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So by connecting the MG650 to the headunit this will allow you to bypass the Bose amp and add your own speakers and amp and not have to worry about the noise cancellation?
Correct. The MG650 feeds a non-Bose-ifed audio signal to aftermarket amps. Then everything works as if you had a normal head unit in the car. To me this is step 1 of any C7 audio upgrade since (IMHO) what the Bose amp does to the audio signal is the main problem with this stereo. Anything you do after the Bose amp (changing speakers for example) while an improvement is still limited by the Bose processing.
Please do!!! I'd love to know what is actually going on with this crazy system. 4 ohm tweeter plus 3.2 ohm mid plus 1 ohm woofer? The more I learn about Bose the more I hate them
Yep all front sound stage for me
And you do NOT want to grab the high level off the Bose amp, its got all kinds of volume based EQ non-sense going on. You could, but only IF you used the DSP's volume control to get around this.
Correct It does but for example, on the new Sony 6 channel amp (if ) it has active summing it will nullify any adjustments that the Bose Nightmare may do. Im looking into it but in the norm, I agree 1000% Beauty of the NAV GM650 Unit....
So basically, a total gut job is necessary ? Replace all DSP, AMP and speaker is the only way to upgrade the sound system out of that terrible Bose dsp.
So by connecting the MG650 to the headunit this will allow you to bypass the Bose amp and add your own speakers and amp and not have to worry about the noise cancellation?
So by adding the GM650 it directly plugs into the Bose amp via Direct harness, Here's NAVTV's direct explanation:
The M650-GM produces a completely flat audio output without any factory time delay or equalization, eliminating the need for summing devices, an audio correction DSP or the removal of the factory audio compensation microphones. It is 100% plug-and-play, installing at the factory tuner in both amplified and non amplified GM vehicles. Installation of the interface requires absolutely no modification to the vehicle or the removal of any factory equipment and can be used when completely replacing the factory speakers, or in any combination utilizing the factory audio components. Volume, Fade and Balance are supported through the factory radio and steering wheel controls.
Utilizing a 128bit per channel floating point DSP and 192 kHz 32 bit DAC, the M650-GM produces a 6 channel analog output (Front L/R, Rear L/R, Sub and Center) with a peak voltage of 6.3V and a S/N Ratio of 112dB. All warning chimes and audible turn signal indications are attenuated to factory levels and, along with Onstar®, Navigation prompts and Bluetooth, are passed to the proper output channels, eliminating the need for an external speaker. The unit provides a 500mA output for controlling aftermarket devices and, additionally, retains the factory 3 band equalizer (high, mid and bass).
I was able to remove the plastic cover at the rear over the 8 inch sub without removing the carpet, but it was not easy. I recommend removing the wheels tub covers, then carpet, then rear plastic panel to get at the 8 inch sub
So by adding the GM650 it directly plugs into the Bose amp via Direct harness, Here's NAVTV's direct explanation:
The M650-GM produces a completely flat audio output without any factory time delay or equalization, eliminating the need for summing devices, an audio correction DSP or the removal of the factory audio compensation microphones. It is 100% plug-and-play, installing at the factory tuner in both amplified and non amplified GM vehicles. Installation of the interface requires absolutely no modification to the vehicle or the removal of any factory equipment and can be used when completely replacing the factory speakers, or in any combination utilizing the factory audio components. Volume, Fade and Balance are supported through the factory radio and steering wheel controls.
Utilizing a 128bit per channel floating point DSP and 192 kHz 32 bit DAC, the M650-GM produces a 6 channel analog output (Front L/R, Rear L/R, Sub and Center) with a peak voltage of 6.3V and a S/N Ratio of 112dB. All warning chimes and audible turn signal indications are attenuated to factory levels and, along with Onstar®, Navigation prompts and Bluetooth, are passed to the proper output channels, eliminating the need for an external speaker. The unit provides a 500mA output for controlling aftermarket devices and, additionally, retains the factory 3 band equalizer (high, mid and bass).
Man you guys are getting me all pumped up!! My Z06 has 50 miles on it brand new stored in the garage. My C5 Z06 was all
done up with a new sound system that kicked ***. I told the wife I was going to miss my audio system but she said you can always upgrade your new car with sound deadening which I also had done. It awesome to have a fast car and awesome sound system.
Putting it back together - now there's the hard part!
I let my audio guy tare my C5 and completely gut it. When he was done never looked like it was apart. Now i’ll be nervous if I let him do my 2019. This is my first brand new Vette.
So basically, a total gut job is necessary ? Replace all DSP, AMP and speaker is the only way to upgrade the sound system out of that terrible Bose dsp.
