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Author Topic: design question vrx jbl  (Read 7511 times)

tkroeker

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design question vrx jbl
« on: January 20, 2017, 07:38:47 PM »

I am wondering what would be the effect of stacking a pair of JBL VRX the " incorrect" direction ( i.e. ) vertical top to bottom would be twelve, horn, horn, twelve.

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Ray Aberle

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Re: design question vrx jbl
« Reply #1 on: January 20, 2017, 09:38:42 PM »

I am wondering what would be the effect of stacking a pair of JBL VRX the " incorrect" direction ( i.e. ) vertical top to bottom would be twelve, horn, horn, twelve.

.............. so on end? As opposed to using any of the integrated flygear that allows for them to be pole mounted, flown, or ground-stacked safely?!?

-Ray
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Ivan Beaver

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Re: design question vrx jbl
« Reply #2 on: January 20, 2017, 09:43:14 PM »

I am wondering what would be the effect of stacking a pair of JBL VRX the " incorrect" direction ( i.e. ) vertical top to bottom would be twelve, horn, horn, twelve.
What would be the purpose?
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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
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eric lenasbunt

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Re: design question vrx jbl
« Reply #3 on: January 20, 2017, 10:01:55 PM »

Please don't see you need more horn coupling, those horns are out of control as it is...
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David Sturzenbecher

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Re: design question vrx jbl
« Reply #4 on: January 20, 2017, 10:09:15 PM »

I am wondering what would be the effect of stacking a pair of JBL VRX the " incorrect" direction ( i.e. ) vertical top to bottom would be twelve, horn, horn, twelve.

Bad things...
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Riley Casey

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Re: design question vrx jbl
« Reply #5 on: January 20, 2017, 11:47:03 PM »

OK, here's the callous answer.  If you have to ask thats a pretty good indication that you should back off from designing a new and different speaker and simply copy ( if you want to get your wood working jollies out ) an existing designed by someone who already knows the answer to the question.  With the sources ( speakers and high frequency horns ) vertically aligned the horizontal coverage pattern will be reasonably predictable.  With the same frequencies being produced from sources offset horizontally the aggregate horizontal dispersion will be an unpredictable mess of peaks and nulls.


...I am working on some DIY mid high cabinets and was considering horns similar to their design but it would work out better to run two of them over and under instead of both vertical. "bad things " means...

Ray Aberle

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Re: design question vrx jbl
« Reply #6 on: January 21, 2017, 12:22:03 AM »

I love how the question changed once people started calling you out. Todd, you'll get better answers (and a better standing in the community) if you give us the straight story from the beginning, as opposed to some bullshit that you then recant rapidly.

-Ray
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Ivan Beaver

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Re: design question vrx jbl
« Reply #7 on: January 21, 2017, 08:18:22 AM »

OK here's why,,, I am NOT doing this with a pair of JBL VRX. I am working on some DIY mid high cabinets and was considering horns similar to their design but it would work out better to run two of them over and under instead of both vertical. "bad things " means ???

I was hoping to get a simple answer because I assumed since I never see array or similar wave guides ran that way then I shouldn't but if its just the way the manufactures just happens to be ...

I used the vrx's as an example to make it easier to picture what the question was.
Whenever you have 2 devices that are covering the same listening position, that are spaced more than 1/4 wavelength from each other at the listening position, you will get notches in the response.

This is called combfiltering. 

Here is a link to somthing I wrote many years ago about it.

http://www.dbaudioandvideo.com/files/resource/loudspeaker_placement_rev041021.pdf
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Ivan Beaver
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tkroeker

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Re: design question vrx jbl
« Reply #8 on: January 21, 2017, 03:55:25 PM »

wow...
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olakunle odebode

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Re: design question vrx jbl
« Reply #9 on: September 19, 2017, 10:41:18 AM »

Whenever you have 2 devices that are covering the same listening position, that are spaced more than 1/4 wavelength from each other at the listening position, you will get notches in the response.

This is called combfiltering. 

Here is a link to somthing I wrote many years ago about it.

http://www.dbaudioandvideo.com/files/resource/loudspeaker_placement_rev041021.pdf

Would you have a more current link to this document, cos its no longer available online?
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Riley Casey

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Re: design question vrx jbl
« Reply #10 on: September 19, 2017, 11:11:39 AM »

While waiting for Ivans update a quick google search on the term 'speaker comb filtering' will provide a lifetime of reading enjoyment.

Would you have a more current link to this document, cos its no longer available online?

Ivan Beaver

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Re: design question vrx jbl
« Reply #11 on: September 19, 2017, 12:42:50 PM »

Would you have a more current link to this document, cos its no longer available online?
The website has changed and it has been removed :(
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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
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olakunle odebode

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Re: design question vrx jbl
« Reply #12 on: September 19, 2017, 08:36:27 PM »

The website has changed and it has been removed :(

Thanks - I found it via archive.org - snapshot copy from web scans taken before it was deleted.
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drew gandy

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Re: design question vrx jbl
« Reply #13 on: September 23, 2017, 10:29:00 PM »

...With the same frequencies being produced from sources offset horizontally the aggregate horizontal dispersion will be an unpredictable mess of peaks and nulls.

Doesn't that almost describe this particular speaker even when used as intended?   :P
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Ivan Beaver

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Re: design question vrx jbl
« Reply #14 on: September 24, 2017, 08:59:50 AM »

Doesn't that almost describe this particular speaker even when used as intended?   :P
That happens with ANY loudspeaker(s) that have drivers arriving at the listeners ears at more than 1/4 wavelength apart in time.

That is why it is important to use a single source of sound, or if you use multiple cabinets, use cabinets that have large enough mouths so that they have real pattern control so the levels from the different cabinets are very different, so they don't interfere with each other.

Small horns-or narrow horns that are not LARGE, simple do NOT provide this needed pattern control
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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
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Ray Aberle

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Re: design question vrx jbl
« Reply #15 on: September 24, 2017, 11:00:17 AM »

Doesn't that almost describe this particular speaker even when used as intended?   :P
The OP wasn't actually talking specifically about VRX; he simply used that as the closest similarity to the design of speaker he wanted to build. Riley's comments, therefore, were directed specifically at the intended deployment that the OP was suggesting.

A bunch of BS & drama later, and several story changes, the OP got upset and left.

-Ray
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Re: design question vrx jbl
« Reply #15 on: September 24, 2017, 11:00:17 AM »


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