Improving the Upgrades... My Klipschorn Quest (Really long - please forgive me)

[RFP]

This posting is about my third pair of Klipschorns and my efforts to make them into my 'dream speakers.' What I have done will surely not be to the liking of some, but the end result delights my [now ancient] ears as well as my asthetic sensibilities. My speaker 'quest' - now in its fifth decade - is over.

The story begins with my acquisition of a pair of 1984 walnut Klipschorns from a local gentleman. These speakers were highly modified by the former owner in close collaboration with Al K... these speakers contain Al's second 'prototype' pair of his Extreme Slope networks. Further, they were fitted with Al's Trachorns, TAD 2001 mid drivers, and Beyma tweeters. They were acoustic magic; even in my tiny music room. However, I felt that there were significant improvements that could be made to the 'mechanical construction' aspects of these treasures. After the trip to Hope last year and seeing the 60th Anniversary Klipschorns, I also felt that a cosmetic upgrade was also in order. I planned to change the '84s to a two-tone appearance just like the 60th's with the same top hat (flush front) design. Later, I abandoned the 'two tone' look in favor of a dark, all-the-same-color finish.

My project...

Eliminting the 'riser' between the top hats and the bass bins was easy; just remove some wood parts. However to move the front of the top hat motorboards to be flush with the front of the bass bins would require making new end pirces (and very careful measuring!).

I then turned my attention to the lower panels of the top hats. I am not fond of veneer 'edge banding' so I cut the original panels down and added 1/2" solid white oak to the edges using 'yellow glue' and biscuits. To add stiffness to these panels, I routed dados in the panels and glued in hard maple stiffners. I went to a lot of trouble on these parts... which will be mostly painted flat black!

The Trachorns actually protruded slightly beyond the motorboard frame, making it impossible to get a perfectly flat front grille. Two hours of careful work with a belt sander fixed that. But my real heartburn with the Trachorns was that the throat plates holding the (super heavy) TAD drivers were attached to the Trachorns by using drywall screws into the edges of 3/4" plywood (not good). So, I constructed an interlocking frame that facilitated 'proper' mounting of these drivers using six 1/4" stainless steel bolts. Believing that twenty-more-bucks-per-top-hat was a big "so what," I sprayed the Trachorns with the aerosol damping stuff from Parts Express (maybe you can tell, I am a firm believer in profound overkill!!)

After putting new grille cloth on the motorboards, I am convinced that the worst job at Klipsch is the poor guy or gal that has to do that every day!

All wood parts were finished with General Finishes "Java" gel stain (a very, very dark, mahogany-like color) and six coats of General Finishes Gel Topcoat "wipe on urethane."

Time for assembly. When I got the speakers the various components of the Extreme Slope networks were everywhere... some in the top hats, and some screwed to the sides of the bass bins. A quick check with Al K verified the new positioning of the network components inside the top hats. By the way, all hardware is stainless steel... mostly screws/bolts and Nylock nuts ot "tee nuts." There are no wood screws in any structural assembly points.

I obtained a pair of brand-new JBL 2404 tweeters and installed them instead of the Beymas. Likewise, I removed the preious owners' tweeter "pads" and replaced them with Al K's Tweeter Attenuators.

Both top hats were wired using ISC Wire & Cable #2220 12-ga OFC cable. All connections made with high-silver-content solder.

http://i5.photobucket.com/albums/y173/z-me-go/Klipschorn%20Update/Mid-HighSectionnumber2completed.jpg

http://i5.photobucket.com/albums/y173/z-me-go/Klipschorn%20Update/Speaker1-WiredTested.jpg

As with the bottom panels, I re-veneered the tops and cut them back and installed full one-inch solid white oak 'edges. These are not the 'permanent' tops... more on that later.

http://i5.photobucket.com/albums/y173/z-me-go/Klipschorn%20Update/CIMG1460.jpg

In the next installment: reworking the bass bins and putting the whole business together (yea)

[RFP]

Overhauling the bass bins was quite a bit simpler (understatement!). The first thing I wanted to do was remove the original 'toe baords' (or whatever those things on the bottom are called). I quickly learned that task was going to be a genuine pain in the butt... each toe board is held on by eleven wood screws - from the back! My original toe boards were the worst parts on the speakers... they looked like they had started life as packing crate material. So I pulled them off, leaving 11 wood screw points looking up at me on each bass bin. The only way I could figure out how to remove those darned screws was to chisel out around each one and pull them through. That left some ugly holes (eleven per side)...