If you want to do it right... then sadly yes.
However I am attempting to just replace the Bose amp and sub, then using a DSP plus aftermarket amp to tune the factory speakers (plus aftermarket sub) back into something usable. I may not succeed but figure its worth a shot. As I found during my testing the stock speakers produce decent mid-range even a high volumes so I don't think the main front speakers are the worst link in the chain. The sub is pathetic so it has to go. The tweeters roll off a little sooner then I'd like so they would next on my list of things to replace. I believe the front woofer is usable once crossed over to more reasonable frequencies. Asking the front woofer to handle bass below 70Hz isn't going to happen despite its 10" size.
Originally Posted by jamiejam1
Correct It does but for example, on the new Sony 6 channel amp (if ) it has active summing it will nullify any adjustments that the Bose Nightmare may do.
The problem is the Bose non-sense is a variable EQ (really just a shelf I bet) based on volume as I found during my testing: Blue line is low volume, red line is higher volume, yellow zone is the infamous "Harman Curve" with a 6db tolerance.
So as you move the volume **** up the Bose amp actively removes frequencies below 1K. It was the first thing I noticed about the C7 once I got it. It drove me nuts so I grabbed my microphone and FFT app and ran some pink noise to confirm my ears weren't broken. Yep confirmed - too much bass at low volumes but not enough at higher volumes.
My testing was done with the factory EQ set flat and the surround setting at "normal" which I believe is off, also Audio Pilot was off too for obvious reasons. I did everything with the least processing possible yet the Bose still messes with the signal. I assume they do this to keep the mid-bass and sub from working too hard. Plus it saves customer complaints about distortion and likely reduces amplifier clipping. Sounds terrible to me because its inconsistent. Great song comes on the radio, you crank it up and... no bass - gee thanks Bose!
The solution is to do all your summing and EQ fixin' at only ONE system volume setting then use your DSP to control the master volume. But who is going to do that? Instead best to grab the signal before amplification which is why the M650-GM has a T-harness between the radio and the Bose amp, - it is working at the pre-amp level.
I will be using the PAC AP4-GM61 AmpPro link 349.00 @ CarId. It is an awesome unit for the GM interface. It also has bass control **** included. Just waiting for the 3.5" to come in
However i am attempting to just replace the bose amp and sub, then using a dsp plus aftermarket amp to tune the factory speakers (plus aftermarket sub) back into something usable. I may not succeed but figure its worth a shot. As i found during my testing the stock speakers produce decent mid-range even a high volumes so i don't think the main front speakers are the worst link in the chain. The sub is pathetic so it has to go. The tweeters roll off a little sooner then i'd like so they would next on my list of things to replace. I believe the front woofer is usable once crossed over to more reasonable frequencies. Asking the front woofer to handle bass below 70hz isn't going to happen despite its 10" size.
The problem is the bose non-sense is a variable eq (really just a shelf i bet) based on volume as i found during my testing: blue line is low volume, red line is higher volume, yellow zone is the infamous "harman curve" with a 6db tolerance.
so as you move the volume **** up the bose amp actively removes frequencies below 1k. It was the first thing i noticed about the c7 once i got it. It drove me nuts so i grabbed my microphone and fft app and ran some pink noise to confirm my ears weren't broken. Yep confirmed - too much bass at low volumes but not enough at higher volumes.
My testing was done with the factory eq set flat and the surround setting at "normal" which i believe is off, also audio pilot was off too for obvious reasons. I did everything with the least processing possible yet the bose still messes with the signal. I assume they do this to keep the mid-bass and sub from working too hard. Plus it saves customer complaints about distortion and likely reduces amplifier clipping. Sounds terrible to me because its inconsistent. Great song comes on the radio, you crank it up and... No bass - gee thanks bose!
The solution is to do all your summing and eq fixin' at only one system volume setting then use your dsp to control the master volume. But who is going to do that? Instead best to grab the signal before amplification which is why the m650-gm has a t-harness between the radio and the bose amp, - it is working at the pre-amp level.
However I am attempting to just replace the Bose amp and sub, then using a DSP plus aftermarket amp to tune the factory speakers (plus aftermarket sub) back into something usable. I may not succeed but figure its worth a shot. As I found during my testing the stock speakers produce decent mid-range even a high volumes so I don't think the main front speakers are the worst link in the chain. The sub is pathetic so it has to go. The tweeters roll off a little sooner then I'd like so they would next on my list of things to replace. I believe the front woofer is usable once crossed over to more reasonable frequencies. Asking the front woofer to handle bass below 70Hz isn't going to happen despite its 10" size.
