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In the Forum: Horn-Loaded Speakers
In the Thread: The most promising “best” commercial speaker
Post Subject: From an experienced TAD (TD2001) user...Posted by Paul Butterfield on: 4/30/2008
Hi Romy, 'tis been awhile, but my friend Neil alerted me to this discussion, and thought I might contribute to it. While this segment of my TAD 'Whitepaper' deals with only the bugscreen, there are many other …" evolved results…" that, to my ear, and others, offer significant improvements. And yes, if you ever come down to Florida, I'd be pleased to set up a demonstration in my listening room. Alas, although we are far apart in ear training, I believe we can find a common ground for reference. Anyway, from my research:
The TAD bugscreen is the fine mesh metal screen in the interior throat of the motor which is held in place by both pressure and glue between the top motor plate and the interior horn throat chamber. Its purpose is to keep foreign objects from migrating to the VC gap area. I have also found (on older models) that the cement that holds the bug screen in place, in some cases, had been grievously over-applied during manufacture, and has caused additional restrictions in the throat area — somewhat like hardening of the arteries. The general opinion among the JoeNet Gurus is to remove it. This is also my advice as well, based on the following:
“It is noteworthy when audio enthusiasts on both sides of the pond are in agreement, but the overwhelming consensus for a significant improvement in sound of the TD2001 is removal of the "Dread Bugscreen." We (the Central Florida Audio Society) had a blind A/B comparison of identical TD 2001 drivers, one with, and one without the bug screen. What was significant — was not that all of the members preferred the sound of the driver without the bug screen — but, in under 30 seconds, everyone that participated in the listen was able to tell which driver had no bugscreen.” ~ CFAS newsletter
TEST CAVEATS:
1) For these listening sessions we used a very fast [NASA surplus] A/B switching relay which all but instantaneously switched between the two horns. The relay was controlled by a push buttons switch, so no one could tell by looking which driver was operating.
2) A pair of exactingly matched TAD 2001 drivers (Measured with LAud w/bug screens in) were used.
3) The small horns were next to each other, with the motors touching each other, so they were as close together as was physically possible.
4) These listening sessions were held in an acoustically damped room. No reflections.
5) The "Dread Bug Screen" listening session have been repeated with consistent results.
6) My reasoned opinion is that by removing the bug screen, one also remove the excess glue wad which compromise both pressure and diffraction.
My personal impressions of the audio presentation without bug screens, in a word, is "unveiled." To my ear (as well as the others who participated in these A/B listening sessions) removing the bug screen resulted in better resolution and transient response with less distortion. IOW, it improved the articulation and speed of the high end. The sound of the horn and driver with the bug screen seemed muffled, harsh and peaky... in a word, " strained. "
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