Final check before I start my install: 2014 w/BOSE & trying to keep full HU function

[Schwacofer]

Final check before I start my install: 2014 w/BOSE & trying to keep full HU function

GOAL: Keep all BOSE head unit, steering wheel controls, backup camera, USB & AUX

In that goal is also to keep the center channel processing that BOSE provides.

This post is an extension of one I made a while back and uses some of the information from this post by jlcpremier

CDT ES 3 ways will be the left and right main speakers and a matching CDT ES 2 way will make up the center channel.

Since the BOSE processing treats the Left and Right dash speaker as tweeters (they are crossed over from the doors speakers at ~3khz within the amp) AND because the HU appears to out put a line level signal, that output can then easily have RCA ends attached and connect directly to after market amps.

https://www.amazon.com (commissions earned)

The bit of "ghetto rigging" now will be in getting the center channel output to work because that it controlled though processing on the BOSE amp AND getting the full range single from the stock HU into the amp.

My thought then is to split the bare wire output form the stock HU and have 1/2 go to the after market amp and 1/2 go to the BOSE amp so that it can continue to do the center channel processing. The speaker output from the BOSE amp will then be converter to line level though a basic Kicker LOC and then fed into after market amps.

Has anyone tried such things, or does anyone see any issues that I might not be considering here? I figure the output voltage from the HU will be cut in 1/2 but I am hoping that the original output strength is enough that it wont be an issues.

 

[silvercoat]

I think I see what you are trying to do but I feel that you may be 1/2 way to where you need to be. You are correct in thinking that if you split the wires your voltage will go down (it may not be half). With BOSE and many other car systems this could pose a problem as the BOSE amp expects 4ch Full range audio at a certain input given the info you have posted. The BOSE amp has no adjustable gain so this would hurt you in the long run. Also keep in mind that going with signal post and pre-amp is not the best idea.
You would want to go with one or the other and if keeping a factory amp I would say go post. To do this the best way possible, I would leave the factory signal chain alone, and get yourself an LOC/DSP/Summing unit that gives you a clean output. You are going to get a much better result using your set EQ's and Xover's from the amp.
The bigger question is what do you look to loose gain with the center channel. Most factory systems outside of ones with surround processing just take the front channels and bridge them together to make the center channel. You can do this with aftermarket amplifiers easily enough and you can split signal at that point because those amps will have adjustable gain.
Don't limit yourself because of the factory BOSE. They make parts to replace everything factory with aftermarket easily enough at this point. I would weigh the cost of a stereo versus having something that gets you clean input to your amp.
In my experience, tapping into factory signal gets wacky quickly and you get better results from not doing so.

 

[Schwacofer]

Thanks for the reply, but I want to address some of the concerns and work though/keep thinking about the plan before I start cutting and splicing wires.

With BOSE and many other car systems this could pose a problem as the BOSE amp expects 4ch Full range audio at a certain input given the info you have posted.

And the BOSE amp would still be getting a full range single from the head unit. Though it would be at some level of reduced strength.

The BOSE amp has no adjustable gain so this would hurt you in the long run.

True it has no adjustable gain, but the aftermarket amps do. So I’m not sure how that hurts anything. Any signal I use as a source will eventually pass through an amp with gain control.

Also keep in mind that going with signal post and pre-amp is not the best idea.
You would want to go with one or the other and if keeping a factory amp I would say go post.

Why is it not a good idea? The various signals are going to different amps and different speakers.

To do this the best way possible, I would leave the factory signal chain alone, and get yourself an LOC/DSP/Summing unit that gives you a clean output. You are going to get a much better result using your set EQ's and Xover's from the amp.

I’ve thought about that, and it’s still a potential solution, but it’s an added expense and complexity at this point. If this current idea fails to yield the desired results I will most likely use some sort of DSP

The bigger question is what do you look to loose gain with the center channel. Most factory systems outside of ones with surround processing just take the front channels and bridge them together to make the center channel. You can do this with aftermarket amplifiers easily enough and you can split signal at that point because those amps will have adjustable gain.

From my understanding and from what I can tell both audibly and though my measurement mic, the Bose Center channel processing is a bit more complex than just a summed mono output.

