K-77 tweeters and speaker dynamics

[taviran]

Hello forum members. In the last couple of months I have been trying to improve my La Scala speakers by turning my attention first to the crossovers and tweeters. With respect to the latter, I tried both Sequerra T1 ribbon tweeters and now Bob Crites. In both cases, I felt that while I got much better 'hifi' sound (smoother, more detailed etc.), I lost the amazing dynamics of the speaker. I do not mean the speakers didn't play loud with the new tweeters, they certainly did, but that the impact of instruments, their ability to move the air in the room, was much affected. At first, I didn't want to believe that a tweeter, which can hardly be heard on its own, could have such dynamic impact on the speaker as a whole. But after playing with and without the K-77 tweeter a couple of times, and going back and forth between the K-77 and the others, it was obvious to me that indeed it has such an effect. I was wondering if other people here have experienced something similar and whether they found a substitute for the K-77 which didn't suffer from a loss of dynamics.

[Schu]

Nope... never experienced that effect

[babadono]

taviran,

Welcome to the forums.

When I replaced my k77s with Bob's CT125s Bob explained to me that the sensitivity of the K77s are all over the map. But his CT125 are much more consistent pair to pair to pair. Perhaps your K77s are just a really hot pair? If you like the K77s better then you like them better. There is really no right or wrong way its supposed to sound. They're YOUR speakers.

babadono

[Guest David H]

Taviran, welcome to the forums.

Dave

[LarryC]

I tried a pair of one of the tweets you mentioned, but didn't find it a very satisfactory experience. I still have a question about whether I wired them out of phase with the other drivers due to the AK-4 x-over design. I found all kinds of unexpected effects, such as an apparent lobed effect when walking from side to side around the K-horns, and lack of blending between the tweets and the midranges on each side. I could always hear the tweeters stand out separately from the blend of the rest of the K-horns.

In contrast, the K-77's blended very well into the system and were not separately audible from the rest of the K-horn.

I'm not sure about the dynamics, but the other tweets sharpened the rendition of ALL the notes, including even the deepest bass! The problem was, the character of the sound, including the transient response, was quicker, which meant the character of the musical sound did not blend between the other tweets on the one hand, and the mid-range and bass horn on the other. The sharper, greater, articulation of the deep bass was exaggerated and not worth it. The K-77's resolved all this.

I thought I was hearing a very confusing mix of good and bad that was beyond my ability to fix with phasing and myriad other possible changes. So I returned the other tweeters and have stuck with the K-77's.

[Sancho Panza]

Less than 2 months in, I love the way mine sound, so, will eventually have the diaphragms replaced & go on with life.

Maybe send them off the day I leave for Floridays, to minimize the down time.

[Islander]

taviran,

Welcome to the forums.

When I replaced my k77s with Bob's CT125s Bob explained to me that the sensitivity of the K77s are all over the map. But his CT125 are much more consistent pair to pair to pair. Perhaps your K77s are just a really hot pair? If you like the K77s better then you like them better. There is really no right or wrong way its supposed to sound. They're YOUR speakers.

babadono

This was my experience also. The two K-77s (which were 32 years old, unless the previous owner(s) had changed them at some point) differed by 2-3 dB, while the CT125s I replaced them with were within 0.5 dB. This was better for stereo imaging, of course.

The output of the CT125s was down 1-2 dB compared with the K-77s, depending on which one I compared them with. This gave the effect of slightly stronger bass, which I liked. A few days earlier, I replaced the original capacitors with a set of Bob Crites's Sonicaps, which improved the clarity of the sound. It seemed best to make one change at a time, so I could hear which change made which difference.

However, as babadono mentioned, if you don't like the change they made in the sound of your speakers, they're not for you.

Also, welcome to the forum, taviran!

There is another way to go, and that's to replace both the K-77s and the K-55s with just a tweeter, converting your 3-way La Scalas to 2-way speakers, which eliminates one phase transition point. The tweeters I'm referring to are the K510 or K402 horns with K-69 treble drivers.

It's not simple or inexpensive, since the whole deal includes bypassing the stock passive crossovers and using an active electronic crossover instead, plus buying a second power amp to match the one you already have, or buying an entirely new pair.

The result of the conversion is called the JubScala, since the tweeters are from the Jubilee, Paul Klipsch's masterpiece replacement for the Klipschorn. The electronic crossover allows for much more precise smoothing of the sound of the tweeters and woofers, plus it allows for time-aligning them with its delay units, correcting for the difference in the length of the horns.

The sound is vastly improved. You can see a 510 JubScala II in my avatar picture.

But that's a story for another day.

[consistent]

Hi...the sound with the K77 will also improve when you position them in the vertical as they were originally intended by EV. They begin to drop away at about 15k where as Crites goes to 20k (most of us can't hear that far up) and certainly the tone and timbre of the K77 is in your face as opposed to the smoothness of Crites, the Eminence driver is not a bad one.

[Sancho Panza]

Should also add that a previous owner had replaced the caps with Sonicaps, replaced some of the wiring to the Squawkers & Woofers, maybe replaced more parts.

All I did was tighten a few loose screws.

Edited January 30, 2014 by Sancho Panza

[Deang]

The K-77 may be an old design and little fragile, but it sounds nice, and it's a big part of the Klipsch sonic signature or house sound. My experience was similar to what Larry experienced. It's like most things, some people like it and some people don't, and I wouldn't get all wound up over it. If you prefer the K-77, then stay with the K-77. I don't want to sound like an advertisement, but I guess it's unavoidable -- a much better tweeter (measurably and audibly) is now available from Al over at www.alkeng.com. I should point out that I haven't heard the thing, but have been told by a couple that I trust that it's an excellent performer.

Edited January 30, 2014 by DeanG

[Guest " "]

which tweet do you have...round magnet...square magent.? some have a button sized wafer between the magnet and the diaphragm which prevents reflections from the back of the diaphragm from bouncing off the magnet , thru the diaghram , and to you. These will sound different than the ones with the botton. Then there's the sound diff between round vs share magnet, then of course the differences between the sound of the tweets quality issues due to such things as ring gap alignment issues due to magnet slippage. so basically, the sound of these things are all over the place.