morespeakers wrote:

If there is any info in this or another post about why the S2 is so much better than the Altec 288c please direct me. If not what makes the S2 drivers so different than a 288C? (I am talking about 288'cs that the 24 ohm diaphragms have been replaced with newer Altec aluminum lower impedance diaphragms which I would imagine by now almost every 288 c has undergone) Both drivers seem to have a very similar looking phase plug looking from the back. Stock diaphragms seem similar too. By the  way my main system has 288c's on 500hz round tractrix poplar wood horn at the moment but always willing to try something different.

I do not know other people who use the Vitavox S2, as least who get any results with S2 that I would consider worth attention.  As far as I know I am the only one “public” person who spared noise/rumors about the “unique” S2 Sound. There is “Unofficial Vitavox Web site” and the folks in there heard something about this driver but it pretty much it on internet. If someone uses the S2 driver advancely then, they have no internet presents.

The S2 vs. 288. This is complicated. To me all Altec are slow, not contrasty and decolorized. They have the “nobility of the tone”, that royal tone of the Prague or Vienna Philharmonics… or that lush wet bass tone of the period instruments. The larger Altec do have some size of the lover frequency harmonics but I doubt that it might be useable in context of 500Hz.

Still, my assessment the S2 might be slightly not objective as I juts have nothing else to like among the compression drives and as a result, I picked the S2 because I hate it mush less then many other drivers. In fact I do not really hate it but rather love it. Still, it does not prevent me clearly see some “issues” with S2 driver. This is why I keep working with it.

http://www.goodsoundclub.com/TreeItem.aspx?postID=1929

Rgs,
Romy the cat

jweiss wrote:

When we spoke at CES, you mentioned that your experience with field coil drivers only extended to cone types. So I assume that you have never heard any field coil compression drivers. That would include the WE 555, 594, RCA 1428, Lansing, etc? Also, I would assume you never heard the later RCA compression drivers either?

Yes, it is correct. I never dealt with compression electromagnetic drivers but only direct radiation cones. Also, the electromagnetic that I did use (Telefunken, Klangfilm, Magnavox, Jensen and a few smaller brands) from my point of view were not very good drivers themselves, regardless the type of the magnet, and therefore of judge from them the befits of shortcoming of the field coil as a concept is imposable. My experiments were around running my electromagnetic drivers high-passed and band bass in open baffle and loaded into my older uppers bass horns. Still, I have my reasons to believe that I would not appreciate the WE 555 and the Altec’s field coil version of 288 as some of people who have them, use them and well familiar with their sound gave me quite detail reference points about their sound. I never heard the RCA’s compression drivers.

jweiss wrote:

Maybe you might want to listen to some of these instead of all the modifications you have either tried or envisioned for your Vitavox S2's?

I always interested to heard new compression drivers, no doubt that if I have them than I would give them a try. Still, I have my “issues” against a blind using of 70-50 years old sound producing devises. In my experience the vintage technologies “as is” never work reasonably well. I have the absolute firm conviction (based upon reasons and facts) that the “vintage” drivers, as they were designed, will not work well in the context of the contemporary higher demand playback. Anyhow, my experiments around Vitavox S2 have dual propose. First off all it will be “clean experiment” that would allow to easy subtract the contribution of the field coil to the sound of the driver. Second, I like the sound of this driver and I know it very-very-very well. There are some shortcoming in this sound as well and I, clearly recognizing them, would like to learn if by the means of field coil would be possible to overcome them – without loosing ANYTHING else. However, I have to tell you that for the last week the electricity in Boston turn out to be absolutely wonderful and what the S2 does recently is juts phenomenal. There are no signs of the “issues with S2” that I observed before and if the S2 would sound like this all year long that I might not have any reasons to experiment with field coils. Well… probably I still would, as there are two more redesign objectives (change the tape rate end fix the pre-gap edge problem) of mine that would be juts much simpler to implement with field coil.

jweiss wrote:

It would also certainly give you some points of comparison to the Cogent drivers which you initially liked. I know you took notice of the threads, such as Mr. Geddes, as to what exactly were the relevant design variables in these drivers that accounted for the current interest.

