Klipsch original alternative to K77 Alnico tweeter

[geoff.]

5 hours ago, RandyH000 said:

Heinz , the DE 10  is cheaper and better sounding than the DE120----it's a ferrite magnet versus a NEO -but  it''s a  way bigger motor --

 

to re-use your CT125 Horn lenses -----this is an adapter for the APT 50  , basically a round plate with a threaded 1 3/8  fitting ---you  drill the holes to match the DE10 or DE 120  screw holes  -voila

 

 

This will not work.

 

This is the discontinued Eminence APT-3 adapter. Still listed on the site that told me it was gone, lol.

 

It would screw into the adapter above, BUT you would need to machine the circumference down to fit under the hood of a La Scala.

 

 

 

[geoff.]

I just happen to keep my feathers numbered for such an emergency...

[KT88]

Very comprehensive information here. So I will experiment for a while with the tweeter I have, the original K77 Alnico. I read a bit today about the history of the T35. I noticed a few things that I find interesting.
Before I go into it, I did a simple test after my reading that I would like to briefly describe. You know that my issue is this hiss which you can hear with spoken S or sometimes with strings or cymbals. I was with my head close to one of the LaScalas tweeters and listened carefully and this annoying hiss is clearly audible. Then I turned my head 90 degrees, one ear to the ceiling and the other ear to the floor. This hiss was as good as gone.

Why did I do this primitive test? I learned things on the net that were new and exciting to me. Before, when I was young and naive, I wondered why a horn (K77) is mounted from the back of the baffle, it was not intuitive to me because I thought the propagation of sound waves would be inhibited and disturbed. I was even confirmed (in my wrong thinking) when Klipsch mounted the K77M flush with the baffle in front in the early 2000s or when it was. 

Since today I know that the T35 was developed originally as a diffraction horn. It has even been relatively accurately calculated for installation behind! a baffle that is (normally less than) 3/4 inch thick, unlike the Lascalas boards. (see the specs in the link below). However, it was developed for vertical mounting. Using the 3/4 inch baffle, it actually radiates more than 100 degrees horizontally when mounted vertically due to the diffraction principle. At least that's how I read it. I'm not going to cut up my beloved Lascala but I will remove the K77 when I have time and place it vertically on top of the speaker behind a 3/4 inch baffle mounted. Of course I know that the distance to the K400 will be too big but I want to hear the intended principle of the K77 tweeter horn. I have fun dealing with it. So it's interesting and a nice development. If I didn't have this interest I could reactivate my Jubilees which are great, which I have listened to for 10 years without interruption, but the Jubilees are so good that I can't improve anything with the exception of testing different drivers or DSP settings.

 

I found this interesting thread among others here in the forum. And the web has some good articles about the usage of the the T35/K77 horn. May be I am totally wrong and many others have tried what I intend to research re the different positioning of the K77 but anyway, I will see.

 

May be the effect is not too huge whether the K77 is mounted horizonally or vertically but I would like to try it out. BTW EV recommends thinner motorboards than 3/4 inch but anyway.

Here is the original EV spec sheet of the T35A/K77M incl. polar response, the long axes mounted vertically.

https://mypicsonline.net/archive/archives.telex.com/archives/EV/Horns/EDS/T35A EDS.pdf

[OO1]

3 minutes ago, geoff. said:

I just happen to keep my feathers numbered for such an emergency...

 

so , it works

[Dave A]

1 hour ago, Marvel said:

Unfortunately, it's not going to fit inside an LS.

The killer of many good drivers for K-77 replacement.

[ClaudeJ1]

2 hours ago, Dave A said:

I speak with Bennett Prescott who is over the North American distribution of B&C products every few months. I asked him about the DE-120's a while back and this is what he said. Yes the DE-120 is in the legacy driver section of their catalogue but they do not discontinue any line until there is no demand for them. I can assure you with the number of DE-120's they sell these will not be discontinued  for some time. Now if they were to discontinue these there are three bolt patterns on the SMAHL clamp plate, which is where these are typically used, and other drivers can fit there. Just got 80 in and there is another shipment  arriving from Italy next month for first come first served. Shipments based on projected sales are planed indefinitely.

I'll chime in here. Since the LMAHL is a wider bandwidth horn that you can cross lower, the DE-10 happens to work better for a lower crossover point you can get down to about 3-4 Khz., whereas the DE-120 sMAHL has a rising response after 15 Khz., which may be adding more "air" up there where most of the older guys have hearing loss. These are the main reasons I recommended them. But you can swap them if you prefer, they will still sound great, just a little different. You own the taste buds and salt shakers, otherwise, the curves are still there for all to see.

