Don't worry Romy, I know exactly what you mean. I tend to discount the opinion of anyone who raves about a system's ability to play back patricia barber. Speaking of which, if I were in her shoes, bunions and corns aside, I'd be mildly gutted that my fan base was comprised entirely of jazz-at-the-porn-shop worshippers.

I have a pal who has heard the 555 on the snail - says on some stuff (ie very simple music), it's astonishingly good, but that setup fell apart on complex material (or even tap dancing, if you're familiar with that story...). Having seen the phase pluig, I think it's actually a very good idea if you don't want to take the driver up into the treble - keeps things simple. Actually, if I were making my own driver, I might dispense with compression entirely; I think one of the big advantages of compression drivers over conventional is actually the lack of spider as much as anything. Complete aside: how about using shaped carbon or metallic foam instead of a phase plug?

Re the MAF crowd, despite never having met them in the flesh, I'm pretty damned sure the Cogent guys are a million miles from that description but reading it prompted a hearty belly laugh anyway, ta :-)
 
I know they aren't hopelessly brainwashed by the whole WE/vintage thing - their attitude seems to be to take the best the past and modern tech has to offer and improve it - viz. carbon fibre diaphragms, for example. Also Steve Schell's day job is tuning pianos...

All of which sounds very promising to me; I hope that I'll be able to afford a pair of their drivers when they're ready. Otherwise I'll have to sneak a lathe into the flat...

Cheers

Romy the Cat wrote:

<P>  slowmotion wrote: I don't know why they insist on using conical horns , though. In my not so humble opinion conical horns suck. Big time. … </P> <P>May I ask why? The only problem that I see is the size, that it king of their problem… Unless they would run 70Hz horn with a curve and then it all will go to a toilet.<BR>&nbsp;<BR> <P>The caT</P>

cv wrote:

I have a pal who has heard the 555 on the snail - says on some stuff (ie very simple music), it's astonishingly good, but that setup fell apart on complex material (or even tap dancing, if you're familiar with that story.

The caT

(don't worry Romy, I think it's available on CD too)

The reason I mention is that generally, I don't get on with chamber music (probably cos of being fairly new to classical) but I love this one (esp. the Prokofiev) for some reason. Excellent recording too.

Well, I've violated the format of this site enough with that aside, so I'l sign off for now.

cheers

Chris,

I wonder what your like in the Quads, the actual performance of the loudspeaker or the way in which those delay lines shape the front of the attack wave?  Anyhow I thin to mention the Quad in the Vitavox S2 thread would not be ethical… :-)

Anyhow there is a lot of significant music in cello sonatas. If you like what Britten did then look also for his entire collection of Cello Suites by Trüls Mörk. Also, all of them: Shostakovich, Prokofiev and Britten have written concertos for cello and orchestra, you might look at them as well (Well, Britten called it cello symphony but it is essentialy the same)

Rgs,
The caT

Allo
These weren't quads but ML CLS panels (well, just the one actually, leaning against a chair, clip leaded up . How's that for even more unethical... To be honest, *I* didn't actually like the sound; found it a bit uninvolving, and muddled and distorted at levels where it would have started getting interesting.
Nonetheless, I think the stacked panels, cutting out the bass and treble, and dedicated amps will fix that...(!)... I hope.

Having said that, you asked what I liked about Quads. Well, as a teen, and before blowing it up, I used to have a single Quad ESL57 (no delay line), driven from an 80s piece of crap Kenwood amp I bought s/h for £40 at an auction.

Obviously you could never turn the quad(s) up loud enough but there was one particular vocal track I played (chick and her guitar) which would result in tears *every* time I played it. No other speaker I've heard since does that for me, at least, not on that tune. But that may just be because that was over a decade ago and I've since turned into a jaded and cynical bastard... Anyway, you asked what I liked about the sound, well, that's what.

A few years later,  I figured the stacked CLS panels, custom amp etc etc might give me more of the same quad magic whilst addressing the weaknesses, so that has been a *long* term project, the Vitavox/horns stuff is a more recent find.

Thanks for the sonata recommendations, will check out.

