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06-27-2011 Post does not mapped to Knowledge Tree
oxric
Posts 184
Joined on 02-12-2010

Post #: 1
Post ID: 16552
Reply to: 16552
"O Vitavox, Vitavox! Wherefore art thou Vitavox?"
fiogf49gjkf0d
At some point last year, after I had been offered an opportunity to buy some Vitavox S2 drivers from someone in Paris, and some S3s from Germany, I decided to approach Mike Harvey of Octave Audio, AKA Vitavox Hifi, to get some information about how I could have my drivers tested, cleaned and remagnetised if necessary. I also wanted to buy some new diaphragms as two of my drivers had that part missing and in fact one unit I had picked up later in fact had a speaker terminal and another part missing.

Mike duly explained to me that he would not vouch for the work of anyone not qualified and experienced with Vitavox drivers, given both the complexity of the work and the number of parts that go into making these drivers. I assured him that I would be more than happy with him doing this work for a fee. We had a chat about the possible costs of parts and labour (to be confirmed). The figures he mentioned were very reasonable and all in all, it seemed the only sensible thing to do was let Mike undertake the work, as Romy had also recommended him in the Vitavox S2 survival thread. Mike assured me that www.vitavoxhifi.com would be imminently going online, the necessary move to bigger premises having caused some delay, and only at this point he would be able to take in my drivers.

And then started a very long wait. In the past year, I have spoken with Mike on several occasions and received repeated assurances that it was going to be very soon! I must say that Mike was always very courteous on the numerous occasions when we talked, although he was very busy with the launch of the Living Voice Vox Olympian speakers.

I waited for weeks, then months... Around February of this year, we had another long chat where he assured me that I should be expecting an announcement in no longer than a month's time. After that, many months went by and I dared not pester him again. But I dared eventually and talked to him two months ago when I got pretty much the same assurances as previously.

I do not wish to pass judgement on a company when I do not know the precise reasons for the delay but if it was my company, a few heads would have rolled!

I have more or less decided to do what I can myself, with the assistance of the Vitavox S2 survival guide Romy has posted on this site, and maybe with the help of others (if you are an expert in Vitavox S2 drivers give me a shout), but would have preferred not to have wasted so much time waiting and then for absolutely nothing to materialise. It would be great if someone who is in the field, who felt confident with Vitavox S2s, would offer his professional and punctilious services testing, servicing, aligning and remagnetising these very vintage drivers. I am aware that we will have to wait for Mike to set up shop when it comes to sourcing diaphragms and other parts, but in the meantime an independent service point for these drivers would certainly be a huge help. I am realistic enough to know there is very little chance of this idea coming to anything but after a year of interminable waiting, even this faint sliver of hope is better than nothing.

Best regards
Rakesh



P.S. By the way, Romy, should you be wondering, I will not be setting up shop servicing a limited run of Vitavox drivers.

06-27-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 2
Post ID: 16553
Reply to: 16552
Vitavox as an autistic obsession.
fiogf49gjkf0d

 oxric wrote:
Mike duly explained to me that he would not vouch for the work of anyone not qualified and experienced with Vitavox drivers, given both the complexity of the work and the number of parts that go into making these drivers. I assured him that I would be more than happy with him doing this work for a fee. We had a chat about the possible costs of parts and labour (to be confirmed). The figures he mentioned were very reasonable and all in all, it seemed the only sensible thing to do was let Mike undertake the work, as Romy had also recommended him in the Vitavox S2 survival thread.

The Vitavox Harvey, or as I call him the Vitavox Mike is THE Vitavox guy, he own the Vitavox original tooling, know-how and I believe the legal name. I would disagree with his moments regarding the “complexity of the work and the number of parts”. There is absolutely nothing in Vitavox that makes it different from any other driver and any capable technician who know how to deal with compression drivers shall be able to test them, cleaned and demagnetize them. Of cause it your drivers are defective and you need new parts then Vitavox Mike would be the man… Sure, with all other equal conditions it would be preferable if Mike does it but it is very much not necessary. I feel that any compression driver user shall learn how to do it himself and it is very simple and owner shall retune the drivers periodically anyhow…

 oxric wrote:
Mike assured me that www.vitavoxhifi.com would be imminently going online, the necessary move to bigger premises having caused some delay, and only at this point he would be able to take in my drivers.

And then started a very long wait. In the past year, I have spoken with Mike on several occasions and received repeated assurances that it was going to be very soon! I must say that Mike was always very courteous on the numerous occasions when we talked, although he was very busy with the launch of the Living Voice Vox Olympian speakers.

I waited for weeks, then months... Around February of this year, we had another long chat where he assured me that I should be expecting an announcement in no longer than a month's time. After that, many months went by and I dared not pester him again. But I dared eventually and talked to him two months ago when I got pretty much the same assurances as previously.

