I am just curious. Is the Pascalite similar or the same as the Altec Symbiotic.
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I am just curious. Is the Pascalite similar or the same as the Altec Symbiotic.
Very different
The Symbiotik has a mylar surround
Pascalite is aluminum
You seem to think Pascalite is a GPA thing? Are you aware Altec made the Pascalites originally?
The symbiotik surround seems to be listed listed as Kapton (polymide) not Mylar (polyester). Both patents of DuPont mind you.
I've always wondered why Altec called it Pascalite. Was the aluminum really extracted from the Pascalite clay or is this just a marketing thing? Where did the aluminum for the Symbiotik's come from, Boxite or Pascalite?
Bauxite.:D Wiki defines it as "the most important aluminum ore"
Cal, your post inspired me to do some reading, i learned things i never knew i wanted to know. Seems Pascalite is used as some sort of miracle healing powder, much akin to ground yak horn, or rhinocerous spleens.
There's even a Pascalite website: Index
It seems in the past where Altec diaphragms are concerned i've seen it said that pascalite is simply "hardened" aluminum, honestly don't remember if it was ever determined if it's an altogether different alloy, or just aluminum that's undergone some sort of hardening process.
Whoops, did I really spell it Boxite? Hehe.
So is there any advantage of using a pascalite over an standard aluminum 'phram?
I remember years ago like in the mid-1970s, the standard aluminum 'phram had like a 10 watt rating, but Altec rated alum 'phram freq response out to 20kH. The symbiotic 'phram was rated at 30 watts but the freq response was only out to 15kH. I believe the symbiotic was intended mostly for PA applications, whereas the aluminum was used for music applications.
Does GPA make symbiotik diaphragms for the small Altec drivers.
AFAIK no-one makes Symbiotiks anymore. You see them on eBay every so often.
Honestly IMHO the Pascalites sound far better than the Symbiotiks, handle more power and you can still get them new, as opposed to used in unknown condition on eBay.
Quote:
Originally Posted by Ronald Lee
The Symbiotik was discontinued and replaced by the Pascalite.
Essentially, the Pascalite is a tougher version of the aluminum fram with a a high temperature former for the voice coil. The concept was to have better highs and more power handling together.
Symbiotiks are only available used or NOS.
I would use aluminum for hi fi and Pascalite in pro apps.
Honestly, Altec one inchers in pro apps make no sense to me...a BMS will sound better and live longer for cheaper.
Radian makes essentially a Symbiotik fram, better due to newer tech. Handles more power than the Pascalite, the Pascalite sounds better.
Regarding the surround material, like Pascalite is still aluminum, just a brand, the stuff is Mylar, just a variant. I should call it by it's proper name perhaps, but can't see a good reason to bother with the effort.
How long have those Radian "Symbiotiks" been around? I took the cover off of one of my 808-8A's awhile back and I questioned if it was an Altec diaphragm. They came from my church, and were out of regular use for years, so I doubt they'd have anything of recent manufacture in them....... and by recent, I mean the last 10 to 15 years.
I don't even know hoe long Radian has been around....... any other non-Altec Symbiotiks?
Mylar = DuPonts trade name for polyester sheet used in window tinting film and emergency blankets.Quote:
Originally Posted by Old Guy
Kapton = Duponts trade name for a polymide used a lot in voice coil formers.
Mylar not = to polymides. Mylar is a polyethylene chain based product. (I believe)
I ain't gonna change habits at this late date.:D You are beating a dead horse Cal.Quote:
Originally Posted by Cal Weldon
The Radian BTW IS Mylar fer sure.
Radian was established in the late 80's I think....
Fair enough.Quote:
Originally Posted by Old Guy
Cheers OG. :)
I was at the Altec factory one day in OKC when Jerry Hubbard was developing the Pascalite diaphragms. Here's what he told me -
EV refused to allow Altec to develop anything new, so they had to couch a lot of their work as "improvements of existing products" so that EV would fund the R&D. Apparently, EV didn't want little ol' Altec outdoing them...
This is what happened when they developed the Pascalite diaphragm - they had to tell EV it was an improvement on the 288 so they could get permission to do so. The result, eventually, was the 909 and the 299, but they were viewed by EV as mere "upgrades" to the 902 and 288, so they let it pass. The same thing happened with the A700...
Looking at the different samples of destroyed diaphragms that Jerry had on a board was quite interesting - he was trying out different allows, materials, etc., to arrive at a diaphragm that performed as well, acoustically, as the 288's diaphragm, but wasn't as delicate. From the looks of what I saw, there were a lot of materials that just weren't suitable - either they burnt to a crisp or the diaphragms shattered (the most common problem, as I recall). Finally, Jerry found the right combination of metal alloy, former material, and high-temp glues and arrived at what we now know as the Pascalite diaphragms.
When I asked him later why they were called Pascalite, he replied that he named them after the great mathematician Pascal, and combined his name with an old=style method of marketing to arrive with "Pascalite".