Cheers

cv

It is interesting that S2 phase plug, if to look at it from throat, ends up with round-head bolt. The head of the bolt has a channel for a flat-head screwdriver. This channel should introduce an asymmetry into a perfectly symmetrical phase plug and into the perfectly symmetrical wave-guide. I wonder if to replace this bolt with a custom-made bolt that would have a conical head with a very littlie hex-hole in it?

The Cat

The voices, the voices...

Just a word of warning, if you do decide to give this a go, remove the diaphragm first and be sure to have exactly the right size screwdriver - that bolt is prone to flaking...

Might I suggest that if Macondo has evolved to this level that you reverse engineer the S2 and use it as the basis of the RTC1, with electropolished phasing assembly, custom exit flare frequency, SET-OTL friendly 600 ohm voice-coil (Mike at Octave couldn't comply with this request alas), cobalt alloy magnetic circuit, field coil drive. Hell, why not a diamond diaphragm (no more "beneficial resonances" is one reason)? I guess one could have a new production one deep anodised for something "accuton style" if one were really that curious...

Well, you did say "absurd" :-)

I would like to post it into this thread, as somebody who cares about S2 should know what I ended up.

Anyhow, now it is officially: I permanently removed a tweeter from Macondo. The properly voiced S2 driver  (with a transparent enough track- here is where the new buffer works!!!), with a metal original diaphragm, and the driver ssitting in a small not-deep horn (I use 400hz tractrix) does not need a tweeter.

slowmotion wrote:

How was the lower midrange affected by the tweeter removal?

Rgs,
Romy the caT

Romy the Cat wrote:

Anyhow, now it is officially: I permanently removed a tweeter from Macondo.

It is very difficult to describe what it is. I call it “aftershock effect”. It is kind of sound when sound already not there but something still ringing. My initial thought was the S2 has some UFH resonance but the “aftershock effect” subjectively manifest itself at approximately 7-8kHz. Probably the UHF modulate it with it’s lower harmonic at the auditable range, does it? I really do not know. Interesting that this resonance I consider very constructive, beneficial and superbly important (“good resonance”) and this resonance is one of the most remarkable qualities of S2 driver. However, I would like to have the amplitude of this effect perhaps 10-20% less then I have it now.

So, believe me or not but I begun to experiment with tweeters again. Well, I do not call it tweeter but, as I called it before, - the HF resonator. I was able to soften those 20% of the S2 “good resonance”. I use the EV T-350, 16R version with 0.1 Teflon cap. This effectively creates 99Khz filter, that arrives at 15Khz at minus 18dB. It hardly has any sound; at least I have to put my ears 3” form the driver to hear anything.

Now, I do not know if the softening of those 20% was due to the acoustic merging of the MF and the minor amount of HFform the tweeter (the driver are superbly time-aligned) or the HF driver acts electrically as a HF Zobel at UHF when the Vitavox run into it’s resonance or the HF driver when it kicks in just parallelling itself with S2 and drops it impedance sufficient enough to roll off the S2 for a fraction of a dB. I do not know the answer and I do not know if I need to know it. Also, I do not know if I will be keeping this approach as I consider some alternative options. However, I thought that the folks who are interesting where I am going with my Macondo should know that am still working with Vitavox S2

Rgs,
Romy the Cat

Romy the Cat wrote:

I thought that the folks who are interesting where I am going with my Macondo should know that am still working with Vitavox S2

The S2’s “beneficial resonance” is quite interesting animal. Pretend that you can manage a subjective perception of “resolution” (whatever it is) of your system, along with dynamics (!) but….  WITHOUT AFFECTING ANYTHING ELSE and without adding any HF extension to your playback? Did you pretend it? I knew you couldn’t because it is impossible without “affecting anything else”. Here is where the “beneficial resonance” comes to the table – it actually does it all maintaining a perfect tonal balance, without taking music apart and without creating the “hi-fi”

