Hornresp

[David McBean]

Then why have the EXP, CON, & PAR segment options if 99% of BUILT models are for rectangular enclosures?

Con is used to model a conical flare horn segment. See Attachment 1 for examples of conical horns.

Exp is used to model an exponential flare horn segment. See Attachment 2 for examples of exponential horns.

Par (parabolic flare) is used to model a rectangular cross-sectional area horn segment having two parallel straight sides and two sloping straight sides.

Other available horn flares are:

Bes - Bessel
Hyp - Hyperbolic-exponential
Lec - Le Cléac'h
Obl - Oblate spheroidal
Rad - Radius
Sph - Spherical wave
Tra - Tractrix

 

[David McBean]

Could I just expect to use this port in the BP6 enclosure and achieve the same tuning and response as before, just with lower port compression?

The results will be a little different because the simulation uses horn segments to specify the flared port, meaning that the internal end correction is not taken into account.

 

[Kravchenko_Audio]

Hornresp models the port tube as a cylinder, open at both ends. Each end can be flanged or unflanged.

Flanged end correction = 8 / (3 * Pi) * Rp
Unflanged end correction = 0.1952 * Pi * Rp

Where Rp = port tube radius

In the BP6S example used previously:

Ap1 = 800 cm^2
Ap2 = 200 cm^2

The Ap1/Lp1 port tube is shown highlighted in yellow in Attachment 1. One end is flanged and the other is unflanged. Because the radiation impedance is known at the flanged end, no correction is required at that point.

The correction at the internal unflanged end is:

0.1952 * Pi * (800 / Pi) ^ 0.5 = 9.79 cm

Total end correction for the Ap1/Lp1 port tube is 9.79 cm

The Ap2/Lp2 port tube is shown highlighted in yellow in Attachment 2. One end is flanged and the other is unflanged.

The correction at the flanged end is:

8 / (3 * Pi) * (200 / Pi) ^ 0.5 = 6.773 cm

The correction at the unflanged end is:

0.1952 * Pi * (200 / Pi) ^ 0.5 = 4.893 cm

Total end correction for the Ap2/Lp2 port tube is 6.773 + 4.893 = 11.67 cm

By double-clicking on the Lp2 slider label in the loudspeaker wizard the internal port tube Ap2/Lp2 can be changed from the default flanged/unflanged to unflanged/unflanged as shown in Attachment 3. The end corrections are adjusted accordingly.

Do we get a physical description of the flange? Width? Angle? Depth? I have read obout flanges and corrections for 40 years. Never seen numbers. I generally do a large round over or thumbnail profile. I guess a chamfer could also work.

 

[stv]

description of the flange

As far as i know it's just a flat (no roundover) flange. E.g. a tube flush mounted to enclosure in contrast to a tube protruding into (out of) the box.

 

[BP1Fanatic]

Con is used to model a conical flare horn segment. See Attachment 1 for examples of conical horns.

Exp is used to model an exponential flare horn segment. See Attachment 2 for examples of exponential horns.

Par (parabolic flare) is used to model a rectangular cross-sectional area horn segment having two parallel straight sides and two sloping straight sides.

Other available horn flares are:

Bes - Bessel
Hyp - Hyperbolic-exponential
Lec - Le Cléac'h
Obl - Oblate spheroidal
Rad - Radius
Sph - Spherical wave
Tra - Tractrix

You didn't post a PAR enclosure because 99% of builds have 2 parallel straight sides. If anything, HR should default to PAR and the modeler would have to switch to the other horn profiles if they are going to build a non-PAR enclosure.

 

[Speedysteve7]

Con is used to model a conical flare horn segment. See Attachment 1 for examples of conical horns.

Exp is used to model an exponential flare horn segment. See Attachment 2 for examples of exponential horns.

Par (parabolic flare) is used to model a rectangular cross-sectional area horn segment having two parallel straight sides and two sloping straight sides.

Other available horn flares are:

Bes - Bessel
Hyp - Hyperbolic-exponential
Lec - Le Cléac'h
Obl - Oblate spheroidal
Rad - Radius
Sph - Spherical wave
Tra - Tractrix

Wow, not every day you get a picture ref by David of something you've created🙂

I of course used Hornresp👍 to model them and get the curve data etc.

