melteye

My head unit died and I recently purchased and installed a Pioneer AVH-X2700BS for $220 or so, using the Metra-70-7551 harness. While I am a bit unhappy with the stereo I'm unable to return it. The volume when connected to the stock BOSE/Clarion subs and speakers (through the pre-amps, of course) is too low and when nearing the top of the volume it starts to distort pretty badly.

I am not looking to spend much money but I would like an increase in volume. I was looking at the Alpine SPR-60 but not sure the head units amp (MOSFET 50W x 4) can power these speakers to above stock head unit + stock speaker volume. Would probably just replace the front speakers.

Any input would be appreciated.

As I'm using the stock sub which is wired to the speakers I'm guessing it isn't possible to adjust things like low-pass filtering and crossover properly... is this correct? Not sure how to make the head unit play well with the stock wiring.

Brudface

The head unit is giving out a lower pre out voltage than the stock head unit. Hence the low volume. Ditch the pre-outs and just wire them in. OR return the pre-out harness and get the other one which works well also.

maxiiiboy

I also replaced my Bose head unit recently. I had it done at an audio store; the job required three adapters - power, antena, and speakers. Does your Metra-70-7551 harness provide all three functions? If not, you should be able to buy and install these adapters failry easily. They are few dollars each.

melteye

According to the this thread: https://maxima.org/forums/audio-elec...nt-thread.html

"This harness is all well and good, but it is taking the raw power signal from your headunits internal amp and sending it to the BOSE amplifiers. This harness is geared for aftermarket headunits without 4 sepaker preamp out jacks. This method will work, BUT, you get alot of distortion because it's a high level signal. TOO much signal produces distortion, too little signal will prevent the volume from reaching a decent level. As I said before, this will work, but you will get a crappier signal."

So they are recommending against your suggestion... as I am having issues with distortion I'm not sure this would fix this. However, I can switch the wires over to test in less than 10 minutes so I'll try anyways.

Wiring the head unit amp to the stock amp would create a lot of distortion as the stock amp is expecting
I installed the radio successfully. All the required connections were made (harness, antenna, power.) I'm not having issues with the installation itself.

melteye

Can't return used harnesses. Just wired the HU's speaker wires to the back of the harness where the RCA plugs come out of. The volume is definitely louder (had to turn off a lot of the volume boosting features), as for the distortion at these volumes I'll give in a test on the freeway on my way to work. Don't want to test it outside at 3:44 AM.

I'll let you know. Thanks for the help.

DennisMik

iTrader: (2)

What you need to do is get a line level adapter between the radio and the Nissan wiring. I only know of 2 brands, but there may be more. The easier one to install is the PAC ROEM NIS2 adaptor. You don't need a cable like the Metra 70-7551. The PAC ROEM unit comes with one.

The other brand is Scosche. They are universal, and you would need to use a cable like the Metra. The Scosche unit is also less expensive.

melteye

Thanks for the advice. I ignored the distortion warnings from the thread I linked and just ran spare speaker wire I had from the regular outputs on the HU to the Metra 70-7551 harness (basically making it a 70-7550.)

Sounds great and loud. I just had to lower the bass in the EQ and it sounds like it should. The PAC ROEM NIS2 would probably be better but this current setup is sufficient for my purposes (loud music while driving to/from work in a 13 year old car I don't want to spend too much on.)

Brudface

Honestly I've had mine wired directly through using the 7550 harness. Because I bought a Kenwood HU which are known for they're terribly low Pre out voltages. IF you do the math on it and according to Ohms law it's legit, the 50w MAX signal voltage that you're HU can send is EXACTLY as much as the original HU gave at 4.1 volts. The deck that I have is 2v which is half that yours is more than likely the same which is why the volume is EXTREMELY low when hooked up with the 7551.
I've had mine in for as long as I've owned it, about 5 years now. EVERY speaker still works just as it did when I got it. Why fix what ain't broke

melteye

That's what I like to hear

kriv0240

does the PAC ROEM-NIS2 work for 2004 maxima ? im having the same problem where i turn up the volume loud and it distorts a lot and thinking about buying the PAC device. i installed the stereo myself and used the scosche unit but it still distorts. will the PAC make a difference then? or did i wire something wrong or is the amp out of date maybe? also i have a pioneer double din stereo intalled with the 50 watts per line or whatever its called. any help would be nice

DennisMik

iTrader: (2)

Yes it will. I have to qualify that - if you have the navigation system, then I don't know for sure.

Your kenwood radio at 50 watts per channel may be too powerful for the Scosche line level adaptor, which means the power level to the speakers is too high. The PAC ROEM unit may be able to handle it. For one thing, the PAC ROEM unit has adjustments on it. If you look at the photo of the PAC ROEM unit, you will see a column of 4 "dots" towards the right side of the unit. These are adjustments for the 4 channels if the factory setting is not sufficient. However, you would have to contact tech support for info on how to do the adjustments.

donpire

Well my Metra 70-7551 didn't last long. After about a month or so, the Metra unit burnt out on me. I went back with the classic harness with the RCA. It is not as loud but again why spend another $50 buck for music. So far this cheap $9 harness with RCA for speakers, after 5 months, is still working.

kriv0240

ok thank you for the reply, very helpful. also no i dont have the navigation system so i plan on ordering the PAC ROEM unit and hopefully i wont have to adjust anything on the unit and if i do i hope its not too difficult otherwise i might just install a new amp cuz im very picky about my sound system, i love music and cant live without it so i am very willing to spend money to get the best (well as long as i can afford it), also i figured out that if i turn the bass down or up for each song individually then it sounds very good however its a little annoying having to adjust it every time. again thanks for the info