it seems that it's not dependant on any particular channel(s). Can you shed some insight on that?

They do it the lazy way.... The woofer (I know they call it a sub, but I can hear where it rolls off, so it's no sub!- as in subaudible) has two voice coils so both L and R signals are fed to it, and it responds accordingly.

So there's a couple of ways they could deal with this. One is to combine the front and rear signals, as you will always have one of them active. The other would be to take, as an example, Front Right and Rear Left and feed them to the woofer, so you always have at least one of them feeding signal. Low frequency signals are usually in both channels on the source material, so this doesn't create any problems.

One way to check this, is to get a CD with known separate channel information and move the L/R F/R to check it. Like a test CD (or an old Beatles album).


Larry, the loss of stereo separation could be a result of one side of the balanced outputs being grounded and therefore it's forcing the reference level of the output stage to move and bleed the audio from one channel to the other. This too, should be fixed with correct wiring of the balanced to unbalanced converter into your system.

 

[larry1960]

Now all ok

OK so now the oem1 by pac is installed
The sound is great. My fiberglass box I made for bass is really great The sub control under by dash is nice to have.


I tied into the factory gray radio outputs wires located at the Bose amp.and installed the pac oem1 their.Then RCA into my 2 amps You have a good amount of room to install 2 amps on 1x2 wood. and all is hidden no room taken up really cool..

That oem1 took out all the noise and gave me back stereo separation.

NOTE, when installing the crossover on the passenger side keep it away from the corner because a buzz comes out on the speaker with only the speaker hooked up to the crossover no inputs that was really weird. Their is some RF noise their..


All is good
I will see how to post some Pict I do not know how.

 

[10413]

looking forward to seeing the pics...