Cardioid with a TH sub - Page 3

Djim · 08:17 PM

Hi Art,

I said "The acoustic centre in a basreflex is in or near the back of the cab". Your example of the cone position (normally its just a couple of cm behind the cone) is considered to be IN the cab. Yes, there are other examples of basreflex where the acoustic centre is positioned at the back of the cab or even just outside the back. Generally speaking, for basreflex it stays close to the centre where you aspect it to be, which is different from horns or TH's.

The reason TH's have a better directivity pattern above their 1/2WL compared to FLH with the same frontal area size is because of the difference between true horn directivity and reflection from the TH front. The same theories still work for both situations and TH's don't have 'special forces' that are different from other systems.

We sometimes don’t agree, but it looks like we actually do agree about this subject

FlipC · 4th February 2012, 09:32 AM

jbell - not I dont have the room etc for that.
Scenario is as follows:
12' from back wall. Trussing with 4 post. Each of the 3 sections is 9' (give or take an inch) I can use all 3 sections. Thinking about it now I dont see why I cant be right against the front of the trussing ... Normally I'm in between the outer 2 due to the LA located there. Maybe I will use some extra straps and strap them to the trussing itself.

And Danley replied that I should treat it as a normal speaker
when doing the math.

jbell · 4th February 2012, 04:52 PM

Quote:

Originally Posted by FlipC

jbell - not I dont have the room etc for that.

How about this... and delay the outer 2 stacks by a couple milliseconds. That might do the trick.

FlipC · 4th February 2012, 08:03 PM

That is on the lines of what I have been working on in the sims Im doing.
Though being messing with delta style array layout trying to get the DJ area a reduction in SPL. (even with the already -10db rear. At 125-135 db (at that location) all night is very tiring. Something close to a heart shape is what I'm going for I reckon.

When siming the above.
Should you treat that as 4 cabs and align from center points?

3rd February 2012, 08:11 PM	#21
Djim diyAudio Member Join Date: Dec 2009 Location: 'Ollanda	Hi Art, I said "The acoustic centre in a basreflex is in or near the back of the cab". Your example of the cone position (normally its just a couple of cm behind the cone) is considered to be IN the cab. Yes, there are other examples of basreflex where the acoustic centre is positioned at the back of the cab or even just outside the back. Generally speaking, for basreflex it stays close to the centre where you aspect it to be, which is different from horns or TH's. The reason TH's have a better directivity pattern above their 1/2WL compared to FLH with the same frontal area size is because of the difference between true horn directivity and reflection from the TH front. The same theories still work for both situations and TH's don't have 'special forces' that are different from other systems. We sometimes don’t agree, but it looks like we actually do agree about this subject Last edited by Djim; 3rd February 2012 at 08:17 PM.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Cardioid Bass	CLS	Multi-Way	312	4th May 2012 08:46 PM
2-way: Waveguide + Cardioid-like	keyser	Multi-Way	126	19th December 2011 10:18 PM
Adventures in cardioid	MBK	Multi-Way	120	13th September 2010 08:14 PM
cardioid design?	Nappylady	Multi-Way	6	24th January 2004 09:07 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	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

4th February 2012, 09:32 AM	#22
FlipC diyAudio Member Join Date: Aug 2008	jbell - not I dont have the room etc for that. Scenario is as follows: 12' from back wall. Trussing with 4 post. Each of the 3 sections is 9' (give or take an inch) I can use all 3 sections. Thinking about it now I dont see why I cant be right against the front of the trussing ... Normally I'm in between the outer 2 due to the LA located there. Maybe I will use some extra straps and strap them to the trussing itself. And Danley replied that I should treat it as a normal speaker when doing the math.

4th February 2012, 08:03 PM	#24
FlipC diyAudio Member Join Date: Aug 2008	That is on the lines of what I have been working on in the sims Im doing. Though being messing with delta style array layout trying to get the DJ area a reduction in SPL. (even with the already -10db rear. At 125-135 db (at that location) all night is very tiring. Something close to a heart shape is what I'm going for I reckon. When siming the above. Should you treat that as 4 cabs and align from center points?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)