I do not wish to pass judgement on a company when I do not know the precise reasons for the delay but if it was my company, a few heads would have rolled!

Well, I do not want to pass judgment about Mike as well as as I was able to observe his operation he has been doing the same “expecting an announcement” mode since 2002. If I migh I would pass a judgment about something that let Mike not-readiness to hold own progress for over a year. Why Mike’s delay bothers you so much. In my mind you Mike delay is obsessed reason for you, not the actual cause.

 oxric wrote:
I have more or less decided to do what I can myself, with the assistance of the Vitavox S2 survival guide Romy has posted on this site, and maybe with the help of others (if you are an expert in Vitavox S2 drivers give me a shout), but would have preferred not to have wasted so much time waiting and then for absolutely nothing to materialise. It would be great if someone who is in the field, who felt confident with Vitavox S2s, would offer his professional and punctilious services testing, servicing, aligning and remagnetising these very vintage drivers. I am aware that we will have to wait for Mike to set up shop when it comes to sourcing diaphragms and other parts, but in the meantime an independent service point for these drivers would certainly be a huge help. I am realistic enough to know there is very little chance of this idea coming to anything but after a year of interminable waiting, even this faint sliver of hope is better than nothing.

Sure, you have to do it yourself, it will take 30 minutes. Post questions if you need any help. If you need to magnetize them then it cost $25 per pair in any good driver servicing shop.

 oxric wrote:
P.S. By the way, Romy, should you be wondering, I will not be setting up shop servicing a limited run of Vitavox drivers.

Nope, you will not be opening the shop. To have a shop you will need to rent a space and when you go renting the space for shop you will discover mice in the facility. You will spend next 3 years to study the mice hunting manuals and to bread the mice-hunting Cats. They you will write a book about the mice-hunting and will start a company that sell rat poison by bulk…

The caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
06-27-2011 Post does not mapped to Knowledge Tree
oxric
Posts 184
Joined on 02-12-2010

Post #: 3
Post ID: 16554
Reply to: 16553
I am not vitavoxed, merely flummoxed.
fiogf49gjkf0d
 Romy the Cat wrote:

 oxric wrote:
P.S. By the way, Romy, should you be wondering, I will not be setting up shop servicing a limited run of Vitavox drivers.

Nope, you will not be opening the shop. To have a shop you will need to rent a space and when you go renting the space for shop you will discover mice in the facility. You will spend next 3 years to study the mice hunting manuals and to bread the mice-hunting Cats. They you will write a book about the mice-hunting and will start a company that sell rat poison by bulk…

The caT



Nope, I will not be making rat poison. The manufacture of a treatment for Rabid Cat Syndrome holds more attraction.

I know you use words in a very random fashion but in my opinion, there is something repellent in qualifying my interest in Vitavox drivers as 'autistic.' The predicament of people who suffer from these sometimes debilitating disabilities should attract sympathy not be the subject of crass attempts at humour. Indeed autism is such a prevalent albeit ill-understood condition that it would not surprise me in the slightest if I actually did suffer from it, maybe at the low end of the spectrum. On the other hand, if you were to scan your website for someone who exhibit the typical symptons that may well be indicators of the condition, namely language problems, problems to socialise, a lack of empathy and odd 'eccentric' behaviour, I wonder who else you might come up with...?

Best regards
Rakesh
06-27-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 4
Post ID: 16555
Reply to: 16554
You need to cut on Mahler becose it is bad for you.
fiogf49gjkf0d

 oxric wrote:
I know you use words in a very random fashion but in my opinion, there is something repellent in qualifying my interest in Vitavox drivers as 'autistic.' The predicament of people who suffer from these sometimes debilitating disabilities should attract sympathy not be the subject of crass attempts at humour. Indeed autism is such a prevalent albeit ill-understood condition that it would not surprise me in the slightest if I actually did suffer from it, maybe at the low end of the spectrum. On the other hand, if you were to scan your website for someone who exhibit the typical symptons that may well be indicators of the condition, namely language problems, problems to socialise, a lack of empathy and odd 'eccentric' behaviour, I wonder who else you might come up with...?

You might find it repellent but not me. It might be a surprise to you but I do not use words in a very random fashion. It is my long standing theory that many audio people use audio (and not only audio) as a getaway to deal with internal or sometimes subconscious autistic inclinations. Many truly deliberating sick with autism people incomprehensibly obsessed with some non- applied and illusionary objects. I do feel that you have this tendency. BTW, saying it I do not put any judgmental value into it. It is not bad or god, it is what it is. But it needs to be self-understood.

