JMII

This is the KEY to fixing the Bose system.

My plan is to replace the laughable so-called subwoofer and leave the other speakers. With proper crossovers, decent amplifier power and a DSP doing EQ / TA adjustments I think the front woofers, mids and tweeters will be good enough. What I've yet to confirm is just which speakers are directly wired to the amp as dedicated channels. The following schematic show the (dash?) tweeters are wired together with the door woofers (why?), while door mids are separate. If this is the case then I'll likely run my own wires to the dash speakers (way easier then the doors) to feed them directly with a true 3-way front stage setup. This requires a 6 channel amp plus a dedicated mono sub amp. I'll leave the rear speakers and center channel disconnected.




As you can see here the subwoofer is a dual voice coil configuration.

DWillys

The reason the door woofers and the dash tweeters are on the same circuit is they only work for the frequencies they're designed for. EG: the woofer acts like a wall to the tweeter frequencies. Physically they're both seeing the signal, but electronically they only reproduce sound in the frequency range they're designed for. It isn't optimum, but GM saves a few cents by eliminating a few wires.

Replacing/adding a subwoofer is probably the most common improvement for the C7's sound system. You can still run the OEM Bose setup yet get better bass, though nothing like you would have with a full system upgrade.

ersatz928

The two speakers wired together is "normal", one is a woofer, the other is a tweeter, which has a crossover capacitor (not shown in the wiring diagram, but the cap is part of the tweeter), which blocks the lower frequencies. The woofer has its own inherent crossover, as its higher mass speaker cone can't respond well to the higher frequencies that the tweeter is reproducing. All the other speakers have an active crossover/filter in the amplifier, which only feeds it the audio frequencies that each speaker can optimally reproduce.

DWillys

The Crazy Cowboy kit (IIRC) doesn't have the sound blocking layer. Instead he uses a foam layer with thermally reflective surfaces. It won't give the sound reduction one would get with the sound barrier. It (the foam) layer is good for heat reduction and the foam does give some (small) noise reduction, maybe a 1 or 2 out of 10, where the sound barrier is a 7 or 8.

Going the full sound reduction route is a major undertaking. I did my C7. What did I remove? The seats and all finish plastic and carpets from the dash back, including the center console. My wife thought I was crazy. I found it pretty straight forward, but I will admit there were a couple times I thought to myself "what the heck are you doing?".

I tried playing my OEM system louder, but I don't get enjoyment when 2 sound sources are trying their best to drown the other out. Adjusting the response with the stock controls didn't help. Then again my wants/goals/preferences for my C7 are different than yours. Each one of us buys a C7 for similar reasons, but not the exact same reasons. That's why some are totally happy with the OEM Bose, and some spend thousands doing a complete revamp.

JMII

So they are using the woofer's natural roll off just because it saves them a few pennies on wires and a proper crossover? WOW so sad. The woofer like suffers break up as it attempts to reach those higher frequencies. This is just POOR system design, but at least they capped the tweeter, well they had no choice as it would likely blow if they didn't.

Overall this doesn't make sense given they have a digital amp here with discrete channels and thus should run a fully active system with digital filters or crossovers programmed for optimal frequencies. To me this is just another reason to get rid of that stupid Bose amp and run your own crossovers. You could likely sharpen up the the midbass punch with a steep bandpass slope on the woofer. I bet its attempting to go too low as well as too high in the stock configuration.

DWillys

Every system in nearly every vehicle is a compromise between functionality and cost. If those compromises weren't done your Corvette would be a better vehicle and you likely wouldn't be able to afford it.

JMII

I get it... but this goes further to prove the premium for Bose is WAY over rated. The system is poorly designed and subpar in many regards. Yet many people love it so clearly they aren't going to spend a nickle more on making it better. Its been said before: Bose is a marketing company that happens to make audio gear. I bet any number of generic drivers from Parts Express would perform as good or better then what Bose put into the C7.

The Chev

I agree with this statement wholly. I cannot figure out though why Chevrolet would have integrated so much into the radio. Why did they not give us an option to scrap the whole system and install an aftermarket radio that would have significantly more features as well as give the option for better sound?

DWillys

agreed.

DWillys

I'm just guessing, but I suppose they integrate things to save costs and to give the owner a better interface. You can control your music on the center display. It also is the best place for nav. It is also a good place for various settings, phone, etc. These settings are integrated, EG your seat belt is unfastened or your door isn't fully closed so sounds need to be played through the speakers, etc, etc, etc. It just doesn't make sense to have multiple systems when they can be integrated. Unfortunately the integration makes it difficult to fully remove something like the radio. We do have the ability to dump the Bose, it is complicated and expensive to do so though.

JerryU

Good to know the correct materials! Looks like the same extensive effort too put on whatever two layers.

Understand why you did it and if my hearing at 76 was better might give it a shot but creating music noise to cancel the road/tire noise works for me! In fact, I don't even notice the external noise BUT then again I can completely block the Tinius as well! (unless I think about it like now but in a few minutes it's lost!) That million miles certificate in two airlines took it's toll! At least I'm a Lifetime Gold member with American!

DWillys

Something I forgot to mention - The sound blocking layer is thick, at least a quarter inch and if you're using MLV it isn't as flexible as one would like. That complicates installing it and is probably one reason Crazy Cowboy uses something else. I ended up using the foil based product just so I wouldn't have to deal with MLV's stiffness, though it was more expensive.

JMII

Its not just Chevy - everyone is doing it this way now. Telsa has gone so far as to put control of the A/C vents into a huge iPad on the dash! Gone are the days of single or double DINs standalone radios. Even further in the mirror are the days when you had a radio delete option.

The integration gains you some nice features (navigation, exhaust mode settings, Bluetooth, etc) but requires you to purchase a $400 interface module just to extract a clean, non processed, two channel stereo signal. They could have just put regular RCA jacks on the amp but nooooo... that would be too easy.