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Horn Basics [message #44367 is a reply to message #44366]

Mon, 12 April 2004 01:01

Wayne Parham
Messages: 18678
Registered: January 2001

Illuminati (33rd Degree)

http://www.pispeakers.com/Midhorn_rendered.gif

Computer Model of π Midrange Horn

It's been a long time coming, but now I've got a pretty good design nailed down. It is inexpensive and extremely simple to build. And we will be offering them complete or in flat-pack kit form which makes them even easier to build.

http://www.pispeakers.com/Midhorn_front.jpg

Front View of Maple π Midrange Horn

Horn Basics

The horn covers the 200Hz to 2kHz band and has 105dB/W/M sensitivity. Maximum power is 300 WRMS, so maximum SPL is over 125dB. Actual response depends on placement, but it is intended primarily as a midrange horn subsystem for three-way (and four-way) π cornerhorns, so corner placement is normal. In this application, the horn is smooth down to below 200Hz, almost to 150Hz.

http://www.pispeakers.com/seven_Pi_with_midhorn.jpg

Seven π cornerhorn with midrange horn and Martinelli tweeter horn

Response is good to 2kHz, and then drops about 5dB and remains at this reduced shelf for almost an octave, to 3.5kHz. This is due largely to breakup modes in the driver. Both the Eminence Delta 10 and the JBL 2012 have rising response that peaks in the region above 2kHz. What occurs here is that the cone begins to flex making ripples in the surface of the cone. These cone surface movements are decoupled from the heavier moving assemblies so it's like having another much lighter cone driving the horn. This makes a second area of response that increases output from the horn above 1kHz.

In some applications, this output can be used making the horn capable of output to 3500Hz. Other applications will want to rolloff the region above 2kHz, and I've found that this can be done with a simple 1mH series coil. This is the same "Pseudo Butterworth" arrangement I've used in the past, and the addition of a 1mH coil does very little to affect horn response below 2kHz. It just shaves the peak between 2kHz and 4kHz, attenuating that region and preventing it from increasing horn output in this range.

Here are the plans:

http://www.pispeakers.com/Midrange_Horn_Page1.gif

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[Message index]

		Midrange Horn By: Wayne Parham on Mon, 12 April 2004 01:00
		Horn Basics By: Wayne Parham on Mon, 12 April 2004 01:01
		Cabinets By: Wayne Parham on Mon, 12 April 2004 01:02
		Implementation By: Wayne Parham on Mon, 12 April 2004 01:03
		Re: Implementation By: Adrian Mack on Mon, 12 April 2004 03:08
		Re: Implementation By: Wayne Parham on Mon, 12 April 2004 03:39
		Re: Implementation By: Adrian Mack on Mon, 12 April 2004 05:00
		Re: Implementation By: Wayne Parham on Mon, 12 April 2004 06:17
		Re: Implementation By: Adrian Mack on Mon, 12 April 2004 06:51
		Re: Implementation By: Adrian Mack on Mon, 12 April 2004 18:03
		Re: Implementation By: Wayne Parham on Mon, 12 April 2004 21:11
		funny old woofers By: Mike.e on Mon, 12 April 2004 20:53
		Re: funny old woofers By: Bill Wassilak on Tue, 13 April 2004 10:13
		Re: Implementation By: Wayne Parham on Fri, 16 April 2004 11:00
		Re: Implementation By: Adrian Mack on Fri, 16 April 2004 18:30
		Re: Implementation By: Wayne Parham on Fri, 16 April 2004 18:39
		Re: Implementation By: GarMan on Tue, 13 April 2004 11:22
		Re: Implementation By: Wayne Parham on Wed, 14 April 2004 08:38
		eight π By: Wayne Parham on Mon, 12 April 2004 01:04
		How about the Beta 10CX By: JLapaire on Mon, 12 April 2004 10:44
		Re: How about the Beta 10CX By: Wayne Parham on Mon, 12 April 2004 16:53
		Dimensions By: JLapaire on Tue, 13 April 2004 06:31
		Re: Dimensions By: Wayne Parham on Tue, 13 April 2004 16:21
		Re: eight π By: wasteh202 on Wed, 02 June 2004 22:11
		Re: eight π By: Wayne Parham on Fri, 11 June 2004 09:42
		Re: Midrange Horn By: dwkurfma on Wed, 14 April 2004 11:46
		Re: Midrange Horn By: Adrian Mack on Wed, 14 April 2004 18:00
		Re: Midrange Horn - Thanks! n/t By: dwkurfma on Wed, 14 April 2004 20:59
		7PI midrange horn angle By: hornT on Tue, 09 March 2010 15:01
		Re: 7PI midrange directivity By: Wayne Parham on Tue, 09 March 2010 15:20
		Re: 7PI midrange directivity By: hornT on Wed, 10 March 2010 01:36
		Re: Midrange Horn By: danielm on Sat, 03 April 2010 08:56
		Re: Midrange Horn By: Wayne Parham on Sat, 03 April 2010 09:19
		Re: Midrange Horn By: danielm on Sat, 03 April 2010 10:16
		Re: Midrange Horn By: Wayne Parham on Sat, 03 April 2010 16:21
		Re: Midrange Horn By: danielm on Sat, 03 April 2010 18:23
		Re: Midrange Horn By: Wayne Parham on Sat, 03 April 2010 19:47
		Re: Midrange Horn By: tom-m on Sun, 04 April 2010 20:04
		Re: Midrange Horn By: Wayne Parham on Sun, 04 April 2010 20:43
		Re: Midrange Horn By: tom-m on Tue, 11 May 2010 22:26
		Re: Midrange Horn By: Wayne Parham on Mon, 19 July 2010 20:13
		MID HORN FLAT PACK By: biglaz on Thu, 02 September 2010 12:23
		Re: MID HORN FLAT PACK By: Wayne Parham on Thu, 02 September 2010 13:28
		Midhorn Flat Pack Tips By: Bane2871 on Wed, 24 August 2011 13:29
		Re: Midhorn Flat Pack Tips By: Wayne Parham on Wed, 24 August 2011 13:37
		Re: Midhorn Flat Pack Tips By: Bane2871 on Wed, 24 August 2011 16:56
		Re: Midhorn Flat Pack Tips By: Wayne Parham on Wed, 24 August 2011 17:02
		Re: Midrange Horn By: Bane2871 on Fri, 26 August 2011 17:28
		Re: Midrange Horn By: Wayne Parham on Fri, 26 August 2011 18:09
		Re: Midrange Horn By: djnagle on Fri, 24 February 2012 11:58
		Re: Midrange Horn By: Wayne Parham on Fri, 24 February 2012 12:47
		Re: Midrange Horn By: cookiemonster on Fri, 06 September 2013 16:16
		Re: Midrange Horn By: Wayne Parham on Fri, 06 September 2013 20:35
		Re: Midrange Horn By: cookiemonster on Mon, 09 September 2013 07:49
		Re: Midrange Horn By: Wayne Parham on Mon, 09 September 2013 08:29
		Re: Midrange Horn By: petew on Mon, 09 September 2013 15:04
		Re: Midrange Horn By: Wayne Parham on Mon, 09 September 2013 18:00