Does anyone out there make their own midrange horns.

[avidfan]

I have a speakerlab clone of khorns, my midranges are made of fiberglass, and their range is of poor sound quality. I am looking to replace the horns. I have already purchased altec 511 B"s but to no avail, they are to big for my cabinets. So if anyone knows some one who has restored the 1978 version of the speakerlab version please let me know. Another option would be to rebuild the tops, I would be willing to pay someone to have this done. I live in Alaska, and there isn't many resources for speaker buliding up here.

Thanks,

Bob From Anchorage

[lynnm]

These might fit the bill:

http://forums.klipsch.com/idealbb/view.asp?topicID=35475&sessionID={10CEE1DF-C060-46A9-8F61-6A38BD97A368}

P.S. Are you the fellow that had the Speakerlabs on Ebay for a couple of runs a while back - If so did your wife let you move them in or did she move out ?

You mention that the mid horns are fibreglass. This leads me to wonder if perhaps they might benefit from damping which involves covering the exterior of the horn with dynamat or rope caulk.

[WMcD]

Some of the following goes beyond the question. But I might as well put it into cyberspace. Perhaps inquiring minds will find something of interest.

I've built a few midrange horns over the years to go with homebuilt bass horns. It can be quite a challenge. The Speakerlab fiberglass might well be a superior product with the moretite tweek than anything you can build without a lot of woodworking skills. Mine are not that great.

For your information: The K-400 was made out of metal. Later Don Keele (big name in audio, in my view) redesiged it in some sort of plastic composite and this was the K-401. I'd expect this is still used in the newly produced K-Horn and LaScala. It was probably used in other industrial Klipsch units. I may have hear K-Horns with this without knowing it. Photos reveal the walls are thick and reinforced with additional ribs.

SpeakerLab used that fiberglass unit in early days. It was probably chosen as a cheap substitute for the K-400. PWK doubtlessly was not going to sell them to SL. That was probably before the K-401 which would have been a better item to copy in plastic. To some extent, the lower price of plastic composite may have forced the Klipsch factory to follow SL, but with a better eye toward sturdiness.

At least one friend of mine has a SpeakerLab-K with the fiberglass horn. I've never heard it.

Later, SpeakerLab went over to a cast metal midrange. They might very well have been chasing the K-400 and missed the boat when Klipsch switched to composite later.

So, you have a few choices. You could buy K-401s from the factory, or find K-400/1 on ebay.

You could also do the moretite thing. This is certainly the most cost effective. $20 buys a lot of moretite and it would only take you an afternoon's work. It should damp out any resonances or artifacts caused by wall flexing. I'd suggest this approach. But I'm not sure your problem is caused by the mid horn alone. There is plenty more potentially wrong with the SL-K.

Please consider that what you're hearing may not just be the effect of the fiberglass SL horn. The LS-Ks had other gross variations from the real thing.

Bass Horn: One of the factory moderators had commented the the basic structure of the bass horn was pretty close. He didn't go much further. That seemed to be most people's concern. There is the plywood versus mdf issue, but it may not be too much of one. OTOH, the SL-K dumbed down much of the other cabnetry. Acoustically it should not make a difference.

There is an issue in the bass designs though. The one SL plan that I have opened up the back chamber to commuicate to the volume (cubic volume) of the wedges at the top and bottom of the bass bin. Then the noticing out of the boards making this possible became optional. PWK's review of the SL-K mentioned that they followed his mistakes and then he corrected them. It might have been this. Incidentally, this inclusion of more volume just invites problems with air leaks and injects another area of complexity to the process of building the beasts. So I played it safe.

Tweeter: SL offered a very cheap horn and something that looked like a plastic version of the K-77 / EV T35. Performance of either is unknown. They're mounted at the side. PWK never did this. One tweek may be to make up a brace to put the tweeter at the center of the mid. Yes, theoretically blocking the sound from the mid. PWK tried it once. The benefits may be more than the downside.

Midrange driver: The ones I've seen from SL look like an Atlas unit. That may be okay in that PWK used Atlas as a source. However, PWK spoke about tweeking them. There are some reports of an enhanced phase plug structure (closer spacing and another channel). Others can tell you more. The SL might not be so bad, though.

