Large scale open baffle - Page 3 - diyAudio
Go Back   Home > Forums > Live Sound > PA Systems

PA Systems A forum for discussion of all parts of a sound reinforcement or DJ system: loudspeakers, mixers (desks) etc.

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 9th May 2013, 12:47 AM   #21
diyAudio Member
 
Join Date: May 2010
Location: Scottsdale, AZ
We are in the process of producing the final item in finish wood with mounting for a grille to conceal the configuration and mask the fact that it is even a loudspeaker. :-) In fact, the video projector for the venue will now have a place behind which to hide. We are incorporating high-wattage Zobels on both the mid/hi drivers and the low/mid drivers as well. Given what we are learning about Behringer Amps the idea of giving them "friendly" loads seemed to make sense...
Originaly we had contemplated experimenting with the Mid/Side concept, but have decided the utility of the array is greater if we treat the difference panel alone and use the center speaker to serve for vocals, speech, and other unrelated signals.
The occasional combination is useful but not the objective.
We fly it once more sans grille and determine if any thing has changed requiring physical modification, put the grille on, fly it once more, and EQ each side.
Pictures to come!
  Reply With Quote
Old 10th May 2013, 01:55 PM   #22
diyAudio Member
 
Join Date: Oct 2012
still no pic's...
i'm still trying to get a handle on zobel's and how to apply them so i was curious as to your component values and is the difference with and without vary distinct?
i was also curious as to overall system configuration as in what amps are driving what? and just how many speakers and what not's are in this rig?
if you can't give us pic's give us details man, or a vivid description!
  Reply With Quote
Old 10th May 2013, 05:44 PM   #23
diyAudio Member
 
Join Date: May 2010
Location: Scottsdale, AZ
Turk: Working on it.
The final piece is sitting on the church platform. We learned this morning that an "engineered trainwreck" in scheduling has forced us to take it out of position to accommodate what appears to be the classical physical impossibility - ie. two objects of equal mass, etc.
Pictures are still in the works - delayed by the "trainwreck"!
We'll keep after it.
Re: Zobels: The main utility for me has been to make crossover implementation more predictable. Parts values will do what your calculations say they're supposed to.
Where we have LMS as a charachterizing tool, we bootsrap by wiring the parts together, measuring the electrical result, followed by measurement of the results with the parts in the loudspeaker.
Thus far the Zobel has delivered on that premise reliably.
Our application here is to make the loudspeaker system - which is being electronically crossed-over - a "friendlier" less reactive load for the amplifiers to "see". If you look at some of the papers, the impedance "tail correction" is essentially what it's about.
Some amplifiers in the pro business are fairly tolerant of impedance irregularities above, or below their specified specification. Other amps - being sold as pro equipment - don't give you that tolerance and it's incumbent on the user to "protect himself".
Audibility of a Zobel - not followed by a crossover - is hard to prove.
Audibility of an amp shutting down is very clear!

More later!

Cheers!
  Reply With Quote
Old 19th May 2013, 03:47 AM   #24
diyAudio Member
 
Join Date: May 2010
Location: Scottsdale, AZ
OK, guys/gals. I'm in possession of a bunch of pictures - I don't have a website, and I'm not as web-savvy as I'd like to be.
If somebody can steer me through the process, I might have some interesting (if not ground-breaking) things to share.
I have jpegs on a laptop running Win7 Home Premium, and some on a thumbdrive.
A little help here!

Thanks!

Cheers
  Reply With Quote
Old 19th May 2013, 04:18 AM   #25
JMFahey is online now JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
1) Start replying in the window below (write a couple words)
2) click [Go Advanced] ... a new window opens
3) ok, now I'm in the new window:
on top , to the right of the white face you'll see a paperclip , click the small down arrow to its right, a "manage attachments" window opens
4) it asks you to browse (find and select) the images you want to upload.
Do it one by one.
When you are done, click [Upload]
Give it a some time to upload (depends on picture file size) , and then click
[close this window]

Important: there are definite size limits per image.
Most common error is to take *huge* pictures (hey!!! I bought a 14 megabyte camera !!!) which will be rejected.
For Forum images, anything larger than , say, 1024 x 768 is a waste (unless it's a black and white schematic, with very small letters) so consider that when setting your camera to take pictures.
And if you already have them, please resize down or downsize using Photoshop or sometuing.

An image 5 times larger than the screen is an absolute waste of bandwidth and server space.
  Reply With Quote
Old 19th May 2013, 04:26 AM   #26
diyAudio Member
 
Join Date: May 2010
Location: Scottsdale, AZ
A JM: Muchas Gracias; Voy a trabajar...
  Reply With Quote
Old 19th May 2013, 05:28 AM   #27
JMFahey is online now JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
  Reply With Quote
Old 19th May 2013, 07:44 PM   #28
diyAudio Member
 
Join Date: May 2010
Location: Scottsdale, AZ
Well, I tried one image - I guess I'll try again. Obviously I did something incorrectly. This image (if - and when you get to see it! - is of the mid/hi drivers mounted on a small panel to see if/how it might work...
Attached Images
File Type: jpg IMG_2409.jpg (990.3 KB, 160 views)
  Reply With Quote
Old 19th May 2013, 07:48 PM   #29
diyAudio Member
 
Join Date: May 2010
Location: Scottsdale, AZ
Previous image: Just sitting on the chair and fed the PLUS signal from the left and right channels, respectively - the panel made some pretty spooky room-filling sound in a space about 20'X12'.
We rotated the panel 90 degrees and made two rows of five drivers each.
  Reply With Quote
Old 19th May 2013, 07:58 PM   #30
diyAudio Member
 
Join Date: May 2010
Location: Scottsdale, AZ
This panel, done in OSB, is essentially where we went with the two-row idea.
It is 29" wide by 48" long. I tried to center each row of drivers at the "Golden Mean" in each direction. Wiring is the usual "prototype messy" - but worked. This panel was taken into the sanctuary and flown behind the speech optimized loudspeaker. Eventually it was lowered to a point where it interacted with the angled side walls of the platform.
Obviously the best "activity" (stereo" is not an accurate description of the so-called imaging), is along the center of the center aisle. However, even off to the extreme front corners, where a "stereo" pair would only project the one device to which the listener is closest, there is a sensr of a Difference between what each ear perceives.
Attached Images
File Type: jpg IMG_2406.jpg (983.7 KB, 142 views)
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Edge diffraction: large, rounded baffle, or narrow square baffle fortyquid Multi-Way 23 12th February 2013 02:23 AM
Upwards aligned open baffle? ( pop box meets open baffle ) OllBoll Full Range 3 28th March 2011 01:00 AM
Hid a large open baffle low woofer bentoronto Subwoofers 2 21st September 2010 07:53 PM
Open baffle With cheap, large, low Fs car drivers bigwill Subwoofers 25 4th June 2006 12:21 PM


New To Site? Need Help?

All times are GMT. The time now is 12:06 PM.


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