The “beneficial resonance” is kind of alien superficial force that spreads across the S2 sound and that control a lot of things – the major dilemma is how to control the depth of this “alien superficial force”. This “beneficial resonance” is an engine that set the S2’s sound apart form anything else. I would depict verbally the “beneficial resonance” as a countless amount of micro-bubbles that are exploding within notes and this liberated bubbly rushing energy, mixed with the actual reproduces signal, create a very toxic and very sonically lethal signature that acts like a “listening catalysis”. Interesting that the amplitude of this catalyses might be higher then necessary and therefore to control the amplitude of the “catalysis” is the key to make the S2 to sing… When the amount of the “beneficial resonance” is perfectly matched to the “signal output” then S2 does something really extraordinary…

Well, the each and single S2 driver that I’ve played with (probably 12 drivers) had own “amplitude of catalysis” and therefore each driver should be individually “comforted” by whatever means you find suitable (acoustic, mechanical or electrical damping, in-channel or external diffusion or whatever else you use). There are many reasons why each driver behaves differently. There was different type of magnets used, different materials for phase-plug and some other critical parts, different diaphragms, different exposure to temperature, shaking, power overloading and so on. Only God knows how many times over the last 50 years the drunk Brit’s movie-technicians dropped those drivers from the top of the Telocom Tower, how many time the amps that droved them had tubes surge, and how many times the drivers were disassembled (bad for the gausses). The S2 has Alnico magnets and the Alnico prone to loose while time goes by. Even when you magnetized them and you shut down the magnetizing machine you instantaneously loose the gausses in the gap. So, the drivers that we use (well, I use, but I do not think that your driver would be different then mine) are totally unpredictable….

The common wisdom suggests that if a magnet were slightly demagnetized then the band-pass efficiently would go down and I have seen it. All my drivers have identical dB efficiency. However, the different type and brands of Alnico acts differently. Some of them when a magnet is loosing its magnetic force begin to act like a filed-coil driver when you drop voltage: the bass become bigger and puffy and the HF roll-off sooner. All of my drivers have the very different HF response and interestingly all of them have different default amplitude of “beneficial resonance”. I was trying to relate the “beneficial resonance” with the HF extension but the relation is not so apparent as I wish.

Anyhow, my six current S2 drivers show different HF response. Some of them roll off at 8kHz-9kHz and some of them go to –3dB at 12.5kHz. The only two drivers that I have and that go up to 12.5kHz have a strong “beneficial resonance”. Some of my drivers despite thier high HF output have no strong “beneficial resonance”. The S2 driver that has no “beneficial resonance” sounds like Altec/JBL – type of the drivers – means boring. I DO NOT KNOW why some of my S2 have diminished “beneficial resonance”, perhaps it is due to de demagnetization of because MANY OTHER REASONS (material and son on). The relationship between sound of the drivers and the technological elements is not well known or understood even by manufacturers. Also, I have no gauss-meter to measure the magnetic density in the gap…

Recently I decided for fun to see “how it might be”. I have one single brand new S2 driver. I is an early “none-ribbed” production probably form 60s; it still in the original paper-damped box, never was mounted, never was connected or used in anyway and it looks like it was manufactured yeastoday. I crewed this driver in my 400Hz horn and the driver measured efficiency-wise identical with all the rest of my drivers. However, to my surprised when I measured it response the drives suddenly pushed 0dB at 13kHz!!!!! Moreover, the driver has such a huge amount of the “beneficial resonance” and such a tremendous transient ability that it scare, and my system has a dificult time to handle it. I paired this new driver with my best “used driver” (that goes up to mild 11khz) but has the largest “beneficial resonance” amplitude and tuned the “beneficial resonance softening” for each driver. I “equalized” the HF differences of the driver by placing the “hotter” driver on right channel – farther from the first violins and sopranos. It works "soft of" fine for now and I will not be doing anything until the Super Melquiades will be built and then will see what I can do with a dedicated channel and with no speaker-level filter.

Manville, just for sake of an experiment, I’ve sent one of my “worst” performing S2 drivers to remagnetize it. I do not know if it affect the ‘beneficial resonance” and if it does I will report the results of its performance after it will be fully recharged.

Romy the Cat wrote:

Moreover, the driver has such a huge amount of the “beneficial resonance” and such a tremendous transient ability that it scare, and my system has a dificult time to handle it.