Jonathan, I do not know if the Cogent are the “electromagnetic drivers”. Whatever they are they are Cogent own drivers with this own sound (like any other driver). How much in Cogent comes from the electromagnetic and how much came form hundreds other design decision that Cogent is made off is unknown to me. I perceive the Cogent and self-contain completed driver with own set of positive and negative sonic signatures. But I do not see Cogent as some kind of prove or disprove of the electromagnetic concept. If I heard the Cogent with a good, old, fully charged Alnico magnet instead of the field coil and then the field coil version then, (and preferably in reasonable horn) I would be able to say where was the Sound of the Cogent driver itself and where was the field coil contribution. I do not have this experiences and the only what I can see is the complete sound of Cogent.

Judging the Cogent’s driver “as is” I find that Vitavox S2 is way more interesting sounding, and therefore  I feel the S2 much more fruitfully ground for my further experiments. I do not feel that at this point would be worth to write any Cogent vs. Vitavox S2 evaluation. Perhaps you should do it. Anyhow, I am not juts bravado about "my driver", and I am very comfortable with presenting the actual results that would justify my words. You are 4 hours away and you welcome to stop by and make you own judgment. It would be also fun if you bring the Cogent MF drivers along. I am pretty sure that I would be able with a couple hours to plug them in. Well, I feel that if you heard a properly applied Vitavox S2 then you would hardly be interested to replace it with anything out there (I am not taking about the ownership paranoia but about the actual sound of the driver, nothing else)

Still, I’m leaving all cards on the table….

cv wrote:

Allo I had a theory that the bug screen was helping to damp horn modes/refelctions caused by a mismatch between the S2 internal flare and the horn flare rate. I have 340Hz flare JMLC horns, which may be expected to give less of a mismatch than the smaller tractrix units Romy is using. So I removed a screen yesterday. Only had time to listen briefly; there was more treble but now what sounded like like a resonance at a few kHZ that kicked in on strings, flute etc and made them, well, almost sqwawk and hiccup... Anyone know what the internal flare rate of the S2 is? Martin Seddon is making me some 160Hz horns with 1.5" throat for a different application. Don't intend to use them with the S2 but would be an interesting experiment to see if the above behaviour is reduced.

So I removed a screen yesterday. Only had time to listen briefly; there was more treble but now what sounded like like a resonance at a few kHZ that kicked in on strings, flute etc and made them, well, almost sqwawk and hiccup...

Anyone know what the internal flare rate of the S2 is? Martin Seddon is making me some 160Hz horns with 1.5" throat for a different application. Don't intend to use them with the S2 but would be an interesting experiment to see if the above behaviour is reduced.

Chris,

The removing of the bug screens very very seldom causes a positive effect in compression derivers. (My view about it are below).In fact among all drivers that I know there is the only one deriver (T350) where the removing of the bug screens works beneficially. Still it works  fine in the T350 just juts because the bug screens in there sited right next to the diaphragm (a few mm) and do not “damp” it with the air between the diaphragm and the “bug screen’s impedance”…. the as they do practically in any other compression driver.

The negative effect that you observe, I think, has nothing to do with the S2’s internal flare. It looks like the S2’s internal flare is about the 180Hz or something like this. All of those compression drivers have very low internal flare. At that time when they were made the compressions drivers used in 2-3 ways installations and they foolishly tried to push out those drivers to the max LF. It started from WE, RCA and Klangfilm and then was embraced by Klipsh, Vitavox, Alteck, JBL and so on… They were not preoccupied at that time with quality of sound but rather about the getting the max pressure at given frequencies… Do not forget that all those vintage compression drivers that we use today never meant to be use in home installations and were targets for large sound reinforcement systems where the efficiency and the ability to cover large spaces was prominent (movie theaters, large public events and so on…)

Anyhow, regarding the bug screens. I had a post before:

http://www.goodsoundclub.com/TreeItem.aspx?PageIndex=3&PostID=974#974

that might bring my view about the bug screens. I would defiantly keep then in there.

Rgs,
Romy the Cat

cv wrote:

Regarding what effects the larger horn will have: my gut feeling is that the larger air mass will provide more damping anyway. It may be that there's an optimal bug screen "density" that varies with the air loading?

I have tried to increase the acoustic impedance of the bug screen by laying there the semi-transparent acoustical material. It defiantly “helped’ in some areas but at the same time it did create some damage in other areas. I think to do it properly it should be manufactured a new bug screen with twice more smaller size of each sell and perhaps twice thicker, as the bug screen also acts and a very effective defuser. I did not do it but if I come across the “ready to go screen” I would defiantly try. Another area of expiration for you if you wish is the back chamber of the S2. It is a clean metal with a lot of reflection at HF. By layering it within it’s perimeter with the 3M’s made Brillo sponge (or similar) yo0u might silently change the Sound.