Cool! Thanks Todd, that's great info.
FWIW, Radian started with replacement 'frams back in the 80s. Then went on to build drivers, too.
I have a pair of 1.4" Radian drivers with the mylar suspension that were built about 1991. Early models, AFAIK.
Radian was formed , as I understand mostly by Renkus, while Emilar was going belly up.Quote:
Originally Posted by Panomaniac
The Emilar factory was padlocked at the time from legal action.
Not sure why he chose to form Renkus-Heinz instead of continuing with Radian, can only assume differences occurred between partners.
Here's an interesting paper by Hilliard and Renkus (who also worked at Altec) describing the development of what I presume became the Symbiotik diaphragm(s);
http://www.nutshellhifi.com/library/...-in_Emilar.pdf
courtesy nutshellhifi
And Cal is right, it was Kapton/polymide...;)
(Although Altec did use Mylar too, in several microphones and the 3000 tweets) :)
If & when need to replace my original Altec 806 'phrams, I can replace it with a GPA Pascalite 'phram, is that right, and it will pretty such sound like the old Altec except there will probably be better high freqs?
Great link bfish, thanks for posting!:2thumbsup:
You may not have original 806 frams if they are Symbiotik.Quote:
Originally Posted by Ronald Lee
It should sound quite a bit better. Either aluminum or Pascalite is an improvement over the Symbiotik, I never cared for them.
OTOH the Symbiotik sounds much better in the bigger driver (291). Just never liked them in the one inchers.
I will make a serious effort, but come on guys, I still catch myself saying CPS for Hertz or calling capacitors condensers....:)
Interesting the 4 inch VC in that paper bfish posted, wondering how much difference there was between it and the old WE 4 incher.
CPS=Cycles per second, rather than HZ. U R show your age. I still use capacitor or condenser interchangeably today.Quote:
Originally Posted by Old Guy
bfish: thanks for the link, I will read it.
Thanks for the paper, good info. I did not know Renkus was from Lithuania. I've used Renkus-Heinz gear and liked it.
Nutshell Hi-Fi is Lynn Olson and Gary Dahl. Both good guys.
A little OT, but since we're mentioning the Renkus connection and his contributions, could someone possibly expand on the Renkus Corporation?
Not Renkus Heinz.
Not Emilar.
http://i107.photobucket.com/albums/m.../Renkus002.jpg
You're welcome guys.
I can't remember where it came from, but I recall someone once said that LTV built a 4" WE knockoff for a government contract. Given the fuzziness of that memory, it might not mean much...Quote:
Originally Posted by Old Guy
Interesting bit of web digging found this from an old LH thread:
Apparently it was the Altec 594B driver...
"Jonas Renkus and his Bowtie horn
As 'Bowtie' suspects, Jonas Renkus was at Altec. He was directly under Hilliard as Lansing had been twenty-five years earlier. In Anaheim, he developed for Ling-Temco-Vought the symbiotic construction using kapton for the compliance and coil former. He told me that the marketing people at Altec degraded the top end response because they wanted an intermediate performance between 290 and 288 responses and power capability. This is illustrated by the thicker aluminum locating ring on the 291 diaphragm that places the aluminum diaphragm further from the phasing plug.
Jonas pioneered the use of silicone elastomeric compliances in LTV's air modulators and used this innovation to avoid compliance fatigue in Altec's 594B 4-inch coil driver that was an alnico reissue of the WE 594A but are even rarer because the government was the purchaser. Most went to White Sands, NM.In the early seventies Hilliard and Renkus had a consulting business on Main Street in Orange and from here they introduced the elastomer surround into smaller format drivers. They established a joint venture project with Bud Bennett of Quad-8 to commercialize a new cinema system. I still have Jonas's prototype HF driver from this project.
The elastomer compliance and the drawings and prototype of what was to become the EC175 driver was the founding basis for Renkus Corp in 1974. The alnico EA model was prompted by Dukane; they marketed Coral drivers from Japan. With investment Renkus Corp became Emilar Corp (Mohageri, Lindsey, Renkus). Harold Lindsey was one of the Ampex founders and had an interest in horn systems from Ampex's 1950s foray into cinema sound using licensed JBL loudspeaker designs.
Emilar's 1970s diaphragm production featured elastomer compliances and this gave fatigue-proof reliability over the the prior art used by Altec, JBL, Coral with embossed Harrison-type complances. Also the resonances in the top octave exhibited by the embossed surround were absent in the emilar drivers but these elastomer diaphragm assemblies were expensive to produce.
I have the original correspondance betweem Jonas Renkus and Harro Heinz that I have shown to Steve Schell. In 1979, after Renkus-Heinz was producing the elastomer featuring 1800 and 3300 drivers and they were being agressively marketed by Algis Renkus, Jonas and I developed the triple lamination construction that resulted in models 1801 and 3301.
