John Warren
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Posts posted by John Warren
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PWK would have used real wood glue, 3/4" thick stock and screws to hold the KLF enclosures together, not Grandma Nellie's Arts and Crafts Hot Melt.
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$1040 purchase of GE stock in 1974 would be worth $73100 today.
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Tom-Sorry for going off on a tangent, the
threads on this board are dull, I'm trying to make things a bit more interesting!
When it comes time to technojabber Joe Sixpack (the guy wearing the Mickey Mouse sweatshirt), the marketing folks turns to the jargon of the Materials Scientist (grain boundaries in cables, alumium oxide coatings on cones, sweet sound of Alnico, Polymers, Kevlar, etc). Why, because it sounds convincing.
This message has been edited by John Warren on 08-01-2001 at 05:11 AM
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IMG]http://216.37.9.58/ubb/cwmsmilies/cwm31.gif
This message has been edited by John Warren on 08-10-2001 at 08:29 PM
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Now here is an interesting quote pulled form another thread on this forum.....
"I just spent some time a/b listening to the 5's & 7's and I liked the 5's better. The bass was tighter but the 7's ARE more efficent. The guy at the store stated that the new copper cones take a LONG time to break-in (100hrs) and the 5's were broken-in..."
Ok, who propogates this information, the dealer, the LLC? What are the physics underlying Aluminum cone break-in vs. paper cone. Why 100hrs? at what frequency? what is "breaking in" anyway??
The BS is so deep its stands alone as its own form of ENTERTAINMENT!
This message has been edited by John Warren on 07-29-2001 at 09:18 AM
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When I buy a used cast basket driver, I give them a close going over with a 10X Hastings Triplet. I have found the ocassional crack in what appeared to be perfect drivers.
Can't do that on Ebay.
This message has been edited by John Warren on 07-30-2001 at 05:02 AM
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I don't think so Gil. Anyone that works in manufacturing today knows that inventory is a thing of the past.
the best drivers have huge magnet assys resulting in large G-forces at the frame web when bumped. By the LLCs own admission, the plastic frames break with 10" baskets. Most pro drivers are 12 and 15" with enormous motor structures.
Also too, I wonder how well the LLC investigated the frames that they say did not crack?
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This message has been edited by John Warren on 07-26-2001 at 06:56 PM
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Made by Beyma of Spain. The numbers look right.
two pages are attached. The cone transducers are impressive! Check out the 21L45, a 21" Woofer with 35 lb magnet assy!!!!!!!!!!!!!! The thing weighs in at almost 50lbs, my aching back! Does Wilson use a couple of these monsters in that sub they sell for $18K? I love these guys.
The web page is
This message has been edited by John Warren on 07-23-2001 at 06:55 PM
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I was in CC this weekend and I saw
Infinity has a gimmick called the
"Ceramic Metal Matrix Diaphragm"
or C. M. M. D. NOT to be confused with
"Ceramettallic" cones.
Joe Sixpack must be "boggled" by all this new fangled
technojumble!!
This message has been edited by John Warren on 07-23-2001 at 10:58 AM
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the Rectilinear III is a six speaker system, 12" woofer, 6" cone "whizzer" mid, a pr. of 4" tweeters and pr. of 3" super tweeters. They were not cheap speakers, cost $600 back in '74 (pr. a pr. of Cornwalls
went for around $750 that year).
As Ray points out, the sensitivity is low.
The IIIB has a slightly different network.
Rectilinear Research Corp was located on Bruckner Blvd in the Bronx (South Bronx!!!). One very, very, very tough neighborhood.
This message has been edited by John Warren on 07-21-2001 at 05:25 PM
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What ever happened to Les Lammers??
Les, you still out there? Hello!!!
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Actually Gil, the "plated horn" version of the RF-7 will be introduced later this year as the RF-10.
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Engineering is a compromise. You never get something for nothing. It comes down to how risk is partitioned between the company and the customer. If the LLC did their homework, you will be listening to these speakers for 10-20 years with no problems. If not, who looses?
Look at it this way, when my L100 and L200 foam grilles turned into mud, JBL offered to sell me cloth grille insert replacements at $155 and $279 per pr. respectively (1989 dollars).
If the LLC wants to try different materials thats ok.
That's what engineering is all about. But when they pull stunts like the "Copper" thing on the cones it makes you wonder about the credibilty of the engineering as a whole.
This message has been edited by John Warren on 07-13-2001 at 07:45 PM
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The baskets' goal in life it to retain alignment of the motor components relative to the voice coil. To do so the basket material must have a suitable elastic
modulus and offset yield strength. Polymerics, especially the ones that lend themselves to injection molding (thermoplastics)have elastic modulii MUCH lower than 6000 series aluminum (100 to 1000X lower)!!
To offset this, the polymeric "matrix" is filled with ceramics (fibers, powders) which possess high modulii and very high strength.
So what's the down side?? 1) the matrix is always a significant volume fraction of the mix so it dominates the long term stability of the composite (creep relaxation over time, a.k.a "sag") 2) the cheaper polymerics experience huge changes in thier elastic modulii over very small temperature changes. On a cool day it's a "stiffy" on a hot summer day is a "limpy" and then voice coil rub, 3) the really good structural polymerics (PEEK for example) are
ALOT more expensive than aluminum, so you KNOW that the LLC ain't going to use that! 4) they are not good in shock load and tend to crack. The reason for this is simple, polymer chains are like a bowl of spaghetti--when you apply a load they need time to slip and slide around to accomodate strain (that's why you get "sag" over time) BUT when you apply a load rapidly they don't have the time to slide around so they just snap!
The bottom line is that composites are engineered materials and like everything else good and bad ones exist. Structural polymerics that have high elastic modulii, high glass transition temperatures and high strength are expensive.
Having said all that>>
The question you need to ask is 10 years from now will my woofers have voice coil rub or no, what about 20 years from now. If they do rub, will the LLC be around to bail you out??
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jfiophSdbjif
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when the LLC actually does something "positive" then I'll have something positive to say.
the Klipschorn is dead, long live the Klipschorn!!
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where do these "ideas" come from? cardboard enclosures and "glow in the dark woofers" can't be too far behind
when they start messing with the color of the cone it's "resume time"
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so which team came to the market first with the "zany" copper tinted driver cones; JBL-Walmart or Klipsch-
BestBuy?
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pls suggest a reasonable value for a pair of
like new 1987 Fortes (not Forte II)
thanks
John
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thanks john! good to see that a few of us around here
still know how to have a few laughs!
"the world belongs to the unsatisfied"
C. P. Steinmetz
(General Electric CR&D, Schenectady, NY)
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sam-all high volume manufacturers source drivers from the same Chinese supplier. everyone buys the flavor of the day.
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Most of us can't tell when were playing music thru
speakers that are either out of phase or the mid-range is blown or disconnected or one channel isn't even hooked up.
pray tell--what does a capacitor that needs to be "broken in" sound like??
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mounted horizontally to reduce enclosure height, saves wood.
vertical mounting better but others on this board will say no.
it's a diffraction tweeter, mathematics says it is better, designed specifically from the mathematics.
Product Identification and Price List
in Technical/Restorations
Posted
IMO, the Ranger/Paragon looks better than it sounds. Hartsfield is a nice system, but for my money, the
Jensen Imperial is the hands down favorite.