LB 76 follow up post to recapping khorns

[sasqwatch]

let me start buy saying this forum is a great tool and there is a wealth of knowledge that is freely shared in my previeous post i ask the question do different caps sound different and recieved several replies .dean wescott was of the opinion they do .witch stirred my intrest so i contacted him to discuss it futher durring my initial conversation dean filled me in on the LB 76 ( for the greens horn like me ) was the last speaker and filter PwK designed with klipsch the company .dean had just recieved the components to build a prototype and ask if i would be his gennie pig and i agreed . iwas excited to be maybe one of the first to listen to this filter . iwas even more nervice to have to report what i thought .about a week later they arrive .do to personal constraints it was 3 or 4 days befor i could put my k horns back together .i had also sent my k77 s and k 55 s to have dean remove the monster cable from them witch he did thanks agin dean i also got new diaphrams for k 77 s and horn to driver gaskets from mr crites . so i get busy putting everything back together only to find i have a terrible speaker balance issue ,i could adjust it on the reciever to center the image but with any adjustment to volume up or down it would be drastically off .after some input from the more than helpful members here it turned out to be my reciever . with that fixed it was time for some serious listen ing . at a low listening they sounded great but a moderate volume there was a skunk in midrange so i report to dean after a short conversation we decide to try the filters in my bells they have the same mid driver low and behold the bells sound wonderful .so its determined there is a issue with k 55 s in k horns dean had spoke to bob and he offered some things to check .so i agin put filters back in k horns i also tightened the k 55 s about a1\4 turn the skunk was a leak from the driver to horn myfault i just didnt get it tight enough .after a short listen with the k77s i pulled the ct125s out of my bells and put them in the k horns so after reading this short novel i bet you are wondering how they sound i wish i were more literate with the termanoligy do describe how amazing they sound . they are crystal clear sounds like there are instruments lined up from one corner to the outher and if you close your eyes you would swear don henly was in the room with you with the eagles playing i have had only one friend listen so far he says they by far are the best speakers he has ever heard he comented on being able to hear all the different instuments playing at the same time .so to say i love the sound of my k horns woul be a huge understatement i would also like to say thank you to dean and bob for their help they both are verry shareing of their knowledge i have done business with both and it is refreshing to deal with honest and careing people for a change .and to that fact they both know the LORD coinsidence i think not . ps bob when my wallet heals from buying the k horns and filters ill be ordering another pair of ct125s for my bells i was on fence about k77s but am sure now they are the way to go and wish you a speedy recovery stacy

[Marvel]

Stacy, it's a wonderful story. Please take no offence, I'm reposting your story below:

Let me start buy saying this forum is a great tool and there is a wealth of knowledge that is freely shared in my previous post where I asked the question do different caps sound different and recieved several replies. Dean Wescott was of the opinion they do. which stirred my interest so I contacted him to discuss it futher.

During my initial conversation, Dean filled me in on the LB 76 (for the green horns like me) was the last speaker and filter PWK designed with Klipsch the company . Dean had just received the components to build a prototype and asked if I would be his guinea pig and I agreed. I was excited to be maybe one of the first to listen to this filter. I was even more nervous to have to report what I thought.

About a week later they arrived. Due to personal constraints it was 3 or 4 days before I could put my k horns back together. I had also sent my k77 s and k55s to have Dean remove the Monster cable from them which he did, thanks again Dean I also got new diaphrams for k77s and horn to driver gaskets from Mr. Crites. So I get busy putting everything back together only to find I have a terrible speaker balance issue. I could adjust it on the receiver to center the image but with any adjustment to volume up or down it would be drastically off. After some input from the more than helpful members here it turned out to be my receiver. With that fixed it was time for some serious listening. At a low listening, they sounded great but a moderate volume there was a skunk in midrange so I reported to Dean and after a short conversation we decide to try the filters in my Belles. They have the same mid driver - lo and behold, the Belles sound wonderful.

So it’s determined there is an issue with the k55s in the khorns. Dean had spoken to Bob and he offered some things to check. So I again put filters back in the khorns. I also tightened the k55s about a 1/4 turn. The skunk was a leak from the driver to horn, my fault that I just didnt get it tight enough. After a short listen with the k77s I pulled the CT125s out of my Belles and put them in the khorns so after reading this short novel, I bet you are wondering how they sound. I wish I were more literate with the terminology to describe how amazing they sound.

They are crystal clear, sounds like there are instruments lined up from one corner to the other, and if you close your eyes you would swear Don Henley was in the room with you with the Eagles playing. I have had only one friend listen so far. He says they are by far the best speakers he has ever heard. He commented on being able to hear all the different instuments playing at the same time. So, to say I love the sound of my khorns would be a huge understatement. I would also like to say thank you to Dean and Bob for their help. They both are very sharing of their knowledge. I have done business with both and it is refreshing to deal with honest and caring people for a change, and to the fact they both know the LORD. Coincidence? I think not.

