gpruitt54

I recently upgraded the head unit in my 99 C5 baby. The head unit (Kenwood DDX9903s) has amazingly improved the sound of the stock speakers. I won't be spending any more money on the car aside from a Performance tune this spring.

But, I am wondering if anyone has replaced the stock tweeters (only) with a better ones. I think the highs are not as bright as I would like. Again, I am not buying amps or complete speaker systems anytime soon. Just wondering if the tweeters can up swapped out for something else.

GCG

Without a doubt, the easiest and least expensive way to upgrade the system with the more bang for your buck is new speakers that can be bolted on in place of the factory ones, keeping the rest of the system intact.

OEM C5 Speaker Sizes:

-Front
Twiddler: 3.5"
Subwoofer: 8"

-Rear Twiddler
Coupe: 6.5"
FRC/Z06/Convertible: 5.25"


Get 3.5" 2-way coaxial speakers to replace the doors' twiddlers and 2-way coaxials of the right size for the rear. Don't touch the OEM subwoofers.

gpruitt54

Interesting. Any idea about possible clearance issues with the front 3.5in speaker depth and/or magnet diameter?

I've seen plenty of photos of the front speaker assembly. However I have never seen photos fo the rear speaker assembly. Are the front and rear speaker assemblies the same layout?

GCG

You will need to further verify fitment, but a quick search produced this:

JL Audio Evolution™ C2 Series 2-way car speakers

• C2-350X (3-1/2")
• C2-525X (5-1/4")
• C2-650X (6-1/2")

Not only they are from the same manufacturer, but they all belong to the same line. This should reasonably assure you they have the same timbre.

gpruitt54

Sounds good. I will need to pull the stock assembly, take out the tweeters and check for fitment. At this point, I am only interested in replacing the tweeters, as the stock tweeters are very muddy.

GCG

They are not really tweeters. Bose calls their plain-cone speakers "twiddlers" because they act as "tweeter/mid range". That's why you can make a big improvement by replacing them with a 2-way coaxial design. Do not touch the 8-inch subwoofers in the doors.

gpruitt54

This is very good news.

jrprich

I changed out my Bose twiddlers and my Bose rears for Kicker front tweeters and rear coaxials.
Much improved sound over the OEMs.

Jim

gpruitt54

Nice, I guess I am on the right track with changing-out the front tweeters with 3.5in 2-way coax speakers. guess I should also look into 2-way replacements for the rears also. I have purchased 3.5 JL Audio Evolution C2 Series 2-way for the front.

gpruitt54

Why not address the OEM subwoofers? You are referring to the 8in door speakers, right?

leadfoot4

I installed a pair of Pioneer TS-A878, 2 way tweeters, a long time ago. Not a day/night difference, but an improvement....

GCG

Yes, the 8-inch door-mounted subwoofers. All other 4 speakers are Bose "twiddlers".

The reason I said don't touch them is because 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 subwoofers are mounted in an inverted position 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

Replacing the 4 twiddlers with 2-way coaxial speakers should give you a very good bang-for-your-buck, enhancing the performance of your new Kenwood DDX9903s.

Sam Handwich

I do some work for a guy in the higher-end home audio business. This is one of the reasons he HATES Bose. Says there are very few ways to upgrade the system because of their proprietary design and interface to those low ohm speakers.
Glad I saw this post so I can look into upgrading the tweedlers.

jrprich

This mod really improved the sound quality of my stock Bose head unit in my Vette.............but others may differ. I had my 99 set up this way for 8 years with no issues. I also rewired my new to me 03 in the same way.

The rear speakers on a C5 are not connected to the Bose amp, only the door speakers are.
The rears have a very low signal as they were designed to simply provide what Bose would call "proper sound placement"..........they will never have the same volume as the door speakers as they were not designed to by Bose.
When I replaced my door Bose speakers (Twiddlers) with small Kicker coaxials (keeping the BOSE amp and subs in play) I rewired the connection to the rear speakers behind the head unit to disconnect the rear channel and run all speakers (F&R) from the front speaker outputs on the head unit. I also replaced the rear Bose speakers (Twiddlers) with 5.5" Kicker coaxials.

gpruitt54

While installing the 3.5 in 2-way speakers in the front doors, I discovered that the woofer in the driver’s side door is not working at all. I made this discovery while pushing the faders to each corner. In the driver side door, only the tweeter works.

Do I need to replace the entire driver side door speaker assembly?
The driver side door tweeter works. This means that the amp is working, right?
Any suggestions on how to resolve the driver side door woofer issue?

Sam Handwich

swap door speakers side to side and see what happens

gpruitt54

Good idea. Are the assemblies left-hand and right-hand specific?

GCG

I don't believe they are side-specific.

Sam Handwich

Doubt it. Can you let us know when you figure it out?

GCG

It could be any one of these 3 possibilities: the left subwoofer is blown, the door-mounted left subwoofer amp is bad, or the Bose signal processor is faulty and is not feeding the left subwoofer amp.

To find out if it is the Bose signal processor, just swap the whole assemblies. If the problem switches sides, your signal processor is fine.

To determine if it is the subwoofer or its amp, you can swap just the subwoofers from one assembly to the other. If the problem follows the subwoofer, then the amp is fine and the culprit is the subwoofer, otherwise is the amp.

By the way, whether is the subwoofer amp or the subwoofer itself, you could get a whole assembly for around $40 or less if you look around.