Thiel Owners

bluetone - and all you 3.5ers - the driver quandary is significant; the lack of suitable replacement drivers is why I have shied away from addressing the 3.5, which is otherwise perhaps the central iconic product that Thiel Audio produced. My caution when substituting drivers is this: Thiel products correct and control for resonances and anomalies for 2+ (sometimes 3!) octaves below and above their crossover frequencies in order to produce proper slopes to blend with their mating driver slopes for first order phase, time and amplitude results.

Thiel drivers are extraordinarily specific to their end use and their crossover is extraordinarily specific to the exact peculiarities of its original drivers. On the contrary, a higher order crossover can cope with a generic driver as long as its basic parameters of impedance, sensitivity and so forth are similar to the original driver - because the out of band regions are steeply attenuated and therefore not very important to net performance. 

It is possible that someone could find a replacement 3.5 (etc) driver, possibly better than the original, and then re-engineer the crossover around the particulars of the new driver, and produce a wonderful solution. In my imagination, such a solution would appear. But in real life, I caution anyone messing with these speakers to be very aware of how much the considerable and particular driver variables matter to the resulting performance.

Bluetone, have you overlaid the response graph of the ScanSpeak8525  on the custom Vifa 3.5? Please share the similarities and differences of those two drivers. Does anyone else have guidance for a replacement midrange for the 3.5?

Thanks,Tom

Thank You for sharing your 3.5 story. Which loudspeaker replaced Thiel in your system? Happy Listening!

Magenpan 3.6Rs. It was a huge step up. Earlier, I said that they are at least four times better than the Thiels 3.5s, but I have to retract that statement because I never liked the Thiel midrange or treble. The midrange was always really shouty and the treble was extremely bright, harsh, and fatiguing. It didn’t matter how the speakers were placed. I tried everything from pointing straight ahead to various degrees of toe-in. I could never listen to the speakers without being on-edge. Due to all of this, I consider the Maggies infinitely better.

The Magnepans have a sweet, lush midrange and the highs are super soft, airy, extended, and life-like with absolutely no boxiness at all. The soundstage depth and width kills the 3.5s, and everything just sounds completely transparent and real. The Maggies are just a totally different animal. They also open up more amplifier choices because they are a relatively easy 4 ohm load unlike the Thiels.

The only way the Thiel might have been a little better was in the low frequencies. They could go lower than the Maggies, but I could never turn the volume up high enough to enjoy it without the woofers slapping and the midrange and tweeters pushing me out of the room, so it’s a moot point. I don’t know if more amplification would have helped with the woofer slapping, but they were already getting 400 watts @ 4 ohms, and at the time, I thought it was a much better idea to get different speakers than more amplification.

Making a speaker move paid off big time for me. I’ve had the Maggies for a few years now and they still amaze me. They have been completely trouble-free, but if I should happen to fry a ribbon tweeter or require any other kind of repair, it’s no problem.

Tom, I don't any info on the original Vifa 3.5, here is the link to the Madisound website / product page for the Scanspeak speaker.  I don't have the info for the original, maybe someone more literate in these things could chime in.
https://www.madisoundspeakerstore.com/approx-4-woofers/scanspeak-discovery-12w/8524g-4.5-fiberglass-cone-woofer/

Bluetone - please pardon me, I hadn't remembered that the original 3.5 was from Scanspeak. The most likely source of comparative data would be from Madisound. Can you get a datasheet on the original 3.5 midrange from them? If so, then we could compare the two and there are folks on this forum who might propose valid XO compensations.
As far as I know, Rob doesn't have the original driver specs, which were lost in the ownership transfer.

For my part, I am working with a user who is providing information for me to reconstruct a 3.5 crossover schematic, which will serve as a platform on which to build.

The more I listen to the CS2.4, the more beautiful they sound. I wish I could go back in time and hopefully I could make a difference.  I've designed my own speakers but they are no equal to Thiel.