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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Tim Weaver on January 01, 2013, 09:38:33 PM

Title: Interesting article about speaker directivity
Post by: Tim Weaver on January 01, 2013, 09:38:33 PM
Although this is geared towards guitar amps, the same principles would apply for any cone driver.

Part 1 http://www.tgpwebzine.com/?page_id=424
Part 2 http://www.tgpwebzine.com/?page_id=443
Title: Re: Interesting article about speaker directivity
Post by: Art Welter on January 10, 2013, 10:57:27 AM
Although this is geared towards guitar amps, the same principles would apply for any cone driver.

Part 1 http://www.tgpwebzine.com/?page_id=424
Part 2 http://www.tgpwebzine.com/?page_id=443
Tim,

The directivity modifier you linked works for widening off-axis dispersion of guitar speakers which are used "full range" by throwing away most (around 10 dB) of the on axis level above 2000 Hz.

What application of this "principle" would apply to subwoofers ?

Art
Title: Re: Interesting article about speaker directivity
Post by: chuck clark on January 11, 2013, 05:14:28 AM
The directivity modifier you linked works for widening off-axis dispersion of guitar speakers which are used "full range" by throwing away most (around 10 dB) of the on axis level above 2000 Hz.

What application of this "principle" would apply to subwoofers ?



A: Virtually none.  Since low frequencies are large (wavelengths larger than source) and the resulting dispersions of subwoofers is nearly 360 degrees it makes little or no sense to try to "widen" the dispersion of subwoofers. You can't get much wider dispersion than 360, eh? As the article states, this modifier has rapidly diminishing results below 1K Hz.
Chuck
Title: Re: Interesting article about speaker directivity
Post by: Tim Weaver on January 13, 2013, 04:30:42 PM
Tim,

The directivity modifier you linked works for widening off-axis dispersion of guitar speakers which are used "full range" by throwing away most (around 10 dB) of the on axis level above 2000 Hz.

What application of this "principle" would apply to subwoofers ?

Art
None, really. I was thinking more along the lines of a 15"/1" cabinet would see much more benefit. You could probably improve a dual 15"/2" cabinet as well.
Title: Re: Interesting article about speaker directivity
Post by: Art Welter on January 13, 2013, 07:29:09 PM
None, really. I was thinking more along the lines of a 15"/1" cabinet would see much more benefit. You could probably improve a dual 15"/2" cabinet as well.
A 1" exit driver on a 90 degree horn may be running out of steam (excursion) to cross over low enough to match a 15" dispersion at around 800 Hz. The foam dispersion modifier would work to widen the speaker's dispersion above 800 Hz, but by 2K, throws away 10 dB of level. Active EQ could be used to compensate, but needing to use 100 watts where 10 would have got the job done is not a good way to fix the problem.