Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Line array steering ?
Line array steering ?
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 7th March 2019, 09:02 PM   #61
mark100 is offline mark100  United States
diyAudio Member
 
Join Date: Dec 2010
Quote:
Originally Posted by Jim Griffin View Post
The shading--approximation of a Legendre roll-off--in Keele's CBT24 and my Modified CBT24 designs are applied in a group of 12 (the lowest drivers to the floor), a group of 6 (upper middle) and finally a group of 6 for the top drivers. The weights are 0 dB for the lowest 12 (achieved via wiring of the drivers in series-parallel) then 3 dB down for the next 6 drivers (achieved by connections and fewer drivers) and finally 9-10 dB down for the final 6 (achieved by connections and a two resistor divider network). Of course with beam steering you can have finer graduations for the approximation depending on the number of channels you allocate which is a good thing.
Those shading values help, thanks Jim.
I'll try to best figure out how to interpolate my arrangement with those and what's in Keele's papers.

And with the removable baffles it shouldn't be too hard to rewire for optimal if needed. I'm bringing connections out to simple terminal strips for such contingencies.
  Reply With Quote
Old 7th March 2019, 09:38 PM   #62
wesayso is offline wesayso  Netherlands
diyAudio Member
 
wesayso's Avatar
 
Join Date: Jul 2007
Nice progress!
__________________
Use Science to design your speakers and they will sound like a piece of Art...
  Reply With Quote
Old 7th March 2019, 09:41 PM   #63
mark100 is offline mark100  United States
diyAudio Member
 
Join Date: Dec 2010
Quote:
Originally Posted by wesayso View Post
Nice progress!
Thanks Wesayso
  Reply With Quote
Old 12th March 2019, 01:00 AM   #64
wesayso is offline wesayso  Netherlands
diyAudio Member
 
wesayso's Avatar
 
Join Date: Jul 2007
I'm getting out the popcorn, hoping to get an update soon.
__________________
Use Science to design your speakers and they will sound like a piece of Art...
  Reply With Quote
Old 12th March 2019, 09:03 PM   #65
mark100 is offline mark100  United States
diyAudio Member
 
Join Date: Dec 2010
Quote:
Originally Posted by wesayso View Post
I'm getting out the popcorn, hoping to get an update soon.
Getting there, step at a time
Straight (corner) version is glued ... cbt next
Attached Images
File Type: jpg straight1REZ.jpg (208.1 KB, 45 views)
File Type: jpg cbt start.jpg (95.7 KB, 45 views)
  Reply With Quote
Old 13th March 2019, 04:15 PM   #66
mark100 is offline mark100  United States
diyAudio Member
 
Join Date: Dec 2010
Sorry for previous pict and run, lacking any real update info...

Projects are going pretty smoothly.
The only real surprise has been how much more difficult the straight corner box has been to plan, cut, and glue ..than has the CBT. It's hard for me to keep the relatively narrow, 7ft long, pieces for the straight box true all the way thru glue up.

And I must admit, I got a little overly confident/tricky with the interchangeable driver baffle. Ended up missing the baffle width for the straight line by needing to trim 4mm width. Fortunately, I knew to complete the straight box first, as the overall design makes it very easy to trim the CBT's width to fit the baffle. It does look like the removable baffle is going to work fine...I got lucky I think

I needed to slow down and figure out removable base plates, to get the proper t-nuts or inserts into the boxes' bases before assembly.
The big circle in the attached pict is for free standing straight. I'm making a big elliptical base for the CBT. And I still have to make a straight base for corners, where the room's base and show molding won't let the box snug to the wall. Oh, and straight box needs a handle(s) like a PA box.

I'll be glad to get the boxes done and painted so I can move on to assembling the driver baffles.

A few iron out details remain...
Perhaps the biggest...despite a lot of searching, I still haven't found a gasket/sealing idea for the TC9's (used front mounted).
Any easy recommendations welcomed !
Attached Images
File Type: jpg straight 2REZ.jpg (206.6 KB, 32 views)
  Reply With Quote
Old 13th March 2019, 05:46 PM   #67
wesayso is offline wesayso  Netherlands
diyAudio Member
 
wesayso's Avatar
 
Join Date: Jul 2007
Good to see progress. For a gasket you could use neoprene. I have found it in convenient width for these purposes on ebay. Another option could be something like 3M caulk. I have used that to seal back lights on my old car but also have used it as a pliable gasket for speakers. Butyl rope could work to but is even more sticky.
I'd use the neoprene in baffle width size. Just cut the driver holes and use the neoprene as seal, ideal for a slightly bent baffle. Make sure not to put too much pressure on that driver frame. I'd use rubber rings to fill the arc for the CBT. The neoprene will fill the gap(s).
__________________
Use Science to design your speakers and they will sound like a piece of Art...
  Reply With Quote

Reply


Line array steering ?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Suspension of tweeter array in front of mids in a line array Zarathu Multi-Way 21 29th January 2019 07:16 PM
30 Driver CBT Line array 30 Fountek FE87 driversper array T85matt Planars & Exotics 3 26th December 2016 06:51 PM
Short Line Array (line source) build perceval Full Range 226 4th January 2015 02:08 PM
Help with converting sealed box line array loudspeaker to transmission line enclosure jb0194 Multi-Way 3 7th January 2012 05:08 AM
Line array tweeter line - On left or right? dhenryp Multi-Way 4 9th March 2005 11:35 PM


New To Site? Need Help?

All times are GMT. The time now is 02:25 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki