Romy the Cat wrote:

Ok, let kill the subject of Oleg Rullit out of this thread. Rullit has very little to do with horn and consequentially with compression drivers. Sine this thread is about MF compression driver I think there is no reason to pay attention what Rullit does. Oleg does whatever is doible and sells whatever is saleable. He most likely has no interest or aptitude to evaluate compression drives.  If you look what playback he is involved then you will see only open baffles or very shallow horn that mostly work as open baffles. His drivers are basically full range drivers and it is very far from environment where compression drivers used. BTW, I do not take audiofilofine unhappiness with Rullit too serious. Any critiques without providing specific reasons or justifications are just shaking of air. The Cat

Romy the Cat wrote:

I will slowly upload, as time permits to write them, different posts on the subject of Ultimate MF Compression Driver.

I wrote a lot about colors at my site and people know that color discrimination of channels is very high in the list of my proprieties .  The color discrimination is a complex subject itself that encompasses the Absolute Tone and, color sensitively, continuing color, stability of colors and many other subjects. It is not my intention to elaborate on color topics in this thread. However, thinking about Ultimate MF compression driver I can’t avoid to think about colors and what is the most important – the color control.

First think first – I do not know where color comes from in compression drivers. Many  people make many claims that they do know but I did not see yet single compression driver that has deliberately proper amount of colors.  Many people think that more colors the  better, they are wrong as usually. Colors in compression driver is like salt on your steak. Without salt the meat might not feel cultivated, with too much salt the meat is destroyed. It has to be very right amount and it has to be very right amount of colors. With excessive amount of colors playback or a channel begin to demonstrate colorations of the satiation when specific colors become overwhelming force. Many audio Morons do not understand different between color power and colorations, I do.  I not only understand it but have ways in my own playback to enforce it.

Still, my way to enforce the deliberateness of colors (with use of Injection Channel) is superbly powerful and I do not even think to use have Macondo without Injection but it is not Ultimate way to have color control. In Macondo I use Vitavox S2 driver that is the most powerful color discriminator I have heard among compression drivers. Furtherer I drive it with very unique output tube that has a lot of own color attitude. Still it is not near enough to serve the colors in the way how I feel they have to be and the additional Injection is employed. The Ultimate way would be to have drivers, and the most prominent MF driver, with color control built in. I mean whatever in a driver is responsible for color need to be adjustable. I do not know what it would be but this is my requirement for Ultimate MF compression driver.

A reasonable question would be: if a manufacturer (if the manufacturer “get” the subject as most of them do not) could not make a compression driver with right amount of color force, then the color strength would not be need adjustment? It is good question. The color strength is dissipate-able force. The precise force of color setting would wary with listening distance, room acoustic, type of loading, amplification, the use of a given channel, the way how the neighboring channels interact with the given MF channel. The Ultimate MF compression driver is like puberty: the driver shall ability to be pregnant but to consummate the pregnancy is the business of the driver end user.

There is no know to me drivers with the adjustable color strength, no one even look in the direction. Still, if I am thinking about Ultimate MF compression driver then it must have control over own color output.

Here is another subject that many people would not understand, however some of the advanced Vitavox S2 user will be able to follow me.

The MF compression drivers hat go all the way to 12K-13K region all have own idiosyncratic way to present own upper region. In this article I would like to touch one subject – the texture. I am not taking about musical texture but the texture of sound presentation. This texture is very fine balance between consistency, coarseness and granularity of upper MF range. In upper MF the diaphragms of compression driver begin to break up. The small 1” metal cones that used in direct radiators tweeters break up at 30K-35K but the large 3”-4” cones that are used in typical compression drivers with 1.5”-2” exit break up at much lower frequency  (break up mans to have non-linear resonances). There are many different ways to prevent or to moderate the breakup of cones and here is where the main question arises: how a driver sounds in near to the break up state?

Before I was introduced to Vitavox S2 I was under impression that break up in compression drivers is something that I need to run away and the best drivers are “clean drivers” where all metallic nastiness is well damped or taken care by many other  than damping means. However, living with S2 and with injection later on I come to realization that not the breakup of diaphragms is a problem but the HOW the diaphragms breakup and the precision of the ration between the “clean” sound of driver and the driver resonances in breakup mode.

