John Curl's Blowtorch preamplifier part II

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Here is a tweeter in the center channel of my HT. It consists of 64 capsules, 12 mm diameter. Can I get distortions similar to horn throat distortions? No way. :D
 

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Well, of course, Esperado. I first reacted to your 'horns and 10KW' PA that you apparently ran for a time, NOT your home system. The GD system was modified to remove many of the midrange horns BECAUSE of horn throat distortion in the original multi-midrange horn setup used for at least 4 years previously. Have you learned anything new, yet?
For the record, what was the PA system that you ran with '10KW and horns' consist of? Then let us talk.
 
Have you learned anything new, yet?
For the record, what was the PA system that you ran with '10KW and horns' consist of? Then let us talk.
"For the record", all JBLs, near everything in their catalog. You know, those very bad horns, plenty of them and bass cabinets...Castles at the side of the scenes...
Absolutely awfull regarding any form of fidelity. But no larsen, very dynamic and impressive for drums, such a directivity that it was possible to project sounds to hundreds of meters, able to keep intelligibility even is some catastrophic hall's reverberations and, once equalized, some guys in the public where even able to recognize instruments :)
You know... PA !

I remember, if you shouted a " bow" in the mike, with some delay, it was like a plane in your face in return from the back of the hall...

At this time,if you spoke to me of some horns in my home system, I would have killed you.
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If i had learned something ? About PA ? Not really.

About Home; Yes.
That * Good horns * can change everything. When i say good horns, i do not include metallic ones, constant directivity ones, or traditional expansion curves (cone, hyperbolic, , parabolic).
... That the horn expansion curve has to be carefully calculated in correlation with the specific drive you use (how spherical is the wave's form, angle of the throat etc...)
That your horn has to present the same surface at the crossover frequency than your bass speaker or, at least, the same directivity curve...
That it is good to calculate-it for one octave under the cross over frequency...
That it is very difficult and time consuming to tune the filter's levels for a perfect coherency...

Once done, i do not know a more natural and dynamic reproduction than the one that offer a two way system with such a horn with a good driver (not easy to find neither).
 
Frank,
I would say that natural and sonically correct are one in the same in my book. To me it can not sound correct if it doesn't sound natural or at least reproduce what was intended. What I don't like is harsh, bright, muddy, smeared or any of those things as that is what I would think of as unnatural.
 
There are so many dimensions to "good" sound, and when two people listen to the same sound different priorities are placed on various aspects. I look for naturalness, others for absolute correctness of some tonal characteristic, there are myriads of permutations ...

I prefer when I don't hear speakers, amps, microphones. When sounds are perceived directly by subconscious mind, way before conscious mind have a chance to analyze "How good it is" :D
 
Well, at least you didn't much of your own PA either. '-)
If that means that have not done much to improve the things on a technical point of view, i can answer. that it was not my own, i was just in charge of it.
What i said about PA, take-it with a pinch of salt. i'm not often first degree, neither i like to take apples for oranges, or over estimate things.
Anyway, i have never heard an acoustic guitar witch sound like an acoustic guitar across ANY PA.
It was may-be the best PA in Paris at this time, and we done number of great concerts, groups artists, tour managers and public where satisfied.
Magic of a concert is more in concern with something between musicians and public... and music magic. You know that, i believe. As well i'm sure that you have heard many good concerts with similar systems, don't you.?
PA quality is just a part of it. The legendary Woodstock PA was ridiculous, comparing to those.
 
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I agree with all of you about sound quality. And specially that: "I would say that natural and sonically correct are one in the same in my book" .
I would like to add that, even after a life on this, if you give-me the choice, for 40 minutes, between listening to a fantastic record (groove, emotion etc...) on computers loudspeakers or the last hit on the best system of the world, i would choose the first... of course :)

In a way, when some musician at home says "wow, your system sound fantastic", i'm asking questions why he noticed that.
I prefer when we talk about the music
 
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I prefer when I don't hear speakers, amps, microphones. When sounds are perceived directly by subconscious mind, way before conscious mind have a chance to analyze "How good it is" :D
That's probably one way I would express it. However, have just gone to a hifi show and then reading comments by other audiophiles, elsewhere, on what they perceived as good sound, there are obviously differences. Where I, and the others, agreed, then a term used by those others was "fun". A strange one, but I would take it as meaning "natural", as in one didn't have dissect the sound to work out whether it was correct, you just "knew", instinctively, that it was so, or at least reasonably so ...

