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In the Forum: Horn-Loaded Speakers
In the Thread: RAAL “Water Drop” tweeter for Macondo.
Post Subject: The Water Drop - the first break through.Posted by Romy the Cat on: 2/19/2007

OK, after a few days to straggling with this damn tweeter I might report that the Water Drop actually made itself to sound civilized. It sounded somehow fine alone but it was a real nightmare with Macondo, I juts was not able to integrate it. I measured it and I detected that the Water Drop sinks my Vitavox’s output as if it runs out of phase with it or has impedance of .2 ohm. I measured the tweeter with reversed phase (I did not measure the fact of reversing acoustically but juts reversed wires) and saw the same almost dive 10dB down after the crossover point. The sound was too wrong, juts very much wrong. I really wonder what it going on and I begin to invent filters, diffusers and ribbons loading in order to soften the sound of this tweeter, the sound that was too ribs-pinching.  It sounded like a typical harsh out of phase tweeter but my acoustic phase tester:

http://www.gold-line.com/apt2.htm

said that the MF and HF channels were IN PHASE. I have measured it 20 times and did not believe that the tester is wrong.  I use this tester for 10 years and this tester is very accurate and I very much trust to it. I mean within my playback I for years never ever cared in where is positive of negative, where it red or black terminals. I connect everything as is” and then I test each driver’s polarity…. Anyhow I was really was wondering what the hell is going on…

This morning, I desired to re-test everything again before I put the tweeter in the long box of projects then went south. Among many other measurements I was making the sweeps with tweeter in and out phase. Suddenly when I begin to see as my RTA was printing the sweep out of phase I said” Holly shit!”. It eventually looks like the MF channels did embrace the tweeter!!! Wow, how the hell I missed it before!!!! Perhaps I reversed the wires twice when I measured it before… Anyhow, I was sa exuberant and could not wait to put everything back in operation to listen now how it will sound.

Of course it was absolutely different and it was absolutely CORRECT SOUND this time. There was not conflict between S2 and the Water Drop anymore. No tweeter anymore was screaming BEHIND the MF and there was no “HF “clipping”. If fact it was very smooth now, very extend and VERY peaceful... Who could believe that I can find peacefulness during the President Day. This President!!! Anyhow, it is not time aligned yet and it probably should be attenuated for a few decibels  (not for 12-15db as I was trying before) but it is already, compare to what it was yesterday, is a “giant leap for mankind”… Now the minor satellites are left but those satellites are perfectly rational and manageable. Evan without the “minor satellites” from what I’m get now from the Water Drop it promises that it will be a phenomenal performer. I am playing now the James Levine with Chicago crashing through the “Porgy and Bess”… The “Water Drop” sits with 6db/octave at 12K and the Macondo with Chicago 1993 does wonderful, just simply wonderful… it is slightly bright but DESPITE OF THE BRIGHTNESS IT HAS NO SIGNS OF HARSHNESS or hardness. It was VERY much what I was hopping for.



I still would like to hold my more or less final observations as I would like to see how it will be when it will be all dialed-in correctly. For now, let to think why I demonstrated the audio-Moronity™ during the last few days. I used 6db/octave crossover, juts a single cap and a single cap NEVER reveres any phase in speakers. Sure, it has 90 degree shit but over the years, playing with many drivers, I NEVER HAVE SEEN that the driver with 6dB should be reversed in phase. Well, I also hardly ever dealt with the drivers that have a transformer between filter and the coil. The Water Drop has a transformer with 3H inductance… so I had effective 1.5th order when the cap begin to roll at 12 KHz and then at the bottom at 4 kHz -5kHz the inductance of primary kicks in and forms with that cap a pure second order… Well, I thoght that this secondary rolls-off is too far away to affective and therefore it’s contribution would be negligible… well, not so simple….

Anyhow, now I feel much better and the future looks bright again… I will be posting more about the actual Water Drop’s sound when I feel I am ready…

Rgs,
Romy the caT

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