EconoWaveguide and KLH-17 (and others)

Paratima

E'Wavin'
EconoWaveguiding the KLH-17

The purpose of this thread is to show "How I Did It". No-one has to follow in my footsteps, but the hopes are it will (1) show someone who's on the edge, how easy and fun it really is and (2) serve as a guide for some who may not have a clue where to begin or what to do first. I sure didn't...

When Henry Kloss designed these speakers, he was using the best technology available at the time, tempered by the need to keep the product affordable. We are not talking Voice of the Theatre quality here; affordability by the mass market was very important. Model 17's retailed for $69.95 in the late 1960's. If there were only a handful of these speakers around, they might be worth a lot at resale, but they were sold by the thousands. No matter what the ads on that auction site say, they are NOT "rare". They are quite common, can be picked up at bargain prices and while they produce "OK" sound, we know we can do better with modern technology. That was pretty well proved in this thread: KLH-17

The Bill of Materials can be found HERE.

Another AK'er, BmWr75, got his KLH-20's upgraded before I could even finish this tutorial. He tells about it HERE.

Thanks for inspiration and encouragement: BmWr75, skywave-rider, secondslc, RayW (great cookies), Urizen, GordonW, dnewma04 and everyone who contributed to the EWG and KLH-17 threads, and especially, Zilch.

Over 30 years of building a career and raising a family and other pursuits, I had never really found out what high fidelity was all about. I have listened to the 1812 Overture hundreds of times on my stock 17's, but after this makeover, I felt it for the first time. I started hearing individual instruments, rather than just "an orchestra". What a difference! What a HUGE difference in jazz! The KLH-17 in original form is a good, easy to listen to speaker. Brought up to date, it's as if you paid six times as much and got top-of-the-line.

The KLH Model 17 was manufactured from 1967 thru 1974. So we're talking about, on average, 40 year old wood. The baffles are made of fairly coarse particle board. They are crumbly. You can drill or saw through them like burnt toast and that's about how well they'll hold screws, staples or pins. Be warned. Also, it's tight quarters inside - not much room to manouver. Here is the object of our affection. This was the first model 17 and is date-stamped 1969.
zlh1.jpg

Sometime in the next few years (no date stamp), the model 17 got a slightly better woofer, with a little better low-end punch and a itty-bitty tweeter. It also lost its lovely veneer and got a vinyl finish. Like this:
zlh1a.jpg

The tweeter:
zlh1b.jpg

zlh1c.jpg

If you have the newer model, you'll have to enlarge the tweeter hole considerably for the Selenium, otherwise the work is all the same.

I freely admit that I have all the woodworking talent of a cabbage. Where I walked, you may run, if you have any talent for this sort of thing.

TOOLS
What I used for this project: Note staple gun that also does brads.
ztool1.jpg

Drum sander fixes a lot of mistakes...
ztool2.jpg

Electrical stuff & hot-glue gun
ztool3.jpg

Pipe stuff & indispensable Elmer's
ztool5.jpg

Simply indispensable
ztool6.jpg


It pays to have the holes drilled square. If you're a woodworking hero, you can probably drill a hole straight in at a perfect 90 degree angle. I can't, so I cheat. This $30 rig, available at many hardware stores, does the duty of a drill press:
ztool7.jpg

Like this:
ztool8.jpg

to be continued
 
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Do all the woodworking first. Then it's done and you don't have to saw/drill/route around components and get sawdust on everything.

I started by removing everything, even the Velcro tabs used to hold on the grille. You will need to find another grille solution anyhow, as the old one won't work with the new parts. If you want to re-use the old connector/switch plate on the back, then just remove the 3-position equalizer switch from it, with the attached crossover components. You can use the switch hole for the L-pad. I removed the plate as well, because I wanted a clean start, with new 5-way connectors. To do that, after you have removed the speakers, get a pry bar under the edge of the plate, from the inside. It's stapled down and will pop right out after a minute's worrying it.

TWEETER

The original tweeter hole is 4.3" diameter and is offset by design. The Selenium drivers are 4.53". I enlarged the original holes just enough to center the waveguides. The Selenium compression drivers install through the woofer hole and screw onto the waveguide from inside the box.