Rgs,
The Cat

This is the project that I been thinking to undertake for years. I have motioned about in multiple times that Vitavox’s S2 lower region is very lucrative but unfortunately not exactly useable if the driver run all the way up, unless you are wiling to screw it up with resonance compensators. My long time idea was to use 2 Vitavox per channel: low frequency S2 before the primary resonance with old metal suspension diaphragm and another HF S2 after the primary resonance, with the plastic suspension diaphragm.  The second version I used for year and today I tried the first version.

First off all I armed the S2 with the original aluminum, metal suspension, cone and removed the phase plug. For the driver that will not work above 1000Hz the phase plug is as necessary as a helicopter propeller for to jelly fish. Then I well aliened the driver, making it sound without any mechanical resonances at 150Hz. Running this LF optimized S2 the drive I at the driver very confidently cared quite low frequency and I was able to get even 220Hz pretty clear. This was very-very good as the driver with the plug was dieing at 450Hz. So, in order to have an octave above the responsibly reproducible frequency I think I might try to load the LF part of my 2S2 tandem into 250Hz horn and cross it at 550Hz with first order. It is interesting to see what will happen and it will be fun to male all of this to work. I keep you folks posted about the successes or feature of this project.

The sad part in all of this that I would need an extra Super Melquiades channel. The positive thing that I will find if S2 lower knee will be able to compete with my current upper bass horn. I doubt but still” the best reproduced 400-1000Hz I even heard was in 2002 in CES during a privet demonstration by David Karmeli when pair of S2+K151 drove the large David’s demos room into something absolutely out of this world (I am talking only about the upperbass only). Also I would like to get more control over the range of the fundamatals….

Rgs,
Romy the caT

angelo,

I do not know what the story about the Vitavox Mike. He travels a lot and sometime he is few weeks out of county, during this time he does not retie emails.… It happened with him before. He runs a shop and you might call his ask how he is doing. Other them him I do not know sources for new diaphragms. In contrary S2 drives are readily available ands use a couple pars per month pops up here and there.  However, S2 drivers and it diaphragms, thanks to a known to me Morons from Massachusetts who believes the he is a feline, become quite expensive recently. Also if you gig them do not forger that they are 50 years old and it might be a lot with them that does not perform well. So, doing for S2 drive one might open a worm box with all possible aggravations….

Also, I would like to note that audio people always foolishly believe that “something” in playback that was “different” is responsible for “better sound”. I have seen quite a few people who were in my room and more or less liked the Sound. Then they asked me what did MF. I said that it was Vitavox S2 driver. Probably a half dozen of them then ran and bought the S2 drives. However, as far as I know today, none of them were able to successfully use it in their installations (because of various reasons). I pretty much did the same: I heard it in 2001, liked some potency of it’s Sound, and ran to buy it. Nevertheless, it took almost a year to learn how to get better sound from it and hot it might be incorporated in context of entire installations.

Rgs,
The caT

This post is split form the thread:

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=4549

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=4556

jessie.dazzle wrote:

"...I very much might try to use the metal suspension again when I will be driving the MF with a single-stage Milq, direct coupled or after I try the Duddanization of the cone. The single-stage Milq should be “a cleaner electronics” and it should be advantageous...." What do you mean by "the Duddanization of the cone"... I would guess you are referring to damping the cone via some sort of coating (saliva from your pregnant adolescent camel... You do realize she has been pregnant for a very long time...)

jessie.dazzle wrote:

"...Since you already do have the S2 driver then buy from Mike one single plastic suspension cone and try it next you original cones..." My S2s have metal diaphragms... In fact, I did not realize that it was still possible to buy the diaphragms with plastic suspension (???). Thank you for your offer to lend me a diaphragm... It would seem best that I try to buy the diaphragms that I don't have (plastic suspension)... If I heard the plastic suspension in my system, and liked it, but then could not buy a pair, I might just become and Audio Psycho...

I kind of fed up to receive those emails (I ordinary do not reply them) with questions and therefore I would a would make one atypical public statement and it will be it. I say “atypical” as I truly do not care about your purchasing habits, still sine it is Vitavox thread and my site is “in play” I think my reaction is warranted.