I do find it a bit funny that you attribute autistic inclinations to me as some kind “defense”.  I am so willingly comply with any diagnoses out there that it is not even funny. The mistake you made is that I have no “problems to socialize”. I do have problems to socialize with Morons but I remain a master of my own universe and I decide myself who is a Moron and with whom I will enjoy to have problems to socialize. For a time being I would like to remind you that we are remaining in different business.  I observe drivers and think how to use them to cure my autistic fixation with Sound. You are inventing the windmills and fight with them in order to satisfy your completely healthy enjoyment of “project managements”.  Again, as long as it make you happy it is fine. There are a lot of people who run marathon just for sake of participation. Marathon is a big tent. The running shoes are very important. Would you like to look into the running shoes design and manufacturing?

Anyhow, I was under impression that this site is about “advanced audio and evolved music reproduction techniques”. How the end we end up with autopsy of Adidas sneakers? Do you really enjoy it? I can open a special forum for people who obsessed with anything near-audio related.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
06-27-2011 Post does not mapped to Knowledge Tree
jessie.dazzle


Paris, France
Posts 456
Joined on 04-23-2006

Post #: 5
Post ID: 16556
Reply to: 16553
The vintage wait
fiogf49gjkf0d
Romy wrote:
"...Well, I do not want to pass judgment about Mike as well as as I was able to observe his operation he has been doing the same “expecting an announcement” mode since 2002..."

Yes this has become something of a "vintage wait"! In my limited experience dealing with small British companies, it is completely normal.

Once in building a prototype car, after waiting 18 months for an order I had pre-paid, I finally ended up taking off from work, renting a truck, putting it on a ferry and driving it all the way to the vendor's door in the scenic North Yorkshire Dales to finally pick up the order. They were surprised; very charming people and excellent quality products but very much not in a hurry.

In the few converstaions I've had with him, Mike seems totally sincere and, as I've mentioned before, I very much hope he will one day come through.

jd*


How to short-circuit evolution: Enshrine mediocrity.
06-28-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 6
Post ID: 16559
Reply to: 16556
OK, now let to diagnose the Vitavox Mike
fiogf49gjkf0d

 jessie.dazzle wrote:
In the few converstaions I've had with him, Mike seems totally sincere and, as I've mentioned before, I very much hope he will one day come through.
Oh, sure, Mike is perfectly sincere and this is BTW might be a reason why he does not commit himself to produce those drivers. To restart the production implies some kind of investment into material and labor and then it understandably implies a need to get at least reimbursement if not profit. It is high possible that Mike does not see that his Vitavox business is a good investment of his energy. Let face it, if not my site then it will no publicity for Vitavox drivers out there and what is my site? 10 derange people who already have the S2 drivers and do not need them anymore?

So, the point is that for Mike to start the new production mean to create publicity complain. Advortise and to become a full time industry-involved, mind you to be “involved” with a product that has very limited target market to begin with. So, I very much understand what Mike does. If I solo own the tooling, patents, know-how for Western Electric, Klingfilm of Marconi then I would do the very same  - did nothing with them. So, the Vitavox Mike might just sitting on all that Vitavox treasure, waiting what a right moment in his life strikes for him.

I think a good option for Vitavox Mike would be to find some kind of Marketing Whore like Joe Roberts (only contemporary and relevant) who would undertake the task to reincarnate the Vitavox name. Then Mike will not need to humiliate himself to deal with people and let the dirty work to do for dirty people. I know, I know, now Rakesh, will jump in and will “discover” one more autistic evidence in me: the social withdrawal. Still, I would prefer to be called anything only do not deal with foolish audio people who are in their “faith buying” mode.

So, I do not see that what Vitavox Mike does as something that is wrong.  The new Vitavox might never rise and if it did then it might keep bleeding for years. The only thingk that I do if I were Mike and if I had an interest to restart the Vitavox wouls be do not come back with new production of drivers but rather with a new production of complete speakers. The complete speakers are much easier to marker and if they have the advantage to use better Vitavox drivers, then it would be good for them.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-01-2011 Post does not mapped to Knowledge Tree
oxric
Posts 184
Joined on 02-12-2010

Post #: 7
Post ID: 16596
Reply to: 16556
Vitavox are 'Go!' And the 'democratisation' of horn loudspeakers.
fiogf49gjkf0d
 jessie.dazzle wrote:


In the few converstaions I've had with him, Mike seems totally sincere and, as I've mentioned before, I very much hope he will one day come through.

jd*


Well Jessie, it looks like your wish has come true. The Vitavox site went live at 9 a.m. this morning. It has very interesting implications for the compression drivers landscape in that it suddenly makes buying a high-end compression driver, and not paying absurd Goto or ALE prices, a much more affordable and risk-free exercise. 

Whilst it does diminish the exclusivity value of these drivers, which may not please everyone, I expect it will enable a much larger number of people to experiment with these.

