Thiel Owners

For some reasons, Tom reminds me of this. Oh well maybe I’ll use the stereo illusions ... But I’ll take my gloves off at the challenge.
https://m.media-amazon.com/images/M/MV5BNjhiMjk1YWYtMjgyYy00YTFhLTk0NTMtN2Q5MDZjMWEyYWI1XkEyXkFqcGdeQXVyMTQxNzMzNDI@._V1_.jpg

It may have to do with the filtering affect of the grille. In a linear system, every frequency passes through the system will only be affected by a constant value, either a gain or an attenuation, which will be applied to all frequencies all equally. This would be ideal or at least preferable.

My System Theory 101 is a bit rusty, and I am not sure if a filter can be called a "Linear Time Invariant" (I am pretty sure about the Time Invariant but not sure about the Linear part), but I am pretty sure any filter will affect the phase of a signal and not just the amplitude. In this sense, a grille will act as a filter, a high pass filter albeit a mechanical one, because it will attenuate the high frequencies more than the low frequencies, and just like any filter, therefore introducing a phase shift at the high frequencies. Therefore the attenuation affect of the grille is not a "constant", and probably therefore one cannot be compensated by a "fix" amount on the treble to counteract the variable attenuation of the grille. And I suppose the phase shift introduced by the grille at high frequencies is what affects the "openess" of the sound that I notice.

I suppose one could match the treble response to counteract perfectly to the frequencies response of the grille, but that’s probably very difficult and probably not worth the trouble. It’s probably a lot easier to listen just with the grille off :-)

Gloves put back.

solobone, I’d really like to put the 2.7 next to my 2.4. I’ve heard 2.4 side-by-side with 3.7, and obviously way too much of 2.3 vs 2.4...


cascadesphil, mine are late-production 2.3s, but my understanding of the changes to the coax wouldn’t affect the soundstaging I’m noticing as a baffle change between 2.3 and 2.4.


Andy2, I’m assuming you mistyped, because a high-pass filter will attenuate the *low* frequencies more than the highs!

I’ve seen a number of frequency plots over the years of grilles on vs off for a variety of speakers, and my memory is they nearly always show some degree of attenuation, ideally just the top octave, but sometimes they have funky and likely unintentional irregularities at much lower frequencies. As the grille rolloff seems < a 1st-order XO I don’t see why some modest XO tweaks couldn’t flatten out the response by a dB or less in the tweeter’s passband. If you know your XO topology to begin with.

But the more ’open’ sound without grilles IMO is as much the lack of an acoustic obstruction between you and the tweeter as it is a slight (relative) exaggeration of the highs.

Andy2, I’m assuming you mistyped, because a high-pass filter will attenuate the *low* frequencies more than the highs!

OK, I was high on weeds :-)  

But the more ’open’ sound without grilles IMO is as much the lack of an acoustic obstruction between you and the tweeter as it is a slight (relative) exaggeration of the highs.

I suppose that is a valid point.  I'll let others "bring it on" as Tom will probably have some say to that :-)

sdecker

Good to see you again. I, too, share your sentiments w/ the CS 2.4 model.
Pretty cool aspect regarding upgrading via SE Clarity Cap.  Did you incorporate any other change(s) to the cross-over (XO)?
Was this a DIY project? Or, did another speaker tech assist?

Happy Listening!

   As soon as the 2.4SE came out advertising its improved crossover.  Thiel supplied me with the XO schematic and that their auditioning chose the Clarity Cap SA.  I went to PartsConnexion and went up one step to the ESA model, matched pairs, with paralleled bypass caps.  Had to use a 10+3 uF paralleled from their stock rather than a custom-made 13uF cap Thiel custom-sourced.  No other changes to XO (yet?).  

   It was a quick one-man DIY.  Decades as a working EE made this straightforward, if tight quarters.

   Despite the break-in time, it was clear the tightly-matched cap tolerances improved the image focus, and a smidge more transparency throughout the upper frequencies.  At this level of hifi, this was great bang for the $135 buck. 

   I'll add that having both coaxes rebuilt from the ground up at the same time by Rob Gillum post-Thiel collapse was similar to the upgraded, matched-pair Clarity caps, and also improved image focus and transparency a smidge.  But probably moreso because I have so many zillion hours listening to these speakers in the same good acoustic with mostly the same components and cables...

  Do you "share my sentiments" because you've *heard* with your own ears that the 2.4 doesn't soundstage quite as well as the 2.3?