Thiel Owners

Prof - Cabinet stiffness including the baffle helps it disappear. I am experimenting with "stiffening" the MDF cabinets, especially the driver mounting recesses with Minwax Wood Hardener. Also that 3.7 cap is far quieter than the 2.7 top. I am extrapolating from how surprisingly active the small top of the 1.6 is. Column ends accumulate pressure and the 3.7 is both very strong and shaped to handle the job.

Prof and you other 02 fans - I just now got my old 02s on line - received from my brother from their life-long use in our parents' system. Drivers are good, coils are good - within their genre. These speakers were made in 1978 before we discovered high-purity wire and baked fusing. These are normal ETP "magnet wire", still the industry standard. We wound these on "Ol' George" - hand-fed with a timer. We then tweaked each coil via weight on a triple beam balance and DC resistance. I checked these today with my inductance meter and they're within 2% of target.
They are considerably better wound than Beetle's Chinese 2.4 coils.

Back to the XO. The resistors are 5 watt carbon composition - all burned to a crisp. The caps are all 50 volt electrolytic - about half of them are blown out, the other half are + 30% out of spec. I replaced all with original grade parts and fired them up.
I haven't heard 02s for at least 30 years. I am impressed! The sonic signature / tonal balance is pure Thiel and they don't screw up the music. They lose a little in direct comparison to the PowerPoint1.2s and the CS1.6s, both 6.5" 2-ways, but really, they aren't shamed.
If we had chosen to take this 2nd order route with our developing company, life would have been immensely easier. However, we may have failed because the territory is so much easier - everybody entering the game played there and it is unknown whether we could have differentiated ourselves.

Anyhow, thank you Prof. Your enthusiasm for the model inspired me to consider it. After hearing it, I am addressing it and will learn a lot in this relatively simple sandbox. The 02R will live. I hope you guys can snag some on the cheap. Rob and I think we made fewer than 1000 between 1976 and 1984 and they would be concentrated on the East Coast and in Germany - go figure.

Can’t say I’ve noticed this trait, Andy2. Some songs with the mix in one channel seem to emanate well outside the bounds of the speakers. The CS2.4 does this at least as well as the CS1.6 and Vandy 2Ce Sig II.

bettlemania,

I suppose it could be recording dependence. Also, although I am not a recording engineer, there are two types of hard left/right mix. One type there is still a phase relationship to the other channel so you hear the image well to the left or right of the speakers (for example at the beginning Welcome to the Machine from Pink Floyd which the CS2.4 does very well). The other type is just a pure left or right without any phase relationship to the other channel so you hear the sound basically directly from that channel speaker.

I think I was referring to the latter one. If you could find some old recordings especially from the 60’s where the sound mix is basically left or right. In this regard, I was wondering if you could compare how the image "flows in the air" compared to other speaker design.

As for the TAD Ref One, it has quite bigger bass drivers and midrange driver so I would expect it has more image density vs. the CS2.4. As I mentioned in my previous post, the 2.4 has a small mid so it does not sound as weighty in the lower midrange sound vs. speaker with larger mid driver such as the TAD Ref One.

Just for jest, one way to eliminate (or mostly) diffraction is to use horns such as this:
https://www.youtube.com/watch?v=Lz7biTHWv4c

I wish I had one of those :-)

So, Andy, even though the 2.4, like the earlier designs, does control diffraction very well, its lower tweeter creates a time discrepancy between side and top diffraction. That effect would be extremely subtle, such that I would be surprised if I could ever hear it. But, your ears are younger than mine.

Hi Tom,

The subject of diffraction is very controversial and there are people who believe that you "can't hear" diffraction and people would go on and on about it without agreeing on anything.  Personally, although I don't know if you can "hear it", but I think diffraction manifests itself in how well the speaker images.  Of course there are other variables such as cabinet stiffness, cabinet shape, but I think diffraction plays a big role.

I was wondering that the CS2.7 and CS3,7 being Thiel's latest designs, and the fact that the coax drivers were placed at the top of the baffle compared to older design, what was the main reason for that?  Was it mainly to improve diffraction or was there other factors?

Thanks.