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.

haralanov wrote:

…. acoustic filter does not rotate electrical phase of the signal.

Romy the Cat wrote:

since I know that you do not deal with horns and discuss it only as theoretical exercise I am not sure what we are talking about.

Romy the Cat wrote:

haralanov wrote: …. acoustic filter does not rotate electrical phase of the signal. I do not think it is correct.

Romy the Cat wrote:

A horn, when it does low-pass filtration due to horn death, introduce the same phase shift as your electrical coil would do.

haralanov wrote:

This experiment was made a few days ago by a friend of mine who is speaker repair person. The modified compression driver is Soviet made 1A-16. If you have the chance to compare the single layer VC vs. the original VC and to hear how much better the lower inductance VC sounds in reality, you will no longer question the inductance importance.

haralanov wrote:

Come ooon, even the monkeys in the jungle know it is correct :-)) Everybody knows that acoustical filters has nothing common with the electrical/digital ones...

haralanov wrote:

The horns are not acoustical filters (although they behave like filters), because there is no sound absorbing material to absorb the HF part of the soundwave. They only boost the lower frequency range of their working spectrum, so their upper octave loses amplitude compared to their lower octave. This is called equalisation - not filtration (and it rotates the phase). The filtration is when you get a towel (or a paper cone) and put it in front of a given source of sound. And it does not rotate the phase :-)