IF
…. a plastic suspension diaphragm is less HF extended then the aluminum one
…. the aluminum suspension diaphragm is so aggressive
…. the “New” Vitavox S2 drivers (or presumably the fully charged) have HF extension higher then the regular eBay stock …

THEN

Would it make sense to try placing a plastic suspension diaphragm into a “new” driver and see what would happen? The plastic suspension diaphragm is softer but the new driver is too transiently brutal… would it be an interesting attempt in context of my smaller and HF extended horn and in the nearfield listing?

This should be fun…
The Cat

So, I did exactly how I described in the previous post and I returned back to the plastic suspension diaphragm sitting in the “new” drivers. I lost ~3dB sensitively and was forced to go back to 3uf crossover, exactly how I described in the beginning of this thread. It performs softer and with less amount of “beneficial resonance”, however now there is as much “beneficial resonance” as my playback can handle, even very slightly more but it is still tolerable. 

I abandon any further study as I detected that the major factor in managing the amount of the “beneficial resonance” is the amplitude of upperbass slope that being crossed with Vitavox S2 driver. Apparently the interference of the upperbass coil with S2 coil does a LOT to the performance of the S2 driver. If the S2 is completely decoupled (second order low-path at 1.5kz) then the rules of the game completely changed and the S2 behaved VERY different. I will wait until the dedicated channel of my Super Melquiades will be driving the Vitavox S2 driver and then will see where I would be able to take the performance of this driver further.

Rgs,
Romy the Cat

Romy the Cat wrote:

Manville, just for sake of an experiment, I’ve sent one of my “worst” performing S2 drivers to remagnetize it. I do not know if it affect the ‘beneficial resonance” and if it does I will report the results of its performance after it will be fully recharged.

The S2 specification suggests that the driver should have has 1.6T in the gap. When people change the magnets that it is imposable to overcharge them. Usually the magnets are charged to the full capacity and the force of flux regulated by the amount of magnet. So, if the fully changed S2’s magnet does 2.1Tesla then:

1) Vitavox “underused” their own magnets by undercharging them and they basically “vested the magnets”. If it is so the shame on Vitavox.
2) They specified in thier documentation the 1.6T of flux as an average magnetic density presuming that it will be severely worsening on the fields. If so, then it would explain why so many different result people get out of this driver.

I do not have the 2.1T Vitavox S2 in my possession yet but when I get I certainly will see how this baby will sing. I will post the results.

Rgs,
The Cat

Romy,

I have seen this a few times with JBL and Altec drivers. This phenomena occurs more often in Alnico magnets than any other type of magnet. When a magnet is recharged, it is blasted with a very strong magnetic field. There is really no way to “half-way” charge a magnet. The magnet just accepts as much charge it can, and the rest of the magnetic energy delivered to the magnet during the charging process is wasted. If a manufacturer needed more flux, then they added more magnet weight. I had Orange County Speaker recharge a JBL 2482 for me once. They told me that the flux had dropped down to 14.7 T. They cleaned up the driver and recharged it. Once recharged, they said they measured 19.3 T in the gap. I checked the flux myself with a gauss meter from my work and it read 19.4 T. After about 6 months of use in a local Bar, I re-measured it and the flux had settled down to 17.2 T. The JBL specification for the 2482 is 1.7 T, so it is pretty close. Others have told me that when Alnico gets recharged it measures high, but decays very quickly down to a more normal charge level. I would not be surprised to see your 2.1 T S2 driver drop down to 1.6 – 1.7 T very quickly once you begin to use it.

rdrysdale wrote:

Romy, I just got a Vitavox S2 into my shop today. I notice that it has a very heavy stainless screen on the front, do you leave the screen on when using the drivers? It looks like it restricts about 50% or more of the throat exit. Rich Drysdale

I experimented with many drivers by removing the bug-screens and ALL of them did not perform well (in MF). Some may argue that within the screen they get more transient and HF but I would reply “get better drivers and better electronics”. The S2 is as venomous as it theoretically possible WITH the bug-screens. Without the bug-screens it will act as a weapon of mass destruction. Be advised that I had in past (believe me or not) a sheet of toilet paper added to the S2’s bug-screens (metal diaphragm + nearfield is a dangers this for this driver). If you play with S2 and if you have a fully charge driver then I would give you 90% that you will end up to use it at 20-30 degree off as you would fide that S2 will be  “too much”. Removing the bug-screens will convert this driver onto a laser beam, try it, it is not difficult to do juts get ring of the 3 bolts. I personally do not thing about the bug-screens as they were the impediments to sound but rather as thy are the DIFFUSERS. I sinisterly feel that the bug-screens are very-very useful tool and should not be removed.