That this should happen on the same day that we are placing an order for the Fane 8M drivers is either an extraordinary coincidence or quite an omen.
 
Best regards
Rakesh


07-01-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 8
Post ID: 16597
Reply to: 16596
The Vitavox alive, again!
fiogf49gjkf0d

 oxric wrote:


Well Jessie, it looks like your wish has come true. The Vitavox site went live at 9 a.m. this morning. It has very interesting implications for the compression drivers landscape in that it suddenly makes buying a high-end compression driver, and not paying absurd Goto or ALE prices, a much more affordable and risk-free exercise.

Whilst it does diminish the exclusivity value of these drivers, which may not please everyone, I expect it will enable a much larger number of people to experiment with these.

That this should happen on the same day that we are placing an order for the Fane 8M drivers is either an extraordinary coincidence or quite an omen.
 

Thanks, Rakesh, this is good news indeed. I still do not know how they market themselves: as parts company of the complete speaker company, I guess the time will show.

http://www.vitavoxhifi.com/main.php

It looks they have a new version of  System CN191 under development, let see how it materialize itself.

The sire is good, the text is good, hey eventually the binding posts for S2 driver that always get broken off become available! That all good things. I wonder if Mike made any modifications to the things that needed to be modified. I did not see that he mention differences between old production and new one. It would be nice if somebody overview those differences and evaluate the results.

I do not think that making new production Vitavox available has any “interesting implications for the compression drivers landscape”. Vitavox drivers were quite available in used market, whoever wanted them had them, so I do not see any change in anything. The opportunity to service Vitavox and to have parts available is of cause great but in one way of another Mike always was able to do it.

I also disagree with the notion that “buying a high-end compression driver, and not paying absurd Goto or ALE prices” has to do anything with Vitavox. The Vitavox S2 driver is not a substitute or alternative to Goto, ALE, JBL, TAD or anything else. The S2 driver had own character Goto or any specific JBL has own character. One might use whatever he wants or need. Here was never any debate about S2 vs. Goto. I am pretty sure that thinking about system organization with use of S2 is different then it would be with Gotos, people do not “get” it now but they will another day, not all of them but some of them will….

The great thing that I see is that Mike preserved the original exponential Vitavox horn with 3 slots at the throat. That is good as, if not to use spherical horns then I do like that horn. Now the Vitavox Mike has it available in wood. This is very-very good.

For whatever reasons I do not see the specification for the S2 drive and the actual response. I do see the link but the PDF file come empty. What I wonder if Mike was able to deal with secondary resonance at 1250Hz. I guess the time will show…

Rgs, Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-01-2011 Post does not mapped to Knowledge Tree
jessie.dazzle


Paris, France
Posts 456
Joined on 04-23-2006

Post #: 9
Post ID: 16602
Reply to: 16597
Now that's what I'm talkin' about!
fiogf49gjkf0d
Nice work; bravo Mike!
 
With regard to improvements to the S2: Apparently Romy's prayer, one of them anyway, has been heard and would seem to have been answered; a diaphragm-centering guide has at last been added. As for the rest (other improvements/differences?), getting rid of the secondary resonance would seem a worthy goal but I believe Mike's aim was, at least at this stage, to offer a driver that is identical in every way possible to the older production S2, so in theory, that would mean they should still have the "beneficial" secondary resonance. I'd love to compare this latest S2 to the ones I use.
 
I see that along with the K15/40s (15 Ohm) and AK151s (8 Ohm), Mike is also offering the AK150 (15 Ohm) and the AK152 (8 Ohm) variants. These last two drivers have a frequency response range from 30Hz-5KHz and "bass resonance" (which presumably means free-air resonance) at 30-35Hz; both significantly lower than the K15/40 and AK151 drivers.
http://www.vitavoxhifi.com/pages/pdf1.php
 
This of course has me thinking... What about using a pair of the AK152s in my 40Hz horns? Those Fs down around 30-35Hz would likely need to be raised (rear chamber volume reduced to non-existent), but possibly worth the trouble as the AK150s have a 3Khz-lower natural HF cut-off. Translation: One might get away using a less sharp filter. Also, even if the AK150 is not driven all the way down to the horn's physical cut-off (40Hz), the fact that this driver is rated to go down to 30Hz should mean that at 40-50Hz it is much less rolled off than an AK15/40 or AK151 would be. It might also mean adding a filter at the lower end.

I imagine Mike will now be flooded by requests for diaphragms and binding posts. What's really of significance here is that it is now possible to put intoproduction a system such as the Macando (or my own system which is Macando-based), using new drivers... Just get Rakesh to keep the Fane-Chain cranking and there'd be no need to find an alternative to the 8M. If I ran Cessaro, I'd be knocking out a prototype version of the Gamma equipped with new production S2s...
 
jd*


How to short-circuit evolution: Enshrine mediocrity.
07-01-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 10
Post ID: 16604
Reply to: 16602
Let see how it all work out.
fiogf49gjkf0d

jd, I cannot see any of PDF files, probably my current networks kills them.

