Diy line arrays!! - Page 4 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #91 of 108 Old 04-01-2014, 12:16 PM
Senior Member
 
WVSyd's Avatar
 
Join Date: Feb 2013
Posts: 333
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 42
Presuming that the resistive shading ( re post #66) is addressing aspects of pattern interference(?)

"Beware of Salesmen: They are the modern Svengali, immune to Science and Reality"
WVSyd is offline  
Sponsored Links
Advertisement
 
post #92 of 108 Old 04-01-2014, 08:14 PM
Advanced Member
 
Rick Craig's Avatar
 
Join Date: Mar 2005
Location: Garner, NC
Posts: 502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 26
Quote:
Originally Posted by WVSyd View Post

I'm guessing the Ribbons xover had an aggressive slope?

Yes - 96db is possible with the DEQX.

Selah Audio

Thinking Inside the Box...
Rick Craig is offline  
post #93 of 108 Old 04-01-2014, 08:19 PM
Bass Enabler
 
Scott Simonian's Avatar
 
Join Date: Oct 2001
Location: Clovis, CA
Posts: 13,533
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 324 Post(s)
Liked: 738
Quote:
Originally Posted by LTD02 View Post

i wonder if the comb-filtering inherent to line arrays is largely filtered out by our brains.

a typical speaker measured in a room suffers from a lot of "grass" in the high frequencies because of all the reflection-based cancellations, but I'm not sure we hear any of that.

I've always wondered that too. I'd like to think that the environment also would play quite an effect on that brain auto EQ.

My Dual 18" LLT subs 120dB down to 10hz

 

Plan9Reloaded Co-host

Listen to the Plan9Reloaded Gaming and Technology Podcast (may contain NSFW language)

https://soundcloud.com/plan9reloaded/sets/podcast - direct pod link

http://plan9reloaded.com/site/ - main website

Scott Simonian is offline  
post #94 of 108 Old 04-02-2014, 03:43 AM
AVS Special Member
 
Martycool007's Avatar
 
Join Date: Jun 2011
Posts: 3,502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 162 Post(s)
Liked: 151
Questions for the experts: how does crossover building & design on line array speakers compare to the crossover efforts on conventional 2-way or 3-way designs?
Martycool007 is offline  
post #95 of 108 Old 04-02-2014, 04:42 AM
AVS Special Member
 
Ivan Beaver's Avatar
 
Join Date: Dec 2005
Posts: 1,639
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 41
Quote:
Originally Posted by Rick Craig View Post

This new design works quite well Ivan :-)

Works "quite well" in what way?

Do you have measured data?

Danley Sound Labs

Physics-not fads
Ivan Beaver is offline  
post #96 of 108 Old 04-02-2014, 06:06 AM
Senior Member
 
WVSyd's Avatar
 
Join Date: Feb 2013
Posts: 333
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 42
Quote:
Originally Posted by Martycool007 View Post

...how does crossover building & design on line array speakers compare to the crossover efforts on conventional 2-way or 3-way designs?
With drivers aligned on an axis: The spatial offset of the drivers reduces the effective coupled bandwidth, so the HF crossover has to be lowered.
* Rick utilized an active crossover with a very high slope on a lower frequency point to allow better acoustic integration.
This slope rate could not practically be achieved with passive components.

* Disclaimer: my take on HIS approach cool.gif

"Beware of Salesmen: They are the modern Svengali, immune to Science and Reality"
WVSyd is offline  
post #97 of 108 Old 04-02-2014, 07:45 AM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,199
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 233 Post(s)
Liked: 948
ivan, i suspect that he is shooting for something like this:

http://www.xlrtechs.com/dbkeele.com/CBT.php

but in a little easier to work with form factor.