The original hole is centered 4.75" from the left side of the baffle. The baffle is 3/4". The hole is 4.3" and is relief-routed 3/4" around the hole and 1/4" deep so the tweeter sits flush. Center is 5-3/16 (5.187") from the sides of the baffle. We don't need to move the hole up or down. We only need to enlarge the hole 1/2 inch toward the center to get the new waveguide centered. So, mark it:
zlh2.jpg


And cut it with a jig saw. I smoothed the edges with the drum sander and the finished hole looks like this:
zlh3.jpg


Next, place the waveguide in the hole, making sure it's centered and level. Mark around the edges and the screw holes. Drill the holes. I drilled them 7/32", so I could use 8-32 T-nuts. If you're going to use regular #8 speaker screws, drill 1/8" holes. I wanted to make sure from the start that I had no air leaks, so I installed this gasket tape from PE. Under six bucks for 50 feet is a bargain.
linky: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-542
Here's what we have so far, a naked box, ready for stuffing:
zlh5.jpg


Cut 4 strips of the gasket tape, about 7-1/2" long. Remove the backing and tape them down, just inside the lines you marked around the outline of the waveguide. Butt the ends together and trim the excess. Now install the waveguide and screw it in place. Take a razor cutter and trim around the outside. You should not have to trim as much as is shown here.
zlh7.jpg

zlh8.jpg

zlh9.jpg

WOOFER

Re-drill the speaker screw holes at 7/32" for the T-nuts. Make sure they're perpendicluar to the baffle. Insert 8-32 T-nuts into the 4 holes you'll be using, as it saves wear and tear on the baffle. HINT: Slather some Elmer's Woodworker's Glue on the base of theT-nuts, where they will contact the wood, when you put them in. They'll stay in place much better. Trust me when I say that you don't want T-nuts coming loose. Mash the T-nuts squarely into place with a C-clamp or screw them in using temporary washers. Let the glue dry overnight.
zlh10.jpg

zlh4.jpg


Here we go again with the gasket tape. Cut a piece big enough to go all the way around the speaker indentation. Before you put it down, mark the location of the four screw holes you're using. You'll need to find those holes shortly. Remove the backing and install the gasket tape. Be sure you don't leave any gaps. Trim the end and stick it down. For the next bit, I used a hole punch. Carefully lift the tape at each of the 4 screw holes and punch a hole in the gasket tape. Believe me, you'll be glad you did.
zlh11.jpg

zlh12.jpg

Install the woofer and screw it down overnight for the tape to set.
zlh13.jpg


BACK PLATE - Skip this section if using the original.
The original aluminum back plate is 4.5" square and covers a hole 3.25" square. I wanted my replacement to be at least as big for adequate sealing. I made it from a 6x6" piece of 1/4" fiberboard. Center the board and mark the opening. Mark holes for the speaker wire connectors and the L-pad. Drill 'em and sand smooth. Glue this plate in place with Elmer's or equivalent and tack it down with brads. (The brads are there, they're just hard to see.) Note marks for gluing.
zlh17.jpg

to be continued
 
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PORTS

You'll need two holes for the ports, on the sides, between the tweeter and the woofer. For 1-1/2" PVC pipe, you can drill the holes 1-7/8 and round them out a bit (snug) or drill them 2" and they'll be a bit loose and require more sealing. Your choice. Just make sure you leave room around the edges, so they're not banging up against the speakers. I drilled 1-7/8" with one a hole saw, then smoothed them out with the drum sander:

There want to be two ports, each 1/12" diameter and 8-1/2" long, bending upwards (away from the woofer). Possibly the only skill set where I'm more deficient than woodworking is plumbing, so you're pretty much on your own. I will say that if you put in regular 90 degree elbows as shown, you'll just need 2 pipes, each 3.5" long for each elbow as shown. Cement 'em together and stick 'em in place with silicone glue. Here's what they look like waiting final assembly - you need 4 just like this. These were made with plain old Schedule-40 PVC pipe. Ask for inch-and-a-half - that's the inside diameter.
zlh14.jpg

My cat inspects the port assemblies prior to final cementing. He does all my QA.
zlh15.jpg

Here they are, installed.
zlh16.jpg


CROSSOVER
You can get all the bits from AK advertizer Parts Express. Here is the crossover bill of materials:
Bill o' Materials

