I keep receiving those emails when people complain about the ballooned publicity and stuffed reputation of Vitavox S2 compression driver.  I completely agree: the Vitavox S2, in the way how the Vitavox originally used it in their speakers and in the ways how ALL people with whom I’ve spoke continue to use it today, is NOT particularly interesting driver and has a LOT of problems. However, there are ways to use this driver and the special precautions, that might take it’s performance at totally a different level, and this level would not only be marginally more “interesting” then the “default” Vitavox S2 but also supremely more remarkable then any another compression driver out there.

The “Vitavox’s S2 Survival Guide” is currently being written and will be posted in here and at the Peter’s Vitavox Unofficial Site (http://website.lineone.net/~empson/) when the writing will be done (I could estimate a couple weeks, depends the time  and mood I have in my disposal). Let stand by and have fun observing the “revised” EBay prices. The VitMessiah is coming….

Here is the list of the thing to do with Vitavox S2 in order to use it in 4-ways installations. The S2 must not be used in 2, 3 ways systems. It possible to do with S2 whatever you wish but pretty much any other way to utilize them produces some very specific sonic negative manifestations that I very much might name.

1) After you get your S2, form whatever junk yard you got it, you should inspect it and to confirm that the magnets are fully charged. I usually do not stress the compression drivers by driving them with 2.38V. I have plenty of know sensitively drivers to make a comparing judgment. However, the most comfortable way is to "measure the both of the drivers and to assure that they produce the acoustic pressure equally within .25dB at 5Khz. (do not use 1Kz with S2, there are reasons for it). It is highly unlikely that both of the drivers would be discharged equally. It is very seldom that S2 would be discharged by electrical force of DC component but mostly it might happen then it experienced a mechanical or temperature stress. If a driver is discharged then charge it at the Vitavox’s Mike’s place. 

2) Peace an order to your horn-maker to manufacture for you a pair of a 550Hz tatrix round horns from as soft/damped wood as you will be able to get. Give to the horn-maker VERY precise diameter of the throat. No adapters from another size throat should be used.

3) Remove the front bag-screens (3 small bolts), clean them up and put them back. Do not remove the bag-screens permanently as the bag-screen MUST be there. Besides performing very important acoustic diffuser role the bag-screens create a front-loading contra-pressure the diaphragm and participate on acoustic dumping. If you find that the compression drivers (and particularly S2!!!) sound better without the bag-screen then you have to trash or your electronics or your ears or your listening taste.

4) Remove six bolts on the back of the driver and take out the back plates.

5) Un-solder the diaphragm’s leads by a low wattage solder, remove the diaphragms, the diaphragm’s plates and the gaskets.

6) Inspect the diaphragm. There is 99.99% that you have an aluminum diaphragm with metal surrounding, that is the original Vitavox diaphragm (they actually had 3 different types of the diaphragms). If you have no aluminum diaphragm with WHITE PLASTIC SURROUND (not clear transparent, metal or milk but white plastic with litz round, not flat, wires) then trash you diaphragms. Order a set of NEW production diaphragm from the Vitavox’s Mike. His contemporary production is WAY more interesting sounding then the original old diaphragm. If you feel that to waste another few hundred dollars to this project is too much then you then have two options:

A) Do not read further on and, concluding that Romy the Cat is idiot, to continue to use the S2 “as is”

B) Get yourself some JBLs, Altecs, TADs or the similar toys: the Vitavox is way above your handling abilities and sonic ambitions.

I personally never was able to get a result that I would consider sonically satisfying from the original fully metal diaphragms. If you see me sealing the “fully-metal” diaphragms on eBay and claming that they are the best because they are “original” then just smile….

7) Unscrew the binding posts and clan the surface under the bottom. Your driver is 50 years old and you have to remove all dirt and the possible cockroach’s legs in there. The binding posts transmit signal via a physical contact to the soldering plates, they are not soldered. You want to make the contact surfaces clean and preferably treat it with any know to you de-oxidizer and contact cleaner/conditioner. Tight the binding post’s nuts quite strongly.  If you on one of those idiots who tight the big and heavy cables from amps to the binding posts with those heavy-duty tools (I am) then be advised that those binding post’s nuts will hold the moment of the tightening. If your binding post is slightly turning then disassemble everything (primary because it will not be a secure contact (pass) for the signal) and tight the nuts again (and at the moment it will be a lot of affords invested into the S2, read on)

8) Clean the S2’s gap. Many people have different ways to clan the gap but old-good mask tape will do. It might be quite tedious. I will not elaborate on it as all percussion and warnings about the gap cleaning are well known. I would only recommend before cleaning the gap to mask out the entire back palate of the driver and collect on the making tape all dirt that will be dropped there from everything. The gap is never could be too clan and I strongly encouraged to over-clean it.

9) When you get the new Mike’s diaphragms install them into the driver according to the his/Vitavox instructions.

10) Place the diaphragm’s palates and screw the palate’s 6 bolts into thier slots. Screw very gently those bolts; the order is not important but DO NOT TIGHT THEM now.

