K-horn midrange 101

[ackpht]

First post, have had La Scalas since college, recently got some used K-horns.

The "compression" in the K-horn's midrange is quite noticeable. I've read up on Al Klappenberger's upgrades and wonder what I should do first- new horn, new crossover, or should I start by checking out the drivers? Could a sick driver make this "screechy" behavior worse? Drivers are K-55-V.

Thanks.

[meagain]

Hi and welcome! What year are these khorns? How old? What does your crossovers' label say as to what type they are?

[jwc]

Hello. Welcome.

W/O knowing the year of the Khorns, I would make a network upgrade first. You might not blame the K401 so much one there has been a cpacitor pgrade or complete network change out.

There are plenty of people who have ditched the K401 for another horn. Yes there are others that you might like better. I would look into network options first.

jc

[Deang]

You have a complaint about the midrange sound, but the LaScalas you have/had use the same horn as the Klipschorn. Depending on their respective ages, they may use the same driver too. IOWs, if you were O.K. with the LaScala midrange then you shouldn't have a problem with the Klipschorn midrange. Now, it's not likely that there is a problem with either of the mid drivers, they are just about bullet-proof.

Sometimes, the harshness people complain about isn't the midrange, but the output of the treble at the lower end of the tweeter's response. If there is a difference between your LaScalas and Klipschorns, it might be here. There is a good deal of audible difference between the round magnet K-77-V and later square magnet K-77-M. They might also use different networks, and that makes a pretty big difference too in as far as how the upper midrange/treble is perceived.

If the caps in the networks of your Klipschorns are completely shot, it will sound pretty bad. Your Klipschorns would have be pushing 30 years old though.

At this point, we need to know more about your LaScalas and Klipschorns. Pinning down their age is the place the start. If you don't know, we can figure it out from the serial numbers.

[Guest " "]

" The "compression" in the K-horn's midrange is quite noticeable"

If the LaScala's have the AA xovers (a gentle slope xover) and the k-horns the AK-3 (a slightly steeper one) the senerio would amplify the differences between the design of the k-horn cab and the LaScala cab.

The design of the K-horn cab vs the LaScala cab, also attributes to a different sound, and yes one could say one was compressed while the other fuller, espeacially if the k-horn cab is not properly sealed into the corners of the room.

The LaScala has less folds in the TOTAL exit path of the woofer than the K-horn (including room coupling). The reduced folds on the LaScala result in a more mid bass getting thru the LaScala. On a K-horn, various concepts have been applied to extend the K-horn upper range into and above the mid-bass area, but the K-horn design has issues above 400hz.

Double check your khorn seating into the room corners. A tight fit would be ideal.

Aside from investigating crossover issues (btw, do the LaScala's and K-horn both have the AA xover? if so , you could swap them and test the crossover theory), you could do forum searchs on reasons for and methods of doing autoformer tap setting changes. You might prefer a mid horn that is less forward, and changing the tap settings will do that (some compromises and side effects), which will also let you hear less compression as you close the gap between the k-horn bass bin mid-bass area and the K-400 mid horn.

Here is a pic from another thread. The LaScala bass bin has a very wide coverage. The k-horn, if not properly installed and coupled ot the room, could appear to have compressed lower mid range.

[PrestonTom]

First post, have had La Scalas since college, recently got some used K-horns.

The "compression" in the K-horn's midrange is quite noticeable. I've read up on Al Klappenberger's upgrades and wonder what I should do first- new horn, new crossover, or should I start by checking out the drivers? Could a sick driver make this "screechy" behavior worse? Drivers are K-55-V.

Thanks.

It is not clear what the problem is. Is the sound "compressed" or is it "screechy". If it is the former, by all means spend $20 and replace the caps (no need to go overboard with fancy caps). If the K55V is soldered, this is considered a good one for that series. The compressed sound could be due to spaeker set up. If they are not tight in the corners you can get a drop off in the 400-500Hz range. Although "compressed" may mean different things to different people. Are the spaekers on axis to the listener? This is preferred. Does the midrange sound that different than the LaScalas? You may try re-locating them (or the listening chair). By all means experiment. At this point there is no reason to spend a bunch of money on crossovers, amps and all that. The sound, except for the bttom octaves, should sound very much similar to the La Scalas.