I do not know the AK150 drivers. I know AK157, AK151 and K15/40. If they have significantly lower free-air resonance, at 30-35Hz then I am not sure that they would be more suitable for 40Hz horns. When you have 40Hz horn then he best driver to use in there would have free-air resonance around 50-60Hz. As you load the 40Hz then the reactance of air will increase the virtual mass of the cone and the resonance will be dropping almost twice. It is a good idea to have the drooped resonance a bit below the horn rate. If you have 40Hz horn then it would be nice to have 55H driver. In horn it will drop to let say35Hz and then you will drive it with back chamber up to 40Hz. If you have driver that are 35Hz in free air and let say 22 Hz loaded then the back chamber will be VERY small. Will it be good? I do not know. What I would be afraid in bass driver and ultra small back chamber is the compression…

The biggest thing that I wonder is how Mick made the Vitavox bass drivers to has 35Hz resonance. You can always use softer suspension and it will drive resonance down but it also make the excursion of the driver and much wider. Does the original Vitavox magnetic structure supports it? I do not know. On a different note Mike might make the gap a bit longer and use longer magma ring… No one knows what he did…. I personally do not see a use of those drivers. They would be fine for open baffles but I do not use open baffles …

Yes, it would be VERY interesting if Cessaro Gamma uses Vitavox S2 driver or Mike would come up with his own Macondo-type configuration. Still, since Vitavox doe only one compression drives and one bass driver then I can see that Vitavox will stick to 2-3 channels setups with big bass bin. This type of the speaker that Silbaone/GIP show up in Munich this year would be the most probable direction that Vitavox would go.

From my perspective I have less interest in the fate of Vitavox S2 driver.  I do not think that anybody would tell me something new about it, as well as the way how I use it in my system make my S2 very much un-orthodox S2 driver. However, the 15” bass drivers are very interesting subject. Vitavox was MUCH more interesting then any best Altec, JBL, Klipsh, EV, TAD, Klangfilm and a few other 15 inchers but I did not play with GIP, Goto, ALE, WE 15-inchers. I would like to see how Vitavox 15” would complete with those drivers in different applications.  Since the AK157, AK151 and K15/40 become available (even with new diaphragm that no one knows what they are made from) I think more and more people will use them and let see how it turn out to be in term of sound results. From a different side: no one built proper horns for 15” drivers. I need to pitch the new AK151 to Jeffery Jackson, he might put it in use….

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-01-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,138
Joined on 10-12-2006

Post #: 11
Post ID: 16605
Reply to: 16602
AK150 vs. 151, and the Voice of God
fiogf49gjkf0d
I am out the door, just wanted to mention, it is my understanding that only one of these was meant for a horn; the other is a direct driver, like the original 515.

I assume the celebrated "slotted" Vitavox horn is not the same as the one and only Vitavox theater horn I have heard.  That one gave the 811 a serious run for the money!  IMO the "raw" S2 is too wild and too... raw.  Like most drivers, this one needs an education and training, not mere "restoration".  Now, hundreds of these excrusiating devices will be unleashed on an unsuspecting hoard of Vintage Sufferers, who will - after waiting and dreaming so long - finally make their dreams come true.

Not to speak for God, but it appears that He was indeed listening, and His sense of humor is still intact.

Best regards,
Paul S
07-01-2011 Post does not mapped to Knowledge Tree
jessie.dazzle


Paris, France
Posts 456
Joined on 04-23-2006

Post #: 12
Post ID: 16606
Reply to: 16604
Specs & speculation
fiogf49gjkf0d
Romy wrote:
"...jd, I cannot see any of PDF files, probably my current networks kills them..."

Vitavox S2 (2011 production) Specs.JPG

Vitavox 15 inch (2011 production) Specs.JPG


"...The biggest thing that I wonder is how Mick made the Vitavox bass drivers to has 35Hz resonance. You can always use softer suspension and it will drive resonance down but it also make the excursion of the driver and much wider. Does the original Vitavox magnetic structure supports it? I do not know. On a different note Mike might make the gap a bit longer and use longer magma ring…?..."

The AK150 and 152 are not new creations dreamed up by Mike; they were made back in the day by Vitavox but nobody ever talks about them and I have never seen either. See the Unofficial Vitavox web site; AK150 = Catalog N° CN143; AK152 = Catalog N° CN327.
http://website.lineone.net/~empson/CN.html

My understanding is that all these drivers use a common chassis and magnet and that it is only the addition of a cone/voice coil that finally determines what they end up; if that is so, then presumably the original AK driver was designed with consideration for the lower Fs. I would hope the lower Fs were achieved via an additional pleat in the suspension. This would of course require additional tooling, so it is possible that the lower Fs were achieved via simple mass-loading of the membrane (i.e. making the cone thicker) which comes at a price.