11) Now you have to tune the driver and it might be complicated. The tightness of those six bolts will HUGELY affect the performance of the driver. In many instances the 5-degree of one of the bolts will distinct the sound of your drive from bad to good. By aligning the diaphragms you will accomplish 2 things:

A) Center the coil in the gap and make it do not scratch the walls) or do not touch the junk that you left in there)

B) Tune the driver sonically, even if it is has been already properly aligned.

12) To accomplish the 11A is relatively simple. Many people use different methods: distortions analyzer, high voltage full-driver-range frequency sweep, RTA with maximum response around 600-900 amplitude, injection a signal into the secondary resonance and so on. Use whatever method you want but your driver should not have any alien sounds during a sweep. To work with 6 bolts alignment is relatively complex. Use 2 opposite bolts to start and when you reach a perfect result for 2 opposite bolts then add the forces of the rest 4 bolts by tightening them in X-order.

13) To accomplish the 11B is relatively difficult. The RTA will not help even if you have a reference sweep from another driver at 0.1 dB resolutions. The problem is that a very minute tightening of those bolts will still maintain the driver in a perfect “11A state” but will quite auditably affect harmonics and obertones, or the “11B state”. The distortions analyzer is very valuable tool but I learned that the best sound I was able to get NOT at the lowest distortions measurable level, not to mention the it is very difficult to fix the diaphragm’s plate at the mathematically best position (remember your have 6 damn bolts in there to screw but just one life). I tune the diaphragms at the 11B level by a hearing, Take a good contralto singer, connect the amp to a driver with it’s opened back plate, pace the driver on the table with a hole to let sound to go out and play music (I accustomed to do it by playing Polish singer Eva Podles singing the Stravinsky’s Oedipus Rex). It will sound for a beginning kind of st
range but soon you will figure out Sound and will be able to detect the relationship between the few degree of the bolts turns and the sonic result. The more LF harmonics you get the best it will be (it will open also a lot of HF). It is possible that you will screw up the 11A setting but it is not important, as when the coil will be properly alighted at 11B then it will be automatically properly set in11A. You may abandon the aligning at 11A but it you want to get all S2’s  “kinkiness” while it will be handle the crescendo of the string group during the second movement of the Tchaikovsky 5th symphony or a dynamic attack of a good soprano then better to suffer now then later. The 11B alignment works strange: some of the drivers could be tuned within a few minutes and I have seen some S2 that I was not make sound good at (11B level) for weeks. Go figure!

14) Remember the final tuning can’t be archived but only escaped or abandoned. Somewhere during this process you should find a peace with yourself (remember you have 6 damn bolts!!!). You have to approach the ceremony of tuning being in a very comforting mood. It is very similar to alighting TT’s cartridge, did you try to do cartridge when you pissed or not completely calmed? You got the message….

15) When you finish with the 11B then place the back plate and not you are ready to move further.

16) Get your new 550Hz horn and screw the driver in. Do not use the 330Hz horns as you loose HF, dissipation, useful upper mid rage resonanses, closeness of positioning a tweeter (larger horn) and few another things.

17) Place the horn in wherever system you intend to use it. Align the diaphragms of your upper bass channel and the S2. I usually do the alignment by connecting the channels in opposite phases, applying the 1KH tone after the crossovers (look lower about the crossovers) and move the horns until the maximum analyzer’s cancellation will be observed.

18) I will talk about the crossovering in context of passive speaker level crossover. IU will do it order not to go into the diversity of line-level, feedback- level or any other crossovers you might employ. Convert my comment into whatever crossovering scenario you use. If you decided to use S2 then I presume that you are not a complete moron. There are a few other conditions of being none-moron, namely: no use any digital crossovers, no higher order filtration for MF then first, no Zobels, no impedance equalization, no resonant filters, no notching and no any other idiocy. So….

19) Let the upper-bass channel to roll of ~ 1000Hz with first order.  The precision of the upper-bass low pass crossover point might fluctuate upon few parameters (driver, topology and many others) but usually it will be around 800Hz -and 1200Hz. I presume that your upper-bass driver was property selected for the “correct” integration and a proper “1 order penetration”. Use whatever evaluation method you know to make sure that you use a correct upper bass driver. (A tip: make sure that the upper bass driver sound good at 3-4octaves of it’s low –pass crossover point)

20) The Vitavox S2 has primary resonance somewhere around 400Hz and the secondary at 1250Hz. Here is the S2 response in the standard Vitavox 330Hz horn     

http://www.goodsoundclub.com/Site_images/S2_NoCrossover.jpg

As you see it is a freaking rollercoaster and the secondary resonance is screwing everything very dramatically. Interesting that in this picture the 109dB sensitively corresponds to 74.5 dB of reference point. Whatever happens between the 400 and 2,5 is pretty much unnecessary for you garbage. So, get any known to you soft capacitor of 3uF and place it in series with the S2 driver. This will introduce to 15 Ohm of the S2’s load a first order slop starting approximately at 3,500Hz. The beauty of this cap that is quite nicely snatched all wildness of the ugly secondary resonance. Ironically, it also slightly boosts HF and “accidentally” progressively flattens the response to the place where the roll off of the horn kicks in. Here what you get with the 3uf cap. (Disregard that it is measured at the different reference volume)

http://www.goodsoundclub.com/Site_images/S2_Crossovered.jpg

21) Now you may listen your S2. Completely disregards that fact that it runs to 10-11KHz only. At this time you can hear what S2 does and why it’s upper mid is totally different then any another driver. Do not be in hurry to peace a tweeter in there and spend some tome to listen it “as is”.