There is a person or a group of the people on eBay who continually (over the course of a few years) sell Vitavox S2 drivers. They have a picture of a group of the S2 drivers, mentioning of Living voice air Partner horns, kink’s to Peter Empson’s Vitavox Unofficial web site and to the sale section of my site. They tell story that the drivers were tested by signal generator at 200Hz and so on…. Also add suggests do not big on eBay but contact directly of some Google, Yahoo or Hotmail account. The seller has a lot positive feedback and good history.

Well, you need to discard this selling item. If you see it then description and the photos were taken from a legitimate eBay sale that took place 3 years ago and this action is posted under a stolen eBay account. I do not provide a link to this fraudulent item as eBay does a pretty good job to delist those actions. Still, it is posted again and again, and I presume that people do “bite”. I do not know how the rest fraudulent mechanism works and how they get money from the people (and I do not want to discuss it here). Still, if you looking for S2 drivers then beware that the Vitavox S2 drivers are on EBay’s “Naked Short List”, right along with some other items that managed to obtain the “deficit” status among the moronic audio collectors.

mark wrote:

regarding point 6)inspect the diaphragms;3 different diaphragms,metal surround(1type only?),plastic surround(2 types?clear plastic,white)the new production style please desribe in detail its physical appearance.are these new style  still available?do you use the newest style currently in fundamental and mf channel?if not what type in what channel?can you provide contact info for people to make optimal soft wood horns?i tried googling bruce edgar,cannot find email or phone.are you currently using 250hz horn for fundamentals and 550hz  horn for mf?

Mark, all those questions were discussed before, some of them in great details. If you have interest about the S2 driver them you might invest some time into reading the legacy posts on the subjects. I do not want to sound like a jerk (well, why not) but the entire idea to have the content of this site publicly available is do not have needs to write it again and again. Do your homework, after all it is your driver and your interest.

Bruce Edgar’s email is bedgar@socal.rr.com, contact him and he will give to you his phone number. However, Bruce provided multiple times his phone at AA.  About the MF, I use 400Hz horn crossed at 3200 electrically 1000Hz acoustically.  I found that 375-400Hz horn is OK setting for the S2 with white plastic suspension.

Rgs, the Cat

…. I would suggest trying to drive this driver with a single stage solution with no capacitance - you might find it very very very very very very  educational.

http://www.romythecat.com/Forums/ShowPost.aspx?postID=4241

http://www.romythecat.com/Forums/ShowPost.aspx?postID=4734

http://www.historyofpa.co.uk/pages/speakers.htm

here is also some PDF files

http://membres.lycos.fr/stephane3000/_private/frameset_vitavox.htm

I picked recently a pair of S3 drivers. Not that I need them but it was good deal – perhaps someone in UK have demolished an old movie theater and a large school of S3 drivers with original diaphragms hit the maket recently. Also, I always meant to try them for my Fundamental Channel as I was interested to see if they would go lower then S2 drivers. The S2 have ceramic magnet, so HF transients shell be too dry with my tube electronics. Still, the Fundamental Channel do not work very high, so there is a remote possibility that I will be able to go away with S2 driver for this channel.

Now, what I wonder: is anybody having the internals drawing of S2 and S3 drivers. The reason I ask is because my S2 in Fundamental Channel is time-aligned and when I screw the S2 in there then the distance between the throat of the horn and driver cone might be different. I really do not want to do re-alignment (because multiple reasons) and I would like to make the alignment decision based upon the drawing of the driver with marked up distances. I do have this drawing for S2 driver but I do not have it for S3. If someone has the S3 mount template with exact distance between the mounting throat and the tip of the cone then post it or shoot me a direct email.

I have a couple of queries relating to the transition from the mouth of the S2 driver to a horn generally, and to a 400Hz or 250Hz horn specifically. 

The profile calculator that I use for tractrix horn (horncalc) does not take into account the depth of the diaphragm of the S2 from the mouth.

I have worked out that at the base of what looks like the conical horn section the diameter is approx 30mm. With a mouth diameter of 38.1mm, the angle is therefore a constant 2.5 degrees. The flare angle at the beginning is a relatively large 6.3 degrees. With a 247Hz horn that angle would be 5 degrees.

Should this be of any concern?

I know that Jean Michel Lecleach's spreadsheet (I have a version from 2007) actually enables one to specify an exit angle. I imagine that one's answer might in part depend on how critical one conceives the transition at the throat.

Best regards
Rakesh