I just installed the Z110BT and so far I am pleased with the unit with the exception that when I increase the volume to 25+ the sound begins to get distorted. I've tried adjusting every setting there is in the unit but nothing seems to help. I know the factory Bose unit would be able to produce audio at higher levels without distortion, so why am I getting this now? I'm still using the Bose amp...

I know my way around electronics so I installed everything myself and soldered all the connections. I'm stumped and kind of disappointed with the sound quality at the higher levels. At low volume the sound is very clean but if you are driving around with the windows down, I should be able to crank it up to 25 - 30 without it sounding like crap.

Any suggestions?

Z110BT
Metra 70-7551 harness

Thanks,

Scott

 

if you have the know how...

the best way ive seen to get around bose amps is to run your own wire.

 

Would there be some sort of conflict with the Bose amp?

 

im saying run a new set of wires from the head unit directly to the speaker(s)

 

I get what you are saying, I just don't see why I would have a problem using the factory amp. Too much power going into the amp maybe....

 

Scott are you saying you used the 70-7551 harness or are you asking if trying that would eliminate the issue?

 

Yeah I used the 70-7551 harness with the RCA's.

This thread seems to indicate that more power would be running to the amp when using an aftermarket head unit. Maybe that is the problem.

https://g35driver.com/forums/audio-v...ket-radio.html

 

I'm not sure what 25-30 actually means as I don't know the full scale range of the headunit. (Whats the max number?), but if you are running close to max, then you are likely clipping and causing the distortion.

The output, both high level and low level, is just a preamplifier with a gain control, so if you run the gain too high, you will saturate the preamps into the supply rails which will cause clipping which sounds like the distortion you are describing.

Not sure if the Bose amp has a gain control, but you could adjust this to put out more power given a smaller signal input.

Or use a line-out converter.

Also, the stock Bose amp is designed for low-level balanced inputs. Not sure what you are feeding it from the headunit you are using.

 

Easiest option here is to just replace the lousy Bose amp with something else.

 

The volume scale is 0 - 40. I can hear distortion as low as 18 at times, which is not really that loud. From what I have read, I probably need to replace the amp. Oh well.


https://g35driver.com/forums/audio-v...tock-bose.html

 

The bose sux. honestly...you got a great headunit there..replace the speakers with 4ohm speakers and go direct from the head. go to diycaraudio.com, caraudio.com, ebay or here and get em used. I got some focal coaxs ill let go cheap..and authentic. guarantee you a cheap pair of speakers will sound better than the bose stuff. u can even prob eq with that head.

 

I agree with both Wrathernaut and mark1478 although changing the speakers will probably be the easier and cheaper solution, but you should not be having that issue. The output on those pre-amps coming from the Z110 is 4 volt, and you SHOULD be ok between 2 volts and 6 volts with the 7551 harness.

Unless something is drastically different in the Avic-F series (also 4 volt preamps outputs) something else may be wrong. Just today I have seen a few posts with people running F-series through the 7551 with everything else stock and all seems well.

Good Luck whatever you do and let us know if you figure anything out.

 

Thanks for all the input. I would have thought the headunit would work good enough when connected to the Bose amp, but I've read a few people saying it sounds like crap when replacing the HU. Maybe it's the balanced/unbalanced connection to the amp, as described below from another thread. I went to a stereo shop to see if I can find out more and they just said oh yea yeah we'd replace it all. 2500 bucks and they'll make my system perfect.... and here shove this big *** box in your trunk.... I don't need all that. I'll probably try bypassing or swapping out the amp first and see how that sounds.



You most likely have an unbalance set of rca outputs connected into the balance inputs of the Bose. This is bad for several reasons including grounding the negative half of the balance input. If a shop did this you may want to go to another shop. If you are staying with the Bose amp (which I would replace) then what you need is what is called 'balance transmitters'. These will convert rca to balance and should be installed as close as possible to the head unit. You may get away with a balance converter which cost about 20 bucks but these are typically inductor based and will degrade the sound and will not impedance match.

 

The Bose speakers, while not great, will sound ok until you replace them with something really good. The only thing keeping you back from enjoyable audio right now is that Bose amp. Drop a few Benjamins on a 5-channel amp and you can be done in less than an hour.

 

Yup... I'm going to go with the amp replacement for now and upgrade the speakers later.... Now I have to figure out what amp to get.