John Curl's Blowtorch preamplifier part III

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#10,383
DPH said:
Wrinkle, something went horribly, horribly wrong with that link.
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scott wurcer said:
How on earth do you get a link that long that actually works?
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I tried to fix it but something strange happens and a whole screen gets filled with letters and symbols.
Anyway copy on your browser this line
gizmodo.com/5025867/horn-subwoofer-takes-up-crazy-mans-entire-basement

and then patch infront of it the https://

It will get you there

>Edit: Hi wrinkle. It's not your falt (We posted simultaneously).

George
 

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#10,386
gpapag said:
Thanks.
Roberto should start demonstrating his system with a ticket. He will recover some of the cost.
(“FULL CLASS A dynamic regulation - 70% efficiency amplifiers”, what the experts have to say?)

George
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I find his interpretation of no amplification by active devices flawed. An emitter follower driving a step up transformer is a power amplifier (Pout>>Pin). Pin at the base of course.
 
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#10,389
billshurv said:
I find putting a drum kit in a high end listening room very funny!
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At the bottom of the page he shows a recording studio.
He may use the listening space for recording space too.
In any case recording a drum set there and playing it back, is the optimum case for comparing “live vs reproduced”


But hats off for total bonkers obsession and max foo in a system.
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+1

George
 
#10,396
john curl said:
TOS, your listening situation is unique, but not that far away from many amateurs and professionals here. A single horn most probably will never give you a wide frequency response. It appears almost impossible at the low end, due to size constraints, and to high frequencies due to driver constraints. You can have a great 'midrange' and that is what you have. The problem was well known in the 1930's when cinema horns were designed, and to get wider bandwidth, multiple horns were put together (like they are today) each specializing in a specific frequency range. This is obvious by the historical work of many famous loudspeaker manufacturers, especially from the past examples over the decades.
Now the problem is that multiple horns tend to damage the sound about as much as they actually improve it. I know this for sure, because I lived with K-horns, first mono, then stereo for about 15years. I also designed full range horn loudspeakers with John Meyer (now of Meyersound) for a couple of years, where we had to interface 3 horns, hopefully seamlessly, back in 1974-1975. We certainly improved on the K-horns, but we still had far to go, but not for not trying to throw money, time, and engineering skill at the problem. It is just a series of almost impossible to manage problems by the horn approach, (or any other).
I gave up on my K-horns about 35 years ago, mostly because I found highest quality direct radiators (or electrostatics) to give a more accurate rendition of the human voice, and I still use direct radiators today. However, direct radiators have the problem of FM (Doppler)distortion that is always there, and it does seem to add a veil (or cloud) in the very low background. Only electrostatic speakers match horns in removing this, but then they have their own problems, as horns can sound effortless, and electrostatics can sound 'constricted'.
Stereo just aggravates the problems with horns, because they usually will not stereo image well due to path length differences. So giving your listening situation, your degree of investment, and what kind of music you prefer, you must chose the optimum speaker type.
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John Curl, wow - nice response - thank you. I have looked at many thousands of pictures of horns through the Google Images looking glass. The variation upon what should be a simple theme is in fact, immense. Having studied 20th century audio history, it is apparent that audio developmental technology has been mainly driven by commercial interests. That's OK, I'm good with that, only it seems that some aspects of development could have gone a lot further before what I feel was obsolescence enforced far too early to reap the real benefits. It is the way of things, and explains why 50 years later, we are planning to finally get back to having humans on the moon again.

I really like horns, they are such beautiful things. Their ability to convey a sense of realism is in the true sense of the word - magical. Paul Voight would find the modern world magical, in much the same way we now find Voight's world - magical. What inspires me is the limitations of horns, they cannot do everything, but what they do well is incredible, and limitation is often a spur to invention. Having said that, I do take your word for it about problems with time delays and phasing issues with multiple horns in stereo. Plus the sheer size needed to get good bass. These are issues that have preoccupied me quite a lot of late, while in search of positive outcomes.

I had a gander at Dick Burwen's website. What a dude, what fantastic synergy! I sensed that nothing this man has done in his life has ever gone to waste, and with such amazing attention to detail. I noticed that his playback room has three conical shaped alcoves/caverns/caves - call them what you will, and in the back of these waveform caves there are speakers. It reminded me, as you say, of my own unique listening situation - albeit on a more modest scale. How timely to see this when I have been thinking for months along similar lines!

My horn building skills involve elements of boat building, book binding, and dress making. And now I am going to include origami. As a photographer, I am accustomed to the modular construction of large format cameras, especially interchangeable camera bellows. I reckon concertina type horn construction is going to be a significant part of my future activities.

I hear what Scott Wurcer says about building a horn speaker into our barn's infrastructure, but I am resolutely determined to build my own battery powered pop-up monster sized celestial horn orchestra. Something that doesn't weigh a ton, is tear down portable, and can fit into the back bed of a pickup truck. Anyway, one thing at a time, eh?

I have never heard electrostatic speakers, I'm sure they sound fab, but I don't think they do batteries all that well, and I am fascinated by batteries. And yes, talking about this stuff is fun! ToS
 
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#10,397
Go for it, TOS! It will be interesting what you develop as far as materials and construction. One (relatively minor) problem with horns is their own self resonance. The horn is really a guide, rather than a container, but it will vibrate and effect the sound. Batteries solve a number of problems, and most people would prefer it, if they could afford to use it. It is still difficult to make a truly sonic free power supply from the AC line. I love batteries, but only the portable Telefunken portable radio (made in the '60s)' with germanium devices is battery powered in my apartment, and replacing batteries is still a hassle, but worth it.
 
#10,398
wrinkle said:
I do not know what happened, I selected a normal few characters where I could see the whole address in the taskbar, but when copied to here it came out as a wall of text, most odd.
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Just to be clear, I was only commenting that the link exploded a wall of text, not on the link's content. Glad George got it sorted out for us all. 🙂

That is some dedication to infrasonics, that's for sure.
 
#10,399
scott wurcer said:
No this one Dick Burwen's Sound System. When your wife wants to finish the basement into a media room show her this. 🙂
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I had to banish my 12 ft^3 sub to basement storage due to aesthetic vetoing by my mate. It is a JBL 2245H 18" I built into a 12 ft^3 (340 L) enclosure weighing 250 lbs. (114 kg) with the proper JBL BX63 dividing/eq box and 800 W of QSC power amp. It has a -3dB point of 20 Hz, and in it's passband can do >118 dB with the amp I had. Others who built it with a couple of KW can hit over 120 dB. Thanks to the cone area and minimal excursion, it has generally <1% distortion below 100 dB or so.

I miss that guy...maybe I'll go downstairs and say hi to it for old times sake...🙁

Howie
 
#10,400
hhoyt said:
I had to banish my 12 ft^3 sub to basement storage due to aesthetic vetoing by my mate. It is a JBL 2245H 18" I built into a 12 ft^3 (340 L) enclosure weighing 250 lbs. (114 kg) with the proper JBL BX63 dividing/eq box and 800 W of QSC power amp. It has a -3dB point of 20 Hz, and in it's passband can do >118 dB with the amp I had. Others who built it with a couple of KW can hit over 120 dB. Thanks to the cone area and minimal excursion, it has generally <1% distortion below 100 dB or so.

I miss that guy...maybe I'll go downstairs and say hi to it for old times sake...🙁

Howie
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Nice.

Got Bass?


🙂 😎


-RNM
 
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