"...I personally do not see a use of those drivers..."

20Hz bass horn anyone? 

So you don't think the tail that starts 3KHz lower may be worth the fight it would take to get the Fs up high enough for use in a 40Hz horn? In any case, I'd share your concern regarding possible rear compression due to an ultra-small rear chamber volume. Assuming DSET or dedicated amps, driving an K15/40 or AK151 low enough and loud enough via a 40Hz horn should not be a problem; in this case, the potentially stronger low-frequency performance of the AK152 is not so much of interest. However, for those that do not give these horns their own dedicated amp, the stronger low end may be more of an enticement.

"...Since the AK157, AK151 and K15/40 become available (even with new diaphragm that no one knows what they are made from)..."

As with the S2, my understanding is that every attempt was made to be as faithful as possible to the older production units which would suggest simply continuing production of the parts unchanged. This in theory is possible, as I read a while ago that, along with the rights to produce the drivers, the original tooling was purchased and is presumably still being used (though it did require refurbishing). If so, the question then becomes one of availability of the materials and of course the know-how. In response to both of these issues, given the fact that this is all taking place in England (wonderfully resistant to change as it is!), there's a fair chance both are possible.

Paul S wrote:
"...it is my understanding that only one of these was meant for a horn; the other is a direct driver..."

In practice it is not necessary to abide by it (as Romy has proved) but the original intent and "official line" as seen on the old spec sheet was as follows: The 15 Ohm drivers were intended to be used as direct radiators and the 8 Ohm (really 7.5 Ohm) versions were intended to be horn-loaded. The reason for this is that in theory, the load the membrane sees as a result of firing into a horn where there's only one way out (down what starts off as a narrow tunnel), is greater than in the case of a direct radiator (which is free to diffuse its pressure over at least 180° hemisphere). The additional load translates to greater Z as seen by the amp and presumably brings it more into line with the 15 Ohm load presneted by the compression drivers which themselves, due to the frequencies involved (less excursion) and being semi-coupled to a far smaller and lighter column of air in the horn, are less prone to having their load upped by the presence of a horn.

"...IMO the "raw" S2 is too wild and too... raw.  Like most drivers, this one needs an education and training..."

I use the S2s with the older metal suspended diaphragms which are known to be the most "raw and wild"; it is true, they are definitely live and with really correctly-mastered recordings, it is in part, exactly that live factor that pleasantly reminds me why I built my horns and continue to let them dictate my real estate options. What is also definitely true is that they make the really sub-par recordings (i.e. most all pop/rock etc, about half of jazz and around 15% of classical) unbearable, and I don't mean just a little. When its good, its extasy; when its bad, its painful. For those who listen mainly to classical, its a no-brainer; there is a sufficient number of correctly-enough mastered recordings to make the affair worth pursuing. If jazz is your thing, it will mean doing a bit more weeding but the results are very worth while. If pop/rock etc is your thing, definitely look elsewhere. The new production drivers are equipped with the more polite Mylar diaphragms (in theory, the same as the last production run of the older production drivers); I plan to give them a listen.

jd*


How to short-circuit evolution: Enshrine mediocrity.
07-01-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 13
Post ID: 16607
Reply to: 16606
New power handling?
fiogf49gjkf0d

 jessie.dazzle wrote:

The AK150 and 152 are not new creations dreamed up by Mike; they were made back in the day by Vitavox but nobody ever talks about them and I have never seen either. See the Unofficial Vitavox web site; AK150 = Catalog N° CN143; AK152 = Catalog N° CN327.
http://website.lineone.net/~empson/CN.html

My understanding is that all these drivers use the same chassis and motor assembly and that it is only the addition of a cone/voice coil that finally determines what they end up; if that is so, then presumably the original AK driver was designed with consideration for the lower Fs. I would hope the lower Fs were achieved via an additional pleat in the suspension. This would of course require additional tooling, so it is possible that the lower Fs were achieved via simple mass-loading of the membrane (i.e. making the cone thicker) which comes at a price.

But adding mass to membrane change the dynamics of everything, it also increases the exertion as it will add moment of inertia of the cove movement. Anyhow, I did not realized that they existed in past, I never seen them. Most likely they were used as direct radiators and have burned out long time ago….

 jessie.dazzle wrote:
As with the S2, my understanding is that every attempt was made to be as faithful as possible to the older production units which would suggest simply continuing production of the parts unchanged. This in theory is possible, as I read a while ago that, along with the rights to produce the drivers, the original tooling was purchased and is presumably still being used (though it did require refurbishing). If so, the question then becomes one of availability of the materials and of course the know-how. In response to both of these issues, given the fact that this is all taking place in England (wonderfully resistant to change as it is!), there's a fair chance both are possible.

