2016.5 CX-5 Sound upgrade: Speakers, dash/front door balance, bluetooth

Thanks for reading--this is my first post, and yes, I have searched and read numerous threads. I need clarification (and this might help others as well).

Short version:

Goal: moderately better sound and less glitchy bluetooth for 2016.5 CX-5 sport with stock 4 speaker stereo
Willing to do: upgrade speakers, minor rewiring of head unit/speakers, update bluetooth settings
Not willing to do: add amp, change head unit, anything that requires major labor or risks bricking the factory infotainment system

Proposed minimum plan: a) buy a set of front door speakers/adapters/harness etc from Crutchfield based on "2017 CX-5 4-speaker" as input with the "no aftermarket amp" option (e.g. Kicker 46CSC674, Rockford Fosgate R1675X2 as cheap options), b) don't buy dash speakers c) don't use rear speakers d) update the firmware somehow

Is this reasonable, or is there a better option? I will be doing all work myself, except possibly the firmware update.

Long version:

I have a CX-5 Sport (2016.5 FWD 4dr Auto Sport, CX5RSP2A) purchased used. 4 speaker factory stereo/head unit (confirmed that no sound comes from the dash grills). No Nav. An aftermarket alarm was installed by the dealer before I bought the car. OS version is 55.00.753 NA N (Failsafe version 55.00.753).

The stereo sounds muddy, bass is loud enough but muddy and like an on/off function. Also, the bluetooth doesn't connect rapidly and sometimes drops. The minimum upgrade seems to be:
1. Buy a pair of 6.5-6.75" high-efficiency speakers for the front doors
2. Update the OS/firmware
3. possibly add a pair of 3" or 3.5" speakers for the L and R dash positions
4. Don't touch the rear speakers and don't use them

So, the questions:
1. Could the presence of the aftermarket alarm interfere with how the factory electronics work? I only ask this because the alarm definitely changes how the power/locks/ignition work vs factory settings, and it seems glitchy. I hate that dealers go in and stick their half-assed alarms into a carefully engineered electrical system.

2. Some posts on this forum report better bluetooth function after updating firmware. Is there any reason NOT to update the firmware, what are the risks of doing it myself, and is there any reason NOT to have it done at the dealer assuming I am willing to pay? Will updating the firmware affect sound quality or sound settings in any way?

3. I get different speaker/fit recommendations at Crutchfield.com when I use 2016 CX-5 vs 2017 CX-5 as my input vehicle. Which should I use?

4. If I install dash speakers (where there are none currently), how will I adjust the fade from front/rear/dash? From some posts I have read, it sounds as if the dash and front are wired together and you can't adjust them relative to each other by default. How about disconnecting the rear speakers from the head unit, then connecting things so that the "front/rear" fade actually controls "dash/front" instead? Are "front" and "rear" functionally equivalent at the head unit? (the stock rear speakers seem much quieter than the front speakers, and I wonder if there is a difference in power available to the front/rear).

5. More dash speakers: people seem to have added Polk audio or Infinity 3.5" speakers here, but Crutchfield says "they don't fit" and in fact the people who have posted their installs report that you have to cut or squeeze to get it to work, and seem to require soldering. If I want to add dash speakers, can someone recommend one that is actually a simple drop-in/plug-in fit? Recall there are no speakers in the dash now--will I need to run wires or are the wires there already?

6. Related to the fade question: How about an alternate configuration in which I add dash speakers, disconnect the front door speakers, and then add new upgraded speakers in the REAR doors? Then the fade would control dash/rear (F = dash, R = rear door, but obviously this could be swapped if there is a reason to), and I would get more of a surround sound feeling vs having the front door speakers.

If you're still reading, thanks for sticking with this and I appreciate any help you can give. Lots of details I know, but details matter, unfortunately.
 
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Pueblo county CO
:
CX-5 Sport 16.5 6M
Dash speakers make a huge difference in midrange and highs. Even the stock oem are better than none and they would be cake to install. The size might be 3.25" vs the common 3.5" size but close enough.

After adding dash speakers I've decided the rest of them are good enough. It is a lot more work to retrofit door speakers.

16.5 model year is part of the Gen1 group, not the current Gen2.
 
Dash speakers make a huge difference in midrange and highs. Even the stock oem are better than none and they would be cake to install. The size might be 3.25" vs the common 3.5" size but close enough.

After adding dash speakers I've decided the rest of them are good enough. It is a lot more work to retrofit door speakers.

16.5 model year is part of the Gen1 group, not the current Gen2.
Thanks for the info. Yes, I just realized that 16.5 should match Crutcfield's 2016 fitments. Can you confirm: on your 2016.5 Sport, you started with the OEM 4 speaker setup, you added mid/high speakers to the dash, and you think it is better now? What speakers did you add, were the wires already in place, and how do you handle the fade between the dash/front-door/rear-door? Thanks.
 
:
Pueblo county CO
:
CX-5 Sport 16.5 6M
Yes, I added some Metra 3.5" and they were a bit tight but ok and completely changed the overall sound. I scrounged some computer power connectors and soldered those to the speakers so I could use the factory plugs.

There are some threads on this forum with info on the 3.5 Polk drivers from Crutchfield.

I think replacing the door speakers might involve some customization as the size is not common.
I did remove the door panels to add Dynamat. It was worth the effort to help reduce resonance in the doors.
 
Sound dampening the doors will help to reduce a lot of muddiness. Here is a link to my thread (also a work in progress thread) with some details in the sound quality after sound dampening just my front doors. I don't know how the 2016.5 OEM system sounds, but can vouch for sound dampening to improve audio quality. I've done it in all of my custom installs. Sound dampening in tandem with a DSP (I understand you're not trying to do this) will suffice most people's audio quality needs.

If wanting to replace the factory 4 speakers, you will be limited heavily to speaker choices, as the power that's provided to them are very low. You're going to want to install high sensitivity and low powered speakers, roughly in the 25W RMS range. This will lead you to speakers in the efficient category with paper cones (same types of speakers in most OEM factory speakers, including the "upgraded" Bose system).

@Mazdiod2 's suggestion is sound advice as well. I would imagine that having no tweeters or dedicated speakers for mid-high range would really hurt sound quality. Honestly, I can't imagine enjoying any music without dedicated mid-high range speakers in general.

Moderately Better Sound is a bit difficult for me to determine in your scenario, as dampening my doors did MUCH more than moderately improve the Bose system in my CX-5. However, the Bose system does have a center channel and tweeters, to which the clarity improved after dampening my doors.