Thiel Owners

Andy - I'll try to fill in some blanks. And this piece of history may interest some of you.The 3-D baffle is a rather difficult item to produce one-off. The 03 had a flat baffle and the 03a added wool felt around the drivers which worked very well, but seemed somewhat inelegant with our high-WAF furniture-presentation. So I devised the contoured wave-launch baffle which, I believe, was unique at the time. The CS3 (1983) was made by hand, assisted with power tools. First the laminated baffle was beveled on a tablesaw to remove excess waste. 45° across the top and 45° x perhaps 15° up the sides. The CS3 was then shaped with a hand-plane and random orbit sanders to its final contours. The CS3.5 (1986) was contoured with a form tool in an inverted router as follows. The excess waste was removed by tablesaw just like the CS3, then the CS3.5 was machined on an inverted pin router: fixtured in a jig, back-side up, where the jig interfaced with an overhead pin centered on the underslung form tool, which was an 8" diameter arc to shape the rounded edges. That semi-manual method produced the early 3.5s. Later, that forming operation was moved to the Computer Numeric Control Router to the great relief of all. The CS2.2 (1990) used the same tool, but was designed and manufactured entirely for CNC Router.

You might consider the CS3 method of table-sawing the compound angles on the sides and the straight 45° across the top and then shaping with a hand plane, sander and an arc pattern to guide you. Divots or other errors can be filled with body putty (Bondo); and paint covers a multitude of sins.  You might also know a CNC job shop to carve it, probably with a ball-end mill. You then remove the swarf with a sander. Or take the Avalon (etc.) approach and make facets without the smooth arcs. I think I would do that and cover the facets with F11 wool felt to absorb the migrating launch wave. I am presently having great fun with felt on the curves and believe that felt on facets would be a good way ahead.

Have fun. Keep us posted.

tomthiel,

I’ve assumed (or maybe read somewhere) that Thiel designed their speakers to be used with the grills on (as in the sonic effects of the grill were accounted for in the design).

Is that correct?

I’ve always listened with grills on, and it seems to be the norm for Thiel speakers from what I’ve seen.

Prof - Yes, we assumed grilles to be on, which affects final frequency balance, knocking the upper octaves down perhaps 1dB. Some grille frames are also inherent to diffraction management. Some reviewers and individuals have used them bare and then take pot-shots at that extra 1dB of treble and/or diffraction effects which they have directly caused by mis-use of the product. End of rant. Good to see you here.
Tom

Thank you Tom. The cabinet seems to be the most time consuming part of making a speaker at least in the DIY world. I suppose with CNC equipment then maybe the process will be much faster. Personally for me the cabinet takes about 70% of the time and the rest for the electronics. But even with CNC, I suspect the cabinets will always be the most expensive part of making a speaker, especially with the high end speakers. One of the most understated part of Thiel is in their cabinetry in term of being "furniture friendly" as most people usually talk of Thiel as just "first order coherent".  

I’ve assumed (or maybe read somewhere) that Thiel designed their speakers to be used with the grills on (as in the sonic effects of the grill were accounted for in the design).

I used to listen with the grill off and I notice the upper frequencies were a bit more "open". Also just like most first order design, the sound balance of the Thiel is a bit sensitive to "toe in". I listen with the speakers pointing straight forward. With "toe in", the upper frequencies were slightly more pronounce than I would like.

I wonder if the grill only affects the sound pressure to the affect of about "1dB" as Tom said. It’s possible that the grill also affect the "resolution" as well and ultimately the "openess" of the sound. My thinking is that the grill may affect more than just "1dB" less. That is even if you fine tune the treble energy to account for the "1dB", it still may not be the same as with "grill off".

There have been some claims with respect to "audible transparent" cloth but I doubt it though, especially where a system has a lot of resolution that will high-light any characteristic of the equipment chain.

Fabric, even polyester made to be sonically transparent, does have multiple effects, as you say. Many Thiel models use the grille frame to fill the cabinet corner with a rounded continuation of the baffle round-over and as such that frame is an important component of the wave launch. And, as I mentioned, the treble reduction of the fabric is part of the intended balance. But many audiophiles dislike grille fabric. Many have gotten good results by removing the fabric from the frame and using the frame as intended for diffraction control. Pointing the speakers straight ahead puts the listener a little off-axis to reduce high frequency beaming. Thiels are designed for straight-ahead pointing, but it seems a majority toes them in, which puts too much energy in the brightness region. The straight-ahead orientation often requires wall treatment at the first reflection point, which solves many imaging issues, while keeping a flat on-axis and power response.