Spkrboy

The idea here is to create a front 2-way component set in the factory locations with passive crossovers using high-quality drivers at reasonable cost. This is the first of several posts documenting the process as best I can over the next week. The target here is to create the best-sounding front stage possible without having to fabricate a-pillar pods or anything else exotic. I’m also not a believer in the golden-sledgehammer approach. While the drivers I chose are certainly not the absolute best available, they certainly are the best anywhere near their prices, and well beyond. The result should far exceed the performance of anything you can buy in a box since this will be
specifically designed for the C6.

TheKomoman and I have been planning something like this for about a year or so, but time has been at a premium and the process I use requires I have access to the car for some time to do in-car measurements. While he’s on a business trip to Europe for 2 ½ weeks, the opportunity is now upon us. The Seas CA18RNX and Vifa D26NC55 are our choices. The Vifa is pretty much the best neo tweeter available, and that includes the two Seas models we see mentioned here often. It will respond well to a passive crossover as low as 2 kHz. The Seas woofer is a robust bass-midrange that has a smooth response through the crossover region and provides a large window of overlap to the Vifa tweeter so that we might optimize the crossover for slightly off-axis response in the confines of the C6.

The next steps involve installing the drivers in the car with some sort of an angle-mount for each so as to keep them as close to 0 degrees as possible, then getting measurements of the first arrivals in order to window the crossover region.

The car:



The existing Focal K2 Power installation:








The tweeter compared to a Focal TN46. Note the heat sink (a nice touch) on the Vifa:




Focal vs. Vifa response plots (it's clear the Vifa is a far better model than the Focal):




The woofer compared to a Focal K2 165 woofer (the Focal is no slouch in its own right, but the Seas is a monster by comparison):







The Seas 180 Response Plot (compare the smooth Seas response to the nastiness in the red woofer trace above 2 kHz in the Focal 165 plot in the first plot near the start of this post):


Any commentary or questions? Part II in a day or two.

scott_fx

i dont think i've ever been more excited about a post on this forum. i can't wait to read about your finding's in the c6. What are you planning on adding into your x-overs (i.e. notch or zobel filters)? Do you plan on running the seas with just a high pass or bandpass?

also, is the vifa the new Chinese made tweeter or is it the old one?

0TheRadioFlyer97

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fej

Nice Spkr, it is about time you get a little "involved" in a car install

I am guessing that tweet is going in the factory 3.5" location in the upper door? Remember to take some pics as there are a lot of C6 installs hitting the forums lately and I am sure this will be a good model to work from.

Fej

Spkrboy

I'm glad someone other than Komo is excited over this.

I'm using the latest Chinese-built version of the Vifa. It doesn't appear to have suffered through the transition. It's an amazing tweeter for the money. I chose these drivers specifically to minimize the size of the passive crossovers and use the lowest number of components as possible. The Seas will work quite well without a Zobel, and neither driver has a response problem that will necessitate a notch filter. The Seas will only see a low-pass filter. I'm aiming for an LR4 response at around 2-2.5 kHz using (hopefully) 5-7 components per channel.

Yes, Jeff, both factory locations as in the picture of the installed Focals.

pentavolvo

I cant wait to see this

leolufse

I'd rather hear it, but excited nonetheless.

Spkrboy

OK, I managed to get the new tweeter mounts done today. I used the original plates from the focal install as a backer. In the C6, the tweeter sits far back from the inside of the grille. I changed this by moving the tweeter further out and I introduced the largest angle I could. A simple piece of 2" PVC angled, epoxied to the phenolic backer and notched to fit around the square magnet base of the tweeter. I also used a trimming bit in a router table to trim back the tweeter's mounting flange to the edges of the PVC. Painted the whole thing flat black. It's not pretty, but it's effective and no one will ever see it.

pentavolvo

i like the tweeter mounts

Gideon's_Test

Spkrboy: As you know (from my active X-over thread) I am looking at the Seas tweeter. Do you think that the Vifa D26NC55 will work well for my application if I give up trying to install it on the A pillar? I've looked for some info regarding it, but haven't found much. It seems that the off-axis performance must be better if you have chosen to put it in, essentially, the stock location (obviously with your custom positioning). You mentioned that it will go down to 2KHz with a passive crossover. How is the usable frequency response in an active set-up? I will follow this thread as I am interested as to how this turns out. Thanks for all of your help and patience with a beginner....,

Spkrboy

I'm happy to see you guys are interested to see where this heads. There are some things I'm not sure how I'll accomplish yet, so it should be at least entertaining.

The Vifa is a slightly better tweeter than the Seas 27. It will work just fine in an active setup, but the problem you'll have is making it fit. If you're not going to the lengths I am to get these in the best positions possible, you're better off with the Seas 27 because it will be much simpler to install. The square extended flange on the Vifa can get in the way compared to the Seas 27, and unless you really work at the positioning, you won't realize the benefits of the Vifa.

BaBa Booey

Vifa, Seas, Zobel, LR4 response, high pass...I don't know what the hell you guys are talking about. All I know is the blose sounds like crap and I want to change it.
I hope you have lots of pics and descriptions. That way maybe I can try it...monkey see, monkey do style.

CraigE

Hey this is great....I hope you will be doing a 3 way comp project as the sequel.
Thanks for taking the time for the project,documenting, posts and commentary.

0TheRadioFlyer97

is this a 3-way setup?

where will the tweeter be mounted? Stock location?

Spkrboy

A 2-way with the woofer in the lower spaces and the tweeters in the upper 3.5 factory spaces.

CraigE

I looked these speakers up on Madisound
Seas Ca 18 RNX........$75.05 ea.
Vifa D26NC55..........$28.90 ea.
WOAH!... we're talking $208 for speakers that will probably outperform 2 way comp sets costing several times more. I can't imagine it will be that expensive to build the Xovers.
Did I make a mistake or am I missing something here ?

Spkrboy

Nope. You're not missing anything. The crossovers won't be too much money. Even as cheap as the raw drivers are, there are very very few car speakers that can even come close to this performance. This is proof there's no reason whatsoever to spend a ton of money on speakers.

Check out Part IV for more proof.