This is the standard EconoWave crossover design, but with different values for the components. I used a printed-circuit board acquired from AKer jackgiff. PM Zilch for details. In most cases the different values are no big deal. Just get the right-valued parts and plug 'em in. Well, this worked fine with a couple of notable exceptions. The first exception is the resistor at R1. This needs to be 60 ohms. Oops! No gots. I used two 30-ohms, in series. You can probably see how I did that in my detail shot below. They're the stacked ones. Just takes a little wire-bending plus hot glue to make sure they don't buzz. Note the jumper J2-J3 for non-bi-amped operation.
zlh18.jpg

zlh19.jpg


Second problem is the L2 coil for the woofer roll-off circuit. 3.5 mH is BIG! It wouldn't fit nicely on the PCB like the 1.5 uH in the EWG design. So, I drilled a new hole in the PCB to hold the end of the coil with the connecting wires and just let the other end hang off. It's screwed down on the backing plate panel. NOTE: I used a substitute L2 coil that was physically too large. The normal size supplied should fit nicely on the PCB.
Xover.jpg


Before soldering, pull each component down tight on the board to prevent parts audibly buzzing against each other. Give anything in doubt a shot of hot glue, like inside the air-core coils. Solder all components on the board with their value markings up to prevent wondering later on.

ASSEMBLY
That's about it. Screw the Selenium driver onto the back of the waveguide and hook up all the wires. At this point, you should re-stuff the box with padding. You can use the original fiberglass, but be sure to include the light canvas sheet that came in the cabinet or a similar cloth to protect the woofer from particles. Or, you can use Acousta-Stuf polyfill or its equivalent, which is my preference. I used about 1/2 pound of Acousta-Stuf for mine. Screw down the woofer and sit back and enjoy the good tunes. Please note that many of these photos were taken during assembly and before final testing. Consequently, lots of wirenutz to be replaced by solder.

TA-DA! The finished product:
3435s.jpg


I'm putting together another instructional thread JUST for building crossovers. To some folks, it's nothing exciting. To many that I've talked to, it's scary. Doesn't need to be. Stay tuned...

CONCLUSION

You can be for it or against it, but it works. If having vastly improved sound, on the cheap, with a sense of accomplishment, doesn't do it for you, oh, well. I'm quite serious when I say that if I can do it, so can you. My skills with electronics are probably a cut above average, but when it comes to woodworking, I'm dead slow & easily confused. I just keep at it. As for acoustics, I'm learning and I love it! Y'all come on in! Now excuse me, I've got a pair of Advents over here that need E'Waving...

The End or maybe not
 
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I think I got all the links fixed. If you find an error, please let me know & I'll fix 'er.

Edit: Just remembered, ya gotta stuff the turkey. Added to last post.
 
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Sweet thread...

Can you add parts list of crossover, woofers, tweeters and source?

I recall the econowaves people are using different woofers etc so I'd like to know what woofers you used and where from.

I have some KLH Six cabs that are in decent re-stainable shape once sanded...One has a dead tweeter and the same has a woofer that the VC is rubbing on. Sounds ok if you press it gently to one side.

As much as I like the sound of the one that works, I really do want to try this Econohype thing out!

Total cost for you was?

Again - awesome write up!

Oh and what's the size difference between the 17 and the 6? Woofers/tweeters the same size? I have the larger tweeters of the two pics you have.
 
Great work, Les.

It is great to see some modifications on the EconoWave concept. Lots of ways to go, and they are all fun.

Teron, the woofer and tweeter types are spelled out in the Bill O' Materials link above.
 
Superb. You've taken a lot of time with photography and great care to write unambiguous descriptions of procedure. From an absolute beginner's perspective, step-by-step threads like this increase motivation and confidence to tackle a project which leads to even more enjoyment of the hobby.
Looking forward to the crossover instructional- 'more might, less fright'.
 
Sweet thread...

Can you add parts list of crossover, woofers, tweeters and source?

I recall the econowaves people are using different woofers etc so I'd like to know what woofers you used and where from.

I have some KLH Six cabs that are in decent re-stainable shape once sanded...One has a dead tweeter and the same has a woofer that the VC is rubbing on. Sounds ok if you press it gently to one side.

As much as I like the sound of the one that works, I really do want to try this Econohype thing out!

Total cost for you was?

Again - awesome write up!

Oh and what's the size difference between the 17 and the 6? Woofers/tweeters the same size? I have the larger tweeters of the two pics you have.

