What year is the best used Klipschorns?

[neo33]

Please give me your inputs.

[psg]

2012 for 2K$ would be great, but not going to happen. I like the old A and AA networks, so up to late seventies?

[LousyTourist]

My year, 1979, is quite good. I think it was the last year of alnico magnets. Earlier years when the class A crossover was standard are considered best by others.

I switched from my AA crossover to BEC's A crossover and am quite happy with the results. The AA was mostly made to offer more protection to the tweeter from the 200w monster amps of the day.

[Chris A]

Please give me your inputs.

That's definitely a strong function of what's important to you. If I had to choose among the original Khorn design models, I'd personally prefer the 60th anniversary version because you can aim the speaker at your listening position better and not have to position it at an exact 45 degree angle to the walls in order to keep both horn "mouths" formed by the speaker and corner walls the same size/shape as each other.

My personal choice is the second generation Klipschorn: the Klipschorn Jubilee (home two-way, active crossover, bi-amped version) with TAD TD-4002 drivers.

Here is a link to the history of the original Khorn that seems pretty complete:

http://www.klipschcorner.com/heritage/KlipschornTimeline

It would probably be a good idea to copy this to this domain in order to make sure it doesn't disappear due to the Klipschcorner web site obsolescence.

Chris

[Chris A]

From the above-referenced link:

Klipschorn Timeline

This is a timeline for the evolution of the Klipschorn speaker from inception to the current date. Having been in continuous production for over 60 years there are still few speakers that can do what the Klipschorn can do, despite having hardly changed from the original design.