So, I used my plunge router and a 1/2" straight bit and made the 'chiseled' holes nice and round. Then each hole was plugged with a 1/2" hardwood dowell. These actually add strength to the lower assembly inasmuch as they go through the glue blocks inside as well as the front panels. Next, I routed a recess for all-new white oak toe boards, and glued the whole thing together.

I also cut back the edges of the bass bins' front panels 3/16" (removing the old veneer edge banding) and glued 3/16" solid hardwood edges (I forgot to photo that!)

Next, the old crossover parts were removed from inside the bass bins and the woofers were rewired with the same wire I used in the top hats.

Then the same finish was applied to the bass bins, and after a lot of polishing and being really careful (!) the speakers were [finally] assembled.

However, I'm really not quite finished. As soon as I can get to it, I am going to make all-new top panels with an 'overhang' edge. This will make the speakers really blend in with the 'Mission" style, Stickley furniture in the music room. They will be truly distinctive... at least I hope so!

If you lasted this far, I truly thank you for your kind interest. This has been a fun project!!!

[pauln]

Wow! You sure did have them opened up on the operating table. The finish of the wood looks rich and gorgeous! Very nice.

[Tarheel]

Absolutely beautiful work...some of the finest ever and I love the overkill aspects of the job. What a way to end your upgrading. Congratulations and now enjoy the fruit of your labor.

Chuck

[PrestonTom]

RFP,

Fantastic! Fantastic! Fantastic!.

They look beautiful.

-Tom

[TBrennan]

Why use a 2001 with a tweeter? The point of the TADs is the extended high frequency response of the Be diaphragms and their resulting excellence in a 2-way. There are drivers better suited to midrange use and with no danger of the high cost of Be diaphragm replacement, I'd sure be leery pushing a 2001 down low.

[rigma]

Very, Very nice work!

[sfogg]

Beautiful work.

Same question as Tom though. With the TAD I'd try pulling the upper ES network out of the circuit and running two way. If your ES is built the way Al typically builds them it should be very easy to try running two way. You will likely loose some dispersion on the high end but that might be a worthwhile trade off.

Shawn

[Erik Mandaville]

What absolutely exemplary work!

Your craftsmanship is really superb.

If you like what you have after all this work and trial and error, seems like a great time to just sit down and enjoy for awhile.

Erik

[RFP]

Why use a 2001 with a tweeter? The point of the TADs is the extended high frequency response of the Be diaphragms and their resulting excellence in a 2-way. There are drivers better suited to midrange use and with no danger of the high cost of Be diaphragm replacement, I'd sure be leery pushing a 2001 down low.

And from Erik Mandaville

Same question as Tom though. With the TAD I'd try pulling the upper ES network out of the circuit and running two way. If your ES is built the way Al typically builds them it should be very easy to try running two way. You will likely loose some dispersion on the high end but that might be a worthwhile trade off.

Yes indeed, This set up gives me all the flexibility that I am ever likely to need... or even want. Actually the "point" of the TADs is the unbelievable performance of their nearly-lighter-than-air Be diaphragms... the extended [high end] range is a bonus. This set up crosses over from the TADs to the 2404s at 7500Hz, so the tweeters aren't really doing very much at all (!)... of course, I can [easily] change the internal wiring in the top hats to do exactly what Tom and Eric suggest... maybe I will one of these days. In the meantime, I'm planning on just doing a lot of listening!

As far as playing the TADs all the way down to the lower crossover frequency, if one "behaves" and doesn't play at blood-from-the-ears levels, their demonstrated longevity is quite good. Playing frequency "sweeps" from a test CD reveals seamless integration of all three horns....to my ears, simply wonderful (YMMV).

[RFP]

Thanks to all for your kind compliments! I really appreciate the judgment and comments from the group.

In my [lengthy] narrative of this project, I mentioned that I was going to make all-new top panels with an 'overahang' detail when I get around to it. Below is a pix of the edge profile that I will be using. The panel will no longer be 3/4"... it's thickness will increase to 1 5/16" and the 'overhang' will be 2.5".

