New ideas for K-55 and PD-5V compression drivers

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Radian, what you are arguing here has nothing to do with what we "discussed" together above, which was only focused on midbass compression driver, and how a 2" Atlas compression driver could be better in this range than a 4" or 8" more modern (and costly, and with far more R&D behind it) compression driver.

No this was the battle field you created. You just brought in the JBL 2482
wich neither is better than the modified K55 and is way more expensive to
obtain. What use was this for the discussion at hand.
The reason I introduced the K55 was that many people who have heard the
WE555 on the big WE horns report excellent sonics in the low region which
tells us that this driver is just very good for this kind of application.
I have yet to see any post that rave about the how excellent the JBL does
in the lower than 250hz region.
Dietmar did not specify the input to the modified K55. What he said is that
the the Line Magnetics 555 was not any better on paper, and that he has
cranked the volume up and he did not percieve any distortion or ill effect.
He has probably heard and set up more big horn systems than most dedicated horn lovers.

Here is a pic of the modified K55. Just a Peavey magnet structure glued
on with a little felt cavity attached to the vent hole.
Before is black and after the mod blue line:
 

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For the record the Azura is a LeCleach profile horn.
Who cares it does not do much better when it comes beaming.
And by the way, in a comparsion his horn did not come out on top.
The old Klangfilm drivers with the Klangfilm horns sounded to most
people present better. Guess what he had to say about this?
The Klangfilm covered more of the audience and that's why more
people voted for the Klangfilm. This is exacly the thing
we are talking about and he even broght a smaller horn with better
hf behavior to the Festival than the huge Azura.

Klaus
 
:bored:
Common Radian, I did not "install" any "battlefield" !?
Reread your post #142
Rewind talked about using a 2" (4" diaphragm) driver and you responded that he would "not find another driver who is more suitable for those frequencies" that the 1" (2" diaphragm) Atlas driver, because of its "very low resonant frequency and a max excursion of 1mm".
I just pointed out that 1mm for a 2" diaphragm was a mere 0.25mm for a 4" diaphragm, and (subsequently) that modern drivers should not be dismissed that quick.
Your statemed "You will not find that in other modern drivers because they have not been designed to cover low fequencies.".
But you do not seem to have really considered those bigger 2/4" drivers (on big horns), and especially the option of using larger cone drivers with a phasing plug (and not necessarily modern ones like the CMCD, but also "vintage" ones like black widow 12" driver + phasing plug used in the peavey MB1 midbass horn).

That modified Atlas might well be very good, but saying it is the best there is is probably a bit optimistic, to say the least.
Refusing/ignoring/mocking other opinions like you did is kind of puerile, especially considering that you probably did not try any of those midbass drivers yourself...
 
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Who cares it does not do much better when it comes beaming.
And by the way, in a comparsion his horn did not come out on top.
The old Klangfilm drivers with the Klangfilm horns sounded to most
people present better. Guess what he had to say about this?
The Klangfilm covered more of the audience and that's why more
people voted for the Klangfilm. This is exacly the thing
we are talking about and he even broght a smaller horn with better
hf behavior to the Festival than the huge Azura.

Klaus

The Klangfilms are tractrix designs (you can even get them from stereo-lab), and in this competition these bested some constant directivity designs.
(by the way it was conjectured by some that the klangfilms won that particular competition because there was a lot of Germans attending, and the comparisons were not blindfold ;))
 
Refusing/ignoring/mocking other opinions like you did is kind of puerile, especially considering that you probably did not try any of those midbass drivers yourself...
Wait a minute I am in the posession of a pair JA6681b wich is still better at low
freqencies than probably 95% of current production drivers.
The K55 that Dietmar modified where mine and I sacraficed them to find out
what was possible. I had the Fane Studio 8m in use as early as 1988 or 87
don't remember exactly.....so what do you try to communicate by saying
the above?

Klaus
 
The average consumer is not knowledgable enough to know that a compression driver driven low can sound nice, especially home consumers. So why would big companies spend money when demand is so low? We have pretty selective taste on this forum.

The JBL PA speakers I mentioned earlier don't use compression drivers below 1.2kHz.
 
There was a time when Altec drivers were used as low as 300hz on a simple 311 horn with a simple passive crossover and this was obviously intended for movie soundtrack reproduction. These were generally phenolic diaphragm 1.4 inch drivers that had little to no upper frequency response about 6Khz at best. Why you are still pursuing this for music production today I just don't follow?

About 1978 I introduced 10" midrange cone driven radial horns for professional audio that was directed at the problems of going from a 15" cone to a compression driver. This went a long way to solving the ever present cone breakup in the upper response of the 15" speakers and the low end honk of the typical compression driver horn combination. I still favor the use of a midrange cone to cover this area rather than trying to force a compression driver to operate this low.

Increasing the excursion of a compression driver running approximately a 10:1 compression ratio really goes against the design of these devices. Increasing the volume of air between the diaphragm and the phase plug goes against all aspects of the design as I have ever been taught and understand. You do not want a large volume of air that can be compressed in this airspace, this just isn't what I would call good practice.
 