This obviously echos what you said, the playback has to sound right, without switching on your analytical mind to do the calculations, or give it a score.

Part of that naturalness is that "difficult" recordings are reproduced correctly: one room was subjectively going up and down in SQ, one moment it hit the right notes, so to speak, and then a major slump. For example, did a classical piece very nicely, and then Frankie Goes to Hollywood "Relax" was a disaster ...

Only one configuration in one room got it right every time, it never failed the "instinctive" test, for me ...

Frank
 
All that I can say, is that horn throat distortion led us to apply more power to arrays of quality cone loudspeakers rather than more power to arrays of horns, where even 2W (think about it) was and still is almost too much for the horn, as far as distortion generation goes.
You are VERY critical of other people's efforts, yet I am sure that your PA efforts were no better than anyone else.
As far as your home loudspeaker is concerned: I used the same concept with Gunther Loof for the Paris studio back in 1975, so I think it is a good direction to go. However, later when I was going to build my OWN speaker, I chose a 2'' throat rather than a 1'' throat, for my home driver. That was the major difference.
Later, I decided to stick with the WATT's because my listening levels are quite modest, living in an apartment for the last 35 years. They are not as 'dynamic' as a horn mid-hi can be, but they are more extended in frequency response, and the drivers work better together. I do not want to parse with you as to specific advantages of your or my system. I have not heard your system, and you do not seem to like anything but what you are associated with, so it would not be useful to do so.
Why don't you start your own thread on your protection scheme? It is a little complex and it does not protect an amp from blowing itself up due to exceeding second breakdown limits, but it would be OK with modest power amps, that don't need such protection.
 
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Christophe, can you put on what many other people would call a really bad recording, say the first Led Zep, and get that same reaction?
i'm not sure to have understood what you wanted to ask, but if it was a question about systems, it is one of my philosophical problem :)
Very few records sound perfect on my system. I can notice every mistake in the mixes, different reverbs supposed the same room, spacial localization, incoherency of space position in depth, tonal balance vs levels, voices with too much presence or volume etc...
Sometimes, i wonder if a less analytic one can offer better pleasure, being more indulgent ?

What did we call a good system ? I wonder what a guy like me (sun of a pianist, sound engineer in real contact with near all musical instruments 10 hours a day during decades) and some audiophile witch have never been in physical contact with them, (outside recordings or PA performances), can have in common, when we listen to music ?
Most of them seems to listen to music "Vertically", while i listen "horizontally", moving my mind from on instrument line to an other...See what i mean ?
 
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Historically, if you were paying attention at the time -- Ed Vulcher et al was quit aware of speaker design issues related to effeciency. he removed the horn and exposed just the dome driver and listened and measured. from this he proved the sound was better. Then he developed a bass speaker (acoustic suspension) to match the lower effec mid and hi domes and thus was born the speakers so commonly in use today. The wider dispersion was a plus because speakers tended to be widely spaced in the home.... they were large and often relegated to the corners. The dome has been with us since. Many jumped on the bandwagon -- Omni directional was born. Bose was born when he combined omni with acoustic/sound with his direct/reflecting means to get the 'new' sound to sound more like a hall affect. Etc.

recently, Harmon brought their mobile room to town and demo'ed thier $100K system using compression drivers. They showed an old western film with original sound track of a shoot out. They were showing off the dynamics of the pistol sounds. Unfortunately, those film tracks had a 8KHz BW...... the film tracks of those days used a photo cell tube pickup with 8Khz response..... notice the A7 Altec 'Voice of the Theater' had an 8KHz response as well (no tweeter and drops like a rock after 8KHz)

bad choise for a demo of dynamics.... guess they couldnt hear the difference between modern film tracks and old? Or dont know what a real pistol shot sounds like. They are not muffled sounding! What is often missing in speaker systems is high dynamic range. High sensitivity and dynamic range are what i find seductive with horn systems.

Some modern drivers (hornless) with high sensitivity are very dynamic and low distortion. What is missing most often in music systems is truely high dynamic range... without early compression -- that is harder to do.... high sensitivity and high power and low distortion... esp in the bass. Thx-Richard
 
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