I want to upgrade my La Scala's Tweeters

[maxdblsbb]

And I want to do it somewhat cost effectively. I'm looking at the Eminence APT-50 drivers at the moment, as they have a more respectable frequency response than the current K-77s and greater power handling as well. I think they will require an adapter (sold at parts express for under 5 bucks) to mate up to the existing horn in the Scalas. Can anyone comment on how this might work out for me? Are the original horns up to the task even?

[PrestonTom]

Well, first things first.

What exactly is it about your K77's that you do not like?

Also, are the crossovers original, refreshed or modified?

I am curious since there are many alternatives. Some do not require swapping them, and some others can be very expensive.

-Tom

[maxdblsbb]

Hi Tom. Well, the crossovers have not been touched. At least, not by me. I would have no idea how to tell if they were. I'm the third owner of this pair built in 1975.

I dont really like the HF extension that the k-77 produces...it seems kind of harsh to me and like it is straining to keep up with the rest of the drivers at loud volumes. I have a pair of RB-75 and KLF-10 and they are much more to my liking in the HF department.

Would the tweet replacement be a good starting point? I do want to recap the crossovers at some point too.

[Islander]

Those are both good things to do. I recapped the crossovers and immediately heard improved clarity. Then I replaced the K-77s with a pair of BEC's CT125 tweeters, which come with custom horns that bolt up just like the K-77 horns, and heard yet more improvement. I was happy with both changes.

Replacing the caps is really a refurbishment, taking the crossovers back to their original performance, with a slight improvement due to the more modern capacitor design, but the CT125 tweeters are a definite upgrade.

[Marvel]

I'm looking at the Eminence APT-50 drivers at the moment, as they have a more respectable frequency response than the current K-77s and greater power handling as well...Can anyone comment on how this might work out for me? Are the original horns up to the task even?

Bob Crites tweeter - CT125 is an APT-50 mated to a new horn, that is a drop in replacement. It took me all of 10-15 minutes to swap out the tweeters in both of my LaScalas. The improvement, for me, was dramatic. Some have not liked them at all. Bob's prices are more than fair, as well, andhe is great to work with.

Bruce

[djk]

"What exactly is it about your K77's that you do not like?"

They sound bright, but with no real high end.

At times it sounds like someone is poking a wire in your ear.

Another vote for replacing the caps and installing CT125s.

[George Roland]

When I had my K-horns, I tried Bob's tweeters and a pair of JBL "Baby Cheeks". I much preferred the smoothness of Bob's tweeters. I also used his crossovers, and the improvement they made was not subtle. One thing I really liked about the tweeters was that you could simply unscrew the horn from the driver, and that allows you to flush-mount the horn in a recess routed into the baffle. I compared this to the tweeter mounted behind the baffle, and the tweeters sound better flush mounted on the front.

Enjoy your music!

George

[Erik Mandaville]

Bob's tweeters were a great upgrade for us, and really made the K-77s sound a little dull. I'm not talking about extracting every microscopic detail, which to me isn't musical, but rather just being able to hear some cleanly reproduced 'highs' and extension.

Very easy to replace, with the added advantage of a lower crossover point. For me, that's 4kHz rather than 6k. I'll let others talk about how to get to the lower crossover point, though!

I agree that the cap replacement doesn't result in new technology per se' but just making sure the crossovers are using the correct capacitance, with possibly improved electrical characteristics (ESR being among those). You might just try a capacitor replacement first, which isn't very difficult, and go from there. If you do to many things at one time, at least in my experience, it can be hard to know what's changed (if anything) and what was responsible for the change. Also: despite what you might hear to the contrary, more expensive capacitors may NOT equate with a proportional increase in improvement. Over the past 18 years of doing this, there are times when I have found the less expensive part to be the one that gave me what I was looking for.

Have fun!

Erik

[Daddy Dee]

One more vote for the CT-125. IMO a slam dunk drop in replacement.

To my ears, they bested the Beymas, too.

The price is a winner and they are bullet proof behind Klipsch Heritage crossovers.

[Groomlakearea51]

I've replaced 2 of 3 of my Klipschorn pairs and my LaScala's K77's with the CT's. They just sound better, more clear, etc. I'm just about ready over the next few months to also replace the Belles, Cornwalls and Heresys K77's as well.

On that note.... Anyone not like their CT-125's? I'll trade the K-77's![H]

[Islander]

Another point in favour of the CT125s is that their output is very consistent from one to the next, like within 0.5dB in the pair I got. The K-77s the speakers came with had 2-3dB variation in output between them.

Matched tweeters should give improved stereo imaging, you would think, although when I installed them, the speakers were too close together (5 feet apart) to really tell. At any rate, the sound was much improved with the CT125s.

[Marvel]

On that note.... Anyone not like their CT-125's? I'll trade the K-77's!

There have been a few that have not liked them. I think Allan Songer didn't like them in his Cornwalls. A couple of others. For the most part, Bob came up with a home run on them.

[maxdblsbb]

Awesome, thanks for all the input! I think i'll be ordering replacement capacitors and then when they are installed i'll order the tweets from bob. From what i've heard and read about them, it seems to me that they are going to accomplish what I am looking for.

[gonzp]

I recently swapped out the round magnet K-77's for the Crites CT-125's in my K-Horns. I was very surprised how much better the Crites tweets meshed with the K-Horns. I also purchased a pair of diaphrams for the round magnet K-77's that will be replaced after my daughter's wedding in May. The original owner came over and said that his speakers never sounded so good. I too would reccomend the CT-125's

[dtel]

Awesome, thanks for all the input! I think i'll be ordering replacement capacitors and then when they are installed i'll order the tweets from bob. From what i've heard and read about them, it seems to me that they are going to accomplish what I am looking for.

That sounds like the best way to go, crossovers first, hear the difference, then Bob's ct 125's , they sound great, thanks Groomlake.

[colterphoto1]

Dtel, did you change your crossover network? Please keep the rest of those components together. That is a matched set of woofer/mids/ networks in those older Heresies. Those are the oldest versions of the K22 woofer- the most prized models.

[dtel]

Dtel, did you change your crossover network? Please keep the rest of those components together. That is a matched set of woofer/mids/ networks in those older Heresies. Those are the oldest versions of the K22 woofer- the most prized models.

No, never changed out any parts, did borrow the two K55v drivers for now, but could always screw them right back on, they are not leaving here. Just trying something, how much do 2 k55v drivers cost without the horns ? I never even found out how much a pair was because I was trying something else out and using the ones out the Heresy's gave me one less thing to buy to try the new project.

It would take me 15 minutes to put the Heresy's back together which I plan to do one day, maby even try my first veneer job on them and make them pretty ? That way I could use them somewhere else here and get them out of the workshop.

I don't need them in the workshop anymore but not sure where they will end up, but they are not leaving, it's part of a set !....... Now where did I get that from ?

[DizRotus]

Michael-

What do you think of those Heresies I sold to you? They have the very CT125s that Allan Songer didn't like and sold to me. I thought they were an inmprovement over K-77s but the difference was not as dramatic to me as has been described by others. Perhaps there would be a larger difference in La Scalas or Khorns.