M. Schneider

Yeap, the Alpine IMPRINT is another DSP based control example, and Harmon's JBL MS-8, BitOne by Audison, etc. The chip sets are getting cheaper, better and more and more mouse traps are emerging, i.e. the Mosconi One series amp modules with the IT chip DSP grafted.
There's a firm in Korea that's recently put into production a powerful DSP audio module for the auto aftermarket - I'll look for the link as you can drive the software somewhat for a test drive. Very Powerful and cheap $ I'll look for the link.

P.S., the Alpine IMPRINT DSP product requires the use of their head units - but you get the idea.

The Eagle

Sorry my fault, corrected.

johnnyC4S

Hey Bart - just clicked on the link for car audio innovations and it appears to be dead... are they still in business. Very interested to see what they have to say about replacing front speakes HiFi option in my 196 C4S.

M. Schneider

There are a handful of replacement drivers for the 993s optional HiFi front door mounted speaker boxes. The 5.25 inch or 130mm LF driver works reasonablely well when updated. I've sourced an updated (uprated) version of the original (ITT LPT 130/25/95 FS) 4-ohm driver and this improves the low end performance of the HiFi's transmission line/bass reflex tuned box very well. The uprated driver is an ITT manufactured unit model LPT 130/25/120 FS, 8 ohm driver. This version was used in the Bang & Olufsen model RL 60.2 loudspeakers made from about 1986 thru 1991 IIRC. Additionally there are several choices when upgrading the mid-range driver (highly recommended) I’m currently using a Dynaudio 3” 6-ohm mid-range (VW OEM Phaeton-Passat sourced) which replaces the 993s HiFi OEM 4-ohm mid-driver perfectly. These two driver upgrades alone absolutely transform the optional 490 HiFi system. There is a full bodied sound stage presentation to the system; the 3 inch Dynaudio dome 6-ohm mid-range is one of the best in the business. Yup,,, even with the tired old Nokia amp and the CDR210 head unit. (-just think what a little of today's herculean DSP EQ will do.) Its night and day what a simple driver upgrade effects sonically.

PS. Don’t let the bass reflex/transmission line tuned enclosure fool ya – it can be tuned very well to the small-ish interior of our 993s. It’s a time honored acoustic mouse trap…..
The Thiel Small parameters of the OEM ITT made (Nokia) 130mm drivers are on the web. I'll fill the HiFi front door enclosures with bead-shot to learn its volume. The location of the mids is quite acceptable for a broad sound stage, its the stupid tweeter location which will require signal time alignment to fix. Sure, an easy fix would be to physically relocate the tweeters forward - at the expense of the 993s original interior asthetic. Not bloodly likely.