This detail, giving a hint of an "oriental look", will compliment the rest of the room perfectly.

[Erik Mandaville]

RFP:

"Same question as Tom though. With the TAD I'd try pulling the upper ES network out of the circuit and running two way. If your ES is built the way Al typically builds them it should be very easy to try running two way. You will likely loose some dispersion on the high end but that might be a worthwhile trade off."

Just a tiny correction, here. The above quote was not from me, it was Shawn's.

Again, very nice! I'm sure you're enjoying your work. If you don't mind, I wanted to ask what amplification you're using.

Erik

[RFP]

Just a tiny correction, here. The above quote was not from me, it was Shawn's.

Again, very nice! I'm sure you're enjoying your work. If you don't mind, I wanted to ask what amplification you're using.

Erik

Oops, Eric... sorry 'bout that. Apparently, I have an occasional reading comprehension problem (!)

I'm using an Audio Research VT-100 power amp... 100 WPC, all-tube push-pull (6550's as I recall). This is driven by a Sonic Frontiers SFL-2 line stage preamp (with a Sonic Frontiers SFP-1 'Signature' phono stage)... also all-tube stuff. The digital front end is a Sonic Frontiers SFT-1 CD transport and a Sonic Frontiers SFD-2 DAC. All of the interconnect are Kimber KCAG and the speaker cables are Alpha-Core Goertz MI-3. I've been gathering up this stuff for a long, long time!

Have great what's-left-of-the-weekend... it looks like we're going to be "iced in" here in the Fort Worth area (yuk). At least lighting all these tubes up warms the room nicely.

Rob

[TBrennan]

" Actually the "point" of the TADs is the unbelievable performance of their nearly-lighter-than-air Be diaphragms... the extended [high end] range is a bonus."

But the extended high end IS the performance gain with 2001s, that's the point of Be instead of aluminum or titanium. You're not using the very benefits the driver provides. Which is your business of course but you might want to give it a try as a 2-way. If that tractrix acts like a saladbowl the collapsing directivity combined with the 2001 should give you extended on axis response without a tweeter.

No doubt with the JBL you can put more high frequency energy into the room which may be a good thing and may not.

Regards

[Erik Mandaville]

Rob:

I bet your system sounds great, and that AR amp should be excellent with the ES networks. I don't remember if you mentioned it, but you built the crossovers too -- is that right? I haven't done very much experimentation with our Klipschorns, other than to put together a few different simple networks, in one case a higher order design that just didn't sound good with my very low power amps. I'm going to get another 511B Altec to complete the one I have now for a stereo pair (thanks to Shawn), and I can start planning how to set those up. I just want to try them to see how it goes. I also bought a pair of the new tweeters from Bob C., and like them very much. We wanted to keep them reasonably 'stock' looking, so the Altecs are going to be interesting.

Yeah, the weather is supposed to get COLD!

Take care,

Erik

[Seadog]

Rob,

Very nice work! I must get over to check them out in person. How would you characterize the difference between the JBL and the Beyma tweeters?

David

[RFP]

Rob,

Very nice work! I must get over to check them out in person. How would you characterize the difference between the JBL and the Beyma tweeters?

David

Sure, David, we would be very happy to have you come give a listen (and a "look" as well). Just call ahead to make sure we are going to be here... bring your wife, too, she and Linda could have a cup of tea and discuss our audio compulsions (!)

I really can't answer your question regarding the JBLs vs. the Beymas. Remember, my ears are the same age as the rest of me (yikes!) and I have the these speakers might sound different to you than they do to me. Of course, I have them all "balanced" to suit my hearing (and preferences). That's one of the reasons that I would be very happy to get another opinion.

Give me a call,

Rob

[Rob H]

Great pictures. Couple of questions, do you like the sound of the trachorns compared to the k-400s. Also i would love to build a pair of the trachorns can;t find any easy plans to construct. Also was wondering did klipsch ever use MDF board in the bass bins?

Thanks Rob

[RFP]

Hi, Other Rob!!

I'm sending you a PM

[Guest David H]

Rob, your work is absolutely stunning. I am impressed to say the least.