K-400 Wood Horn drop in relacement

[Dave A]

While cutting parts today I began working on the design for a K-400 prototype. Meant to be a direct drop in with the mouth flush to the front of the motorboard. This is just the basic idea without refinement. It will have a 2.5" throat and adapters for 2",1.4" and 1" drivers which will extend the over all horn depth to 8".  I have had enough inquiries from people to prompt me into looking into doing these. Along with the other projects it will be later in the year before anything gets cut, tested and good drivers vetted but it is in the queue. On the one inch adapter I am also going to make  one that has 1 3/8 18TPI internal threads for the K-55 driver. The adapters will be 2" long and taper cut for specific throat of horn to throat of driver combinations. All three sizes can be mounted on these horns but you will have to match your driver to the adapter. If you elect to change drivers later all you will need is the correct adapter.

[OO1]

I think you can even make  motor boards while you're at it -----not sure what kind of wood this is , but this is certainly a show piece  versus regular MDF

[Dave A]

11 hours ago, RandyH000 said:

I think you can even make  motor boards while you're at it -----not sure what kind of wood this is , but this is certainly a show piece  versus regular MDF

One of my primary goals in making the things I do is that they be direct drop in replacements. Now I may do things like change the horn section motorboard on La Scalas to allow for using the LMAHL over the SMAHL but those are personal projects I do for speakers I am working on. I have also provided cut diagrams elsewhere on my various projects so people who are interested can do them too. But in general I am not a fan of altering existing Klipsch Vintage speakers in ways that can't be reversed unless it is with things like internal bracing.

 

  This was a rendering out of Walnut but nearly impossible to get true to life with my skill level plus Solid Edge lets me make these renderings but since I did not spring for the full cost add on sticks those lovely Keyshot things everywhere. I guess they figure showing you what you could have and plastering their logo on it all is their way of convincing you to pony up some cash.

 

  Also what was not shown since I have not spent much time on the model is that it will have a flange to allow for screwing into the motorboard just like the K-400 does. I am also going to do something similar for the Bell and KHorn but it will have both the tweeter and mid cut into it.

[Panelhead]

  Looking good. 

  Assume each section could get smaller as you stack it up. The pictures of the Fastrac Kit looked that way. Would save some board feet of lumber. 

  Lastly, if overall is 10” from 8” horn and 2” adapter will this get down to 400 Hz? I think the Belle squawker is about the same depth.

[Dave A]

On 9/17/2020 at 4:01 PM, Panelhead said:

  Looking good. 

  Assume each section could get smaller as you stack it up. The pictures of the Fastrac Kit looked that way. Would save some board feet of lumber. 

  Lastly, if overall is 10” from 8” horn and 2” adapter will this get down to 400 Hz? I think the Belle squawker is about the same depth.

This is not a stacked cut a layer at a time horn. The pieces will be glued together before cutting and the goal is to eliminate virtually all the hand finishing that went with the traditional Fastrac. The OAL depth would be 8", 6 for horn 2 for adapter. Now I will probably use reduced size sections going towards the throat for the K-400. For freestanding ones though I will more than likely just leave it a block of wood with no stepdowns.

[Godataloss]

Following with interest to perhaps make some Cornscalas of my own from my various pieces/parts lying around here.