Date	Event
1930	While working In Chile, S.A. Paul W. Klipsch was an amateur radio enthusiast. Comparing various types of radio speakers, he recognized the superior efficiency of horns.
1933	Back in the U.S. at Stanford University, PWK made note of a classmates comment that "speakers sound better in a corner".
1934	Still at Stanford, PWK read the Symposium on Auditory Perspective by Bell Telephone Laboratories.
1939-1941	The above mentioned facts were blended into a design philosophy. PWK drew pictures and built paper models that were to become the "Klipschorn®".
February 5th, 1940	Paul applies for a patent on his first prototype cornerhorn, the X-1. It was during patent "negotiations" that he first learned of prior art cornerhorns. There were several.
1941	While stationed at the Aberdeen Proving Grounds, PWK reviewed and corrected his first manuscript on corner horns.
(Exact date unclear)	A second design was prototyped as X-2, but was destroyed by termites before meaningful measuremets could be made.
May 1942	The first successful prototype (X-3) was built in PWK's garage using only hand tools. This basic corner woofer has changed little over the years. This was serial number 1.
October 3rd, 1942	Paul applied for a patent on X3.
February 9th, 1943	Paul received a patent on his first (unsuccessful) prototype, the X-1.
April 17th, 1945	A patent was granted for the third prototype (X3) which was to become the Klipschorn.
June 15th, 1945	Another patent was applied for describing Paul's second high frequency horn (X-5). This later became the K-5-H horn.
1946	Klipsch and Associates was incorporated
Early 1947	The first production run of 12 units (S/N 2 - 13) were built to Paul's specifications by the Baldwin Piano & Organ Company of Cincinnati Ohio. The high frequency driver in these was the WE713A. At least one of the woofers was a JBL.
Late 1947-Early 1948	Seven more (S/N 14-20) were built by hand in a local cabinet shop. Paul recalls that no more than two were alike. It was during these "experiments" that the LF horn's "sinus" cavities were added to the woofer's back air chamber to maximize acoustic capacitance. Component Designations: High frequency Western Electric 713A, Woofer unknown.
June 1st, 1948	The first Klipschorn to be built in the first actual Klipsch factory was S/N 121. The building was formerly the telephone exchange building for the Southwest Proving Grounds and is currently the Klipsch Museum of Audio History. Component Designations: The early production logs (1949) first make reference to the use of the Jensen P-15-LL woofer. The production log makes reference to a total of 26 Klipschorns built this year. (Editor's note: as of 2007-2008, the museum is in the process of moving to Indianapolis)
1949	The Stephens P52LX2 becomes the primary woofer. This driver is used through August of 1953 when the transition to the Stephens 103LX2 was made. The Stephens P15 High frequency driver starts appearing in the logbook.
August of 1950	The ElectroVoice EV 15WK woofer is first referenced in the production logs and is used interchangeably with both of the Stephens woofers and the early K-33-J woofers until March of 1961.
1951	The University SAHF replaces the Stephens P15 as the primary high frequency driver.
June 2nd, 1951	The first three-way Klipschorn incorporated a Jensen RP203 tweeter. This tweeter came from the famous Jensen G-610 Triaxial 15" driver and required considerable negotiations with Jensen. It was not until mid-1952 that all Klipschorns were three-way. A two-way Klipschorn with response to 12Khz was generally adequate for program material up to that time. The University MID-T- 4401 replaced the Jensen unit as the tweeter of choice later in 1951.
July 25th, 1952	The original K-5-H high frequency horn of the patent was modified to become the K-5-J. This involved changing the vertical taper so that the dividers ("boats") could be removed. This resulted in a production cost savings, not an acoustical improvement.
September 2nd, 1952	A cardboard shipping container was used for the first time. Prior to this all Klipschorns® were shipped in wooden crates. The last wood crate was used on S/N 912 on June 13, 1955
August, 1953	The Stephens 103LX2 Woofer starts to be used.
1955	K-500 / 5000 network phased out in favor of the 1 RC (Type A network)
November 25th, 1957 through May 5th, 1958	This was the transition period between the University 4401 tweeter and the Electrovoice Alnico magnet T-35 (K-77) which yielded substantially flat response to 17Khz.
August 26th, 1959	The first shipment of ElectroVoice T-35 tweeters designated as K-77 is received. The K-77 is first used in S/N 1445 on Oct 15, 1959.
November 14th, 1958	Driver polarities were first observed and made consistent. This practice was initiated due to marginal improvements noted during listening tests.
April 1960	Transition to the K-33-J Woofer (Jensen) from the EV 15WK began. And University SAHF mid-range drivers started to be designated and labeled as K- 55.
May 31st - September 18th 1961	This was the transition period between the 6" high woofer horn throat and the current 3" high throat. This boosted output in the 400 - 500 Hz range further smoothing the response. Multi-tapered wedges were also added to the woofer throat (opposite side of the motor board from the driver) to further improve the response in this region. The use of these wedges was soon abandoned but the smaller throat dimensions were retained and are in use today.
