Thiel Owners

rop45 - can you provide a link, etc. A search of Audiogon says there are no listings for Thiel CS2. Or perhaps you could describe your offering here.

rop45 - I found it.

Tom Thiel,

I have a new speaker rebuild and elected to place the crossover out board for final tuning. It will always be outboard.  Components are mounted on a solid 1/2 inch poplar board and grounded to the floor via threaded 1.5 inch Audio Points.. Originally the 2 8gauge inductors were tied down to the board each with several zip ties. After listening for a couple of weeks I felt the sound was dynamically restrained and cut away the straps, so now the inductors only rest on the board under their own mass and physical size. Immediate improvement was heard in soundstage size, everything was much more dynamic and with much  more acoustic air.

These 2 small inductor values are physically large with a space of about 2.5 inches between them. They are placed 90 degrees to each other. I decided to move 1 another 2 inches from the other. Way different again in performance. I thought that placing the inductors apart and with 90 degrees of separation would eliminate any magnetic field inner play but that is not the case...So my thoughts and observations leads me to question.  What are the magnetic actions and reactions when a crossover is placed inside a cabinet in proximity to a woofer magnet or powerful neo tweeter magnet and or the variable fields under power of confined inductors? 

Today I will be receiving 4 sections of mu metal to place around all of the inductors or a large portion of the facing circumference of each. If this case study of the magnetic field, external to the confines of a cabinet makes for an improvement then why wouldn't the same hold true for crossovers inside the box but even much more than those outboard? TomD

Prof - I ran the painted driver experiment; and I’ll call it a success.

I used Krylon ’Fusion’ because it claims ’5X the adhesion’ (of whatever?). Its solvent cocktail includes acetone, which makes a good scrub agent.Careful. I chose dark oiled bronze because it’s nearly black and so much more visually engaging than 'plain black'. I cut a cardboard mask, laid the speaker on its back and misted just enough paint to knock the aluminum down by perhaps 85%. First measurements were 1 hour later, which showed significant harm, especially in the mid bass and lower midrange with frequency erratica and time domain throbbing. After 4 hours it was much better and after 24 hours is hardly visible. The paint cure cycle is 48 hours.

At 24 hours, the top octave rolls off perhaps an additional 1dB at 20k and there are some harmonic differences. Generally, the 3rd to 7th harmonics are smoothed out and 3 to 5dB lower. On balance I would say the lightly painted cone is superior to the bare aluminum one. It is plausible that a crossover tweak might get that top octave air back, since the CS1.6 has a notch filter at its oil-can resonance. Note: there is none of the typical resonant peak at 28k (etc.) When using my Earthworks QTC40 into a 96kHz interface. The high end of the 1.6 just keeps rolling off around 12dB / octave out to 50k. That’s very nice.

I will experiment with a midrange driver when I get the 2.4s into the studio.

I suggest leaving tweaters alone, at least until we do some real homework.

If you paint cones, go easy. I certainly like the look better and it opens a door to using nylon window screen for a protective grille with far less resistance than Thiel’s polyester - plus a peek-a-boo allure.

By the way, the 1.6 grille shows differences in two areas. In the deep bass from 20 to 50 the grille introduces time domain throbbing, although I can't hear it. The FuzzMeasure sweep goes full power from 1Hz to 48kHz. This grille seems quite transparent up to about 7500Hz where it gradually rolls off the top to about 1-2 Hz at 20k. I like the sound better with the grille.

That's 1-2 dB at 20k.