I know that some Morons who read this site will scream “Ok, now Romy advocates the sound of distorted drivers and sound of compression driver diaphragms with auditable breakup!” Well, I am glad that Morons have their typical idiotic feelings; the fear of what they cannot understand is their main guiding principle. The reality is that a properly implemented MF with properly tuned deliberate metal diaphragms breakup does sound as clean than any other driver topology but it has something else that not many other topologies offer: it has an ability to present very fine texture of compression driver in breaks up mode as the part of organic sound that driver produces. The key in it is right amount and right quality of that none-existing artificial texture.

In a way it works very much like a Photoshop. An image that was shot always has some room for applying a very deliberate amount of Unsharpened Mask. So it too much and you kill the image but if the amount is very deliberate, sensible and very well measured then it works very fine. After all the beef ageing is just a control deliberate spoiling of meat…

So, from all said above I envision that an Ultimate MF compression driver shall have some kind of mechanical HF texture control. Vitavox S2 has fine result in term of texture control but it has no internal way to do it and to set S2 in right controlled break up mode it requires a LOT of ballet with this driver and lot of experience, not to mention that at time some of the ways to control S2’s texture might be worsening for other aspects of this driver sound. So, what I would like to see is the Ultimate MF compression to have an independent from anything else texture control that would allow very accurately to see the bandwidth, depth and damping of the driver HF break up. I think it might be possible by modifying the acoustic impedance of the throat’s screen and creating a front contra-pressure.  It might be also possible to do by having the geometry of phase p-lay to be very slightly modifiable in order to rearrange how pressure is reflected back to the diaphragms. Think about the jet fighter with adjustable configuration of wings… There are a few other ways that I might think of but this is not an attempt to design the Ultimate MF compression driver but rather to build requirements for it.

In conclusion, the most important message is that Ultimate MF compression driver shall have upper knew break up control INDEPENDENT from the way how the driver loaded of low-passed. To my knowledge there are no such drivers in existence.

zako wrote:

THE ONLY COMPANY THAT HAS ADVANCED THE DESIGN OF A MODERN DRIVER IS JBL,,, GOING FROM THE WESTERN ELECTRIC DESIGN TO THE 375,,376...PRO VERSION 2440,,2441...  TO the 2450 types..USEING COHERIENT PHASE PLUG DESIGN TOPOLIGY that unit was adapted to the new 475..476 ultimate PHASE COHERIENT PLUG DESIGN AND USEING BERYLLIAM DIAPHRAMS...    TAD HAD TO REDESIGN THE 4001 driver to the new 4003 driver,,REDESIGNING there PHASE PLUG (5 slit configuration) TAD BERYLIAM MANUFACTURE IS DONE DIFFERENTLY THAN LANSING,, TO KEEP UP WITH JBL,,,JBL HAS ALSO DONE A SMALLER VERSION,,WITH TAD FOLLOWING,,     BRUSH WELMAN,,TRUEXTANT is now making BERYLIAM diaphrams to be used in earlier older JBL UNITS,,,($700 each)  JBL IS NOW MAKING A MAGNESIUM DIAPHRAM for the 476, YOU CAN ORDER either type of diaphrame,,BUT driver are costly..  I FEEL THE NEW VITAVOX S2 is a none starter in design,,  BUT MAYBE BRUSH WELLMAN WILL MANUFACTURE A Be diaphran to fit...

zako wrote:

I SEE IT NOW,,,I DONT UNDER STAND HOW MUCH AUDIO ENERGY COMES FROM THAT COIL CORNER (Thats what I call it) BUT I GUESS EVERY BIT HELPS...

zako wrote:

Recardo,,,,its obvious you dont know how to read...soon all schools will also drop cursive writeing,,,how will the kids place the signature on a document,,,print it?  Your luckey a didnt write  in russion,,,offensive would be if i told you to feck off,,audio speaker design has takin a slow but positive advancement in quality design.. A good example is the jbl 1501 woofer a engineering marvel..the new vitavox company is going over old ground hopeing to cash in on old nostalga..i hope in the future they will introduce some thing better..

Romy the Cat wrote:

So, if the Ultimate MF Compression Driver is used from 1000-1500Hz then why shall it be able to play 500Hz? The answer is: he harmonic reserve – the driver that will be suited for 500Hz will have larger cone and softer sustention and consequentially it will play 3khz with more harmonic richness.