November 14th, 1961	The Atlas K-55-V Alnico magnet mid-range driver is introduced. This driver was patterned after the famous Western Electric 555-W.
1963 - May 15th, 1964	The K-5-J mid-range horn was replaced with the K-400 resulting in a flatter overall spectral balance, particularly in both crossover regions.
October 24th, 1966	The designation for the Type 1RC crossover network was changed to Type A.
September 1967	Transition to the K-33-M. The records are not clear as to the origin of this driver but it is believed to be an Eminence driver with an Alnico magnet.
January 1968	Transition to The K-33-P Woofer (CTS Paducah KY)
July 1971	The Type AA crossover network was introduced featuring Zener diode tweeter protection.
1975	Transition to The K-33-B Woofer (CTS Brownsville TX)
1975-1979	K-33-E (Eminence) and the K-33-B were used interchangeably. The records are not specific about the actual start date for the K-33-E but it is believed to be in the early to mid 1970's.
1979	The Eminence K-33-E woofer is used exclusively
February 1st, 1983	The two piece Type-AK crossover network was introduced incorporating fusing and steeper filter slopes for enhanced tweeter protection and smoother response in the crossover regions. Heavy gauge (10 AWG) internal wiring was used throughout and binding posts replaced the traditional screw type barrier block as input terminals. The tweeter was flush mounted in the baffle using "Z" brackets. Rubber wall gaskets were added to the sides of the tailboard to improve the seal to less than perfect wall surfaces.
October 19th, 1983	The Type AK-2 network was introduced to accommodate the new Ceramic Magnet K-55-M mid-range driver. This ElectroVoice sourced driver was essentially the same as the previous K-55-V with a ceramic magnet and a smoother response.
April 1st, 1987	The "D" style decorator cabinet (no cosmetic panels or grilles) was discontinued.
November 20th, 1987	The Aluminum K-400 horn was replaced with the K-401 structural foam horn resulting in slightly improved distortion figures.
October 1st, 1989	The AK-3 network was introduced to correct for a shift in the output of the K- 55-M mid-range driver.
1995	A limited edition of the Klipschorn is produced to mark the 50th anniversary of the company and the Klipschorn. A total of 150 pairs were offered in three different finishes but less than 50 pairs total were sold. The only changes to this model were cosmetic.	http://www.klipschcorner.com/images/Klipschorn50_large.jpg' target="_blank">
August 1st, 1995	The "C" style cabinet (no intermediate collar or kick plate) was discontinued.
2000	ElectroVoice ceases production of the K-77-M and K-55-M tweeter and mid- range drivers. The search for replacement drivers and the acquisition of the EV tooling is sought. Very limited production of a few pairs occurs at the end of 2000 and the early months of 2001 using existing part stocks.
May 2001	The Atlas PD-5VH (Current version of the previous K-55-V) is modified slightly and christened the K-55-X. The various components of the K-77-M tweeter are either retooled or sourced from the new owners of the tooling and assembled by a third party. This variant of the tweeter is designated the K-77-F. An entirely new one piece network, located on the woofer door, (AK-4) was created to accommodate these driver changes. Fusing is eliminated in favor of a polyswitch for tweeter protection and a trap circuit was added to tame the longstanding response peak in the middle of the woofer's pass band, resulting in an improved spectral balance. The number of variants available was reduced by the elimination of the Brown and Cane grille cloths and oil finishes.
December 2005	The Type AK-5 network was introduced to compensate for the improvement in low frequency response resulting from the addition of a horizontal wall seal to the top of the low frequency cabinet. The style "B" cabinet was discontinued by the elimination of the inset "intermediate collar" and visible "woofer top" panel in favor of a 3/8" gap between the cabinets. The long standing angle brackets, hanger bolts and wing nuts used to attach the HF and LF cabinets together were replaced with thick rubber spacers, on the LF cabinet, indexed into recesses on the HF cabinet.
April 2006	The horn portion of the K-77-F tweeter was re-tooled to include a recessed flange eliminating the need for the separate "Z" bracket and attachment rivets. This also allowed the updating of pre-Z bracket Klipschorns (prior to Feb 1,1983) to flush tweeter status without motor board modification. This variant was designated as the K-77-D. A special limited edition Klipschorn was produced to commemorate the 60th anniversary of the company and the speaker itself. Low frequency response was enhanced with the addition of rear low frequency horn panels. This eliminated the need for a tight fit into the corner and permitted toe-in and toe- out flexibility for the first time. Additional upgrades were made to the binding posts, internal wiring, and network component specifications. Aesthetic enhancements included a Lacewood veneer finish on the LF cabinet and a high gloss Black finish on the HF cabinet. The traditional wood kick plate was replaced with a machined and anodized Aluminum version containing a Silver finish PWK logo containing a real diamond. The rear of the HF cabinet was totally enclosed with finished panels featuring display windows for a commemorative numbered plaque and the HF network. 200 pairs were produced.

