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Klipschorn AK-3 horn mods


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I’ve got 1992 AK-3 klipschorns. I’ve had them for about 2 years and never been completely happy with the sound. The upper range sounds a bit bright and harsh to me. I’ve swapped out amps and am now actually using a biamped configuration with a decware “Rachel” powering the squawker and tweeter and a parasound a23+ the bass bins. I’ve tried each of those on their own as well as an adcom 555ii on its own. I’ve used digital EQ (not analog) and this helps tame the beast. I haven’t done digital room correction. But I am now using a active dsp  to apply EQ and split the frequency crossovers for bass and upper in the line level preamp signal. 
 

Are there good 3rd party options to improve the sound? I’ve been doing a bit of reading and of course everyone has a different opinion. Some love the mid driver & horn while others really believe it’s inferior. I ran across the person selling a build your own Eliptrac 400 2-inch elliptic wood tractrix replacement horn. Would this MDF horn really offer an improvement on its own with the existing driver? There is also a modifier you need to attach it to the driver. This sounds a tad “clugey”. Has anyone swapped the horn out? Are there any other horn or driver/diaphragm options?

 

Are there any crossover changes upgrades I can and should make noting that I’m still using the upper speaker level crossover to divide between the 2 upper drivers.

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dont touch the Midrange horn or the driver ,  instead , you can have JEM verify your passive XO  -capacitors , 

 

-the current supplier of klipsch Heritage caps is @JEM Performance  , you can reach them via PM   -they  can verify your crossovers and rebuild them to specs , if needed -

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@RandyH is spot-on. Your Klipschorns are stunning loudspeakers when operating according to design, and new capacitors in your AK-3 networks is a good idea and requires little commitment of time and money. The second step is to setup your listening room properly, after that you may be so thrilled you won't want to modify the loudspeakers. If not, you'll be in a better position to determine exactly what kind of changes you'd like to make.

 

Have fun! : )

 

God bless you and your precious family - Langston

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5 hours ago, RandyH said:

dont touch the Midrange horn or the driver

What horn / driver do I (should I) have in 1992 klipschorns? I’ve read that a lot of people do not like the “400” and that’s what I assumed I had. Before I had read in several places that the 400 horn was sub par, I thought it wasn’t sounding right. I actually had my ‘76 cornwalls set up for a time next to my klipschorns. It was easy to compare sounds. I was able to put one on each channel of the same amp and level match them. The klipschorns had “more” and we’re better but I wished they sounded more like the Cornwalls as they were very “edgy”, “bright” and a bit too “harsh” compared to what I thought sounded better to me. And that’s where I’m headed hear. I don’t necessarily have to experience the “klipsch” sound. I want as best sound to me that I can get given my budget. My klipschorns have just sounded a bit off from what I wanted.  
 

Whats the likelihood that the caps in the upper xover have drifted out of spec? And couldn’t I test for this myself with a fluke meter? 
 

and it begs the question if the upper crossover has gone out if spec maybe the bass has too? If this is the case, why not simply bypass the bass crossover since I’m using an active dsp and isolating the bass frequencies before amplification?

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5 hours ago, DVDMike said:

Whats the likelihood that the caps in the upper xover have drifted out of spec? And couldn’t I test for this myself with a fluke meter? 

 

Those caps would be 29 years old and could very well be out of spec.

5 hours ago, DVDMike said:

couldn’t I test for this myself with a fluke meter? 

 

That would depend on your Fluke. You would need to be able to check the capacitance and the ESR.

 

The K400 is not a bad horn, however playing at higher volumes, the 1 inch throat can get overloaded.

 

It's a complete system, with all parts designed to work together. Changing things can lead you down a rabbit hole. I'm not necessarily against that, but you need to realize that ahead of time.

 

If you haven't yet, check out member Chris A's pages on going active.

 

 

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12 hours ago, DVDMike said:

I’ve got 1992 AK-3 klipschorns. I’ve had them for about 2 years and never been completely happy with the sound. The upper range sounds a bit bright and harsh to me. I’ve swapped out amps and am now actually using a biamped configuration with a decware “Rachel” powering the squawker and tweeter and a parasound a23+ the bass bins. I’ve tried each of those on their own as well as an adcom 555ii on its own. I’ve used digital EQ (not analog) and this helps tame the beast. I haven’t done digital room correction. But I am now using a active dsp  to apply EQ and split the frequency crossovers for bass and upper in the line level preamp signal. 

If you're using a DSP crossover (i.e., not an active analog crossover), try inserting ~6.5 ms of delay on the tweeter channels, and ~4.8 ms delay on the midrange channels (assuming tri-amping).  Then you'll correct the timbre shifts due to time misalignments of the horn-drivers, which are part of your 'bright and harsh' sound. 

 

Alternatively, if you release the tweeter from its position inside the top hat and bring it out to rest on top of the top hat, you can also time align it to the midrange by placing it at the back of the top hat--with the joint of the tweeter/horn approximately right over the top of the midrange driver/horn joint--with the tweeter...and perhaps a little farther back from the front of the loudspeaker to correct the phase shift due to the electrical crossover network itself. 