Listen. It's All Good.
LTD02 is offline  
post #98 of 108 Old 04-02-2014, 09:20 AM
Advanced Member
 
Rick Craig's Avatar
 
Join Date: Mar 2005
Location: Garner, NC
Posts: 502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 26
Quote:
Originally Posted by WVSyd View Post

Presuming that the resistive shading ( re post #66) is addressing aspects of pattern interference(?)

It helps smooth out the vertical response. Here's a link to Don Keele's AES paper for further explanation http://audioartistry.com/Papers/CBT%20Paper6%20PerformanceRankingof%20Line%20Arrays.pdf
WVSyd likes this.

Selah Audio

Thinking Inside the Box...
Rick Craig is offline  
post #99 of 108 Old 04-02-2014, 09:42 AM
Senior Member
 
WVSyd's Avatar
 
Join Date: Feb 2013
Posts: 333
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 42
Yeah Rick:
Keele's papers are an invaluable source ( downloaded and read them repeatedly cool.gif )
Didn't want to speak for you - but surmised as much;
As I recall "resistive shading" popped up on occasion in Ed Dell's mags, and Phillips experimented with it as well.

"Beware of Salesmen: They are the modern Svengali, immune to Science and Reality"
WVSyd is offline  
post #100 of 108 Old 04-02-2014, 09:57 AM
FOH
AVS Special Member
 
FOH's Avatar
 
Join Date: Apr 2010
Location: Midwest
Posts: 4,747
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 16 Post(s)
Liked: 208
Key being ... frequency invariance, that's the good stuff.

Keele is an audio giant.

I've been fortunate enough to have experienced Rick Craig's CBTs, head-to-head up against Synergies, Catalyst', and Noesis, they're great ... and a real effort to mitigate acoustic distortions imposed by the room.

------------------------------------
Flat, Deep, Clean, Linear, and Loud
------------------------------------
Active 16.8kw, 7.3 system
(3)Seaton Cat12C up front, (4)QSC K8 sides/rears
(2)Seaton SubM-HP, (4)18" IB
FOH is offline  
post #101 of 108 Old 04-02-2014, 10:24 AM
Senior Member
 
WVSyd's Avatar
 
Join Date: Feb 2013
Posts: 333
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 42
Nice...
RE: Keele selections:
#32 "Implementation of Straight-Line and Flat-Panel Constant Beamwidth Transducer (CBT) Loudspeaker Arrays Using Signal Delays,"
http://www.xlrtechs.com/dbkeele.com/PDF/Keele%20(2002-10%20AES%20Preprint)%20-%20CBT%20Paper2.pdf
Is a classic wink.gif

"Beware of Salesmen: They are the modern Svengali, immune to Science and Reality"
WVSyd is offline  
post #102 of 108 Old 04-02-2014, 01:29 PM
Advanced Member
 
Rick Craig's Avatar
 
Join Date: Mar 2005
Location: Garner, NC
Posts: 502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 26
Quote:
Originally Posted by Scott Simonian View Post

I've always wondered that too. I'd like to think that the environment also would play quite an effect on that brain auto EQ.

We can measure many things but sometimes it's difficult to define how audible the results are. This kind of falls into that category.

Selah Audio

Thinking Inside the Box...
Rick Craig is offline  
post #103 of 108 Old 04-02-2014, 01:44 PM
Advanced Member
 
Rick Craig's Avatar
 
Join Date: Mar 2005
Location: Garner, NC
Posts: 502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 26
Quote:
Originally Posted by Ivan Beaver View Post

Works "quite well" in what way?

Do you have measured data?

I've been taking measurements and hop to have everything done in a week or less. I'm not sure if you know but I've worked with Don Keele on some CBT array designs including the largest one ever built
I understand that with pro sound being your main focus that you're often bidding on jobs where others are suggesting line arrays. All speakers have their limitations, regardless of the design - it's just a matter of what tradeoffs you want to make (or what the room dictates). I have heard commercial arrays that sound very good as well as not so good. The same is true with more conventional horn systems and also Danley designs.

