Jump to content
The Klipsch Audio Community
Chris A

A K-402-Based Full-Range Multiple-Entry Horn

Recommended Posts

Forgot to mention that when making the holes 3M Blue Painters tape is a great way to see where to drill.

 

I would like to post my REW files and those are too big to post here.  I am hoping there might be a way to shrink those but I doubt it.

 

I have attached pictures of the CELESTION measurements for comparison.

 

Yellow trace is EQ (duh)

red trace is no EQ at minum 10 dB

green is no EQ at the same level as EQ.

 

The distortion is purely for comparison - I have no idea how much trust to put in those measurements.

 

All are psycho-acoustic smoothing with 2 dB per step .

 

Overlays are stuck with 5 dB per step

 

Phase for no EQ at full level is the closest to 0 degrees.  All of the others lag.

 

I am using plenty of PEQs!

 

I hear NO ill effects of using these drivers this low.  Every night I listen to them expecting to hear THE BIG FLAW and it has not appeared yet.  I love these drivers.

 

Just for fun.

 

 

distortion.jpg

frequency response.jpg

phase.jpg

setting output channel.jpg

Xilica settings celestion.jpg

Share this post


Link to post
Share on other sites
42 minutes ago, rickmcinnis said:

I hear NO ill effects of using these drivers this low.  Every night I listen to them expecting to hear THE BIG FLAW and it has not appeared yet.  I love these drivers.

 

Cool. What is your hi-pass (crossover?) frequency to the Celestion compression driver?

Share this post


Link to post
Share on other sites

There is not one within the XILICA - just using the PEQs.

 

My amplifier is probably presenting a 85 hz high pass filter - using the output coupling caps to act as a high pass filter -  using 140 uf assuming an 8 ohms impedance.

 

I have yet to measure the impedance vs. frequency of the CELESTIONs so the 8 is the figure supplied by CELESTION.

Edited by rickmcinnis

Share this post


Link to post
Share on other sites

Another thing I wanted to suggest to those about to put holes in their K-402s:

With a strip of paper  - mark it at 9 & 15/16 inches this will be ever so slightly large but is a mark on the yardstick - for the obsessive 9 and 59/64ths is even closer!

 

Use card stock.  Connect the two ends with some tape. You can then easily see where you are with your port.

 

There can be an advantage to putting an angle on the port.  I am going to try this - to have it continue the 45 degrees I want for the baffle.  Not there is a chance in hell of me getting that with any consistency.  I am not skilled with a router and my extra layer of baffle towards the mouth precludes being able to use one well.  I feel certain getting close is all that is needed.  Lots of barrel sanding bands are on hand along with sandpaper.

 

Draw a "circle" around the port -.75" out - (the thickness of the baffle in this case) to see where you need to finish up.

 

I am thinking about, for the sake of curiosity, of going ahead and cutting the holes in the other K-402 while it remains just a high frequency horn to hear and measure what happens.  I can use a sheet of paper with a blob of MORTITE on the back until I am ready to install in the second box.  It is finished but needs to be shellacked and that will take two weeks.

 

I know I will lose the frequencies in that part of the horn but want to see what happens above that.

 

Main motivation is go ahead and do it while I still remember what i did right with the first horn.  Using the epoxy to repair is easy but it does take lots of time to allow it to dry before adding a subsequent coating.  I am concerned that putting it on too thick, like BONDO, is a bad idea.

 

With hopes of helping someone not repeat my mistakes ...

 

Take care,

Edited by rick mcinnis
addition
  • Like 2

Share this post


Link to post
Share on other sites

Still working on frustums.

 

Knew I would need to add material to the horn to allow a better seal between baffle board and horn. Two of the ports are as close as they can be to the wall of the horn and this requires a fair amount of material.  A fair amount of material requires numerous applications which means extra time.  Hoping I have learned something that will allow speaker number two to move along much quicker. 

 

Was buying the two ounces tubes at HOME DEPOT and see AMAZON has 10 ounces tubes at a substantial savings.  AS quick as I will use it it is a good thing.  I have found if you do not use JB WELD quickly it gets funny,

 

Knew this would be tricky - not hard - but time consuming and it is easy to obsess over getting them as close to perfect as possible,

 

Picture is a rough version of the baffle facing the driver.  Grey is JB WELD patching. The inside side of the frustums are sharp at the horn entry.  These are not finished.  What I would call "roughed in".

 

frustrum.jpg.4e474b6eadcff7387d8e349ce6a340cd.jpg

  • Like 3

Share this post


Link to post
Share on other sites

In case it is of interest - have one horn really close.

 

Use of JB WELD to make ears/saddles to insure sealing of port to baffle.

 

The surface is flatter than it looks.

 

Hope to have one actually working over the weekend.

 

And then to the other one.  Learned so much with this one I feel sure the second one will go much quicker.

 

 

side one 401.jpg

side two 401.jpg

  • Like 2

Share this post


Link to post
Share on other sites

What size are ports, they look small. Didn't Chris suggest something like 2 in by 9.5 inch.port?

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...