Both Jonas and then Algis left R-H and returned to a failing emilar in 1981. There the expensive elastomer construction was abandoned for the triple lamination technique and the 314 and 320 drivers were developed and produced. There was litigation from Heinz but he dropped the charges during the hearings. Subsequently this construction technique was adopted by B&C in Italy.
When emilar was abandoned by its British owned holding company E3MC in 1995, rent arrears were paid to the sheriff by Ken Brown and the locked factory was opened to him and the assets were plundered. There followed litigation threats from Algis Renkus to Plus One as Algis had been financing the company and taking leans on assets. I bought these from Algis' widow in 1997, incliuding the emilar trademark.
Thank you Bowtie for your perceptive admiration of Jonas' innovative work; there are few of us who recognise and acknowledge this. Innovative emilar branded drivers might appear next year with implementations of US patent 6,744,899; the slot aperture driver. I can be emailed at [email protected]. "
Thanks for digging that up OG, i'd forgotten that was at LH. I've searched for it here, and now it's painfully obvious why i couldn't find it. Further painful that i didn't remember the mention of Renkus Corp. The gray matter ain't what it used to be.:doh:
Thanks OG, that's probably where I got it.
"Emilar's 1970s diaphragm production featured elastomer compliances and this gave fatigue-proof reliability over the the prior art used by Altec, JBL, Coral with embossed Harrison-type complances. Also the resonances in the top octave exhibited by the embossed surround were absent in the emilar drivers but these elastomer diaphragm assemblies were expensive to produce."
Further OT, but that highlights something I've often wondered about... the 2 peaks in the valley of nothingness (15-20K) in Altec small formats... response or resonance?
Some simple sines should tell that tale. :)
Well next year you can post it for me when I can't remember it:DQuote:
Originally Posted by bowtie427ss
I run into that same problem every single day.:(Quote:
Originally Posted by bowtie427ss
"The mind is the 2nd thing to go, I can't remember the 1st."Quote:
Originally Posted by Altec Best
Okay, if and when my Altec Symbiotic needs replacing I can replace it with the GPA Pascalite?
The top octave is entirely generated by dome break-up modes and surround resonances, so damp the surround and most of the 10-20 kHz BW goes away.Quote:
Originally Posted by bfish
WRT the Ultralights, at least mine had thinner, more compliant surrounds and somewhat more HF 'air'/'snap' out to ~22 kHz and quite audible once the horn was EQ'd flat enough, though by the time you heard them they were decades old of course and the surrounds and been super-glued back in place after partially splitting away from the VCs, so combined with dome work hardening, their HF 'sharpness' was shifted considerably lower in frequency.
In theory then, these are all so old now that even if NOS they're more than likely brittle enough to only be able to safely handle a fraction of its power handling and lost at least some, if not all, of their top end 'magic'.
GM
If this is a prosound or 'Head Banger's Ball'/HT type of app, replace it with whatever GPA VC has the highest power rating, otherwise use whatever is recommended for HIFI. If for the latter, then to get the most out of them will require CD horn EQ, i.e. by-pass cap around the shelving pot or similar.Quote:
Originally Posted by Ronald Lee
GM
That's what I suspected, thanks!Quote:
Originally Posted by GM
Unfortunately, this fact goes unnoticed to (most) of those that rely entirely on full-range noise sweeps*. You can't (easily) tell the difference between signal response and distortion. Sooo... follow with endless network tweaks to raise and flatten the top octave, when all you're doing is raising and flattening distortion.
(FWIW, marketing deserves some of the blame for the misconception.)
*Don't get me wrong, noise sweeps are a valuable tool, but not the only tool. Stepped sines (a real PITA) will reveal HD, or ~one-octave, band-limited sweeps overlaid (differentially) on a full range sweep can too.
I can hear the bubbles bursting from here...
Added
Even without testing for proof, I'll wager that the wavelength(s) of those two nasty peaks in the top octave have a mathematical relationship to the diameters of the two compliance hinge points.
You're welcome!
Correctomundo! Fortunately, our hearing acuity up high is generally so poor that even a crappy piezo sounds 'HIFI' to all but a few folks (women and children only IME) if BW limited to > ~8 kHz.
Dunno, if the distance between inner an outer hinge points is around 5/8", then this could do it. Problem is, any output from the diaphragm has been homogenized (for lack of a better term ATM) in the filter chamber, but mathematically correlates close enough for me to the throat diameter making it the more likely culprit. That, or eigenmodes within the phase plug where the next design 'breakthrough' needs to occur IMO. Regardless, damping either will lower the driver's HF amplitude, though damping the throat will also affect a much wider BW, so damping the suspension gets my vote.
Sound maybe round, but a circle also generates a theoretically infinite number of eigenmodes, so if Dr. Geddes's Oplate spheroid really is the ideal WG shape, then so should it be for the initial expansion and why any potential future compression drivers for myself will be ones with only a short round filter chamber that can be suitably damped simply with a fine mesh bug screen, same as the original WE 555 driver. They got it right as practical the first time, so why did they 'fix' what wasn't 'broke', he asks rhetorically............?
GM