22) If (a REALLY BIG “IF”) you have very obligating amplifications, very “honest” cables and generally your installation and your listening preference have high demands then you might detect some idiosyncrasy of S2 at its HF. I intentionally do not name those idiosyncrasies and I do not want to plant the placebo into the process.  Now you might search for a tweeter. However, this tweeter should not inject measurable sound above the S2. Find a tweeter that you believe has the same sonic attributes that S2 has (use whatever evaluation and assessment methods you find necessary to use). Alight the diaphragms, use of course a first order and inject into a listening space a sound from the tweeter at ~15kHz and minus 12dB. Slowly increase the output of the tweeter by ½ db until suddenly the S2’s idiosyncrasy will be gone. If you run .25 dB resolution of your TRA and if you see that the tweeter output have rise over the S2 roll off then your tweeter it too hot. The complete “fixing” of the S2 will happen approximately form minus 10 to minus 6 dB at  ~15kHz or when the tweeter’s output begin to intricately modulate/resonance with the S2’s HF slope.

Now, your S2 is “cooked” and you may listen what it dose “full time”. Do not be bothered that it looks on the paper that it dose not go up enough.  The quality of HF that you have now is not even remotely approachable by any other driver/s or any other method of sound reproduction.  I assure you that if you do not look at the response curve and do not show it to your friends than no one, even in their sickest imagination would complain about “not enough HF extension”. The MF-HF superiority, nobility, alacrity, transient response, musicality, handling dynamic contrast and tonal discrimination that you got now form your “helped” Vitavox S2 driver should make you forget about existence of any doubts to reproduce MF-HF and should make you entitled to show a big middle finger to any another compression driver.  You may spend some time to work on your horn if you wish (damping and mass-loading never hurt) but regarding everything else about the MF-HF: your “hobby” is over. Welcome to the REAL S2 club.

PS: this is what I have now at the top of my mind. Possibly I missed something then I will add it later on.

Added March 2005: Please read the thread to the end as some of the my view about the use S2 have changed since I've written this article.

Hello,

What about the S3 and the other 2 compressions drivers from Vitavox S5/S6?
Are they bad?
Have you try the PA like horn for voice application only. It looks like the Goto!!!

Regards

I would not call them “bad”. They use very different magnets and meant to be used with higher power (with all negative consequences). You see the ceramic magnets are more or less OK for LF application but when a driver goes up and hits upper midrange then the ceramic magnets structure become to sound very distinctively miserable. The ceramic-centered drivers have no bad response, have very low dynamic contrast and few other none-pleasant things. At least it was my founding with the compression drivers generally and with a single S5 that I experimented with.

Rgs,
Romy

Allo Romy,

I have no idea about the above - my gut feeling is that the required thickness of material would be too great, still, I bow to your experience in S2 mods.

I just wanted to mention something that came to mind that might be of interest: I recall reading about some Japanese fellow whos day job was gun ballistics or some such; anyway, apparently he used some tapered rear tubes to load the rear of his compression drivers.

A bit B&W Nautillus tweeter type thing. Should be possible to maintain the correct loading on the driver and absorb the backwave too.

If you wanted to get crazy about it, how about loading the diaphragm with an S2 shell and horn so it sees a symmetrical load?

Cheers

cv

PS the proto of that aircore transformer is due in the next few days;  don't get your hopes up too much cos my winder couldn't measure any pri-sec coupling, but we shall see...

I have posted this idea at the Peter’s Vitavox site a few month back but there is no activity at that site. It sucks that there are no advanced S2 users out there. I am planning to try it myself and in a month or so and will report the result.  Meanwhile, I decided to add this post to the local S2 knowledge base:

*****************From the original post ******************

I have "a thing" that is drilling in my mind for almost a year.
The S2 (and alike) drivers have sealed back chambers. Also, some people (who for instance do not use my twittering techniques that I descried in my “S2 - Survival Guide…”) who use S2 “as is” are familiar with it’s upper frequency harshness…

So…

Making a lot of experiments with back chambers at upper bass speakers I have learned how the reflections in there affect sound. I would project those conclusions to the S2’s back chamber. S2 has a mean metal chamber that SHOULD reflect HF and therefore putting all together here what I think…

How about if to take a back plate of S2 out (it will not screw the driver aliments) and inside a back chamber a thin layer or wool-like or any other material. It should be a very little of it (probably only on the perimeters). It should slightly subdue the reflection but do not change volume. Alternatively it might be a lot of damping there but then the delta of the resonance frequency (volume of the chamber) should be corrected back to where it used to be by making the back chamber smaller. (Wool-like material will drop the Fs, making the chamber virtually larger)
Anyhow, did anyone tried to do it with S2. I would love if someone try and report what would happen. Unfortunately I have no time nowadays. But I will definably try in future…

Meanwhile it is all yours and I have a feeling that it SHOULD work

The Cat
September 15, 2004 10:19 AM

Hi Romy,

I own myself a pair of S2, but still have not time to listen to them. I have just received a pair a 380Hz "hypex" round horns especially designed for them.

