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For anyone wondering, the jbl gx502 5 1/4 inch speakers DID NOT fit in the back of my 03 z06 or i should say did not fit well. The driver side went in ok, the passenger side the speaker magnet sticks out just a tad too far and the corner of it pushes hard against the curve of the body behind the speaker hole. You can still screw it down however it does not sit even on the speaker hole and the hole is a bit exposed on the left side (toward front of the car) due to the magnet pushing against the body and not allowing you to line the speaker up properly. I would imagine since the corner of the speaker magnet is pushing so hard against the body and it seems the body is some sort of composite plastic or such behind the speaker it will eventually cause it to crack. I did get a chance to listen to them though and they do sound much better then the stock speakers.
With the stock speakers i had to turn the treble way up to get some highs and even then it wasn't as clear and crisp as these with the treble on normal now.
I did some research and it seems the club series speakers (which are just updated versions of the gx series) mentioned earlier in this post have a shorter mounting depth and should give enough clearance (i hope) so im waiting on those to arrive now, while the back of my z06 is left apart so i don't have to take it all apart again. I will update once i get the new speakers.
I found this to be the case for my Z06 as well. The JBl Club speakers are a HUGE improvement over the Bose shitbox speakers.
Just a reminder: See posts 77, 79, 89 & 91. If you are using a separate amp that's rated for 2 ohm loads the JBLs are great but they are 2.3 ohms and most replacement head units are only rated for 4 to 8 ohm loads. I installed a Pio DD head unit and Pio front and rear speakers. The Pio speakers sound very nice and they're inexpensive. This all-Pio system in the vette sounds better than the "premium" factory HK system in my Subaru. YMMV but the point is, don't use 2 ohm speakers with a 4 ohm receiver.
And FWIW, again see post 77 but I do not believe the original Bose twiddlers are 2 ohm. I think they are 4 ohm.
You can easily put any 6x9s of your choice in the doors.
All you have to do is gut the covers and use that to space out the speaker to clear the window track.
The door panel fits no problem.
I currently have the Hertz premium high energy 260 watt continuous rms HCX speakers powered by an old school made in USA Rockford Punch 500a2
I also upgraded the rear speakers and powered them and the sub with a Punch 600a4
Last edited by StrangelovesM6Vert; Nov 8, 2019 at 04:32 PM.
i just upgraded my speakers, sounds good . heres what i had done so far ,
Pioneer AVIC-7200 NEX with nav and back up camera
Pac audio ROEM-VET1 adapter
TS-WH500A powered sub
had this set up for a few years just added
GX 302
GX 602 JBL speakers
every upgrade made a difference for the better, happy with everything i have done.
Last edited by jrbartholomew; Jan 2, 2020 at 03:13 PM.
I'm about to change my factory speakers in my 97 C5 coupe and I see people saying they used 5.25" for the rear and others use 6.5" Since I have not taken it apart yet I hope someone here can clear this up.
I'm about to change my factory speakers in my 97 C5 coupe and I see people saying they used 5.25" for the rear and others use 6.5" Since I have not taken it apart yet I hope someone here can clear this up.
as well. One kit will do both rears. It is very important to make sure the new speakers are in phase with each other, and more importantly, in phase with the door subwoofers. Otherwise, you might experience sound cancellation, resulting in tinny sound and lack of presence.
Using the above mentioned adapter harness to install new rear speakers should take care of this for you, however, the factory connectors for the "front" OEM Bose 3½" twiddlers are "spade" ones and they do follow Bose's standard, which is the opposite of what aftermarket manufacturers use.
To properly connect your new front speakers, you will need to cut the factory spade connectors and crimp new ones following the "normal" standard (reversed in relation to Bose), or create your own adapter harnesses if you don't want to cut and crimp the front OEM wires
Take a look at this Post for more details and tips on how to proceed.
I'm about to change my factory speakers in my 97 C5 coupe and I see people saying they used 5.25" for the rear and others use 6.5" Since I have not taken it apart yet I hope someone here can clear this up.
Z06’s use the 5 1/4, and coupes use the 6 1/2 speakers. It’s because the FRC doesn’t have much room for a larger speaker at all, especially in terms of depth and you must be mindful when ordering speakers for that location.
Thanks for clearing that up. From what I can tell most people just change the 3.5 in the door and not the 8" sub right?
That's correct. Those are subwoofers with dedicated amps mounted right besides them.
It is my understanding that their impedance is just 1 or 2 ohms. That is not common, and if you replace them with 4 ohms units, right there you will be effectively limiting the power output of the subwoofer amps to just 1/4 to 1/2 of their current output with the OEM subwoofers.
On the other hand, there is the issue of physical limitations. These are reverse cone subwoofers mounted in a very tight assembly. Finding an 8-inch aftermarket subwoofer with an impedance of 1 or 2 ohms that also conforms to the physical limitations of the OEM mounting is going to be a challenge 
A bunch of us have used the JBL GX302 for replacing the front 3.5” speaker because it is ~2 ohms. They were a pretty significant improvement over the Bose paper speaker.
Just got the JBL GX302 and GX602 and installed them. They work great and the installed. Even took the opportunity to repaint all the grills, silicone the Bose logos down and even add a little dynamat behind the speakers. Came out great and sounds much better! Thanks for your help!
For me my stock Bose is working just fine and I kind of like the OEM look. The JBL speakers are a stop-gap for a bit of improvement until I decide I need to gut and redo the whole system. And that doesn't even make my top 10 of my C5 wish list.
For anyone wondering, the jbl gx502 5 1/4 inch speakers DID NOT fit in the back of my 03 z06 or i should say did not fit well. The driver side went in ok, the passenger side the speaker magnet sticks out just a tad too far and the corner of it pushes hard against the curve of the body behind the speaker hole. You can still screw it down however it does not sit even on the speaker hole and the hole is a bit exposed on the left side (toward front of the car) due to the magnet pushing against the body and not allowing you to line the speaker up properly. I would imagine since the corner of the speaker magnet is pushing so hard against the body and it seems the body is some sort of composite plastic or such behind the speaker it will eventually cause it to crack. I did get a chance to listen to them though and they do sound much better then the stock speakers.
With the stock speakers i had to turn the treble way up to get some highs and even then it wasn't as clear and crisp as these with the treble on normal now.
I did some research and it seems the club series speakers (which are just updated versions of the gx series) mentioned earlier in this post have a shorter mounting depth and should give enough clearance (i hope) so im waiting on those to arrive now, while the back of my z06 is left apart so i don't have to take it all apart again. I will update once i get the new speakers.
Update: The club 5020 speakers fit perfect and gave the extra bit of clearance needed. I could already see rub marks where the gx502s were digging into the body when i removed them on both sides.
How do you like the sound of the Club 5020 as compared wit GX502 or stock speaker? I'm thinking to replace mine (04Z06) and if GX does not fit well, I might as well go for Club series for both front and rear if they sound better than Bose stock speakers.