 

When you get the tweeter aligned with the midrange (usually this is within ±1/4 inch from exact time alignment), you'll hear the soundstage of the loudspeakers open up wide and produce a much more realistic feeling of the original recording space (acoustic-only instrumentation - like an orchestra or solo acoustic guitar within a reverberant venue are the best recordings for hearing this--sometimes really good vocals that were not multitrack recorded and stacked together on a mixing board). 

 

Additionally, if you put at least 1" thick absorption material on top of the loudspeaker, you'll absorb a fair amount of the re-radiating midrange energy between 400--2000 Hz, where the midrange horn is spilling its vertical polar energy into your floor, ceiling, and on the top of the loudspeaker.  If you let the absorption material hang out a little over the top of the top hat, it will be more effective at controlling ceiling bounce.

 

If you place some of the same thickness of absorbent material on the front face of the bass bin, it will also catch more of that re-radiating midrange energy that adds to your bright/harsh sound.

 

Chris

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27 minutes ago, Chris A said:

try inserting ~6.5 ms of delay on the tweeter channels, and ~4.8 ms delay on the midrange channels (assuming tri-amping).


Thanks for the great info!  I am only bi-amping. So I cannot do this in my current configuration. 
 

The other suggestions sound very interesting. However, I have aesthetic conditions to consider. There’s a trade off between the looks of the speakers and the best sound possible in this case. I’ll have to think on this. And most of these changes you suggested are fairly easily reversed. So I could try it.

 

let me ask you, is wrapping the horn in something like dynamat advisable or helpful? I have read that others seem to believe it is. It’s not “too” expensive to try this but it’s less reversible since it stuck onto the horn. 

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1 hour ago, Marvel said:

The K400 is not a bad horn, however playing at higher volumes, the 1 inch throat can get overloaded.


this is where I’m noticing the most annoying sound.

 

I did look at the pinned post about bi/tri amping but didn’t pay much attention to anything about tri-amping since I’m just doing bi. Fr several months, I was using my decware amp to do gain control matching for pass through into my bass bin amp. But recently, I’ve moved over to the active dsp to match gain and apply some minor digital eq pre amplification. 

 

 

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I have a pair of 1989 Ak2 K horns and am researching the same thing. My system doesn't quite meet the same objections you have,but I'm looking at improving the SQ.

I have looked at different compression drivers and found 3 options :BMS,Fostex,and Radian. Still researching,but I found this thread. Not a Khorn but the Radian is a 1 inch 8 ohm driver.

Also the Fostex look interesting but more expensive...they do make the best super tweeters in the world.

Good luck and following this thread.

 

  https://www.diyaudio.com/forums/multi-way/229225-midrange-compresion-drivers-fostex-d1400-vs-tad-td-2001-a.html

 

https://www.fostexinternational.com/docs/speaker_components/HornDrivers.shtml

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3 minutes ago, DVDMike said:

Thanks for the great info!  I am only bi-amping.

Then add the 4.8 ms delay to the midrange/tweeter channel.

 

4 minutes ago, DVDMike said:

let me ask you, is wrapping the horn in something like dynamat advisable or helpful?

Not in the least.  PWK showed this conclusively 50+ years ago when he showed the effect of adding Dynamat-like damping material to the outside of the K-400 horn--which did almost nothing at all.  However, when the midrange horn mouth is clamped to the front baffle, all the ringing ceased (just like you'd get if you clamped the rim of a bell and tried to ring it). 

 

If you really want to avoid the problems of midrange horn polar control loss and harsh K-77 tweeter sound, I'd recommend using a K-510 clone horn and a good "full range" 2 inch compression driver (e.g., FaitalPRO HF200, HF20AT or HF2000, BMS 4592ND dual diaphragm, Radian 950PB or 950BePB, or Celestion Axi2050, etc.) crossing over at 450 Hz to the bass bin using a DSP crossover.  The problems with harshness, time alignment and all other related acoustics issues will disappear (after you dial them in with a DSP crossover and some measurement app like REW). 

 

If you can find K-402 horns, it will sound even better.  I'd recommend the Celestion Axi2050 or BMS 4592ND for the K-402 horn.

 

Chris

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5 minutes ago, Chris A said:

If you really want to avoid the problems of midrange horn polar control loss and harsh K-77 tweeter sound, I'd recommend using a K-510 clone horn and a good "full range" 2 inch compression driver (e.g., FaitalPRO HF200, HF20AT or HF2000, BMS 4592ND dual diaphragm, Radian 950PB or 950BePB, or Celestion Axi2050, etc.) crossing over at 450 Hz to the bass bin using a DSP crossover.


interesting. That 510 close appears to be much smaller depth than the k400. Let me ask specifically that in order to use the a 510 I’d also need to pair it with one of the compression drivers as well? In other words, I couldn’t use the stock compressing driver with the 510.