You speak about a new (and better) diaphragms for these babies, could you tell me where to find them? I have try to make some research on Vitavox's Mike, but without success (maybe I should learn how to use the internet).

Thanks in advance,

Jean (France).

Try Mike at info@octave-aw.co.uk in Bristol, UK.

Good luck,
Romy

Here are never opened before 50 years old S2 drivers dissected and ready to be "cleaned".

Last week I have written an article: “Upperbass preoccupation and Vitavox S2 driver” where I ran over some my thoughts how the specific sonic virtues of Vitavox S2 driver allow to get an “interesting” upper bass from an upper bass channel, even thought the S2 does not go to upper bass. In that article I said that the Vitavox S2’s 500-1000Hz region is so stunning that I can hardly imagine that a person would hear it once in a proper horn and with adequate amplification and then he would ever consider any other way to reproduce those frequencies. Really, no other driver or methods of reproduction, even in wildest dreams can’t even REMOTELY touch the quality of Sound at the S2’s lowest region(<1000Hz). So, in the article, besides everything, I was bitching that in my playback I was not able to take a full advantage of the S2’s <1000Hz.... However, after reading for a few times I decided do not post the article. Some of the comments I made in there made me to think again. So I did, and while I was thinking I stared to question if is there another way to use the S2, distinctively from how I’ve been using it for a while.

After some thinking I spent an hour to rewire the Macondo and another hour to re-measure everything. Then another 3 hours to search among all my S2 drivers the one that would perform at the new demands (they all quite different) …. In the end I've found an interesting combination when Vitavox S2 was not used as before but very differently; with quite different measurable results. It sounds quite different as well: I can’t say if it is better or worth and there are some objective reasons that prevents me make any assessments at this point. I will elaborate in a couple days on the way in which I’m trying to use the S2 now and how it sounded.

Rgs,
Romy the Cat

I just posted yeastoday the post above and have got already a few emails asking about the “new” ways that I am planning to use S2. OK, let me to explain what is going on.

The default Vitavox S2 driver comes with thier default aluminum diaphragm with metal surround/suspension. My previous experiments indicated that this diaphragm has some harshness and the very high frequencies (10-12kHz). I would describe is as some king of resonanses that although sound spectacularly attractive but they still alien to authentic sound. There are many ways to fight with those resonanses starting from a radical-barbarian approach that used by some guys in UK (they use S2 with very-very mild low-pass coil) to the way in which I do it (use a HF resonator to stretch/modulate those resonanses into useful HF) However, this is all about a degree of the affect. I learned that my “HF modulator approach” (more about it at “My Playback” at the Macondo section) works wonderful ONLY if the effect of S2’s HF harshness is very minor. If the harshness is too much then the “HF modulator approach” can’t eliminate it completely but juts minimize it.

Continue playing with S2 I discovered a few years back that the contemporary production of Vitavox S2 diaphragms (the aluminum cones with plastic surround/suspension) introduce way less HF harshness and for the years this was my chose how to use the S2 driver. With the contemporary S2 aluminum diaphragms the top frequencies are way smoother. However, those diaphragms have a huge secondly resonance at 1250Hz. To deal with it I used 3uF cap injecting 6dB per octave at 3.8kH that brought the S2 to 1kHz slop effectively flattening the secondly resonance bulge. (Refer to the image) Form one point of view this prevented to use the magnificent lower knee of the S2 driver but I have good-enough upper bass channel that took if form there. Also, the 3.8kH solution introduced a high electrical crossover point permitting the driver to have plenty spare exertion and to have a few “auxiliary” octaves under the crossover point.

Recently after writing the unpublished article “Upperbass preoccupation and Vitavox S2 driver” where I admired the S2 lower slope I asked myself if could I do something to take more advantages of it. In past I tried everything (including use of two paid of S2 – before and after the bulge) but I never was able to do anything with the secondly resonance swelling. And opened 6dB filter worked fine in there but as I was closing the EQ with another slope (a typical Zobel filter) then the bulge went away and along with the bulge sound when to toilet. I learn long time ago that if a speaker uses any impedance normalization networks then those speakers should not be used. My countless experiments with the Zobeling the S2’s swelling did cure the swell but converted the Vitavox S2 into Altec/JBL…

Anyhow, a picked among my S2 drivers the one that with old production diaphragm (metal surround/suspension) gave me a flat response all the way down to the horn’s roll-off, aligned the diaphragms, placed a huge (size of Coca-Cola can) Jensen 15uF/200V cap in serial with the driver (~700Hz first order) and screwed the driver into the Macondo.