The problem is the Bose non-sense is a variable EQ (really just a shelf I bet) based on volume as I found during my testing: Blue line is low volume, red line is higher volume, yellow zone is the infamous "Harman Curve" with a 6db tolerance.
So as you move the volume **** up the Bose amp actively removes frequencies below 1K. It was the first thing I noticed about the C7 once I got it. It drove me nuts so I grabbed my microphone and FFT app and ran some pink noise to confirm my ears weren't broken. Yep confirmed - too much bass at low volumes but not enough at higher volumes.
My testing was done with the factory EQ set flat and the surround setting at "normal" which I believe is off, also Audio Pilot was off too for obvious reasons. I did everything with the least processing possible yet the Bose still messes with the signal. I assume they do this to keep the mid-bass and sub from working too hard. Plus it saves customer complaints about distortion and likely reduces amplifier clipping. Sounds terrible to me because its inconsistent. Great song comes on the radio, you crank it up and... no bass - gee thanks Bose!
The solution is to do all your summing and EQ fixin' at only ONE system volume setting then use your DSP to control the master volume. But who is going to do that? Instead best to grab the signal before amplification which is why the M650-GM has a T-harness between the radio and the Bose amp, - it is working at the pre-amp level.
When I can find some spare time, we should Collaborate the efforts... My shop is in Coconut Creek!
However I am attempting to just replace the Bose amp and sub, then using a DSP plus aftermarket amp to tune the factory speakers (plus aftermarket sub) back into something usable. I may not succeed but figure its worth a shot. As I found during my testing the stock speakers produce decent mid-range even a high volumes so I don't think the main front speakers are the worst link in the chain. The sub is pathetic so it has to go. The tweeters roll off a little sooner then I'd like so they would next on my list of things to replace. I believe the front woofer is usable once crossed over to more reasonable frequencies. Asking the front woofer to handle bass below 70Hz isn't going to happen despite its 10" size.
The problem is the Bose non-sense is a variable EQ (really just a shelf I bet) based on volume as I found during my testing:
\ Blue line is low volume, red line is higher volume, yellow zone is the infamous "Harman Curve" with a 6db tolerance.
So as you move the volume **** up the Bose amp actively removes frequencies below 1K. It was the first thing I noticed about the C7 once I got it. It drove me nuts so I grabbed my microphone and FFT app and ran some pink noise to confirm my ears weren't broken. Yep confirmed - too much bass at low volumes but not enough at higher volumes.
My testing was done with the factory EQ set flat and the surround setting at "normal" which I believe is off, also Audio Pilot was off too for obvious reasons. I did everything with the least processing possible yet the Bose still messes with the signal. I assume they do this to keep the mid-bass and sub from working too hard. Plus it saves customer complaints about distortion and likely reduces amplifier clipping. Sounds terrible to me because its inconsistent. Great song comes on the radio, you crank it up and... no bass - gee thanks Bose!
The solution is to do all your summing and EQ fixin' at only ONE system volume setting then use your DSP to control the master volume. But who is going to do that? Instead best to grab the signal before amplification which is why the M650-GM has a T-harness between the radio and the Bose amp, - it is working at the pre-amp level.
BTW The graph just kind of Proved my suspicions that the 10" is a low freq playing mid bass 70ish hz up to 300's is the typical mid bass range in a 3 way component system this just give upper low support to the tiny 8" bringing the sub bass to the front... which in lieu of the missing time alignment in the car and lick of phase reversibility just replicates a BS soundstage....
I will be using the PAC AP4-GM61 AmpPro link 349.00 @ CarId. It is an awesome unit for the GM interface. It also has bass control **** included. Just waiting for the 3.5" to come in
I searched for this on carid and came up with zilch.
When I can find some spare time, we should Collaborate the efforts... My shop is in Coconut Creek!
For sure. I'm right down the street from you in Margate
My plan is AX-DSP-MOST1 to JBL MS-8 then NVX JDA 900.5 for power with a Kicker CompRT 8” sub. Likely will not happen until late spring, gotta get wheels and tires for the track first as the stock rubber is nearly done.
The sound stage isn't terrible when it set to "Driver" position - the Alpine Imprint in my truck is much better of course but honestly the C7 is decent for stock. The problem is compared to aftermarket its still sad. If you could shut off this auto loudness feature and if it had any real sub bass response I think it would be acceptable.
When I can find some spare time, we should Collaborate the efforts... My shop is in Coconut Creek!
Hey thats not too far from me. I have been considering having someone do a sound system in my 2LT Z51. Subscribed as I'd like to see what your solution is. My interest would be in looking totally stock with the factory head unit, but much improved sound and bass.
01-14-2019, 04:53 PM
