OK... FINALLY! All the pieces came together this weekend and I was able to do some tuning. The Zapco DC Ref amps are amazing pieces, the power of the DSP is pretty incredible. I am running the components on the front channels (150x2) and have the subs bridged on the rear channels(500x1).

The cabin gain in the C6 is pretty brutal in the upper frequencies. I wound up using a high shelf filter @ the tweeter xover point of 2000 to knock it down -5db and I will probably knock that down another -1db after listening a bit more. The subs are crossed over at 65Hz with a 24db slope on the high pass and 12 on the low pass(Linkwitz-Riley). The Zapco also allows for delay and since the system was HEAVILY left-sided from the driver's seat I was able to balance the stage nicely using delay. The Zapco software allows you to save 7 presets and you can also save the settings to a file so you can really play around and go back & forth on the settings - tweaker's delight.

I'm sure I will play with the sub over frequency and slopes a bit more to really tune it in, but dropping the xover to 65 from the 80 that I was running on the Xtant made a dramatic difference in midbass response. The 7" Seas drivers seem to play down to that range very well. The Vifa tweets, now that they don't dominate the stage, are extremely smooth and easy on the ears while still being very detailed. With the tuning applied the components that Spkrboy put together are far more forgiving to more modern, compression-heavy mixes and sounded quite good even playing back Evanescence from an MP3 CD.

We're going to take the tweak experience using the Zapco and apply some changes to the crossover, then do some more intensive cabin tuning from there. My experience with this makes me absolutely sold on applying EQ in the cabin, it's really the only way to maximize your investment. Patrick @ Pinnacle Audio gave me a killer deal on the DC1000.4 I'm using(and yes, he's an authorized dealer!) and while they're not cheap amps, if you're looking to upgrade then I'd strongly recommend them.

I'll update again when we get around to the next step in the process but DAYUM does it sound good already!

 

Hey Dan,
Did I miss your update ?
I am interested in your tweaking and final results to conquer the cabin gain. Also how do you like the Seas Speakers
I have a friend with an 06 Vert and I was telling him about your system.
I'm sure there are other vert, as well as coupe owners, that would be interested in what you have done. Maybe a recap on your major parts and cost, with a few pix of the final install would be appreciated.
How about "C6 High-End High-Value Front Stage, Part VI, The Final Chapter"

Thanks,
Craig

 

Hey Craig,

Unfortunately the summer got away from us before we could get back together to do some additional tweaking on it. The shelf filter made a major difference and we wanted to see if we could incorporate it into the crossover. Also we were going to change the xover a tick to boost the midbass output. Despite the dusting of snow here in the Philly area today I think it won't be too long before she can come out of hibernation and we can take another shot at it.

To add insult to the injury of not getting this done, I saw the other day that the Vifa tweet is no longer available and I'm not sure what would be a viable replacement. I picked up an 08 Z06 over the winter and was looking forward to using those speakers in that too!

Dan

 

We will look forward to your final results.
In part I Speakerboy mentioned the Seas 27 as a good tweeter.
Perhaps that would be a good replacement for the Vifa.
Congratulations on the Z06, very cool

Wow, with the Z06 you have the perfect opportunity to do the sequel with a 3 way front stage.

Thanks,
Craig

 

Fortunately for Komoman, I have two extras still in their wrappers.

Otherwise there are a few new Vifa alternatives, the best of which is only $16.

 

Now that's planning ahead.

I should add that another reason that I'm so interested in this thread is to see how you guys tune to deal with the "cabin gain".
It was a beautiful So Cal weekend and I did some cruising with the top off and windows down.
I'm amazed at how much better the system sounds in open air mode.
I can easily identify the individual instruments and the bass guitar has a lot more oomph. It is just much more pleasant (easier) to listen to.
With the top on and windows up, the female voices are taxing to my ears. I have tamed the female voices considerably by moving the mids as far away as possible and padding the tweets -2db.
I've searched " cabin gain" both here, and on DIYMA, and although there were some "spirited" discussions, there were no definitive answers.
I do know that this is more of a problem in a small cabin like the Corvette.
I look forward to future posts.

 

An active crossover would cure your problems quick!

I have an Alto Mobile UCS PRO with the RM2 that I'd be willing to part with... You would have COMPLETE control over everything in your car. EVERYTHING & MORE!

OOPS, sorry, I didn't read about the passive goals....hehe

 

I love the Vifa's, but have you ever looked at the Hiquiphon tweeters?
http://www.ellisaudio.com/hiquphon.htm

 

The ones I've seen have quite good frequency response, but among the reasons these are unsuitable for this project are cost (there are better tweeters available for fractions of the price), physical size (they won't fit and can't be trimmed back), and unreasonably high harmonic distortion numbers for their price range. Most importantly, they can't be crossed over as low as the Vifa, which was one of the strengths of this project.

 

This was a great thread.... Dan, (Kokoman)how did things turn out? Is there a future replacement that will work well with the c-6 application/ custom crossover that Spkrboy made? The discontinued tweeter (vifa D26nc55). I was following this thread very closely based on what you guys found, but I want to build my own crossover using a good tweet.

 

Unfortunately this is exactly where it was last time we discussed it. Life its own darned self is in the way of moving forward on it right now. We'll post again if we make progress, sorry.

 

I just picked up a set of the Vifa D26NC-55-06 brand new on Ebay last week. Nothing on there now, but I'll keep an eye out for you.

Randy

Here you go. Hope I don't get in trouble for this. http://cgi.ebay.com/M-K-D26NC-55-06-...lenotsupported