Geddes on Waveguides - Page 594 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 31st March 2013, 06:19 PM   #5931
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Earl,
Even if you used a device that would go from a round diaphragm to a square exit phase plug aren't we just moving the diffraction point farther back into the device and creating the exact same problems that we would if doing this in the waveguide itself? I don't see the advantage to this except that the diffraction would happen at a higher frequency point in time rather than farther down the waveguide where the waveforms would be at a large scale and lower frequency?
  Reply With Quote
Old 31st March 2013, 06:25 PM   #5932
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Pano,
No matter how you cut it square or rectangular you have created many problems that have no solution really. Parallel walls and corners where the waveform will be forced to detach. There is no solution for that. The waveguides that I have worked to develop never have any parallel walls and never have a square corner. This is one of the reasons that I find so much fault with the multicell horns you so love. I know in the original theory it seemed like a good solution it was just another band aid. If you used multiple oblate spheroids that joined at the mouth cutoff frequency you would be way ahead of the game with a multicell waveguide. There is no way around the problems caused by rectangular cross sections which by the way includes square as a subset of rectangular.
  Reply With Quote
Old 31st March 2013, 06:56 PM   #5933
gedlee is offline gedlee  United States
diyAudio Member
 
gedlee's Avatar
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by Pano View Post
Do you see square as much different from rectangular - for the purpose of waveguides?
Square - rectangle, completely synonymous, except that a high aspect rectangle would be even worse.
  Reply With Quote
Old 31st March 2013, 07:00 PM   #5934
gedlee is offline gedlee  United States
diyAudio Member
 
gedlee's Avatar
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by Kindhornman View Post
Earl,
Even if you used a device that would go from a round diaphragm to a square exit phase plug aren't we just moving the diffraction point farther back into the device and creating the exact same problems that we would if doing this in the waveguide itself? I don't see the advantage to this except that the diffraction would happen at a higher frequency point in time rather than farther down the waveguide where the waveforms would be at a large scale and lower frequency?
No actually it is possible to go from an annular slit at the diaphragm to a square aperture without diffraction. This is what my patent is about. But once the annuli have been combined into a circle then it can't be squared again with diffraction at the edges.
  Reply With Quote
Old 31st March 2013, 07:25 PM   #5935
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Earl,
Care to share the patent number, and is this patent still active? I think I saw this doing a search for unrelated information once. but looking without having a patent # can take a major effort with the USP&TM office/
  Reply With Quote
Old 31st March 2013, 07:34 PM   #5936
FrankWW is offline FrankWW  Canada
diyAudio Member
 
Join Date: Jul 2004
Location: n/a
Phase plug with optimum aperture shapes - Patent # 7095868 - PatentGenius
  Reply With Quote
Old 31st March 2013, 07:43 PM   #5937
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Frankww,
Thank you for the link on the patent. I will read that over, it is the same patent that I have seen earlier doing another search.
  Reply With Quote
Old 31st March 2013, 07:56 PM   #5938
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
Quote:
Originally Posted by gedlee View Post
Square - rectangle, completely synonymous, except that a high aspect rectangle would be even worse.
Thanks, makes perfect sense.
At one time I had begun building a honeycomb multi-cell horn. Actually it was more of a soccer ball face than pure honeycomb. (see below) Still, many of the sections had parallel walls. It would have made a nice section of a sphere, and that was the point. I was saved from the tedium by a good price on some used Altec horns.

I think that an oval or round mouth multi-cell would be interesting, but what does one do with the spaces between the mouths where they don't touch?

FWIW, two of the most amazing, cleanest horns I've ever heard are rectangular - the WE-15A and its little brother the Vitaphone 11A. But of course they have the luxury of going from round to rectangle over a throat distance that is longer than the total length of many other horns.
Attached Images
File Type: png honeycomb-horn-2.png (5.1 KB, 214 views)
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 31st March 2013, 09:49 PM   #5939
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Pano,
If you ever really want to make a multicell horn without using rectangular sections I am sure I could walk you through that, It would be an interesting project to say the least. Not really that hard to do.
  Reply With Quote
Old 1st April 2013, 01:59 PM   #5940
gedlee is offline gedlee  United States
diyAudio Member
 
gedlee's Avatar
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by Pano View Post
But of course they have the luxury of going from round to rectangle over a throat distance that is longer than the total length of many other horns.
But why go to rectangular at all - I don't see any advantages. Some quote a larger mouth area, but really what's the advantage in that? It the distance across the mouth that matter not the area. I don't see where the area enters into the problem at all.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 10:32 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2