I installed the JVC AVX710 in my 03 Z today. It originally had the Bose HU and still has the Bose speakers. After hooking it up, though, it seems to not be NEARLY as loud as the original unit. I have adjusted the volume, eq, everything. I do know that this new HU only has 1 RCA output, so i had to use RCA splitters to go to the speakers, could this be the reason why? Thanks for the help!

 

A simple drawing of how the head unit is connected to the speakers would be helpful. The KW-AVX710 has a built-in amp (20 watts RMS/50 peak x 4 channels).

BTW how did you power the subwofer?

 

The headunit is connected to the speakers via the RCA outputs (not speaker wires from the HU) bc the Bose is an amplified system. I assumed the amp for the sub would be getting signals same as those for the front and rear speakers. Sorry if i sound stupid, im not used to an amplified system, im used to honda civics and preludes

 

if you are still using bose speakers and bose amplifiers.. its not nearly as loud because the bose speakers are a different ohm than the new head unit will put out at the same audible level.

when you replace bose.. its best to replace everything

 

Correct. The Bose head unit feeds all audio signals to the amplifier. Are you using some type of modified harness the turn the amplifier ON?

 

^^ I'll be honest, i simply soldered the wires. I do know i did not use any of the "speaker" wires coming off the harness for the headunit, i did hook up the remote wires which made the amps come on (i know this bc i didnt hook them up at first and got nothing) the harness i am using is the one that came from Crutchfield.

 

Check out this thread (LAST 3 PAGES SPECIFIC)--i also got the harness from crutchfield (7550) Not (7551) and had a similar problem/question. This thread will explain the diff in harnesses and what you need harness wise for any A/M HU.

https://my350z.com/forum/audio-and-video/278145-avic-d3-install-guide.html

 

Umm, this thread here will tell you more about how to connect an aftermarket unit with the oem Bose system. Youll need a PAC ROEM-NIS2 between the head unit and the bose system.

https://my350z.com/forum/showthread....highlight=bose

Hope this helps

 

Well if you read towards the end of this thread...youll see why the Pac audio harness is not absolutely ness. **** im using the 7550 and my sound is great...no SQ issues what so ever--it gets rediculously loud as well.

But ya you can use the PAC if you want---the diff in equalizing the the A/M HU and the bose amp is like damn near impossible to notice SQ wise...

As long as you hook either the 7550 or 7551 to your pre-amp outs on the back of the HU using RCA connections. Even on your thread that guy says that PAC is not needed if you hook 7550/7551 this way---cause it does the same thing.(w/ exception of A VERY LITTLE output leveling)

But ya man this might be your prob. Make sure the specific wires DONT go into HU harness plug and instead plug into pre-amp outs

 

^^ my stereo only has 1 set of pre-amp outs. so i was forced to use them. I have the 7551 harness. So i know the RCAs are hooked up correctly, as well as the remotes. Still clueless, ha ha ha

 

See, here is where you run into problem's. In the "other" thread, we determined that the omission of the PAC can be "acceptable" if you're lucky because the output voltage of the AVIC-D3 accidentally happens to be pretty close to the line output of the stock hu (and consequently what the Bose amp expects.

So here's the caveat. If the line output voltage of THIS head unit in question isn't a good match, then just "plugging in" the RCA's isn't going to provide a good signal to drive the Bose amp. What might be a symptom of that situation? I'm glad you asked. Low system volume.

Hmmmmmmm. Could be your problem, something to at least troubleshoot anyway.

 

So your sayin he might HAVE to get the PAC-audio adapter (more needed with this particular HU) to equalize btw the the HU and amp??

 

Well if he can't troubleshoot the problem down to any other solution, there could definitely be a output level/input level discrepency between the aftermarket HU puts out and what the bose amp expects/wants to see. I'm sure in his headunit specs he can find what the output level of his unit is and go from there.

 

Why not just replace the speakers? The low ohm numbers that the bose systems runs on will be hard to get sounding half as good as some aftermarket component speakers with your headunit.

 

In my opinion i dont think the speakers are the problem...its how hes got the HU hooked up i think. From what ive learned lately lots of folks with the bose system are having this very same problem.

However im not...mine sounds pretty damn good--my bose sub is twice as percise with this new A/M HU and it sounds better than any other AM sub ive ever had. Volume gets REALLY loud as well.

I think the fact that he used RCA splitters MIGHT be the prob...it doesnt sound right to me, but i need backup on this opinion. Wouldnt that just split the overall output running to each speaker, therefore lower overall volume?? just a thought.

 

^^ Thats what im thinking also. And these RCA outs were only 2.5v. I have a JVC AVX800 on the way, it has 3 pre-amp outputs, and all are 5v. So we'll see if this helps any! Im about 99% sure i hooked up the harness correctly.

 

The line level output of the JVC AVX710 is 2.5 volts.

 

you're going to need the pac roem-nis2

 

the 7551 harness wont work? Even if plugged in to HU pre-amp outputs and into the wires going to the amp

 

i dunno. Crutchfield recommends a 7550 not 7551 for your car--like mine. It works fine on mine but other people have problems with 7550 so i dunno.