Hey guys, so im having a bot o a problem explaining WHY we use par flares instead of con to represent most basshorns that are actually built/folded.
Ive hit multiple threads that highlight the par recomedation (post from lilmike, tb46, and others), but few people actually get into WHY we use PAR flares. Can anyone shine some light on this?
Ive attached a pic of how things should he in my mind, but im unsure if thats correct.
Ive hit multiple threads that highlight the par recomedation (post from lilmike, tb46, and others), but few people actually get into WHY we use PAR flares. Can anyone shine some light on this?
Ive attached a pic of how things should he in my mind, but im unsure if thats correct.
Attachments
Hi sine143,
I think you got it correct in your sketches; generally, for Par v. Con see Post #1328:
http://www.diyaudio.com/forums/subwoofers/97674-collaborative-tapped-horn-project-133.html
That's in the middle of the respective discussion.
Regards,
I think you got it correct in your sketches; generally, for Par v. Con see Post #1328:
http://www.diyaudio.com/forums/subwoofers/97674-collaborative-tapped-horn-project-133.html
That's in the middle of the respective discussion.
Regards,
so, a synergy style horn would be regarded as a CON flare, as shown in the pic below, and a bass horn (just about any of them) would be multiple PAR flares correct?
Still got people trying to tell me a basshorn is Oblique CON flares....
Still got people trying to tell me a basshorn is Oblique CON flares....
Attachments
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Correct x2.
Never heard of an oblique conical flare and couldn't find it in a quick Google search except as an oblique cut through a cone, but if the horn was expanding at other than a parabolic flare, say exponential, then the sum of the differing parabolic flares may be one, though I’m not seeing it. Mathematically this is too far over by head, so hopefully one the higher math and/or geometry whizzes will chime in.
Regardless, the name conjures up cutting a Synergy horn at an oblique angle, which the parallel wall with a straight divider board horns usually discussed here clearly aren't.
GM
Never heard of an oblique conical flare and couldn't find it in a quick Google search except as an oblique cut through a cone, but if the horn was expanding at other than a parabolic flare, say exponential, then the sum of the differing parabolic flares may be one, though I’m not seeing it. Mathematically this is too far over by head, so hopefully one the higher math and/or geometry whizzes will chime in.
Regardless, the name conjures up cutting a Synergy horn at an oblique angle, which the parallel wall with a straight divider board horns usually discussed here clearly aren't.
GM
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Hi sine143,
Post #3: "... synergy style horn would be regarded as a CON flare..."
yes, designs like the SH60 are conical horns.
When you look at many of the horns in question you can see that there is often more than one flare. E.g.: in jbell's SS15 you have a number of Par section adding up to an app. exponential horn (for the overall flare rate). Or, many of the synergy horn designs look to me to be overall exponential even though the individual sections are conical horns.
I have never heard of "Oblique CON flares" in the context of loudspeakers, so I have no opion on the subject.
Regards,
Post #3: "... synergy style horn would be regarded as a CON flare..."
yes, designs like the SH60 are conical horns.
When you look at many of the horns in question you can see that there is often more than one flare. E.g.: in jbell's SS15 you have a number of Par section adding up to an app. exponential horn (for the overall flare rate). Or, many of the synergy horn designs look to me to be overall exponential even though the individual sections are conical horns.
I have never heard of "Oblique CON flares" in the context of loudspeakers, so I have no opion on the subject.
Regards,
Hi sine143,
A Par flare is used in the simulations because the cross-sectional area of an axisymmetric Par profile horn changes at a linear rate, the same as for a rectangular cross-section horn having two parallel straight sides and two sloping straight sides.
(The cross-sectional area of an axisymmetric Con profile horn changes at a non-linear rate).
Kind regards,
David
'Par' flare = parabolic, the horn width is proportional to an expression involving the square root of x. The cross sectional area (pi * horn radius squared) is a linear equation involving x. It is a parabloid turned on its side.
'Con' flare = conical, the walls increase linearly, so the cross sectional area increases in proportion with x^2.
If you're building a bass horn with two parallel walls and straight expanding sections, then two walls increase linearly and two walls stay the same width. This means that the cross sectional area increases linearly so you want the Parabolic flare.
The easiest way to visualise it is the difference between a section of a cylinder (a slice of cake) and a solid angle section of a sphere.
'Con' flare = conical, the walls increase linearly, so the cross sectional area increases in proportion with x^2.
If you're building a bass horn with two parallel walls and straight expanding sections, then two walls increase linearly and two walls stay the same width. This means that the cross sectional area increases linearly so you want the Parabolic flare.
The easiest way to visualise it is the difference between a section of a cylinder (a slice of cake) and a solid angle section of a sphere.
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