Stacy

ps Bob, when my wallet heals from buying the khorns and filters, I’ll be ordering another pair of CT125s for my Belles. I was on fence about k77s but am sure now they are the way to go and wish you a speedy recovery.

EDIT: I got a nice PM from Stacy. He sent that long post from his phone [:S]. That makes typing difficult at best. - Bruce

[Daddy Dee]

Stacy,

congrats. it is a great feeling when such work turns out with really pleasing results to the ears. Two good men there, Bob and Dean.

[Deang]

Thanks Stacy, it was a nice adventure.

"Dean filled me in on the LB 76 (for the green horns like me) was the last speaker and filter PWK designed with Klipsch the company."

About this particular network, on my site I state: "This network incorporates the final publicly available thoughts of PWK on how the stock components on big Heritage should work together. The network is a modified Type AA, utilizing the configuration and some of the values specified in patent #4237340."

I think the first part of that is accurate. The patent is rather late in his life, and the only other published work I'm aware of is the JAES paper on the Jubilee. If I'm wrong about that, I'll remove the comment from my website.

I did not come up with the idea for this network on my own. In fact, I stole it from Dennis (DJK). I found his comments/suggestions years ago while searching for information about the P-trap.

http://forums.klipsch.com/forums/p/1233/10329.aspx#10329

The suggestion sounded interesting and I always wanted to try it -- just never got around to it for some reason or another. I was doing PK patent searches a few months ago and came across it again. I really wanted to build a pair, but needed an objective set of ears. People with a strong bias are not objective. Enter Stacy, but first I had to put a call in to Dennis for a sanity check (whether his or mine I'm not sure).

When I had AK-4 Klipschorns and started trying different networks, I developed a strong preference for the Type A. Later, I dropped in a set of Trachorns, JBL 2470s, and some Beyma CP-25s. After the mods, I still ran a Type A. It's a great sounding network, but just starts running into some trouble when you push a lot of power through it. The AA is only marginally better in that regard, though it does better than the Type A if you go to a better horn. For live level listening I prefer most of Al's designs over the stock networks. I'm going to exclude the AK-4 and AK-5 here. Those things are beasts and handle high power levels very gracefully. I built some really nice AK-3s and tried real hard to be impressed, but just wasn't. So, on my side of the house so to speak, I've always liked the Type A and the two versions of the ALK (SuperAA/ALKjr & Universal Type A). I thought it might be cool if there was a Klipsch network that could actually hang with Al's without sounding like it was choking on a chicken bone.

So what's up with this LB-76 thing? Part of the loudspeaker patent included a network. Parts of that network are used to modify the Type AA. The 2nd cap in the tweeter filter goes from 2uF to 6uF, and the coil goes from .245uH to .236uH. In the squawker section, a .230uH coil runs in series with the K-55 while a 4uF runs in parallel, and then you strap 128uF across the K-33. The values in the tweeter section are close to the Universal Type A, and the low pass section is similar to what we see in the later Klipsch networks. From the patent:

"The peaking effect derives from the fact that the LC crossover network has lower input, or driving point, impedance near the resonant frequencies of the various peaking circuits. At these frequencies, the input impedance drops from 8 or 16 ohms to as low as 4 ohms. Consequently, conventional solid state amplifiers, which are characteristically designed to deliver their maximum output into a 4 ohm load, produce a high output near the crossover frequencies of 400 and 6,000Hz. where the outputs of the loudspeakers are drooping."

Okay, two things here.

1) the filter is designed to take advantage of solid state's ability to increase its output as impedance drops. So, in the areas near the crossover points where the response begins to fall, the filter provides some lift. PK calls these "peaking circuits". This is applicable to both the low pass and squawker sections. With this in mind, this is not the filter for someone running tube gear. I'm sure it would work just fine, but you would lose a little of what PK is trying to accomplish here.

2) The squawker section is optimized to work with the original K-55-V. This would be the single phase plug design with the spring loaded terminals. So, the question that naturally comes up is why would one run this thing with the dual phase plug K-55-V or K-55-M? Well, I've looked at a lot plots of the different versions of the K-55 and most of them show falling response in the area of PK's concern. The circuit also starts cutting output to the driver pretty hard at around 5kHz, which takes a load off of that aging horn. The tweeter section is obviously optimized for the K-77, and I know a lot of you are running CT-125's -- all I can say here is that none you have a problem running those tweeters with any of the other networks, and they're "optimized" for the K77 too. After trying it both ways, Stacy preferred this network with the CT-125's, so we have at least one positive subjective report with the combination.

[Daddy Dee]

Thanks Dean. really interesting material here.

[CECAA850]

Wish I had scrolled down to Marvel's post 1'st!

[Marvel]

[]

[CECAA850]

Thanks Dean, good read.