Hm…. I do not think that mike would “as faithfully as possible” reproduce the original S2 diaphragms. I do not like the original S2 diaphragms, at least they need to be used very differently from how I would like to use my S2 drivers.  The Mike’s production from 2000, with white plastic suspension was much better then the original diaphragms, even they had that ugly response. I hope he will use the white plastic suspension in his new production…. The bass driver is a different story. There is no materials that were available 60 year back and nothing you can do with it. It for sure will be new production with new sound. It might be even better but it will not be the same as 50-60 years back. No one company ever was able to make a comeback with the same sound…..

Anyhow, my main concern is that Mike in his documentation stated the S2’s poser handling of 100W. This is very interesting. There are two option why I think it happens. He might consider that original 10W of power handling would scare the Morons who accustom to drive horns with 1000W digital amplifiers.  So, he wrote 100W to be more conventional among the competitors. Alternatively Mike could use the thinker wire for his voice coil and to make the S2 driver to be able to handle 100W. This would mean that the new production has thinker VC and consequently heavier diaphragm then before. Heavier diaphragm = lower Fs = different dynamic of back and front loading = pretty much different sound. Mike could find new ways to wind the VC that would add thermal-resistance of VC with preservation of mass, I do not know what he did but generally I would prefer to use a driver with lover power handling, not higher….

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-01-2011 Post does not mapped to Knowledge Tree
jessie.dazzle


Paris, France
Posts 456
Joined on 04-23-2006

Post #: 14
Post ID: 16608
Reply to: 16607
More guessing
fiogf49gjkf0d

Romy wrote:

"...But adding mass to membrane change the dynamics of everything, it also increases the exertion as it will add moment of inertia of the cone movement…"

This is what I meant when I stated that it comes at a price. In any case, I would expect the new version to manage Fs in the same way the older production drivers did it; whether that be via mass-loading or rendering the suspension more compliant (an additional pleat).

"...The Mike’s production from 2000, with white plastic suspension was much better then the original diaphragms, even they had that ugly response. I hope he will use the white plastic suspension in his new production..."

From the Vitavox site (I mean the new, "Official" site):

"...The surround is formed from polyester, a material virtually immune to vibration fracture, and is stiffened by means of heat-formed tangential ribs which allow free movement of the dome over the required excursion..."

Color or opacity of the material in itself means nothing; it could very well be white, pink or have leopard spots (I'm betting you'd like that!), all independent of its physical characteristics.

By the way, for those who don't know, Mylar is a trademarked name for polyester sheet or film:
http://en.wikipedia.org/wiki/Mylar

The 100W thing caught my eye as well and raised an eyebrow...

jd*




How to short-circuit evolution: Enshrine mediocrity.
07-01-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 15
Post ID: 16609
Reply to: 16608
Color does mean the things in this case.
fiogf49gjkf0d
 jessie.dazzle wrote:

Color or opacity of the material in itself means nothing; it could very well be white, pink or have leopard spots (I'm betting you'd like that!), all independent of its physical characteristics.
Of cause the color of the material in itself means nothing. I am not so damn to do not understand it but the irony is that in this particular case the color of the material is significant. Yes, many manufactures damp metal with Mylar, I think Goto driver are Mylar-suspended titanium. However, no one knows what Mylar is being used. I am sure that people who work with materials would give 304505 versions of polyester that all will have trade name of Mylar. It is like Alnico or Amorphous core the name imply the topology but not brand specifics and there are many different types of Alnico magnets and many different type of Amorphous steel.

So, Vitavox to the best of my knowledge did two types of Mylar-suspended or plastic suspended diaphragms: with white plastic and with clear plastic (transparent).  I do not know if it is the same material but I know that sonically the white suspension sound more friendly. So, when I refer to Vitavox suspension as “white” suspension I do not mean to differentiate it from pink or leopard spots but rather to differentiate it from “clear” (transparent) version of suspension.  

BTW, the “clear” (transparent) version of suspension was the Vitavox original designs that was advised to be use for high power handling….

