Summiz

Hello, I have read many posts and cannot get this answer. I have a 2003 z06, and know very little about audio. So I have just put in a Pioneer AVH 490x and a set of 6.5 Precision power component woofers and tweeters to replace the front door speakers. My only interest is to replace the twiddler. The factory amps and wiring are fine. I wired them to the existing pos and neg terminals after confirming that the factory crossover would ensure the new tweeter wouldnt take the full range and become blown. I wouldve wired in the crossover that came with the new speakers but I cant find how. They have 6 total slots: 2 "in", 2 "TW out" and 2 "WF out". The answer I get is "inputs from the head unit or amp go "in". I have NO idea what these two wires are. Are the new tweeters ok using the factory crossover? Will the speakers sound much better using the PP crossover? Any assistance is greatly appreciated.

knewblewkorvette

Okay.
I take it you used a interface of some sorts between the Pioneer radio and the Bose speakers (the factory 8" in the doors has it's own amplifier). While I'm sure the 3.5" twiddler has a frequency crossover I'm sure it's lower than the tweeter alone can handle. You can use the supplied crossover to help the tweeter by taking the leads to the twiddler and putting them onto the "in" on the crossover. Then wire the tweeter to the "TW" out. But, I would NOT do this. I would NOT use the speakers you purchased at all. Instead, buy a set of aftermarket 3.5" speakers. JBL speakers seem to be popular on the forum. No crossover needed. I say a 3.5" over just a tweeter is that 3.5" also provides the mid-range as well as the highs. The tweeter pretty much only provides the highs.
Another option is to yank the 8" and the 3.5" twiddler and install both the 6.5" woofer and tweeter in the door. Then I would run the speaker leads from the new Pioneer to that crossover. This would be a little more involved but would probably result in better sound.

Summiz

Thanks for your reply! I used a ROEM Vet1 harness adapter to install the head unit but the rest of the harness is factory. I think based on your info, I will just get some aftermarket 3.5s. What specs am I looking for? 2-way coaxial? I want to make sure I get the right one

GCG

You received very good advice from @knewblewkorvette . It's right on the money!

​​​​​​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.

The C5 OEM speakers do not include any real tweeter. Bose used 4 plain-cone (paper) speakers to handle high and mid frequencies and called them "twiddlers". That's why you can make a big improvement by replacing them with a 2-way coaxial design.

OEM C5 Speaker Sizes:

-Front
Twiddler: 3.5"
Subwoofer: 8"

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


For bolt-on speaker upgrades, 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.

The JBL GX Series is an excellent replacement and they are very efficient. These speakers have a soft dome tweeter, which should deliver a smooth sound with a wide dispersion pattern. Add to that the Harman-Proprietary Tweeter Deflector, that according to JBL "acts as a waveguide, allowing for an angled, rotating speaker, which optimizes the off-axis sound performance. Because all cars are designed differently, this allows impeccable sound to travel throughout all locations in the cabin".

JBL GX Series 2-way car speakers:

• GX302 (3½")
• GX502 (5¼")
• GX602 (6½")

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.

You are going to need as well. One kit will do both rears.


Independent confirmation that upgrading the 4 twiddlers makes a noticeable and worthwhile upgrade.

As for installation tips, 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.
​

GCG

In case you are wondering...

The reason I rather not touch the OEM subwoofers 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 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 

Summiz

Thank you for the all the great info! I will get the JBLs and I have those adapters

GCG

Glad to be of service!

Let us know what you think when you're done.

Hitman227

Interesting combinations, for sure. I was going to go full 5 channel aftermarket amp, powering 4 coaxials, with a 10" sub in the trunk, but never got around to it..

Sounds like you are on track with what you want to do with the factory system!

dskinsler83

I did the small Sound Ordinance 4 channel amp (75w per channel) and the Sound Ordinance under seat 8” powered sub with remote and by passed all the aftermarket harness part for sounds. Used JBL speakers and aftermarket plates. Tweeters are mounted in the dash pad and the crossover mounted where the upper speaker would go on the aftermarket door plate with the component woofer in the lower part. Replaced the rears with same line from JBL as fronts. Wave breakers behind the door and rear mount with sound deadening through the car. Very nice little system for very little money. If I had to do again I would change the speakers to the Focal line.

RichyB33

I opted to take all of the factory crap out. Bose is history. Good Riddance. I picked up an aftermarket 4-channel amp and new front and rear coaxials. I massaged 6 1/2" speakers into the front and back and now everything sounds waaaay better than stock did. I also have a sub amp and sub to mount on the truck eventually, but I'm undecided on how I want to design my box.

Summiz

i value clear sound over any kind of raw power, so I think the greater quality woofer and coaxial 3.5s and rear 5.25s will suit me well.

Summiz

I thought about mounting some pillar tweeters, howd you mount them?

dskinsler83

measured to have equal holes where they could be placed without running into things underneath. My car has the HUD but there is the passenger side air ducting to worry about there so it wont be “perfectly” symmetrical but will be close. Used a hole saw and then enlarged with a dremel as needed for a tight fit.

knewblewkorvette

Pictures please

dskinsler83

Summiz

I finally got those JBL 3.5 coaxials put in the doors today. It sounds so much better and well worth it! Thanks again for the tips!

GCG

I'm glad you liked the results!

Harleyyac

Hi,
Thanks for the info. I pretty much did what you spoke about here. I replaced the Twiddlers with JBL GX328 ( same as 302) and the 6 inch in the rear. It sounded much better than the stock. I found that the front stock "twiddlers" Positive connection fell off of both front speakers. I reconnected but they were not tight at all. Now to my point.
I have a Pioneer Head unit (AVH 2550 NEX) and the PAC ROEM Vette interface. Since I am basically using the BOSE amps and wiring, is the built-in "Crossover menu" on the Pioneer HU workable or should I just turn it off? I think that for the front the Bose is doing the processing and as for the rear, I'm not sure.
Thx

GCG

I answered a question similar to yours in another thread. Click here for details

Harleyyac

Hi,
Thanks! I ordered the filters (300 ) for the front. I'll play with the crossover software for the rear. This should do the trick . (I am editing this reply, Justin from PAC confirms what was stated. ) Thanks again. I now have a degree in Crossovers LOL
Thx All!!
Lee