Bass driver: Dr. Bruce Edgar announced some disgust with them. The modification suggested was to take a sledge hammer to them and put the remains on the curb. The T-S parameters were all wrong. In some of my home brews I used a Pyramid unit which was not too far off in parameters. It is arose from a demented thought that I didn't want to rely on the factory. To quote a very old TV commercial, "Mother, I'd rather do it myself." I didn't want to be cheating.

The SL unit has a very high Qts. Edgar points out that a low Qts is needed to get the driver to put out energy at high frequencies (other factors like Fs considered), specifically around 200 to 400 Hz. PWK published a frequency response of the out put of a "speaker from the Northwest" (an allusion to the SL). It had very poor performance in that range. Bruce may have been reading things the same way.

Crossover: There were two versions of the SL that I know of. A later one used three way toggle (!) switches for level control (I'd say the very cheap way to go). An earlier one used L-Pads (more expensive). Sitting at the computer, tonight, I can't give you info on which used what combination of first order or second order filter design.

Neither of the SL cross over designs used an autotransformer in the midrange like the Klipsch units. One can only guess that spending an extra $10 bugged them.

Out of fairness to whoever made up the SpeakerLab-K, it must have been a daunting project. There is also much to be said that the result mimics much of what PWK put into the factory K-Horn. My brother in law has a pair and they're . . . um . . . pretty darn good sounding. It is a three way corner horn system. Plus, some people just like to build kits. The falacy with the latter is that they didn't get the QC, very enduring woodworking, selection of best components, or value of the matters made by PWK.

The bottom line is that I think you should patch up the fiberglass horn with Moretite. Then there are other things to consider if you're still unhappy.

Best,

Gil

[avidfan]

No, I am not the same guy who had the spl horns on ebay. I however did see them they are a exact match of mine. Thankyou for your advice and help.

Best wishes,

Bob

[avidfan]

Hi Gil,

you are quite an authority on the sl version of horns. The drivers on the midrange are atlas pdv-5 series. The tweeters are metal versions of the ev T-35 alinco magnets and are well built. My version of horns were bulit by a rep in the company around 1978 from diy kits that were opffered at the time. I contacted the company and asked about specs on them, they said they didn't have any information about them, I know this isnt true. They just didnt want to talk to me. AS far as a comparison to the klipschorn, their sound is more refined and they are not built as well. I have decided to save my money and buy a pair of klipschorns, just got to have them. I really dont know enough about the speakers to improve them.

I have learned a lesson though, make sure you check serial numbers on all klipsch speakers these are a clone, the seller said they were klipsch, they are not just a imitation.

Thanks for your help,

Bob

[j-malotky]

Bob

You may want to check with Q-man. He was selling a bunch of k400 or 401 a few months back. He may still have some.

JM

[johnnyp]

Avidfan,

I have the Speakerlab fiberglass horns (K-400 taper replicas) and had the same complaints as you. When I turned up the volume, the distortion increased geometrically. I put my hand on the fiberglass (about 6" from the mouth), they "bounced" excessively as the volume was increased. A little mortite or rope caulk isn't going to help.

To solve the problem requires a little work. I have reinforced the horn by wrapping the narrow part of the horn with fiberglass cloth and epoxy resin. This was very easy but a little messy. While the resin was still wet, I wrapped a long length of #14 magnet wire tightly around the horn (like filament winding) beginning where the driver mounts for about 10" - 12". The wet resin oozed between the wire and when it was dry it was very strong and rigid (I am not set up to post a photo, sorry).

I attached 3/4" x 1 1/2" wood blocks to the horns using screws and epoxy resin, about 5 inches from the horn mouth. The blocks are located on the horn top and bottom surfaces (4 places) . I was careful to make sure the screws did not penetrate to the horn inner surfaces. I used the blocks as attachment points where I secured the horn to the inside portions of top and bottom surfaces of the upper cabinet using additional wood braces. My squawkers are now securely attached to the cabinet at 3 places. I will add a 4th attachment point, near where the driver mounts (similar the the Khorn).

The results were fabulous. The horn does not vibrate or "bounce" regardless of volume level. I think these glass horns actually sound smoother than the cast AL K-400's my brother used in the same room.