But it is another easier solution to get a functional center channel in the car.

Don't limit yourself because of the factory BOSE. They make parts to replace everything factory with aftermarket easily enough at this point.

With the high level of Bose integration from the factory, replacing the HU with something after market has some distinct disadvantages. Re-integrating the backup camera, losing the stock USB/AUX inputs, steering wheel controls, internal light timers ect.

 

[silvercoat]

Reply back to concerns

Thanks for the reply, but I want to address some of the concerns and work though/keep thinking about the plan before I start cutting and splicing wires.



And the BOSE amp would still be getting a full range single from the head unit. Though it would be at some level of reduced strength.

The reduced strength is the problem. I have BOSE in my car (2005 Cadiallac, Not Centerpoint but I have dealt with all the flavors of BOSE) and even with the proper integration harness that has adjustable gain I still think it could perform better. Im my experience I have found once you mess with the factory input signal its usually some sort of compromise in sound


True it has no adjustable gain, but the aftermarket amps do. So Im not sure how that hurts anything. Any signal I use as a source will eventually pass through an amp with gain control.
The aftermarket amps do have gain adjustment, but if you are introducing issues into the signal chain ahead of them either it be noise or something else, eventually you will hear that on the other end.


Why is it not a good idea? The various signals are going to different amps and different speakers.
Level balancing can become an issue and it tends to permeate throughout equipment. One affects the other and even for simplicity sake I would go post BOSE amp


Ive thought about that, and its still a potential solution, but its an added expense and complexity at this point. If this current idea fails to yield the desired results I will most likely use some sort of DSP
The cost of something like a Mini-DSP (https://www.minidsp.com/products/minidsp-in-a-box/c-dsp-6x8) will be outweighed by the benefits. Heck you might be able to find a good used JBL MS-8 on Ebay which is another great choice. These devices will give you not only tuning capability, but clean signal from your factory equipment.



From my understanding and from what I can tell both audibly and though my measurement mic, the Bose Center channel processing is a bit more complex than just a summed mono output.

But it is another easier solution to get a functional center channel in the car.
The DSP solution solves this too. Unless you play something with a 5.1 its just another BOSE effect considering all your sources that the factory head unit can play are probably stereo.


With the high level of Bose integration from the factory, replacing the HU with something after market has some distinct disadvantages. Re-integrating the backup camera, losing the stock USB/AUX inputs, steering wheel controls, internal light timers ect.


Harness: (Keeps BOSE and Steering wheel control, also easy to bypass BOSE with a cheaper harness): http://www.pac-audio.com/productDetails.aspx?ProductId=1142&CategoryID=26
Keeping Camera(Need 3 pieces): Harness: http://www.metraonline.com/part/AX-MAZCAM
Voltage Adapter: http://www.metraonline.com/part/AX-CAM6V
Keeping USB: http://www.metraonline.com/part/AX-MAZUSB

They make a kit and antenna adapter. You would have to run your own mic(its easy). AUX usually you have to hardware although there may be a harness for it. Internal light timers now thats an amusing one that I am surprised you cannot program some other way in the car.

The big decision would be keeping the factory head unit or not. Either way when dealing with an upgrade to factory premium sound I would ALWAYS suggest some form of DSP. They take all the guesswork out and do exactly what you need to do. To truly have an upgrade from factory I would suggest either:

BOSE headunit > BOSE Amp > DSP > Amps > Speakers

or

Aftermarket Headunit > DSP > Amps > Speakers.

There are even now amps out that have DSP built into them too.

 

[silvercoat]

Sorry for the long replies btw. The only reason I do is because these are the thoughts that I have been racking my brain over for like 2 years now because a CX-5 is my next vehicle.....

 

[twiztedlemon]

Get a sound processor. It strips output from headunit. Rebuilds the signal how you want it. It's amazing. I got a Rockford fosgate 3sixty.2.... But I'd suggest the newer model but know they are quite pricey

 

[twiztedlemon]

With it I have kept all functionality, steering and command console usage, and Bluetooth/alarms (blindspot ect) while adding my 2 subwoofers/1000 watt and 600watt amp, and replaced all interior speakers