Now, the S2 covers the range from 700Hz (6dB) to 12KHz with quite interesting benefit at the bottom knee. However, what I found surprising that the upper knee harshness now is way less aggressive then I anticipated and then I remember. Last time I did it those experiment 3 years ago and I remember that the harshness was un-handleable. There was nothing changed since then besides introduction of Melquiades and getting rid of the Lamm preamp from my system. I do not think that Melquiades might be a factor (?!) in it. However, the L2’s brutality at high frequency (with it rusty, "afterburned" sound) is something that very well documented and proved by me and I am sure that it was it. The L2 preamp had wrongly designed PS that made very difficult to get any civilized sound out of is if the tubes were more then 2-3 weeks old; also that preamp was hugely susceptive to the imperfections of power lines. 

Ah, such a beautiful beautiful beautiful beautiful discovery!

After all, after the years of dealing and fighting with it I come up with the observation that the Vitavox S2 driver could and actually should be used “as is”. The harshness that I was reported over the years, and that many people have concurred, is not the problem of the driver but a problem of “not clean” signal path (In my case it was a miserable courtesy to the Lamm preamp)

With the original “metal surround” Vitavox diaphragms and a “clean” signal path (for now Bidat directly to Melquiades) the upper range of the Vitavox S2 driver turned out to be crystal clean with no signs of any harshness! Bingo!!!

It always mystified me how come the S2 driver had this harshness. The Vitavox should not be problematic. Contrary to all other compression drivers out there the Vitavox S2 never was designed to be use as PA driver and never meant to pump an acoustic pressure into the stadiums. The S2 was originally designed to be use excessively for sound reinforcement installations when the acoustic system operates along with a symphonic orchestra. The initial low power handling S2 design meant to be used as sound reinforcement in Royal Albert Hall and Queen Elizabeth Hall where conductors and musicians should not be able to acknowledge that thier orchestra were sonically reinforced.  The S2 must not had any harshness!!!! It always asked myself how the hell they were able to use it if the S2 in my hand always had that “sound a cello with cracked deck” and that “HF of a oxidized tenor”?

After all, after the years of playing with S2, massaging it performance, learning its behavior end providing for it what needed… it turned out that I was using electronics that was not able to handle the transient and speed of this driver! As the result I was curing and headlining the problem that in fact did not exist!

Well, I was wrong, no mater who and how “helped” me to be wrong. I know that there are some people of there who listened me and bought the contemporary plastic suspension diaphragms. So, I did, as they are "softer" at HF. You could look at the graph above and made up your own judgment. Yes, with the contemporary plastic suspension diaphragms you still have Vitavox S2 driver and it still sound very fine. A distinction between the Vitavox “old” and new “diaphragms” is not as dramatic as the distraction between the Altec aluminum and symbiotic diaphragms for 808 and 802. In fact the Vitavox cones sound very much alike but they should be used differently.

The plastic suspension diaphragm has the secondary resonance bulge that pretty much prevents to use the driver across 1000Hz, also it has ~2dB less output about 3.5Khz.

The original metal suspension diaphragm is dead flat form 500Hz to its top and it has +2db at its upper knee compare to the cone with plastic suspension. I do not know if the plastic suspension diaphragm is more forgiving above 8kh or what whatever other reasons but with SS-like electronics (whatever it means) the plastic suspension diaphragm sound cleaner and much less stressed. However, with the clean and high quality signal I would go for the metal suspension due to linearity of the response, due to ability to use the stunning S2’s lower knee and due to gaining the the 2dB of sensitively.

What I am saying might lead to a conclusion that the vintage metal suspension cone has a higher resolution at HF. I would not say so. The word “resolution” is not really applicable to Vitavox S2 – it really operates above this definition. The S2 has own very idiosyncratic upper range with own helpful resonances injected into sound.  I feel that that original metal suspension diaphragm does it bolder and more aggressively then the plastic suspension diaphragm. As the result, the metal suspension diaphragm operates at more dangers “resonances mode” and presumably it imposes an extra strengthen/demands to the cleanness of signal, at least my Lamms were not able to handle it. For people who are not familiar with a properly sounding Vitavox S2 the idea a driver inject some kind of artificial resonances would be ridicules and threaten. Find your ways to hear what S2 does and then made up your mind.

I hope, this thread will be useful for S2 users out there. I have now my S2 running with the original diaphragms in the very same way in which it was made 55 years aback: I have no HF harshness at all.  The Probably to finalize everything it would require to bring my Lamm ML2 and L2 back to my system, get the harshness back and to name exactly which component was responsible for the failure. I can tell with 100% confidence that the guilty party in my case was the Lamm L2 preamplifier (or what they call “L2 Reference”).

Well, it was quite interesting and educational journey, learning, investigating and debugging of playback. The good part that everything turned to the direction and has settled down how it should be and the final result got better then the previous one. I made in past some mistaken conclusions about the use of S2,  I made them due to my blind trust of due to my Moronity I do not know and do not particularly care. The important part is that I moved forward and this is what an evaluation is all about…

guy sergeant wrote:

I feel very pleased for you. I was always somewhat puzzled by your descriptions of how you felt the S2 sounded, particularly between 600 and 1200 Hz. My experiences with a few different horns but always with a good quality SE amp were invariably to the contrary.