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-01-2011 Post does not mapped to Knowledge Tree
jessie.dazzle


Paris, France
Posts 456
Joined on 04-23-2006

Post #: 16
Post ID: 16611
Reply to: 16609
Relevance of color
fiogf49gjkf0d
Here's what's behind my comment regarding the irrelevance of color:
I strongly suspect that the new production diaphragms will come with transparent Mylar suspension. In that case, I would hope they turn out to have the mechanical properties of the white Mylar suspended diaphragms. This is nothing more than me reminding (reassuring) myself that, though less likely, it is in theory still possible.

jd*


How to short-circuit evolution: Enshrine mediocrity.
07-01-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 17
Post ID: 16612
Reply to: 16611
About the new S2 drives.
fiogf49gjkf0d
 jessie.dazzle wrote:
Here's what's behind my comment regarding the irrelevance of color:
I strongly suspect that the new production diaphragms will come with transparent Mylar suspension. In that case, I would hope they turn out to have the mechanical properties of the white Mylar suspended diaphragms. This is nothing more than me reminding (reassuring) myself that, though less likely, it is in theory still possible.
I see, I did not get that it is what you meant and I did not catch that new production will come with clear surround. If it is the case then we need to abandon any believe in vintage clear diaphragms and in new clear diaphragms and just treat the new diaphragms as the new production, version 2011. The material it was made is kind or irrelevant as if it was Mylar 50 year back, Mylar 10 years back and now then Vitavox used anyhow different suppliers.  So, the production will come most likely with new diaphragms that very much might make S2 a different driver.

The most interesting question I would have is how new S2 drivers deal with those very idiosyncratic breakups that S2 has at very top. That amassing throaty texture that S2 has a very tricky – a bit more or less make deference between S2 sound rich as expensive as S2 sound like distorted.  I found that amp loading that drive S2 has to be set to much greater preseason then with any other drivers. If one use TAD for instants then 4 time change of loading did not impact sound as much as ½ loading against S2 driver. I use my own techniques to ideal the tube as much as I can (using very distorted tube) and to hold the very top of S2 with a very-very mild inductance. I am sure no one does it out there in the field but in my estimation it does the best with old S2 with white cone. Will the new S2 need all ot it> will it has that throaty texture? Will it breaks up atop? No one knows.

I am not planning to buy new S2 drivers. I have plenty vintage one but if it turn out that new production has a very substantial edge over new one then I might consider them. Still, I do not use S2 along but it works with my Injection Channel, so I think in way the difference between the old and new S2 in my playback will be less visible then in another playback.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
05-15-2012 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,515
Joined on 05-28-2004

Post #: 18
Post ID: 18179
Reply to: 16552
The new Vitavox S2 testing. Someone, perhaps…
fiogf49gjkf0d

Peter Empson from United Kingdom, the guy who use to run Unofficial Vitavox site and Forum has open a High-Fi shop in Aylesbury with a sentimental name “Deco Audio”. He sells the new production of Vitavox parts: The S2 drivers, the 15” woofer and the new version of the mid-range “Dispersive” horns. Peter has price list at his site and they want pretty much £3.5K per any unit.

http://www.decoaudio.com/drive_units.html

It would be interesting theoretically to try the new S2 drivers and to see if they any different than the vitage drivers with new Mike’s diaphragms. I say theoretically as I am not planning to do it. if the new  production of S2 units lend on my laps then I will certainly do it but I do not have any plans to instigate the testing.

Rgs,
Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
05-16-2012 Post does not mapped to Knowledge Tree
jessie.dazzle


Paris, France
Posts 456
Joined on 04-23-2006

Post #: 19
Post ID: 18184
Reply to: 18179
Part of the story
fiogf49gjkf0d
Romy wrote:"...It would be interesting theoretically to try the new S2 drivers and to see if they any different than the vitage drivers with new Mike’s diaphragms. I say theoretically as I am not planning to do it. if the new  production of S2 units lend on my laps then I will certainly do it but I do not have any plans to instigate the testing..."

The price for the new production membranes is reasonable, so one could imagine fitting them to old production S2 drivers as an experiment; this in fact is what I have been planning to do. I have not yet done it due to circumstances that have thoroughly taken me away from the world of audio for the past two years but I have every intention of returning. How relevant the results of such an experiment might be with regard to the sound of a complete, new production S2 is anyone's guess, as the membrane is only part of the story. Still, if anyone were to beat me to it, I'd be all ears. The same goes for the AK bass drivers.

In the mean time, I'd like to see the manufacturer post on his web site a frequency response plot of an old production S2 with its original diaphragm vs one of the new units.

jd*


How to short-circuit evolution: Enshrine mediocrity.
05-17-2012 Post does not mapped to Knowledge Tree
Jorge
Austin TX
Posts 137
Joined on 10-17-2010

Post #: 20
Post ID: 18186
Reply to: 18184
Same factory
fiogf49gjkf0d
I spoke on the phone with the manufacturer and he assures me the new production is exactly similar to the old drivers, the machines and people making them are the same.
About the diaphragms, the last batches of the old drivers already had the diaphragms with the plastic suspension.  So there is nothing really "new" about the latest production run of the drivers.
I havent listened to them yet!
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