Hornresp

[David McBean]

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[David McBean]

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Just to clarify - my smiley above was in response to Dix's Post #8300.

I included copy of his message in my original post, but it seems to have disappeared overnight. How strange.

 

[David McBean]

You can view it this way: the acoustic load on, say, a diaphragm, is the ratio of pressure on the diaphragm to the velocity of the diaphragm.

Further to Bjørn's comments, in case anyone was wondering why the above should be so, it can be considered as simply Ohm's Law at work, but applied in an acoustical sense.

Ohms Law:

V = I * R

Rearranged:

R = V / I

Where:

R = Electrical resistance
V = Electrical voltage
I = Electrical current

If V and I are complex values (i.e. each having real and imaginary components) then resistance R becomes electrical impedance Ze.

The acoustical equivalent to electrical voltage V is sound pressure p, and the acoustical equivalent to electrical current I is volume velocity U, so that the acoustical equivalent to Ze = V / I is Za = p / U, where Za is acoustical impedance. For the driver diaphragm, U = u * Sd where u = velocity of the diaphragm, so that:

Za = p / (u * Sd)

To complete the picture:

The mechanical equivalent to electrical voltage V is force f, and the mechanical equivalent to electrical current I is velocity u, so that the mechanical equivalent to Ze = V / I is Zm = f / u, where Zm is mechanical impedance. For the driver diaphragm, f = p * Sd where p = pressure on the diaphragm, so that:

Zm = p * Sd / u

Therefore:

Zm = Za * Sd ^ 2

 

[jazbo8]

Just to clarify - my smiley above was in response to Dix's Post #8300.

I included copy of his message in my original post, but it seems to have disappeared overnight. How strange.

David - it's not necessary nor desirable to quote the post directly above yours. Please see the Forum Rules and notes for the details.

 

[David McBean]

Many thanks jazbo8, for clarifying the mystery for me.

I will brush up on the Forum Rules and notes as suggested, and try not to transgress again .

 

[USRFobiwan]

David is it possible to allow more than 8 chars on the creation of a new *.dat file. I want to put more info in the text.

 

[David McBean]

Hi USRFobiwan,

User-created *.dat files can have names up to 16 characters in length.

Kind regards,

David

 

[Brian Steele]

Hi David, what's the possibility of having an option for the OD type sim(say, "OD1") that has the driver positioned at S3 instead of S2?

I'm trying to model the layout shown in the diagram, which requires the driver be positioned at S3 in an offset-driver sim in Hornresp.


If it's TOO much trouble, don't worry about it.

 

[David McBean]

Hi Brian,

Unfortunately it would require a lot of work to implement. Another one for AkAbak it seems .

Kind regards,

David

 

[David McBean]

Hi Brian,

Further to my message above, despite the significant amount of work involved and the likelihood that the feature will get minimal use (it has taken this long for someone to request it), I can't resist implementing the OD1 functionality in Hornresp .

I am not sure how long it will take, though.

Kind regards,

David

 

[Brian Steele]

That's great news, thanks. I was thinking that perhaps moving the driver position to another segment of the horn might not be that difficult to do, as it was done with the newly-added "CH1" option .

With this particular fold, I'm trying to address one of the shortcomings, i.e. the driver ended up being in the wrong position for a perfect offset. By putting the driver at S3 and modifying the expansion/shape of S1-S2, it might be possible to address this. Being able to sim it will show if that's really possible.

 

[Kravchenko_Audio]

More people use the obscure parts of Hornresp than you might know. We just don't post to much about it!

 

[epa]

Hi David, what's the possibility of having an option for the OD type sim(say, "OD1") that has the driver positioned at S3 instead of S2?

I'm trying to model the layout shown in the diagram, which requires the driver be positioned at S3 in an offset-driver sim in Hornresp.


If it's TOO much trouble, don't worry about it.

good one
tnx david

 

[David McBean]

I was thinking that perhaps moving the driver position to another segment of the horn might not be that difficult to do, as it was done with the newly-added "CH1" option .

Hi Brian,

Adding the CH1 option was also major exercise . It is not that difficult modifying the simulation model itself - it is everything else that needs to be done to fully integrate the new feature, that takes up most of the time.

Kind regards,

David

 

[Sabbelbacke]

very nice addition, looking forward to it!

 

[USRFobiwan]

Hi USRFobiwan,

User-created *.dat files can have names up to 16 characters in length.

Kind regards,

David

Let me 'rephrase' the question:. more than 16 chars, for example 256 chars.

 

[David McBean]

Hornresp Update 4500-180601

Hi Everyone,

CHANGE

Offset driver horns can now have the driver offset point at either S2 (using the OD option) or at S3 (using the OD1 option). Attachments 1 and 2 refer.

Just out of interest I kept track of the number of coding changes required to fully integrate this new "minor" feature. Changes were made to 141 different parts of the program. Nothing is ever as simple as it might seem .

BUG FIX 1

When the Response, Index, Beam Width and Polar Map directivity tools were used with a spherical wave (Sph) horn loudspeaker system, a fatal "Subscript out of range" run-time error would be generated. Attachment 3 refers.

BUG FIX 2

Under certain conditions the Loudspeaker Wizard was not being disabled for Hyp, Lec, Obl, Rad, Sph and Tra horns. Attachment 4 refers.

BUG FIX 3

Under certain conditions the Multiple Entry Horn Wizard could be accessed from other than the Input Parameters window. Attachment 5 refers.

BUG FIX 4

The Edit button was not being disabled when the Add button was used to copy an existing invalid record. The Edit button was enabled even though the added record was already in edit mode. Attachment 6 refers.

These four bugs have now been fixed.

NEW KNOWN PROBLEM

I have been advised that the Hornresp Help file will not display correctly if the monitor used has a screen resolution of 2560 x 1440 pixels. Some words or parts of words are shown twice. Attachment 7 refers.

Unfortunately my monitor is limited to a maximum screen resolution of 1600 x 900 pixels, so I cannot observe the problem for myself.

Kind regards,

David

 

[David McBean]

Let me 'rephrase' the question:. more than 16 chars, for example 256 chars.

It's not going to happen .

 

[Brian Steele]

Hi Everyone,

CHANGE

Offset driver horns can now have the driver offset point at either S2 (using the OD option) or at S3 (using the OD1 option). Attachments 1 and 2 refer.

Just out of interest I kept track of the number of coding changes required to fully integrate this new "minor" feature. Changes were made to 141 different parts of the program. Nothing is ever as simple as it might seem .

**Only** 141 different parts? Not that difficult then . Thanks! I'm going to resume work on that OD1 workbook today, and perhaps spend some time on the W-bin one if I get the chance.

Thanks again,
B.

 

[BP1Fanatic]

Unfortunately my monitor is limited to a maximum screen resolution of 1600 x 900 pixels, so I cannot observe the problem for myself.

Kind regards,

David

We need to get you a HDR monitor!