Hm, I do not think I ever question how the S2 sound between 600 and 1200 Hz. In fact I always told that this is the one of the most magnificent regions of S2 (actually any region is wonderful in there). However I never was able to use the S2’s 600-1200 Hz with the contemporary plastic surround diaphragms. Pretty much the post above all about exactly that.

guy sergeant wrote:

I would never have used the drivers with something as complicated and nasty as the Lamm electronics and expect to get a good result.

Hm, OK. May I ask you what you find as complicated and nasty in Lamm electronics?

guy sergeant wrote:

To what extent does the inherent inaccuracy of the Lamm Electronics modify your opinions of your preferred Cartridges and corrector.

“Inherent inaccuracy of the Lamm Electronics” … Hm, I thin you guy did not read my comment correctly. If I commented on the very specific and the very exact negative attribute of a Lamm preamp then how it get converted into the “inherent inaccuracy of the Lamm Electronics”. I would like to learn about it “inaccuracy”. Just because I got of this preamp it does not mean that I or anyone else should trash, and particularly without having reasons to do so.

guy sergeant wrote:

It may perhaps explain your fondness for the very ordinary, woolly, and warm sounding EAR phono stage not to mention the murky Koetsu cartridge.

Would you please explain what kind rationale you used and how you connected my two posts above with my positive results regarding EAR and Koetsu. I juts am not following you. From a different prospective this is a thread about the Vitavox S2 driver…

Rgs,
The caT

cv wrote:

Honestly, we're gonna have to start calling you Romy "magnetar" Bessnow if you keep changing your mind like this...

I understand you sarcasm but it is what it is. I did not change my mind but the conditions of the game were changed. I consider it as a positive change as this change is something that connects something else that that address the multiple issues at the same time.

cv wrote:

Reassuring to hear that the S2's empire is expanding its borders unchallenged. Looking forward to hearing how Macondo evolves; may I suggest that if you are going to try a bigger horn with the driver that you consider the JM Le Cleac'h flare? The large roundover helps prevent reflections and I believe it may be less susceptible to the tractrix in this regard anyway. I suspect this is why you find fur balls in the throat of the horn useful, the JM may not be as needy.

Chris, my first reaction when I got the S2 win flat all the way and with no HF problems was exactly like you suggest namely to go for 250Hz flare and run S2 down to 500Hz. Then I started to think  - the deeper horn the narrower dissipation and more HF roll off… So, I do not know… In addition I really would like do not introduce second order high-pass on S2. A short tractrix is fine by me because it is short that has huge number of benefits. I have no experience with JM Le Cleac'h curve. I still here and there consider it but at this point I have ho motivations.

cv wrote:

Oh, on a side note, Roy Gregory said in this months HiFi+ (in the review of the Zanden CD system): "We learn lessons along the way; in the case of hi-fi, they can be attributed to individual components. The Lamm ML2 taught me about tonal (as opposed to spatial) separation."

Lamm ML2 is totally different story – it is problem-free amp, has some limitations but has no problems. I was talking about the L2 preamp… BTW, I did not read the article but I would agree with Roy – Lamms are in some way limited in their spatial qualities and their primary accent on tonal accuracy and about tonal connectively. I the last the Lamm’s SETs are undisputable kinds.

cv wrote:

Sounds like he needs to pay the cat a visit....

You most welcome to visit me, Chris. Anytime…
The caT

guy sergeant wrote:

In your earlier piece about how to use the S2 'properly' you wrote "Whatever happens between the 400 and 2,5 is pretty much unnecessary for you garbage. So, get any known to you soft capacitor of 3uF and place it in series with the S2 driver. This will introduce to 15 Ohm of the S2's load a first order slop starting approximately at 3,500Hz. The beauty of this cap that is quite nicely snatched all wildness of the ugly secondary resonance." You also recommend the use of a 550 Hz horn which will really only allow the S2 to work effectively above 1000 Hz or so. There's no mention in this earlier piece of how good it can sound from as low as 500 Hz upwards. I don't think I've ever seen you mention this before.

Guy, the lower knee of S2 was always a subject of my attention and admiration, (actual this was what attracted to me this driver initially) however I never was able to use it over the “bulge” This why I experimented with running two S2 in dual configuration: one before the secondary resonance and one after it. You might look at the Vitavox forum where I bellied I have wrote about it. My problems was the I in the very beginning of my excrements I was not able to get a clean upper regions out of S2 and consequentially I disregarded the original “old” cone with metal surround. I remember I spent a lot of time fining with this problem, sparking with few flask out there, including Mike. At that time I did not know that the problem was not with the cone but with the Lamm preamp. In the end I went to the contemporary cones that are “bulgey” and make the use of the lower S2 knee impossible.

guy sergeant wrote:

Now you seem to have realised that the Lamm preamp was adding an unpleasant element of hardness (distortion) to the sound. Having removed it you now find the S2 to be both more usable and more acceptable all the way up.