Gil,

Thanks for the info on the Speakerlab SK. I always thought the SK's weak link was the crossover they used. They claimed their bass units could extinguish a candle. At one time, their squawker driver was advertised as filled with "ferrofluid" (whatever that is?). All the industry Khorn copycats ("Speakerlab SK" , "Speaker Factory Romao", etc) ceased production when PWK & company pressed them for patent violations.

I would like to follow-up on your discussion of khorn bass driver, QTS, and fequency response but I save (or start) that in another thread.

[WMcD]

I did not mean to say anything authoritarian about the moretite thing. I haven't done it.

A few decades ago a buddy with the fiberglass SL horns showed them to me and I got some vague engineering impression the walls were too thin. But this was just a gut impression looking at the business end. Two other friends have the SL with metal midrange. I would think there can't be too much different performance from the K-400.

PWK had spoken about how a horn structure has to be reasonably rigid, the other part was the shape. It seemed to me the SL fiberglass got the shape correct, but not the rigidity. Therefore, more structural work suggested should bring them up to a good level of performance akin to the real McCoy. That is what I think.

The crossover design is a very difficult issue. PWK was critical of giving the owner control. He blamed the owner's room for being too lively, lacking in dispursion of frequencies, lacking proper dimensions. In fact, he was criticizing his own listening situation and asking owners of his speakers to mimic his listening room solutions. Good if you have the money.

It is an ongoing problem. When we get a recording, we're actually hearing what the mixing engineer heard in his studio, with his speakers. Our living rooms and speakers are different. Some of the differences can be reduced by placement.

None the less, I believe that Al. K.'s crossover design is a very good solution for the midrange issue and room issues. It addresses the issue of maintaining filter response and allowing adjustment of the midrange response. There is some consistent criticism that PWK's settings are too high. In an optimal room that might be not true. But for those of us with difficult rooms, bumping down the mid, per Al.K. makes a lot of sense.

I'll also point out that Al.K.'s design gives a lot of flexablity and will work with the Atlas units, at least in theory.

The bottom line is that you might do the physical reinforcement suggested. The next one may be Al. K. type crossovers. I'm not quite the believer in high tech components that some are. So you could probably put them together without the most expense caps and inductors and perfect geometry.

I await hate mail on the latter. Smile.

See you all in Indy.

Gil

[Gregorius]

tsk tsk Gil,

Don't you remember the AL K and Randy B. thread about use of components in Al's crossovers? You may very well receive hate mail if either reads this.

Regards,

Greg

[dougdrake]

Why is it that everytime I scan this thread I expect to see a post from Martha Stewart?

"Yes, of course I make my own horns. I started by planting a fine crop of trees as a toddler, then harvested them recently using dental floss stretched between two oxygen-free copper posts, as a sort of saw but without those sharp tines to hurt the wood..."

Doug "Always Available for Useful, Insightful Posts" Drake

[djk]

"patent violations."

Expired.

Try copyright infringement.

[davmar]

Wow Bob from Anchorage, a fellow horn man in Anchorage, send me a e-mail! davmar@gci.net

[WMcD]

No, I beliveve this was presented as a trademark issue. That is a subset of the law of "unfair comptetition."

It is a though issue in intellectual property law.

Gil

[avidfan]

Hello,

I was the person who started this thread. I want to thank everybody for their help and valuable comments. I have bought a new pair of Khorns from a local dealer at close to dealer cost. I would like to fix the old pair by adding new horns, and will probally sell them. Thanks for the offers qman and jon warren, I may have a freind who might want to fix them, and will try to get him to contact you.

Best Regards,

Bob

[djk]

The stylized 'Klipschorn' was a trademark, 1954.

Speakerlab was not using the script form and thus not in violation of the trademark.

As a copyright issue they stopped using 'Klipschorn' and started using K-horn.

After this Klipsch filled for a trademark on K-horn in plain typed form, 1976.

After this Speakerlab advertised their kit as just the model 'K'.

Klipsch has abandoned the trademark on Jubilee.

On March 11 2003, Klipsch applied for the work mark 'Klipsch' to cover goods and services including: Audio receivers, Preamplifiers, Processors, Compact Disc Players, CD Players, Digital Video Disc Players, DVD Players, and Tuners