Selah Audio

Thinking Inside the Box...
Rick Craig is offline  
post #104 of 108 Old 04-02-2014, 02:00 PM
Senior Member
 
WVSyd's Avatar
 
Join Date: Feb 2013
Posts: 333
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 42
Quote:
I have heard commercial arrays that sound very good as well as not so good.
So have I - In a couple of cases it was the fault of the operator.
Sometimes one hears a bad review of a system and has an opportunity to hear it in real life, and finds that reviews are not the fault of the system but the failure of the installer/operator.

"Beware of Salesmen: They are the modern Svengali, immune to Science and Reality"
WVSyd is offline  
post #105 of 108 Old 04-02-2014, 07:21 PM
Advanced Member
 
Rick Craig's Avatar
 
Join Date: Mar 2005
Location: Garner, NC
Posts: 502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 26
Quote:
Originally Posted by Martycool007 View Post

Questions for the experts: how does crossover building & design on line array speakers compare to the crossover efforts on conventional 2-way or 3-way designs?

It really depends on the design - some are more difficult and others less complicated.

Selah Audio

Thinking Inside the Box...
Rick Craig is offline  
post #106 of 108 Old 04-10-2014, 09:22 AM
Advanced Member
 
Rick Craig's Avatar
 
Join Date: Mar 2005
Location: Garner, NC
Posts: 502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 26
Here are some of the initial measurements of the Lineoceros. I'm using a DEQX for the crossover but have not applied the room correction.




Scott Simonian likes this.

Selah Audio

Thinking Inside the Box...
Rick Craig is offline  
post #107 of 108 Old 04-11-2014, 05:08 AM
AVS Special Member
 
Martycool007's Avatar
 
Join Date: Jun 2011
Posts: 3,502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 162 Post(s)
Liked: 151
Quote:
Originally Posted by WVSyd View Post

With drivers aligned on an axis: The spatial offset of the drivers reduces the effective coupled bandwidth, so the HF crossover has to be lowered.
* Rick utilized an active crossover with a very high slope on a lower frequency point to allow better acoustic integration.
This slope rate could not practically be achieved with passive components.

* Disclaimer: my take on HIS approach cool.gif

So you are saying that the space between the drivers, (mid-range or tweeters?) reduces the way the mids and tweeters couple or sum in certain areas of the bandwidth? So the lower the frequency that you crossover the tweeters to the mid-range drivers, the better they will couple or sum to form one wide pattern of sound that the listener perceives as one complete & cohesive sounding speaker? Do I have the basic theory right or am I way off in left field? How does having the HF's crossed over lower affect the coupled bandwidth?

So being that the tweeters have to be crossed so low, is this the reason for the ultra high slope used in the active crossover? If I understand correctly, with a 96db slope crossed at 1200hz the tweeters would be 96db's down at one octave below that at 600hz, thus saving the tweeter from playing lower than it's intended, and keeping the SQ clean with reduced distortion as you would normally have with a tweeters crossover slope being higher at say 6db or 12db. Do I have this part correct as well?
Martycool007 is offline  
post #108 of 108 Old 04-11-2014, 06:22 AM
Senior Member
 
WVSyd's Avatar
 
Join Date: Feb 2013
Posts: 333
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 42
You are one the right track in both paragraphs:
The key phrase is "mutual coupling"
See if you use Google Books to get to page 78,79 of
Electroacoustical Reference Data
By John Eargle
Acoustic Summation is not an easy concept to convey
However mutual coupling is a concept in optics and electronics and radio/microwave communication.


http://hyperphysics.phy-astr.gsu.edu/hbase/audio/spk.html
http://www.bnoack.com/index.html?http&&&www.bnoack.com/audio/mutualcoupling.html
http://www.zainea.com/mutualcoupling.htm

"Beware of Salesmen: They are the modern Svengali, immune to Science and Reality"
WVSyd is offline  
Reply DIY Speakers and Subs

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

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