Exactly, what it is.

guy sergeant wrote:

The Lamm will have been imparting this characteristic of harshness to everything you fed through it, be it the CD player, the phono stage/cartridge combination, whatever. You surely must feel the need to re-evaluate the components in your analogue playback knowing as you now do that the Line stage was introducing sufficient distortion to make the S2 unlistenable in that region. I know I would. I suppose the problem now goes back to your earlier post about finding or trying to build a totally transparent buffer.

You are not exactly correct in here. It is correct that Lamm preamp have contaminated everything I fed through it (the roughness of it changes dramatically depends of severity of some aliments) but in my playback, using the S2 with plastic surround and HF resonator the problem did not exist most of the time. It did show up sometimes but always attributed it to the external reasons and always was able to address it via managing those external reasons. Now I understand that it was a self-delusional. Well, I ma not particularly proud about it but it is what it is. Once again: when the electricity was correct and when the L2 rectifiers and regulator where no older then 2-3 weeks also the system sounded quite fine with not signs of harshness. Actually it is not juts the alleged S2 harshness. When L2 begin to die then there were some other negative qualities crawl to the picture…

guy sergeant wrote:

Based on limited exposure to the Lamm electronics a year or two back, on speakers I know well, I would say that I found the poweramps ok, if a little slow and vague. The linestage I heard then sounded, (for want of a better word) dirty and not interesting enough for me to pursue it further. Whether they were or are exactly the same models you use, I don't know. I was underwhelmed. I have had the opportunity to look inside a few of the pre-amps when they are exhibited at various shows. I don't have the schematic diagrams. As I recall they use quite a number of large electrolytic capacitors and solid state rectifiers. They're built on printed circuit boards. They use solid state regulators as I recall. You might tell me that all those items can sound ok but you're also the one telling us that the Lamm pre-amp has been the culprit hindering your efforts in getting the best from the S2's.

I understand what you are saying. Look at this: I have been using (and fighting) with Lamm preamps since 1999 and had before and after 1999 all possible preamps (regardless the price and complexity). I never heard preamps that do anything even remotely similar to what L1/L2 (not LL2) dose to sound. I described it in the following article:

http://www.goodsoundclub.com/TreeItem.aspx?PostID=257

I still feel that only for the introduction of X-factor (intentional of not) the L1/L2 should be placed at imaginably high pedestal. What the do form point of view audiophile transparence is a totally different story and they never were an exemplary.

guy sergeant wrote:

Don't take too seriously my comments about the EAR and the Koetsu. Both have always sounded 'lush' in my experience. I was only wondering whether the Lamm linestage had made their characteristic bloated qualities (my opinion) more amenable.

I have no problems with both EAR and Koetsu with or without Lamm L2. However I do not remember that I was such a huge supporter of Koetsu. I like it and I use it (Onyx only) but I never consider it as my favorite cartridge. In my First stereo arm never was Koetsu.

guy sergeant wrote:

Of course this is a thread about the S2 but your whole re-appraisal of it is due to your pre-amp or now your lack of one, hence the comments regarding what other re-evaluations its removal/replacement might necessitate.

Ironically, I do not feel that my appraisal or re-appraisal means anything. There are a lot of people coming to this site pulled by the “Vitavox S2” keywords. I think that all comments in this thread, including my appraisals, suggestions and sometimes Moronity would paint quite divert and indicative picture about the capacity of S2 driver and the ways to deal with it. There is no further agenda within this thread then to make information available to public.

Romy the Cat wrote:

The S2 has own very idiosyncratic upper range with own helpful resonances injected into sound.  I feel that that original metal suspension diaphragm does it bolder and more aggressively then the plastic suspension diaphragm.

Many people have read it but ironically no one requested any further explanations. However, this was the only one phase in that entire article that worth something. I think I should elaborate on it.

The Vitavox S2 upper range (above 5K I would say) is in a way unique and quite peerless compare to any other compression drivers. It has own beneficial granularity or beneficial graininess and that granularity has own superbly interesting MODULATIVE QUALITY. This modulative quality combined with some other matchless characteristics create the distinctive S2 Sound that is very much different from anything else out there. The tone of S2 has sort of attractiveness of Koetsu with it lush and honey appeal but at the same time it has a tremendous speed, stunning contrast and incredible transient. The ability of S2 dive into a dynamic extreme is unprecedented but what is interesting about S2 that while the driver dose its “jumps” it maintains its tonal integrity. And it is not juts a “tonal integrity” but a phenomenally nubile tone.