 

I believe I have the bass crossover to be at around 1000 or so Hz presently. But the original stock passive xover is still in the signal path. 

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45 minutes ago, DVDMike said:

I couldn’t use the stock compressing driver with the 510.

You could use the K55 midrange driver, but then you'd have to use a separate tweeter--like the K-77 or other tweeter, since the K-55 dies at about 6 kHz. 

 

If you instead use the K-510-clone and a full range 2" compression driver (just like the Jubilee design), then you're converting to two way and eliminating the separate tweeter with all the attendant issues of time alignment and acoustic polar lobing of having the tweeter and midrange mouths more than 1/4 wavelength from each other at the crossover frequency (nominally 4.9 kHz). 

 

If you really got to have a three-way design, then use the BMS 4592ND, which has two diaphragms internally, and you tri-amp the bass bin, and the two internal diaphragms of the 4592ND.  I'd got the PEQs posted on using the 4592ND on a K-402 horn posted on this forum. I recommend the Celestion Axi2050 or Radian 950BePB if going two-way. This eliminates the lobing problems and all the harshness associated with the stock Khorn design.

 

The K-510-clone horn eliminates the loss of polar control problem until you get down to ~500-600 Hz, which is a big elimination of the issues requiring placing the absorption material around the top and front of the loudspeaker.

 

45 minutes ago, DVDMike said:

That 510 clone appears to be much smaller depth than the k400.

Yes.  This is the same technology that's used in the K-402 horn that's the top horn on the Jubilee.  It's a straight-sided horn with a tractrix mouth roll-out.  I also use the K-402-MEH by itself in the K-402-MEH design.

 

 

 

Chris

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10 hours ago, DVDMike said:

I’ve got the klipschorns toed into the corners already. There is really no other placement option for the room except to be right where they are. 

not really -

You can adjust the toe  in and not be limited to corner fitting -----1st   by making false corners  or , 2) by  enclosing the backs of the khorns -

and  3)  VIP  -upgrading  the passive XO with  klipsch  Factory capacitors   -

Klipschorn 70th Anniversary Edition | KlipschKlipschorn Floorstanding Speakers | Klipsch

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3 minutes ago, RandyH said:

you can adjust the toe  in and not be limited to corner fitting


this is not really an option for my room to place them anywhere except for the 2 corners where I have them. There are 2 corners and if they are not close to the corners they will block my projection screen. Now I could make sides like the new ones in the photos if that’s an advantage yet still be tucked into the corners. But I still need them up into the corners due to my room size and screen size. 

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3 minutes ago, DVDMike said:

 I could make sides like the new ones in the photos if that’s an advantage

the enclosed backs actually  improves the bass  a tad   -

given you have room restrictions ,

if you cannot alter the bass bin 's position  , you could always move the top hat ,  by altering it's orientation or by re-positioning it to suit your room's dynamics-

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1 hour ago, RandyH said:

the enclosed backs actually  improves the bass  a tad

In looking at those photos again, where are the speaker level inputs on the ones with the enclosed backs? 
 

my upper bins are actually pointed exactly to the primary listening position. But I was wondering how they could be adjusted if needed.

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46 minutes ago, DVDMike said:

where are the speaker level inputs on the ones with the enclosed backs? 
 

my upper bins are actually pointed exactly to the primary listening position. But I was wondering how they could be adjusted if needed.

 

As  Requested -

 

https://img.av-connection.com/2/AVimg_27496.jpg?_gl=1*1fi2lkc*_up*MQ..*_ga*MTE2NDgwNjQwMy4xNjI2OTk0NTk0*_ga_Z626FNM6XY*MTYyNjk5NDU5Mi4xLjEuMTYyNjk5NDYwOC4w

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For clarification. You are using an active crossover to bi amp. The crossover is at 1000Hz? Then you are allowing the passive crossover for the bass bin to further low pass the signal to the woofer down to 400Hz? Then what about the high pass to the squawker/tweeter is it also at 1000Hz? If this is true you have a band from 400 to 1000Hz not being reproduced.

Maybe I am not following what you are doing correctly.

One of the main advantages of using an active crossover and then bi or tri amping is to get the reactive components of the passive crossover and their phase shifts out of the signal path.

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Just a observation. I purchased a set of 1989 AK2 a month ago and they are stock. After reading a lot of posts about the sound quality and reading threads about modding this and that. My conclusion after listening to mine with all kinds of music at moderate volume levels is Khorn sound quality is 95 percent dependent on their room placement,just like any other speaker. That means Khorns are room dependent. I have a 16x20(16ft on centers) room with one opening leading to a door that acts like a vent or resonator. I can find no serious fault with my setup

 

I think adjusting the high hat for dispersion angle is a good idea. If that still leaves issues then a recap. You can start down a path and spend a lot of time and money. Luckily I'm satisfied with mine....my 2 cents and that's all it's worth.  

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