If the sound is "screechy" (what ever that means) it could indicate some damage. Is it both channels? It is unlikely that the both drivers are bad, were these used in a bar? Follow the advice previously given

good luck, you have some dynamite speakers (soon the trouble will be solved),

-Tom

[ackpht]

OK, the La Scalas date from 1978 (I bought them new) and have round-driver tweeters and AA crossovers. Their midrange has always been "bright" but not shrill. Serial numbers seem to have faded away- I think they were LS17655 and LS17656.

A couple of years ago I bought a second pair of La Scalas (price was right) but haven't listened to them much. They have AL crossovers, K-55-M midranges, and square-driver tweeters.

The K-horns have no paper labels but there are numbers stamped in the plywood at the top rear of the lower section. They are 16U841 and 16U842. If these aren't the serial numbers, please tell me where to look! They have AA crossovers, the K-55-V midranges as mentioned before, and square-driver tweeters.

The K-horns do not sound damaged- there is no "raspy" sound that I associate with damaged drivers- but the midrange does sound shrill- as though some frequencies are being distorted or over-amplified (as though driving a resonance in the hardware somewhere?)

My house isn't big so most of my listening is from only 6-8 feet away. At the moment they are flat against a wall (no corner room available) and I built plywood extensions to simulate corners.

Any suggestions appreciated.

[Guest " "]

And to determine if there is any cancellation occuring with other speakers....are these the only speakers in use, or are other speakers also on during your assestment?

[ackpht]

For now just the K-horns powered by an old Sansui receiver. Source is audio CDs.

[DrWho]

What's the size of your room? Does the bass response seem normal? (sometimes lacking low frequency can sound like shrill midrange). Do you have the khorns sealed well into the corner of your false walls?

[johnyholiday]

For now just the K-horns powered by an old Sansui receiver. Source is audio CDs.

midhorn is now at ear level ,an you can now hear the old Sansui' beaming grand dementia of symptoms

[meagain]

Johny - 'My' Khorns' mid are above my ears at my listening position and I really doubt it's his amp. I'm sure the amp was the same for the LaScala as well.

Screach is a real problem for some of us.

Ackpht - I had the same thing happen. 1978 LaScalas with orig. crossovers didn't screach in same position, with horns pointing exactly where khorns were in same room, etc. At least not as bad. At the end of the day, and countless biatch threads from me, I was figureing it was the midrange horn. That I just didn't like this horn. But how could that be logical when the LaScala had the same horn? The LaScala have the k77-V (round). Khorns have the k77-M (square) tweeter driver. Just gave a long listen over the weekend to Cornwalls with k-77m and loved them. IDK.

Don't let anyone tell you it's the amp and a proper amp will fix it. It might help, but if the 'screach' is there, it's there. I chilled it out by buying a $200-250 digital EQ (Behringer) to chill out certain areas and still hope to create a fix to not have to rely on it. I hope someone can help you cuz you and I certainly aren't the only ones that have complained of this.

[JohnA]

The K-horns have no paper labels but there are numbers stamped in

the plywood at the top rear of the lower section. They are 16U841 and

16U842. If these aren't the serial numbers, please tell me where to

look! They have AA crossovers, the K-55-V midranges as mentioned

before, and square-driver tweeters.

The K-horns do not sound damaged- there is no "raspy"

sound that I associate with damaged drivers- but the midrange does

sound shrill- as though some frequencies are being distorted or

over-amplified (as though driving a resonance in the hardware

somewhere?)

Any suggestions appreciated.

I

doubt it is the horn, but for the sake of being thorough, tighten all

of the screws in the K-horn tops. Then, swap your La Scala K-55-Vs

for the ones in the K-horns. Some spring-terminal -Vs have a 9kHz

"bounce" in the response that can cause them to sound harsh. The

solution is a "P-trap" (or changing to solder-terminal -Vs). Do a search and you'll find the

description; it's a cap and coil in parallel, in series with the

squawker. If that's not it, swap the Type AA crossovers from the

La Scalas to the K-horns. Bad caps will change the crossover

points and levels of the drivers. Finally, if THAT's not it, swap

in a pair of K-77-Ms from your La Scalas.

We

have all discovered that Dynamat and/or rope caulk covering the K-400

damps some ringing it has and is very satisfying. It "calms" the

sound and cuts an edginess.

[cjgeraci]

Johny - 'My' Khorns' mid are above my ears at my listening position and I really doubt it's his amp. I'm sure the amp was the same for the LaScala as well.

Screach is a real problem for some of us.

