Addressing high-end “grain” in my vintage Klipschorns

[dopeihope]

I recently picked up a pair of 1989 Klipschorns. They’re pretty awesome, but do have an area I’m looking to improve. To my ears, the highs sound grainy or dusty, sometimes. It’s particularly noticeable to me with vocals. 

 

I’m running them through a Schiit Freya+ tube preamp and Schiit Tyr solid state amps. (I got these previously for my Maggies, which needed more power.) It doesn’t seem to make a difference to the grain whether I engage the tubes or not.

 

My question is - what should I try changing to address this? I’ve heard other horn speakers (e.g. Ojas, Altec) that don’t have this quality, so I don’t think it’s an intrinsic property of horns.

 

I can think of these options

• Try different amplification
• Recap the crossover network (AK2 that hasn’t been touched since ‘89 afaik)
• Update the crossover network to AK3 spec
• Replace the crossover network (e.g. ALK)
• Replace the tweeter
• Replace the midrange horn
• Room treatment

 

How should I approach narrowing it down?

Edited November 10, 2023 by dopeihope
Spacing

[Bacek]

As this is no longer modifications forum and mostly restorations so I would say.

Did you heard KHorns anywhere and you know they are off? For a start I would play some time and freeze some drastic mods.

Of course would be good to check if you have original drivers inside. People (including me) got those speakers with mixed tweeters (round and square version) or could be case when diaphragm of one was replaced (after some failure) with some poor quality aftermarket one.

 

1.  Room treatment is always welcome regardless of speakers

2. Try full solid state setup, skip tube preamp for some tests.

3. Leave midrange alone, this is really nice driver. If it has black/plastic cap so it's K55M. In this case test if this cap is not loose. There where cases when glue was bad on those and vocals sounded strange.

4. As AK-2 and AK-3 are not so different when it comes to tweeter, update squeaker and tweeter capacitors to mylar kind. Probably you could convert but then you will need new coil for midrange part. Not sure if we have DCR of it documented in here.

 

Then play them more to learn how they sound.

If this not enough for you then ask question on Klipsch Korner.

[Deang]

Nice amps. I doubt it has anything to do with that. 
 

@Bacek gives solid advice. 
 

One thing to consider with anything used is being generally in the dark regarding their history. I always wondered if K-77’s sound a little rough due to years of being driven hard. 

 

I stock the parts to update the AK-2. 

[billybob]

Welcome @dopeihope

[OO1]

@dopeihope2 possibilities here .

 

 -the AK-2 were  plagued with corrosion of the old monster style wiring  ,  the corrosion occurs  between the clear plastic jacket and the copper wire    ,  discard the old wire  end to end  , remove all traces of the old solder   . 

 

 -a dirty voice coil gap or a worn out VC  can also cause a grainy sound  , remove the 4 screws , slowly , gently separate the magnet assembly , clean the VC gap  , retest .

[Schu]

I find that 'Granularity' is usually always Distortion...

[JohnA]

Aside from pretty obvious terminal strip corrosion and other visible issues with the network, I'd recommend looking for very late K-77-Fs that have a recessed flange so the mouth of the tweeter is made flush with the motorboard.  That cured some grittiness my La Scalas had.  PM me for more ideas. 

 

[Marvel]

On 11/12/2023 at 1:24 PM, Deang said:

Nice amps. I doubt it has anything to do with that. 
 

@Bacek gives solid advice. 
 

One thing to consider with anything used is being generally in the dark regarding their history. I always wondered if K-77’s sound a little rough due to years of being driven hard. 

 

I stock the parts to update the AK-2. 

IIRC, Dennis always thought the k-77 sounded gritty. (of course they don't go as high as newer drivers)

 

Probably why I liked that Tonsil tweeter Eminence driver that Bob used. I know it was a mod.

[the real Duke Spinner]

I solved this in sevel ways Alyrc 511 horn and driver

JBL 2360 horn and Driver. 😀

YMMV

[Khornukopia]

Your speakers (should) have the K-55M drivers. The back cover on those can sometimes become loose and buzz. Read about an easy fix here,