The only one driver that I find that the removing of the bug-screens was very beneficial was EV T350. The removing the bug-screens killed the midrange in theT350. In my case, when I use the tweeter over 10kHz it did not bother me, quite oppositely – it was very beneficial.

In the end I will bring below my old writing that I found on my file-server. I remember I wrote it to post somewhere within the Sewers somewhere in 2001 in response to the Morons’ tendency of striping the bug-screens from the Avantgarde tweeters (operating from 4.500kHz in context of default Trio). I do not know if this post survived in the archives. At that time the moderating dirt of that forum was trying to beg for itself some accommodation from some crappy manufacturers and they vandalized anything that mentioned the “competitors”.  Be advised that my initial credibly-Moronic suggestion to people to remove the screen was improperly understood… my myself. I did find during my experiments in 2000 that to remove the AG bug-screen was advantageous but at that time I was not able to interpret why it was so. Fist, I use the MF driver that went all the way to 10kHz and my AG tweeters were kicking-in then (eventually I replaced it with “inverted 808A”). Second, the AG tweeter does not have a back chamber, so they have not damped cone anyway.

Anyhow, here is comes as it was written.

********************* Beginning of the original post ************************

About the Avantgarde-tweeter-screens plague or a note for the archives.


“The concert of so many different birds become so disturbing that Ursula would plug her ears with beeswax so as not to loose her sense of reality” - Gabriel Garcia Marquez “One Hundred Years of Solitude”

If you look under my AA’s profile you would ask: why the hell are you still here? Well, I am not here anymore, but I still feel a certain sense of not-settled guilt (in fact I never suggested to anyone to remove the Avantgarde tweeter screens. I just admitted that I did it, which added confidence to some “waiting for the miracle to come”- type people). Now, I would like to reconcile this dilemma and probably to preserve some people from the spending time and money on the worthless and could-be costly exercise of their worst audiophileism. (Contrary to some funny “Audio industry shepherds” I have no problems to admit wrongdoing or wrongsaying.)

Below, I have compiled some of my raw thoughts regarding the topic: how can one improve the performance of the Avantgarde’s tweeters. “Improve the performance…” Do you feel that itch? If you do then buckle up and read on.

History:
For some time I experimented with the deferent cables to drive my Avantgardes. All my system are wired exclusively with the Dominus . (I sincerely consider the Dominus being a reference cable for any properly built electronics and properly assembled system). I asked myself why the connectors between the Avantgarde’s crossovers and the driver couldn’t be the same? Well, I went for this and while I was dissecting my poor Trios I discovered those “thick metal screens” on my Trios tweeters. Exploring them further, I learned that I might “painfully” remove them. I asked myself: “Are those screens between me and Music?” The virtual images of the “smelling a rose without the gas-mask” and “a beauty of the unsafe sex” popped up in my barbarian head and in 5 minutes my Trios were screenless. (The removing of the screens is not a reversible procedure).

The Conclusions:
(I will eliminate all relevant and non-relevant variables and pass the ONLY differences inflicted by the removing of the tweeter’s screens. I know what I needed to listen and I have processed the results of this research.)

Advantages:
1) I did not detect any sonic improvements or changes besides my intellectual satisfaction that “there is nothing alien on the path of the sound”.

Disadvantages:
1) Without screens the tweeters began to sound louder. I would estimate a gain somewhere around .3-.5 dB. The sound became too “hot”. Do not forget that the crossovers were designed and tested with the screens. The insertion of a sheet of “acoustically transparent” paper could resolve the problem.

