John Curl's Blowtorch preamplifier part III

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First, Scott finally agrees with Richard Heyser who also told me: "If any two people hear a sound difference, then it is REAL!"
Unfortunately, he was deprived of car appreciation as a youth.
When it comes to horns, T and Richard Marsh, you have good ones, but most don't, and that is the problem.
I was enamored with horns, back in 1965, when I started working in a hi fi store part-time while finishing college. I even bought my first K-horn in 1967, when I had my first professional job. At first, I loved my K-horn (mono) compared to my previous Acoustics Research AR-1 (with added tweeter) that I had from 1963-1967. It was effortless sounding, very natural with large orchestras, etc. and I had met Paul Klipsch, who impressed me a lot. Later, in 1974, I worked for 1 year with John Meyer in making an improved 3 horn speaker, with time delay correction that really kicked up. That horn design proved too expensive except for the most advanced pro work, but it was very impressive. So far, horns were great!
Then John Meyer returned to the USA, and I stayed in Switzerland and asked to make a speaker system for a Paris recording studio by Kurt K. (Z knows who this is) and I spent about 9 mo with a hybrid, much like T has, except I used an Emilar 800 Hz horn with a 1" throat and a direct radiator woofer, (the best that I could find). Now, the Emilar, much like the JBL that RM has, was not a ROUND horn, but it did have controlled dispersion. Richard Heyser independently measured this Emilar horn and found it to be very good, certainly better than Klipsch.
Now, mating this horn with a direct radiator was a B#tch! Virtually all the electronic crossover types that I tried were a compromise. Horns have excessive phase shift near their low frequency cut-off, but I made it work (more or less). Also virtually all of the horn drivers made at that time (44 years ago) had a sharp cut-off at some frequency below 20kHz on the high end, and could not be practically corrected for, which made for an added horn tweeter, along with its attendant problems.
Here is where JBL, many decades later, came up to the plate, and built an improved horn driver (like the one in RM's speakers) that can be practically EQ'ed electrically to well beyond 20kHz, so there you critics! Apparently T, lives with the roll-off comfortably but it should be there. Probably better than trying to add a super-tweeter.
Now, Bill went another way with an electrostatic mid-tweeter and a direct radiator woofer. I heard one at a show recently and it was very good for the money. I would buy these speakers. Now, I could go on, but it really comes down to: Horns are usually really compromised, but the best ones can be outstanding in their performance. K-horns are too much of a compromise to be successful these days, JBL (the latest, can pass serious consideration) and maybe a custom horn is OK, (like T uses), but usually horns sort of suck! And this is why quality direct radiators speaker systems are still popular at all price levels.
 
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How in blazes are you driving those things? IIRC they go down to 1.8 Ohms and 60 deg phase or have I got the wrong speaker?


I've got the hybrids so just a 26" hybrid mid-tweeter and std box woofer. Ribbon from 450Hz. Needs a larger room to really strut its stuff, but the general effect is enjoyable. Given the largest horn I could fit in my room and still remain married is 10" (giving about a 13" wide speaker) I can't enjoy a lot of the benefits that a horn might give.


Sometimes we Americans grow up and realize our fathers were right it's just all tin and tires. then we can spend money on audio.


Says the man with a light aircraft as his avatar. A toy that makes cars and high end audio look cheap :)
 
One thing that play in favor of cones for home use, is that, if, on my opinion, good horns can be razor sharp and sound better than cones with perfect recordings, they forgive no mistakes on the source quality or poor/average recordings/mixes. Impossible to use my big system with the TV sound, as an example and each record sound different.

Cones are a lot more indulgent.

So, if some is looking for the pleasure of easy listening and want to enjoy more records, may-be it should be better to use a less sportive but more comfortable system.

I should be interested to have "Lucky" Richard's opinion on this subject with his (state of the art ?) JBL M2.
 
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I know of no others connecting the dots, as well.

This is worse issue than power line AF/HF/RF which also causes audible change in sound in many amps.

Awhile back D.Self did a test by injecting HF into PS and the THD DID increase on signal measured. This is like that and why some of the CD "sound" has been an elusive issue.



THx-RNMarsh
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I don’t doubt this at all, have noticed great improvements from parts/circuits that shouldn’t make any difference within the normal listening frequencies.
 
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who me? what measurements are you looking for, again??-RNM

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Originally Posted by Bonsai View Post
Nice article T.

Funny he says that JBL and Revel follow the Toole frequency response model like the KEF’s but when you listen to them you get a different impression. I would never guess in any event that the KEF’s sloped off as much as they do.

I also use a sub with mine - but I doubt it’s anywhere near as well integrated as Mitchco’s set up - I just dialed mine in until I liked the sound.
The measured response in my system with M2 do NOT roll off.


-RNM

:)
 
Car crazy, not.... I have driven more than 1,000,000 miles as for many of my projects driving is the fastest way to get on site. Also can take lots of stuff with me.

Now flying a million miles wasn't nearly as hard.

However I am still under 10,000 miles by train.

So my auto crazy priority is a comfortable, reliable, economical, and survivable automobile. So far only two hospital visits following interesting bits. (The last police report after an interesting experience concluded the other fellow would have been charged if he had lived.)

So it just might be reasonable to pay a bit more attention to something one could spend several years of real time driving.
 
I find it amusing, since we were just discussing this a few days ago, that a recent product (J E Sugden Masterclass LA-4 line preamplifier, $3750) uses a fairly old 8-legs (OP275) with discrete class A/B external current buffer as an output stage.

I find that lots of gear is amusing once the lid is removed.

And cars can be very rewarding on many levels. I have found that I prefer to make a reliable car perform better than to try and make a higher performing car reliable.
 
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