[garyrc]

• We like the sound of the k77, both the round magnet type and the flat magnet, and have both in our house.  Both types are flush mounted, i.e., not behind the baffle board,  

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• The round mags are both connected to the bedroom TV, as the top end, 3.5K up with a 12 dB/octave crossover, mated with a Klipsch Promedia 2.1, believe it or not.  They immediately give the Promedia more depth and better imaging.
• The round mag tweeters are oriented horizontally, just like in the Khorn, La Scala, Belle, Older Cornwall, etc.  These emit a minuscule amount of sibilance, rarely -- I'd say about twice a month, and who knows if it was in the original recording, in which case I want to hear it.  I also want to hear it when used deliberately, as in a literary device.  We used to sit close up at the American Conservative Theater, almost always with no sound reinforcement, and could not only hear sibilance, but could see actors inadvertently spitting.  Also, if you put your ear as close to some people's mouths as some hand held mics are held, in some cases, you will hear sibilance.  Try it.  Most of the time, engineers try to remove it.
• I've had these round mags many years, and back when I had top-notch hearing, they didn't seem to have any more sibilance, and I could hear 16K from behind the speakers in a fairly live room.                                        

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• The flat mags (K77F) are in our AK4 Khorns and our Belle Klipsch center channel, in our home theater/music room.  Just as the round, the flat are both horizontally and flush mounted.  With movies, no sibilance (and once in a while I ask the young people who see movies here to listen for it).  Male and female speaking voices are startlingly present -- Bosch & his screen daughter, for instance.  With critical listening to music, they sound great.

 

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• I don't have the spec sheet right in front of me, but, I believe both the round and flat versions have superior dispersion occurring when vertically mounted only just above the crossover point typically used by EV (3,500 Hz).  In a Klipsch product using the K77, i.e. either 6KHz at 6 dB/octave or 4.5 KHz  with a 36 dB/octave Klipsch crossover as in the AK4 and AK5, the inferior dispersion may be out of there by the time the tweeter cuts in (sorry, blends in) -- I'll have to check the sheet when I find it.  Even with the 3.5K Hz, 12 dB/octave crossover EV designed the originals for, c.1956, the dispersion is not too bad on that vulnerable low end, but they are pointed at my wife, the cat, and me.   I'd rather see off axis treble, 3.5K to 4.5K bury itself in the rug or hit the high ceiling, than I would for it to hit the side walls.  Even so, we had acoustical padding where even horizontally oriented tweeters might direct the sound.

 

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• FWIW, in 2009, or so (I think), Greg tried a blind test (literally, with a blindfold) of three randomly numbered tweeters, and his wife activated them one at a time, with a repeating piece of music, at a 10 foot distance.  He quickly eliminated the Beyma, and had her switch back and forth between the K77 square magnet and the Ciare.  He really couldn't decide definitively, but finally picked the K77 square magnet, because it seemed a bit smoother sounding!

 

[jimjimbo]

10 hours ago, Dave A said:

I speak with Bennett Prescott who is over the North American distribution of B&C products every few months. I asked him about the DE-120's a while back and this is what he said. Yes the DE-120 is in the legacy driver section of their catalogue but they do not discontinue any line until there is no demand for them. I can assure you with the number of DE-120's they sell these will not be discontinued  for some time. Now if they were to discontinue these there are three bolt patterns on the SMAHL clamp plate, which is where these are typically used, and other drivers can fit there. Just got 80 in and there is another shipment  arriving from Italy next month for first come first served. Shipments based on projected sales are planed indefinitely.

 

Thanks Dave.  Nice to hear from someone that actually knows what they are talking about.

[OO1]

On 5/23/2021 at 9:45 PM, Deang said:

 

”The DE-120 is best on the......

there are  other lenses that can be used with the DE 10 and the LS -

[OO1]

On 5/23/2021 at 10:43 PM, Marvel said:

 

 

Unfortunately, it's not going to fit inside an LS.

 correct , with the stock  k400   ,there is  no room on top  for a large tweeter motor or a large tweeter lense , that reminds me of your APT 150 setup

[Marvel]

Just now, RandyH000 said:

that reminds me of your APT 150 setup

 

I had some CT125s mounted inside, but placed the APT 150 horns with the APT 50 driver on top so they could be time aligned with the midrange (since you brought it up... 😉)

 

 

 

[OO1]

.......

[Deang]

On 5/24/2021 at 5:27 AM, garyrc said:

I don't have the spec sheet right in front of me, but, I believe both the round and flat versions have superior dispersion when vertically mounted only above either crossover point typically used in a Klipsch product using the K77.

 

That's what I think too. It's just been so long since I've had to think about it that I don't remember. I know there is some "pattern flipping" going on. Danley had a long post on the Asylum about it, but that was a really long time ago and I sure don't feel like hunting for it. 

[Deang]

T35/K-77 discussion should maybe just be in this thread, not the Heresy II titanium diaphragm thread. I don't know about everyone else, but I'm losing track of what's being said where. 

 

I fall into the camp with those who don't think there is anything of significance going on with AlNiCo. What I do know is that those old drivers measure terrible - Beryllium leads non-withstanding. 

[KT88]

I want to apologize, I lost track myself yesterday sometime in the evening and accidentally posted in both threads. There was also a bottle of wine on the table....