KP-301 crossovers

[ArmandCroft]

Aaah! The mystery unravelled. What a cool piece of Klipsch history. Thanks for posting that. I hadn’t ever seen the original brochure.

[OO1]

3 hours ago, Dave A said:

Your information is incorrect. The 301-1's use the K-76

 

incorrect ....... There are no k-76   tweeters........ in a klipsch Pro Speaker

 

 

[Dave A]

5 minutes ago, RandyH said:

 

incorrect ....... There are no k-76   tweeters........ in a klipsch Pro Speaker

 

 

Well ya got me on that typo didn't you 🤣

[OO1]

...😂

 

 

 

 

 

[geoff.]

...I don’t know about the titanium midrange, or the K-792 tweeter in the 301s with the 3.0B crossover

 

All four of my KP-301s had the K-57-K midrange and K-79 tweeters(blown, lol) and 3.0B crossover.

 

One of the 301s was a mismatch with the 4 clips holding the woofer, which was the K-48-E, WITHOUT the PWK dustcap, vented motor, and 5-way binding posts(I can only think of 3 ways...). The other three KP-301s had the wicked woofer version, the K-48-K. The matching pair has no handles, the mismatched pair does?

 

Klipsch is always a mixed bag over the years of production.

 

What I would like to get straight though, is a confirmation of the crossover points for the 3.0B. 

 

Does the 3.0B in fact cross at 800 and 6000hz?

[jjptkd]

3 hours ago, geoff. said:

...I don’t know about the titanium midrange, or the K-792 tweeter in the 301s with the 3.0B crossover

 

The original 301's used the same horns and drivers as the Chorus 1; k-79 tweeter and k-57 mid both are exponential horns.

 

The 301-II's updated both horns to Tractrix-- k-792 tweeter and k-65 or 66? Titanium 2" driver on the treaded insert k-604 horn. 

 

Both tweeters use the same diaphragm but mid drivers are completely different. 

[ArmandCroft]

Here are pics of the actual crossovers that were in the speakers.....

[ArmandCroft]

Actually, here are pics of the crossovers. (forgot to hit insert) 

[geoff.]

It looks like someone clipped your Klip circuits!

[ArmandCroft]

1 hour ago, geoff. said:

It looks like someone clipped your Klip circuits!

Is that the circuitry that prevents blowing the tweeters and mids by limiting the signal? I don’t have any clipped wires that I can see.

[geoff.]

Yes, but I can’t see the “little yellow flat capacitor looking thing”, the polyswitch and the second ceramic resistor it is paralled with.

 

It sits beside the red coiled inductor on the right side of the picture of the KP 3.0B.

 

Only reason I seem to be so knowledgeable about this is that I asked a question on here about my very same crossovers a few months back, lol.

 

My polyswitches were visibly smoked, in need of replacing. Some said for home use it would be ok to just remove the circuit, others said to just buy the 70 cent part and replace it.

 

I bought 10, just to keep my feathers numbered in case of emergency.

 

But in the past week or so I have read that they are really a “one time deal” as their inline impedance pretty much triples after the FIRST time they save your tweeters. They will continue to save your tweeters until you fry them, as mine were.

 

I have replaced ANY tweeter of consequence in my preferred Klipsch with either DE-120s or DE-10s on a Dave A. horn (LMAHL or SMAHL) and have one Crites CT-120 in rotation. So I MAY go back into my crossovers and clip my Klip circuits as these drivers take more power. 

 

 

[geoff.]

...this is one of my KP-3.0B crossovers with the fried Klip polyswitch, if I didn’t shrink the resolution too much you may be able to see the scorch marks on it.

[ArmandCroft]

I see what you mean now. I’ll see if I can dig up the original schematic for the KP 3.0B crossover. I plan on using these as PA speakers when my band plays and shop/practice space speakers when not in live use, so I would like the protective circuitry in place. Also, are you saying that once they protect your tweeters once  they become less effective or even useless in terms of protection? Thanks.

[ArmandCroft]

After priming one speaker, I could still see faint 80 grit marks so on the unprimed one I decided to skin the whole box with wood putty before priming as it's easier to sand than automotive primer (cheaper too). I'll get the primed one right with some spot putty before painting it. Got my Crites Titanium diaphragms for the K-79-K tweeters but held off replacing them because I'm not sure if I should replace the ferrofluid. Also the person I bought the speakers from sent me the Klipsch woofer that was in the speaker before she replaced it with the JBL, but it is a K-43 not a K-48-K as it should be, so now I have to figure out where to get a K-48-K or maybe I'll just have to replace both with Kappas or another suitable woofer.

[ArmandCroft]

Have to remember to hit 

[Dave A]

11 hours ago, geoff. said:

My polyswitches were visibly smoked, in need of replacing. Some said for home use it would be ok to just remove the circuit, others said to just buy the 70 cent part and replace it.

I have visions of the drunks hollering to the drunken DJ "turn it up"  and he does until they fry. Pro gear really gets hammered at times by clueless people.

[billybob]

Yes, there will be a K-48-k in your future. You can find one.

Patience..☕

[Dave A]

5 hours ago, ArmandCroft said:

After priming one speaker, I could still see faint 80 grit marks so on the unprimed one I decided to skin the whole box with wood putty before priming as it's easier to sand than automotive primer (cheaper too). I'll get the primed one right with some spot putty before painting it. Got my Crites Titanium diaphragms for the K-79-K tweeters but held off replacing them because I'm not sure if I should replace the ferrofluid. Also the person I bought the speakers from sent me the Klipsch woofer that was in the speaker before she replaced it with the JBL, but it is a K-43 not a K-48-K as it should be, so now I have to figure out where to get a K-48-K or maybe I'll just have to replace both with Kappas or another suitable woofer.

Always nice to see a working shop and real hands on speaker projects. Far better then mere words and never any examples of what is being talked about.

[geoff.]

[geoff.]

7 hours ago, ArmandCroft said:

... Also the person I bought the speakers from sent me the Klipsch woofer that was in the speaker before she replaced it with the JBL, but it is a K-43 not a K-48-K as it should be, so now I have to figure out where to get a K-48-K or maybe I'll just have to replace both with Kappas or another suitable woofer.

 

 

Once again, this brings up the subject of a “suitable” replacement for the K-48. I know, accept no substitutes, lol.

 

I have loved the Kappa 15C in everything it’s been tried in from Cornwall’s to La Scalas. Tight and articulate bass.

 

From what I have on a spec sheet, the voice coil of the K-48 is 1.25mH, would it be prudent to change the inductor in the woofer circuit to 2.5mH (from 4mH) if using a Kappa 15C with an “Le” of .88mH, or a Crites woofer with an Le of 1mH?