The Klangfilms are tractrix designs
No, that's the common mistake. It is a Kugelwellenhorn
It has a different horn contour wich is close to a tractrix but not quite.

....in this competition these bested some constant directivity designs.
Some constant directivity and some regular tractrix and some LeCleach and some other well respected horns.
Will they sound better than a well designed CD like some Seos iterations,
I don't know cause I never heard them but chances are slim.


(by the way it was conjectured by some that the klangfilms won that particular competition because there was a lot of Germans attending..-))
And Germans have bad hearing?

.
 
The reality of both horns and waveguides is that they all are a compromise in some aspect or the other. There is no perfect device of any design, you have to carefully choose what is important to your situation. I may prefer the loading of a hyperbolic expansion while someone else likes the polar response of a conic horn. There is no one design that will meet everyone's expectations. If there was a clear winner that would be all you see, but that is far from the case.
 
Kindhornman: Good, then JBL finally listened to you after the SRX 725, when they made the STX 835. :)

I listen to horn because cone drivers and now also AMT's bore me. I want an intense clarity that I can't get elsewhere. True ribbons I use as supertweeter. Cones are good for sub, and maybe midbass. This is what I wonder now if I can fix with something else. Planars and bass AMT's I have not tried yet. They might sound exciting, but I suspect that they probably can't give me the same feeling I get from compression drivers.

I know there are problems with compression drivers, and you can't hit them with any kind of crap music.

Listen to this video to have an image of what Goto horns can produce. http://www.youtube.com/watch?v=KXaKrG59G9g The JA6681B on a short horn cannot reproduce that sound.
 
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Kindhornman: Good, then JBL finally listened to you after the SRX 725, when they made the STX 835. :)

I listen to horn because cone drivers and now also AMT's bore me. I want an intense clarity that I can't get elsewhere. True ribbons I use as supertweeter. Cones are good for sub, and maybe midbass. This is what I wonder now if I can fix with something else. Planars and bass AMT's I have not tried yet. They might sound exciting, but I suspect that they probably can't give me the same feeling I get from compression drivers.

I know there are problems with compression drivers, and you can't hit them with any kind of crap music.

Cones for both sub-bass and mid-bass, horns for the pure mid-range, and a ribbon super tweeter. I'd have to agree.

Kindhornman: just how high would you say it's okay to run a cone mid-bass/low mid-range driver before you'd cross to a compression driver?
How about the "classic" 500 Hz ?
 
There was a time when Altec drivers were used as low as 300hz on a simple 311 horn with a simple passive crossover and this was obviously intended for movie soundtrack reproduction. These were generally phenolic diaphragm 1.4 inch drivers that had little to no upper frequency response about 6Khz at best. Why you are still pursuing this for music production today I just don't follow?

About 1978 I introduced 10" midrange cone driven radial horns for professional audio that was directed at the problems of going from a 15" cone to a compression driver. This went a long way to solving the ever present cone breakup in the upper response of the 15" speakers and the low end honk of the typical compression driver horn combination. I still favor the use of a midrange cone to cover this area rather than trying to force a compression driver to operate this low.

Increasing the excursion of a compression driver running approximately a 10:1 compression ratio really goes against the design of these devices. Increasing the volume of air between the diaphragm and the phase plug goes against all aspects of the design as I have ever been taught and understand. You do not want a large volume of air that can be compressed in this airspace, this just isn't what I would call good practice.

Good practice is that wich sounds good. Why in all the world do people rave
about the effortless, natural well defined bass reproduction when they herad
the WE 15A with the WE555 if this driver would not be suited to do the task.
There is obviously more to this compression driver with that little 2"
diaphragm than our little brains can digest. Dietmar has listend to his
modified K55 driver in his Sato horn and he is impressed. As I said before he
installed many horn systems and he has visited allot of horn gatherings. If he
says it's good we can count on it.
If it would not work WE would not have coupled the 555 to their 15A
and installed it in Theatres. After the modification of the K55 the
resoponse is almost identical to the LM555 telling us that Dietmar achieved
the goal we were persuing with the K55.
Theoretical arguments are all valid and fine but at the end our ears decide
what works and what not.

Klaus
 
No, that's the common mistake. It is a Kugelwellenhorn
It has a different horn contour wich is close to a tractrix but not quite.
the difference is only at the mouth, so it only affects the lower part of the range. Directivity up high is the same (ie beamy, but smooth).

And Germans have bad hearing?
As you know Klangfilm is a German company, and those German audiophiles that go to the triode festival are (with good reason) proud of that company and its history.
Looking at your nickname I think that you know what "brand loyalty" means ;)

That said I was not there, and did not hear any of the horns presented there, but I think nothing can be concluded from those results for various (and numerous) reasons (nothing was equalized for precise matching, some drivers were defective, the test was sighted, the listening conditions were clearly bad with a lot of reflective surfaces nearby, etc.)
 