2) Screenless tweeters do introduce very-very-very-very minor heights distortions. (I do not know what they are by nature.) In fact you won’t be able to hear them with most of amplifiers and cables. For the sake of research I brought 4 amps for a test and tried some alternative cables as well… this problem did not manifest itself. (BTW: 3 out of 4 of those amplifiers are considered the AA’s Mecca…) To reach the depth of the Avantgarde’s tweeters capacity you would need a killer: the single-ended Lamms. With those suckers everything was there including those “non-existing in the real world” heights. (I have to note that practically any “step down” turned on the “masking effect” and made this problem less annoying or inaudible) I made a bunch of experiments to verify that the Lamms were not the guilty party and tried all “audiophile tricks” known to me, but was not able to eradicate this problem. So, what was it? Well, you have seen the drummer’s cymbals? They have the little resonators that create that “Ketchup sound”. So, this Ketchupness was presented in the ALL high frequency sounds and slightly fluctuated with the volume. The effect to some extent reminds me of the “ornamented” sound of the HT cables within the neutral electronic components only in the very-very minor scale. I played a lot with that effect and ended up with the conclusion that it can’t be fixed unless I intentionally “dull” the system.

3) For some reason removing the tweeter’s screens apparently screwed the phases somehow (soundstage allocation). I began to have a difficulty getting my “Trio Sound”. In my room properly set, properly powered and properly “massaged” Trio horns usually “compress” air and produce what I call a “hurricane/tornado effect”. I use to be surrounded with thick and tangible clouds of compressed air that spun around intensifying space and musical time, filled with bubbles of Sound, appearing and exploding somewhere within the room, opening the sealed-within music memories and revealing Life. Since screens were removed I had only the beautiful “wide and deep soundstage”. In fact, I am still able to create my “hurricane/tornado” effect however it happens only within extremely small listening space that eliminates some desirable listening experiences. (Like exploring the Sound from the “side”, ability to “walk into the sonic event”, to “conduct” the orchestra by changing the listening position, to “torment the Sound” and so on…) I spent a long time moving everything that was movable but I failed. For some reason without the screens the heights ground down my attention to reality. I am sure the engineers would explain it more intelligently than I do.

Do I consider the removing of the tweeter’s screens as a “barbarian act”? Yes, I do, and I’m strongly discouraging the Avantgarde listeners to do so. Should the folks who have already done it be worried? I do not think so. God blessed us with the famous “masking affect” and I have some reasons to believe that you shouldn’t experience any problems.
If you aren’t happy with your Avantgarde highs then here are some notes:

1)After auditioning a number of the serious speakers ($20K and up, up, up…) I summed up (considering many other variables) that the properly driven Avantgarde’s tweeter could be considered as the reference high frequency available for the sound reproduction.

2) Under no circumstances one should use with your Avantgarde’s tweeters following height frequency vandalisms: the silver cables (they burn heights), the silver output transformers (they dehydrate heights), the push-pull amps (they impersonate the heights/mid integration), any frequency boosters (they substitute heights), ***ty DACs if you listen to the digital (do you like to feel like a dolphin?), digital correction devises (this staff combined with ***ty electronics and a horn is direct recipe to be contaminated by the sonic moronism)

3) Without going deep into the explanations and justification… here is the rule: if a listener uses a word “top end extension” to describe his/her perception of Sound then the person who designed-built-sell-suggested the amplification-cabling should be granted with the title: idiot.

4) Spend some time to play with the different amps using the stock Avantgarde speaker cables. Most of the time the Avantgarde’s tweeter will be in the order of magnitude more superior then your current or your prospective amplification. The existence of the “big tubes”, widely reputed “audiophile” name, saliva-dropping “songs” of your idiot-dealer or the sweet “help” of your inmate-amp-designer dose not automatically indicate that your amp will handle the demands of the Avantgarde’s tweeters…. The removing of those tweeter’s screens should not be the first think you have to do.

5) Under no circumstances angle the Avantgarde’s tweeter relative to the horn’s frame. It creates a huge amount of problems.

6) Avantgarde USA accumulated extensive experience with their product. I never heard them refuse to consult anybody. Prior to the violation of your Avantgarde’s tweeter virginity and removing the screens you may find it beneficial to ask them about the consequence or to read this post again.

Best regards,
Romy The Cat

PS: I won’t argue or responses to any follow-ups. The subject is all yours.

********************* End of the original post ************************