[CaptnBob]

From talking to people and real unscientific research,

For those who like the sound of the wood midrange horn, Mid 1958 (start of the EV K-77) to middle 1960 (end of the 15WK)

For those who like the more modern sound, 1978 - 1985 or so.

[neo33]

I really like the alnico magnet drivers and AA crossover networks in my La Scalas. Which year of the Klipschorns has both of these?

[Budman]

I really like the alnico magnet drivers and AA crossover networks in my La Scalas. Which year of the Klipschorns has both of these?

79 would be about right for the round mag tweeters

[Chris A]

I really like the alnico magnet drivers and AA crossover networks in my La Scalas.

Pardon me, but can you describe the difference in sound between the Alnico permanent magnets and the ceramic - do you actually hear a difference?

Chris [:-*]

[neo33]

The alnico magnet has a smooth compression whereas the ceramic magnet does not compress. Thus, the alnico will sound smoother with seemingly louder average volume whereas the ceramic will sound a bit edgy (harsher). I can hear the difference between the two magnets. Think of this in term of amps: solid state and tube. When both amps reached max power, the solid state will clip hard but the tube amp will compress nice and smooth. Which would you rather hear?

Pardon me, but can you describe the difference in sound between the Alnico permanent magnets and the ceramic - do you actually hear a difference?

[Fjd]

The alnico magnet has a smooth compression whereas the ceramic magnet does not compress. Thus, the alnico will sound smoother with seemingly louder average volume whereas the ceramic will sound a bit edgy (harsher). I can hear the difference between the two magnets. Think of this in term of amps: solid state and tube. When both amps reached max power, the solid state will clip hard but the tube amp will compress nice and smooth. Which would you rather hear?

Pardon me, but can you describe the difference in sound between the Alnico permanent magnets and the ceramic - do you actually hear a difference?

Isn’t the issue of Alnico vs. ceramic more of an issue in guitar pickups since it can impact the guitar’s tone and guitarists are always trying to capture that certain “sound”?

Is this still a problem for speakers in general? After the initial adoption of ceramic, for music reproduction, I thought the engineers quickly re-designed the motor structures and magnetic circuits to make any difference negligible?

[Chris A]

I can hear the difference between the two magnets.

The reason why I ask is that horn-loaded drivers really don't move very much...which is the reason why the fully horn-loaded Khorn sounds so good (clean) relative to the other Klipsch Heritage speakers.

Hearing a difference in permanent magnet effects with a Khorn I would think would be very difficult: the K-33 woofer moves about 15-20 dB less for the same SPL output than operating as a direct radiating driver - such as the same K-33 driver used in the Cornwall. That's 5 to 10 times less peak-to-peak motion for the same SPL in the Khorn. Hearing any non-linearities in the K-33 due to permanent magnet nonlinearities in the Khorn would have to be heard at least 15 dB louder (...PWK claimed 25-35 db louder...) to hear the same % level of modulation distortion due to permanent magnet effects:

"...When you measure the response [of the same driver used as a direct radiator and then horn loaded]...you see 15 dB difference between the two conditions of direct radiation and horn loading. The frequency modulation distortion products...for the direct radiator are 25 dB down. With a hom on the driver...the distortion products are 50 dB down. So you have a 25 dB improvement in distortion with a 15 dB increase in efficiency."

(PWK quoted in Speaker Builder magazine, April 1989, "A Visit to the Klipsch Kingdom", pg. 11, article by Dr. Bruce Edgar)

Chris

[mark1101]

I have a pair of lascalas with the ceramic magnets and a center channel lascala with all alnico drivers. All 3 have the exact same DeanG built ALK Jr. networks in them with ALK tweeter attentuators.

There is absolutely a difference in the sound. The alnico have a softer more vintage sound and the ceramic a denser more brittle sound. I agree with the poster who used the tube vs. solid state comparison. That is a good analogy although I am speaking more about the difference in sound between tubes and ss and not the distortion comment.

I wish my PAIR were the all alnico models, and the single was the ceramic. To me, the all alnico are more preferred. That's just me.

The Khorns I had were all ceramic...........and I loved those too. I just think the original alnico sound was more pleasurable to me.

Late 70s........

[Chris A]

The alnico have a softer more vintage sound and the ceramic a denser more brittle sound.

This sounds like increased modulation distortion, such as AM distortion, which also results in higher harmonic distortion in the driver. Could the cause be a difference in magnetic hyteresis or non-linear changes in permeability? Here is a link to an article written by Siegfried Linkwitz on this subject: http://www.linkwitzlab.com/frontiers_3.htm (see "Q - Estimate of L_e(i) induced distortion at high frequencies").