The KLH-6 cabinet is much larger than the KLH-17. So, the exact same drivers and crossover as used by Paratima will not yield the same results in the KLH-6 cabinet. The Econowave thread may help you pick the right components for your cabinets.
 
The KLH-6 cabinet is much larger than the KLH-17. So, the exact same drivers and crossover as used by Paratima will not yield the same results in the KLH-6 cabinet. The Econowave thread may help you pick the right components for your cabinets.

I recall there is some KLH six econohype conversion info on AK...was just curious of they were similar in size.

The write up is excellent and makes the whole task seem a lot easier seeing it all laid out step by step so nicely!

I will search out the six stuff sometime hopefully sooner than later as I'd love to hear some of these econohype speakers for myself.
 
Y'all are entirely welcome. It was fun to do, although I sure didn't realize what I was getting into... organizing the photos (Oops, nope, that one's too blurry, have to re-shoot), organizing the flow (Uh, which of these did I do first, anyway?) and organizing my thoughts! Not to mention realizing how much something can be clarified by, for instance, having a hand in the picture, actually punching out the gasket tape. Ha! Then figuring out how the heck to get my hand in there AND take the picture! Lotsa fun. :D

Already started the crossover thread - there's more to it than I thought, too... :scratch2:

Hope it all helps someone. I'm just grateful for what I've learned here. And still learning! :music:
 
/me hearts pictorials. If only those silly words weren't mucking things up.


Seriously, nice post! Just the kind of post that makes me want to hack up my fives.
 
Les, great work and thanks for putting this thread together. You have some good advice on the t-nuts. I wish I knew them made a drill guide for the hole saw. I did mine by hand and they were pretty straight but for my next project I'll buy a guide. :thmbsp:
 
Hey, Duff. :D Yeah, that thing has come in so handy so many times... The only problems are (1) you got to have a lot of space to make it work - forget using it inside anything and (2) it needs a flat surface. Sometimes, I've had to kludge a surface for it to rest on. Shims help, maybe. But boyoboy, it is great when it works. Also has notches at the bottom so you can drill a hole dead center through a pipe! I've used that feature more than once. Best $20-30 tool money I ever spent.

Dennis, sorry, I didn't make the bill of materials easy to find. I may move it to the first post to make it easier. It's a Dayton 7" square guide that Zilch found. http://www.parts-express.com//pe/showdetl.cfm?Partnumber=270-316
Note that it's elliptical, not round. Excellent dispersion. I'm using it with the Selenium D210Ti driver. It's just the teeniest bit razor-edged, so I'm going to try the Bauhausler's trick to tame it with foam plugs.
 
TRUTH IN ADVERTISING - An Update

Remember, back in Post #1, I told you that (a) I'm all thumbs at woodwork and (b) these old boxes are literally flakey. I wasn't kidding, on either score.

In the desire to get different measurements and make sure I'd tried everything that might be helpful in this conversion, I've had to take one or sometimes both boxes apart and fiddle with this and that. I've experienced a lot of frustration with these cabinets.

About the speaker screws / T-nuts: I finally wound up drilling new holes, ever so carefully, and using plain old #8 x 3/4" speaker screws. The T-nuts came out time after time.

Further, the boxes vibrated a lot. You could put a hand on top of either cabinet and almost tell what piece of music was playing, the vibrations were so bad. In an effort to damp this down, I finally stapled in a couple of big strips of 2"-thick cotton insulation. Picture follows.

zlh20.jpg


It worked. There's still enough vibration that you can tell something's happening inside, but it's way down from where it was. The box is loosely stuffed with 1/2 pound of Acousta-Stuf.

These ZLH-17's sound way better than the originals. I love the sound! But there are hazards to working with boxes this old. I'll say it again: The baffles in these boxes were made with particle board, not MDF. They aren't big on structural integrity. If you're contemplating doing this conversion, be sure of your woodworking skills or choose a better base. The New Large Advents that I've been working on are 9 years newer (1978) and made of real MDF. They're a joy to work with by comparison. You've been warned.

I should add that if all you're doing is a straight conversion to EconoWave, you won't have to putz around like I did. You'll take out the old woofer and put in the new one - done deal. Well, and a couple more steps. ;)

I also moved the Bill of Materials up to Post #1 and added some acknowledgements.
 
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