Kevin Catalano

During a recent system planning session, a customer brought me an Alpine CDA-7998R. The system will consist of three amps, running subs, midbass, and mids which passively cross-over to the tweeters.
Problem is, this head-unit's on-board high-pass (in 3 way mode) has 1kHz as the lowest point. Even with a 6db slope, it's far too high for the mids I'm using. Puts a big hole in the wrong place.
Does anybody know of a programming mod to alter the crossover point?
[img]graemlins/dunno.gif[/img]

SweetnLow91SC

If you could get full-range signal out of the high pass..... just use an outboard x-over or an amplifier with a build in one to go to a lower x-over point.

Chadxton

iTrader: (1)

Why you live in HK? You sell to me lah? kekeke

Kevin Catalano

The beauty of this deck is that it has the bass engine pro, which gives you six discrete channels of time-alignment, plus 24db/oct filter slopes (selectable from 6db/oct-24db/oct) and 5 bands of parametric eq. When it's configured for a 3-way crossover, the high-pass section will go no lower than 1kHz. If I configure it F/R/S, then I lose the band-pass on the mid-bass channel. I'd have to use two outboard crossovers to be able to retain the time-alignment; one to give me the high-cut on the mid-bass channel, one to provide the low-cut on the mid-tweeter channel. I'm trying desperately to keep the component count to a minimum. The vehicle is already wired (and very nicely) for six channels from the head-unit.

My only option is to cross it over at 6db, which would put me -6db at 500 Hz, which isn't too terrible, but then I have to drop the level the mid-bass channel to get things to line up acceptably well.

At least with the pxih990, you could configure the system through the menu, to provide the necessary channels, even though you might have to combine fronts and rears to get things right.
(did that in a Bentley Arnage T with new F-1 and Steg MasterStroke amps. Very sweet!)

A bit of digression that you might appreciate, Joe, is a system in a new mini cooper (Demo car for Focal in China) that's using a Chord DAC. Talk about over-the-top! They need some help with alternator whine. That sounds like not much fun at all. I've seen the car while it was being built. SCARY.

No need to kill for that head unit, Dave. Let me know if you want one. I'm sure they're still available here.
Thanks for your suggestions.

Kevin Catalano

I'll PM you tomorrow, Dave. I've got to go to China tomorrow, so I can find out soon enough.

P.S. Where do you get those inspirational, upbeat quotes?

SweetnLow91SC

What are the Steg MasterStroke amps? I have never heard of them.. are they Vacuum Tube, hybrids or transistors?

I guess there ARE serious audiophile in Hong Kong too then! So.. they actually put the Chord DAC in the Focal demo car....... Wow. I definately like to hear it! I guess the Mini must have the Focal Be in it too... Do you have any pics? [img]smile.gif[/img]

I could try to help out troubleshooting the noise problem if they need it. Just give me some detail on the system wiring..... email me the details to: advanced@smartt.com

[ September 03, 2005, 12:14 PM: Message edited by: SweetnLow91SC ]

Kevin Catalano

Well, I finally decided to run F/R/S on the head-unit, with an Audio Control 24XS taking the top off the rear (assigned to mid-bass) channel. The front (mid-high) and sub will operate directly off the HU's internal crossover. All the delay adjustments still work as the factory intended, and the 24XS allows me to keep nice, steep filters throughout the system.
Thanks one and all for your suggestions.

Dave, I'm more than just a little hesitant to modify a new deck, which is now rather scarce in this part of the world. Bad enough to void the customer's warranty, worse yet to render the nearly irreplaceable unit unusable. You know how it goes; no matter how carefully you proceed, the closer you are to the deadline, the greater the potential for disaster!