Scott,
I have used cone driven midhorns from as low as 300hz and up to 1.5khz with the 10" cone driven radial horns. I also have a much smaller horn that you can somewhat make out in my avatar that is good from 600hz on up to perhaps 2.5khz though I normally used it also up to about 1.6Khz. The horn has a compression chamber, no phase plug and a sealed back chamber. The loading is approximately 25% depending on the actual driver used. The mathematics and the shape were covered by patent at one time long ago. Basically I will tell you that from the pinch, or narrowest point the flare rate was an inverted flare following either an exponential or hyperbolic rate. This removed any flat sections in front of the driver and created a small chamber that was only as large as the sd of the speaker used. There were no reflective surfaces and the rate could be varied to load as you wanted to do.

Radian,
I suppose I am much older than you are and have grown up with horn loaded systems, so to say that I don't know what they sound like is your mistake. I still enjoy them but not so much in a small room with large horns, the integration of multiple large horns just doesn't work well for me. Smaller horns like in my avatar I can work with in a smaller space as the center to center distances are not so much as to cause problems. If you are talking about WE horns and devices you really need to look at what they were made for, and this was movie sound tracks that were nothing to speak of at the time. At the same time I still think that the Ubangi double 15" radial bass horn was one of the best designs of its time. I actually have 8 throat sections molded for double 18" bass horn sections that I have sold to people for PA in the past and they would work wonders as a pair in a large enough room. We replaced 16 John Meyer horn loaded cabinets with 4 of these horns in an outdoor PA and then trounced on the JM cabinets with 16 15" drivers. So don't think that I don't like or appreciate a good horn or waveguide design.
 
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Thankyou, Sir

Scott,
I have used cone driven midhorns from as low as 300hz and up to 1.5khz with the 10" cone driven radial horns. I also have a much smaller horn that you can somewhat make out in my avatar that is good from 600hz on up to perhaps 2.5khz though I normally used it also up to about 1.6Khz. The horn has a compression chamber, no phase plug and a sealed back chamber. The loading is approximately 25% depending on the actual driver used. The mathematics and the shape were covered by patent at one time long ago. Basically I will tell you that from the pinch, or narrowest point the flare rate was an inverted flare following either an exponential or hyperbolic rate. This removed any flat sections in front of the driver and created a small chamber that was only as large as the sd of the speaker used. There were no reflective surfaces and the rate could be varied to load as you wanted to do.

Thankyou for your answer>
I have, on the "back burner projects list" an intention to do a VERY modified
Altec A7. I'll call it the 515 for reasons that will be revealed once I build the dog-gone thing. After studying the classic old design, I thought, why on earth
should I mount my prized 515-8G such that it faces some flat piece of wood on it's edges (?) I only intend to go as high as 500Hz with said driver.
 
Scott,
Anyone who is nearly as old as I am will know the Altec A7 anywhere in the world. It is just so iconic. That being said the ports on those cabinets never really were a great idea. The way that they covered a major portion of the driver face with the flat section was for ease of manufacturing with the available materials at the time. I would take a good look at a Ubangi bass enclosure if I was you. Not sure if that was RCA or Western Electric but I want to say it was an RCA enclosure.
 
No this was the battle field you created. You just brought in the JBL 2482
wich neither is better than the modified K55 and is way more expensive to
obtain. What use was this for the discussion at hand.
The reason I introduced the K55 was that many people who have heard the
WE555 on the big WE horns report excellent sonics in the low region which
tells us that this driver is just very good for this kind of application.
I have yet to see any post that rave about the how excellent the JBL does
in the lower than 250hz region.
Dietmar did not specify the input to the modified K55. What he said is that
the the Line Magnetics 555 was not any better on paper, and that he has
cranked the volume up and he did not percieve any distortion or ill effect.
He has probably heard and set up more big horn systems than most dedicated horn lovers.

Here is a pic of the modified K55. Just a Peavey magnet structure glued
on with a little felt cavity attached to the vent hole.
Before is black and after the mod blue line:

Decent looking plots, is there a link you can provide to a thread detailing the build, I understand it may be in German, that is ok.
 
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Joined 2008
Paid Member
RCA

Scott,
Anyone who is nearly as old as I am will know the Altec A7 anywhere in the world. It is just so iconic. That being said the ports on those cabinets never really were a great idea. The way that they covered a major portion of the driver face with the flat section was for ease of manufacturing with the available materials at the time. I would take a good look at a Ubangi bass enclosure if I was you. Not sure if that was RCA or Western Electric but I want to say it was an RCA enclosure.

Kind Sir,

IIRC the Ubangi was an RCA design. I had certainly entertained the notion to replicate it, but, it requires dual 15" drivers mounted verticle, and I just don't think for my listening distance (13 feet) I'd be comfortable with the overall height that would put my midrange at. What I DID LIKE about the Ubangi, was, the curvature of the Ubangi "lips" would match that of my EV HR 9040's that I intended to use above it. Yes, I do realize an exact A7 is just as high (maybe even more so? not sure?) as the Ubangi, but that was why my
intention was to seriously modify an A7 down closer to what the "Perkins" enclosure was. In the mean time..... I am seriously enjoying my hodge podge.
(see enclosed)
kindest regards from the land of Dixie :)

Scott L
 

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