 

[Kravchenko_Audio]

As far as i know it's just a flat (no roundover) flange. E.g. a tube flush mounted to enclosure in contrast to a tube protruding into (out of) the box.

You may be right. That is not a great way to terminate a port. But it is a way to terminate a port.

 

[David McBean]

Do we get a physical description of the flange? Width? Angle? Depth? I have read obout flanges and corrections for 40 years. Never seen numbers.

The generally-accepted standard end correction formulas (as used in Hornresp) assume that a flanged tube terminates in an infinite baffle, and that the end of an unflanged tube is free.

 

[David McBean]

You didn't post a PAR enclosure because 99% of builds have 2 parallel straight sides.

I didn't post a Par enclosure example because you queried the need for the Con and Exp options, not for the remaining Par option. I assumed that you already understood the need for the Par flare because you had stated that "99% of BUILT models are for rectangular enclosures".

If anything, HR should default to PAR

There are not many cases in Hornresp where the segment flare type is automatically specified by the program, so the concept of having a default flare does not generally apply. One example of the flare being set by Hornresp however is when a paraflex horn template is created using the Input Wizard and conical segments are specified. Conical segments are used simply because given the options of Con, Exp or Par, Con is the first alphabetically and there is no certainty that the built system will use parabolic segments anyway. It is left up to the user to alter the flare in the simulation model as necessary. Making Par the default flare profile anywhere in the program, is not going to happen.

 

[David McBean]

Hornresp Update 5540-240429

Hi Everyone,

BUG FIX 1

The system volume for offset driver BP6S and BP6P loudspeakers was not always shown to three decimal places on the schematic diagram. This has now been fixed.

BUG FIX 2

When the L12 value for a stepped segment PH or TH loudspeaker was changed in the loudspeaker wizard the S2 value was copied to S2S and the S4 value was copied to S4S. This problem along with a number of other similar related issues has now been resolved.

My thanks to Bluewoldemort for reporting the bug in Post #14,622.

Kind regards,

David

 

[Kolbrek]

You didn't post a PAR enclosure because 99% of builds have 2 parallel straight sides. If anything, HR should default to PAR and the modeler would have to switch to the other horn profiles if they are going to build a non-PAR enclosure.

Having two parallel straight sides does not automatically qualify as being a PAR segment. If the two other sides (given a rectangular cross section) are also parallel, it doesn't matter what kind of segment is specified, because they all behave like straight tubes in that case. If the two non-parallel sides are straight and expanding, the segment will be PAR, but if they expand in a more complex way (i.e. not straight lines), the shape will be CON, BES etc.

 

[BP1Fanatic]

I didn't post a Par enclosure example because you queried the need for the Con and Exp options, not for the remaining Par option. I assumed that you already understood the need for the Par flare because you had stated that "99% of BUILT models are for rectangular enclosures".



There are not many cases in Hornresp where the segment flare type is automatically specified by the program, so the concept of having a default flare does not generally apply. One example of the flare being set by Hornresp however is when a paraflex horn template is created using the Input Wizard and conical segments are specified. Conical segments are used simply because given the options of Con, Exp or Par, Con is the first alphabetically and there is no certainty that the built system will use parabolic segments anyway. It is left up to the user to alter the flare in the simulation model as necessary. Making Par the default flare profile anywhere in the program, is not going to happen.

No built paraflex enclosure has a horn section that look like the CONical picture below.

I was not asking you to change the default horn profile. However, it would help new HR users learn the difference between what is modeled and what is built. It also prevents folks from accusing HR for their built enclosure not measuring right.

Good thing Filter Wizard doesn't default to Bessel! Bessel is before Butterworth alphabetically.

 

[BP1Fanatic]

Having two parallel straight sides does not automatically qualify as being a PAR segment. If the two other sides (given a rectangular cross section) are also parallel, it doesn't matter what kind of segment is specified, because they all behave like straight tubes in that case. If the two non-parallel sides are straight and expanding, the segment will be PAR, but if they expand in a more complex way (i.e. not straight lines), the shape will be CON, BES etc.

No CONical horn profile has parallel walls. ALL square and rectangular enclosures are parabolic due to the 2 parallel sides.

B and C are the only 2 horn profiles that can be folded into a square or rectangle.

B & C = PARabolic.