Ackpht - I had the same thing happen. 1978 LaScalas with orig. crossovers didn't screach in same position, with horns pointing exactly where khorns were in same room, etc. At least not as bad. At the end of the day, and countless biatch threads from me, I was figureing it was the midrange horn. That I just didn't like this horn. But how could that be logical when the LaScala had the same horn? The LaScala have the k77-V (round). Khorns have the k77-M (square) tweeter driver. Just gave a long listen over the weekend to Cornwalls with k-77m and loved them. IDK.

Don't let anyone tell you it's the amp and a proper amp will fix it. It might help, but if the 'screach' is there, it's there. I chilled it out by buying a $200-250 digital EQ (Behringer) to chill out certain areas and still hope to create a fix to not have to rely on it. I hope someone can help you cuz you and I certainly aren't the only ones that have complained of this.

Lisa, are there any Trachorns up near Chicago? You need to hear a pair. If you ever swing by St. Louis, you are welcome to hear mine.

Carl.

[johnyholiday]

Johny - 'My' Khorns' mid are above my ears at my listening position and I really doubt it's his amp. I'm sure the amp was the same for the LaScala as well.

Screach is a real problem for some of us.

Ackpht - I had the same thing happen. 1978 LaScalas with orig. crossovers didn't screach in same position, with horns pointing exactly where khorns were in same room, etc. At least not as bad. At the end of the day, and countless biatch threads from me, I was figureing it was the midrange horn. That I just didn't like this horn. But how could that be logical when the LaScala had the same horn? The LaScala have the k77-V (round). Khorns have the k77-M (square) tweeter driver. Just gave a long listen over the weekend to Cornwalls with k-77m and loved them. IDK.

Don't let anyone tell you it's the amp and a proper amp will fix it. It might help, but if the 'screach' is there, it's there. I chilled it out by buying a $200-250 digital EQ (Behringer) to chill out certain areas and still hope to create a fix to not have to rely on it. I hope someone can help you cuz you and I certainly aren't the only ones that have complained of this.

don't see the supposed linkages between your artistic endeavours an Ackpht's endeavours ,the Sansui receiver is on death row an should be executed,put away like an old brush for it's new destiny's calling , an your running VRDs correct, why not afford Ackpht with the same brush for his artistic presentation

[meagain]

I assume he was using the Sansui with the LaScalas which didn't screech.

[johnyholiday]

Blanket question what mid drivers are involved............, is there truth in the one ring/ two ring phase-plug?.... "Great Screech Controversy!",...... read this sellers copy>>>>>

ebay.com/Klipsch-Klipschorn-La-Scala-Midrange-Horn-Driver-K-55-M_W0QQitemZ190068734122QQihZ009QQcategoryZ61378QQssPageNameZWDVWQQrdZ1QQcmdZViewItem ... "Do not confuse the K-55-M with the standard K-55-V midrange drivers which are common on eBay and that only have an inferior single-piece port phasing plug and as such have great difficulty with frequencies higher than 4500 Hz (not to mention the dreaded 9k Hz glitch that requires a P-trap to correct) and as such are far less desirable than the superior K-55-M midrange drivers which utilize the improved and much more desirable two-piece phase plug design (sometimes mistakenly referred to as dual port ring phasing plug) that expands the frequency response easily past 6000 Hz and eliminates the 9 kHz problem.".....

[m8o]

From all I've read, I think a Smith Horn / JBL 2397 would be the mid-horn I would swap to. I was about to open a thread asking for thoughts comparing the K401 to the Smith Horn / JBL 2397 in a Klipsch La Scala. This idea is right on topic with this thread with that so I'll piggie-back here.

DeanG, I hope you read this. I read in a post from 2003 regarding a tube active x-over, that you and another in that thread use the Smith Horn. Is this true and still the case? I started by thinking of going to a 2405 tweeter; better move that I'm working on right now is to a change over to a mini-Smith Horn clone using a JBL 2402|2405 driver (just the driver, sans their own horn or course). I'm then considering replacing the K401 with the 'life-size' 2397 too (I'll be tri-amping).

...so, Do you feel the Smith Horn would mate well with the La Scala's base horn? (forget the tweeter, as I mentioned I'm changine that) I have no idea however if the Smith Horn would be 'too' wide a dispersion compared to the La Scal Horn. I have no idea of the dispersion characteristics of the La Scala's bass horn to compare .... I have no idea of the K401's dispersion for that matter. (Anyone know dispersion of both?) The other factor is the lowest recommended x-over frequency. JBL states 800Hz, even though I understand some use it lower. I don't know how the horn responds that extra octave lower; I'm hoping you can say. (I started a thread where people told me the La Scala horn can work up to about 800)