It seems to me that the effects of magnetic non-linearities is increased harmonic distortion (which turns into AM distortion), and this is still proportional to the displacement of the driver's diaphragm, right? Otherwise, it probably has to be related to other driver issues other than the permanent magnet, such as a voice coil that is too short or is experiencing transient increases in voice coil resistance due to heating effects. These causes aren't directly caused by Alnico vs. Ceramic change, unless the permanent magnet flux density decreased in the ceramic magnet thus causing a change in the total magnetic circuit design including the voice coil size, winding design, or voice coil wire gauge.

Chris

[CaptnBob]

I have a pair of Shorthorns which, despite having consecutive serial numbers, had one ceramic 15WK and one alnico (I belive.) One had the huge plush pink magnet and one had the smaller one with the chrome "bow-tie" on the bell cover. The one with the smaller magnet sounded noticeably better, both in the speakers and out of the cabinet, side by side on the bench. The one with the bigger magnet just sounded "chestier" and a bit muddier.

Any one else have a similar experience? No less an authority than PWK told me there shouldn't be "A dime's worth of difference," but there sure was to me. No, this doesn't discount the possibility of old fashioned unit to unit difference.

[Chris A]

djk's rationale why Alnico sounds different than ferrite...

"I'm sorry, I thought everone knew that the main reason alnico sounds

different than ferrite is that it is electrically conductive, and thus

acts as its own shorting ring for signal induced currents in the magnet

structure.

JBL made its first ferrite drivers use the same cones as its alnico models.

They sounded horrible, and were never released to the public.

After putting in a very simple aluminum shorting ring they released

these new models. The next generations used different cones and further

improved magnetic circuits. The latest generation use neo motors with

triple shorting rings.

The alnico are still prized by musicians

as they have more harmonic distortion, and higher dynamic compression

than the latest neos do. If you want an accurate reproducer, rather than

a producer, the current drivers will be of more interest to you.

Alnico is a good 'talking point' and has a good 'back story', both good things for the marketing department.

Field-coil technology is also experiencing a resurgence of interest, and for many of the same reasons.

This is something found in some old field-coil drivers that is being adapted to modern neo motors:

Active Impedance Control technology (AIC), consisting of an additional

coil fixed on the pole piece and connected in parallel to the moving

coil.

The magnetic field generated by AIC coil has the following effects:

1) Impedance linearization

2) Acoustic and electric phase linearization

3) Significant increase of sensitivity and total SPL

4) Total harmonic distortion reduction

5) Constant power transfer"

Another excerpt from that thread [badman 08:33:08 04/27/09
(0)] http://www.audioasylum.com/cgi/t.mpl?f=speakers&m=282863:

"To reiterate:

Ceramic has noise known as "Barkhausen Noise"

that AlNiCo avoids. It's preventable with proper shorting rings

however. Ceramic doesn't change its properties with exposure to

magnetic fields, like those from a voicecoil, AlNiCo does. This also

can be helped, via underhung or oversized motors. This effect is both

short and long term, and leads to a 'soft clipping' characteristic that

limits the motor strength at very high outputs. It also can lead to

long-term motor strength loss that typically maxes out at about 3-4 dB

in sensitivity loss...

Ceramic, however, is affected by temperature. This leads to a loss of

sensitivity when the magnet gets warm, mostly an issue in situations

with long continuous output, like a PA environment. It returns to

normal after cooling, however under heavy use like this, it changes the

alignment just like magnetic loss above. It's also more sensitive to

physical shocks.

There is an advantage in thermal

conductivity for AlNiCo as well, which means that it helps evacuate heat

from the voicecoil better, which is a big plus, to my way of thinking.

It ALSO is inherently self-shielding which is a bonus.

More than any of this is motor design. A ceramic motor must have some

significant shorting paths to compete with a good alnico motor, in my

opinion. Modern ceramics can perform very well indeed, but ones with

good shorting paths and overall motor design are still pricey. There's

unique merit to the classical drivers with AlNiCo too..."

Chris

[neo33]

Regarless of how technical you want to get, the alnico difference can be heard and preferred over ceramic.

[Don Richard]

I replaced a pair of blown K-77s with EV T-35As and the ceramic tweeters seemed to have more output, making the system sound more bright. I put new diaphragms in the K-77s and put them back in.