So, what the original metal suspension diaphragms do different? The modulative quality of the “beneficial granularity” is kind of more effective with the original diaphragm and the sound jump form granule to granule more distinctive but less observable then with the plastic diaphragm. I know, it kind of sound almost semantically-idiotic but try to “get” it:

Pretend that you have a surface that is not smooth but consist with micro-granules and each granule is unique and valuable. Now you move your head across this surface very fact and your hand do not recognizes that the surface is not smooth because the speed of the head is too high. So, with the original metal suspension diaphragms the hand move faster and the granules are sharper. With the contemporary plastic suspension diaphragms the hand move slower and the granules more dull. The total effect of smoothness of the surface is preserved in both cases but in the case of the sharper granules there is more chance for the each granule to introduce own impact to the process of hand scratching. Now parent this: a 1000 around granules on sq feet and you smashed your hand 100 miles per hour across the granules. This was the sound of JBL 375. Then, you move your hand with the same speed over those granules but the granules now are not round but the shape of pyramid – this would be the sound of Vitavox S2 with a plastic suspension diaphragm. To get an effect of Vitavox S2 with metal suspension diaphragm you have to visualize that you move your hand over the same granules only this time each granule is not a sharp-edged pyramid but an erupting micro-volcano…

I hope you did not loose yourself among my associations and got the picture…

There is another interesting moment that the posters in this thread failed to pay attention. When I go with my “bad” Lamm ML2 the harshness with my Vitavox S2 driver I contacted a number Vitavox S2 users around the world. None of then (NONE OF THEM) told me that they have idea what harshness I was talking about and all of them confirmed it and shared with me their ways to deal with it. Only one of the people with whom him I spoke used Lamm electronics and all the rest of them probably never even heard about the “Inherent inaccuracy of the Lamm Electronics” (Sorry, Guy, I can’t resist). So, would it be possible that that upper region of S2 is not juts hightailed the problem of Lamm L2 preamp but also this driver impose something very demanding to electronics that is difficult to come by? Should the upper frequency harshness of Vitavox S2 be considered “inherent” is not the S2 are running in my system and have thier upper range crystal clear?

This all juts education folks. The time will show up and will provide the correct answers to the correct questions. For now, I’m quite happy Cat, who still has some exciting ideas under my hood….

I recently made some highly attractive changes with the way in which I use S2. Now, since the S2’ top got cleaned up the universal misery of universe bothers me tremendously. :-)

Really, the S2 runs in my 400Hz horn up to 12.5kHz and the S2’s 12.5kHz sound more effective then TAD 4001’s or JBL 007’s 20kHz. I was trying to compliment the S2 with tweeter but it really unnecessary. Most of people out there use the S2 in thier default 330Hz 26” horns that put the driver deeper into the horn where it cuts-off ~2kHz. With the shorter horn the last 2khz jumps out and the S2 do not really need any tweeter. Well, it would be nice to have one (do not ask me why – probably juts in order to please my spectral-analyses) but I do not think there is any tweeter out there the would be able to handle what S2 dose at 12Khz.

Now, how should I use the bottom end of the S2? This is real dilemma! From one perspective I might drop the crossover point and drive it at 500Hz into 250Hz horn. But then I will loose 2kHz at the top. I’m clossing now the upperbass at 70Hz where the S2 kicks in… So, I was wondering.... How about to palace the S2 into an ultra-small ~5kHz horn and then to compliment it from bottom with another S2 in 250Hz horn at 500Hz. In the 5kHz horn the S2 will push probably 16hz and it will be HF that would be untouchable. Ay the bottom this HF channel will face the identical driver in a larger horn. The lower knee of the HF channel would decay acoustically with the horn rate and the low pass on the MF would be a first order. Considering that the are identical drivers it would not be problem to have a tail of any length in there…

Hm, this sounds quite interesting. At the bottom S2 channel I would use probably a plastic diaphragm as they can dissipate more power and less prone to that cracking… This sound quite attractive… Did anyone went to those extremes of Votavoxisisation?

From a different viewpoint now I have the S2 running in it’s optimum configuration for 4-way installation: S2 has a spare octave at the bottom allowing a nice midbass channel entry and it sits in a shorter and wider horn allowing to use it’s maximum HF. What the hell I want from it? I want somebody else to try and tell me how it was… Then I would object it... :-)

:-)
The caT

cv wrote:

The acoustic transformation's probably done by the time the wave reaches the throat.

Yes, it is. If we loom how the S2 internal channel done then it would clearly indicate the it should not be a great tweeter but what whatever reasons it is. Go figure…

cv wrote:

I'm currently running *one* S2 barbarically, while tweaking a few things. It's x/o'd 1st order before the amp at 500Hz on a 340Hz JMLC horn. Btw, the JM flare has a "T factor" parameter that can be used to control how open the flare is - larger T, shorter horn - you may be able to produce a horn that loads the S2 correctly down to 500Hz without sacrificing top.

Are you saying that the JMLC curve could be shorter then tractrix to the same flare rate?

cv wrote:

What you really need Romy is to find someone who will build 2 scale models of the S2; one twice the size for midbass and one half the size with electropolished phasing slits for tweeter duty, stick the standard S2 in the middle and you're done...

Here we go! Not we are taking!!! I would not need the S2 tweeter and what it dose now in 400Hz horn is perfectly enough. I would go only for the midbass S2.  Something with 6” cellulose diaphragm, low to medium compression, 3-4” throat, >2T in the gap and with Fs around 80-90hz. Something similar to the Community M4 compression driver only that would sound good

Ok, now I am officially hallucinating..
The caT