Hornresp

[David McBean]

New Hornresp Website

Hi Everyone,

Further to Post #591, Hornresp can now be found at:

www.dmcbean.bigblog.com.au

The latest release is Product Number 2320-090929.

Please note:

1. The new site takes longer to display.

2. A number string is automatically added to the Setup.exe filename.

3. Any premature termination problems experienced when downloading Setup.exe over a dial-up connection should be reported to:

dmcbean@bigpond.com

Kind regards,

David

 

[Sabbelbacke]

Thanx david for the news update.

@all with dial-ups

try using a download-manager (getright, "free-download-manager", etc...) or the proxy of your ISP in case you experience download problems (in generall, not only in this case).

 

[thend]

Hi Oliver,

Excellent .

Just to illustrate Jean-Michel’s point regarding reflected waves, for a thin cylindrical horn having a length of 244 cm, impulses can be seen at:

(1 x 244 + 100) / 34400 x 1000 = 10.00 msec (+ve phase)

(3 x 244 + 100) / 34400 x 1000 = 24.19 msec (-ve phase)

(5 x 244 + 100) / 34400 x 1000 = 38.37 msec (+ve phase)

(7 x 244 + 100) / 34400 x 1000 = 52.56 msec (-ve phase)

(9 x 244 + 100) / 34400 x 1000 = 66.74 msec (+ve phase)

as shown in Test1.jpg attached.

Kind regards,

David

The simulation seems to be good, the reversal of phase come from the closed side of the tube, ie the side of the compression driver.
Each time, the sound is inverted when it's reflected by the compression driver.

 

[thend]

The simulation seems to be good, the reversal of phase come from the closed side of the tube, ie the side of the compression driver.
Each time, the sound is inverted when it's reflected by the compression driver.

However, my measure does not show a pure reversal of phase.

I think because the membrane is reactive, so phase shift depending frequency, like a filter (it's the same thing).

(For the closed tube measure, I used a marble piece)

 

[David McBean]

try using a download-manager (getright, "free-download-manager", etc...).

Hi Sabbelbacke,

Many thanks for this!

After installing a copy of Free Download Manager (Light) Version 3.0, I now find that I can download Hornresp over my dial-up connection with no problems at all.

Once again, you have proved to be "worth your weight in gold". Thank you.

Kind regards,

David

 

[David McBean]

Each time, the sound is inverted when it's reflected by the compression driver.

Hi thend,

Correct, the phase will be inverted if the driver has a rigid plane diaphragm.

Kind regards,

David

 

[David McBean]

I think because the membrane is reactive, so phase shift depending frequency, like a filter (it's the same thing).

Hi thend,

Correct again .

Kind regards,

David

 

[Don Hills]

David,
Horns with decreasing segment areas don't export. The Hornresp error message warns that, for example, S2 is less than S1 and is thus invalid for Akabak. To make it work in Akabak, you need to write the dimensions out in increasing size order but reverse the nodes. For example:

An increasing area segment:
Waveguide 'Horn segment 1'
Node=8=9
STh=10cm2
SMo=20cm2
Len=50cm
Conical

A decreasing area segment:
Waveguide 'Horn segment 1'
Node=9=8
STh=10cm2
SMo=20cm2
Len=50cm
Conical

Waveguides and ducts are bidirectional, ao Akabak handles this correctly.

 

[David McBean]

To make it work in AkAbak, you need to write the dimensions out in increasing size order but reverse the nodes. Waveguides and ducts are bidirectional, so Akabak handles this correctly.

Hi Don,

Many thanks for this feedback, I had not realised that AkAbak could handle negative flares . I will modify the AkAbak script export functionality in Hornresp so that node numbers are reversed in such cases.

I am pretty busy at the moment, so it may take a few days, but I will let everyone know once it is done.

Thanks again!

Kind regards,

David

 

[David_Web]

So there is a workaround? Sweet, that always bugged me about AkAbak.
It still won't do straight segments right? Could probably be replaced with ducts then. Or a very small taper.
Lots of IF and AND statements I guess

 

[Don Hills]

So there is a workaround? Sweet, that always bugged me about AkAbak.
It still won't do straight segments right? Could probably be replaced with ducts then. Or a very small taper.
Lots of IF and AND statements I guess

The famously impenetrable AkAbak manual describes how to do decreasing section waveguides. First two paragraphs, top of page 194, in the description of the Waveguide component.

As you say, waveguides with throat size = mouth size have to be represented by ducts.

 

[David McBean]

I am pretty busy at the moment, so it may take a few days, but I will let everyone know once it is done.

Hi Don,

I have just discovered that AkAbak predicts results different to those calculated by Hornresp for negative flare horns. I need to investigate further. It seems that it may now take me more than "a few days", before I can release anything .

Kind regards,

David

 

[David McBean]

Hornresp Update

Hi Don / Everyone,

Just letting you know that Hornresp now exports AkAbak scripts for both positive and negative flare horn segments. Product Number 2320-091007 refers. Hornresp and AkAbak predictions are identical.

Kind regards,

David

 

[Henkjan]

The famously impenetrable AkAbak manual describes how to do decreasing section waveguides. First two paragraphs, top of page 194, in the description of the Waveguide component.

Just letting you know that Hornresp now exports AkAbak scripts for both positive and negative flare horn segments. Product Number 2320-091007 refers. Hornresp and AkAbak predictions are identical.

now there's some good help AND some good news on 1 page! thanks lads

 

[Kravchenko_Audio]

Thumbs up!

Thanks David!

This makes working in AkaBak so much easier. I just did an export of my funny bowtie horns and it works perfectly. It also simulates fairly similarly. Not exactly the same. My guess is that being able to excite the horn from different locations with movable driver points is what makes the greatest difference.

Mark

 

[David McBean]

It also simulates fairly similarly. Not exactly the same. My guess is that being able to excite the horn from different locations with movable driver points is what makes the greatest difference.

Hi Mark,

For a single-driver system, the un-combined power response, electrical impedance and diaphragm displacement results should be identical.

The AkAbak pressure response will be different from the Hornresp power response.

Kind regards,

David

 

[David McBean]

For a single-driver system, the un-combined power response, electrical impedance and diaphragm displacement results should be identical.

Hi Mark,

I should have perhaps clarified that identical results require that the Hornresp chamber resonances are not masked, and that the AkAbak settings are as detailed in the header to the exported script.

Kind regards,

David

 

[Kravchenko_Audio]

Hi David

I'm still in the process of changing over an existing box into a new fold. So I will carefully measure what comes of the changes and report back.

Mark

 

[David McBean]

Hornresp Version 23.30

Hi Everyone,

Hornresp can now export SPL and Ze data in files suitable for direct importation into loudspeaker design tools such as LEAP, Boxsim, SoundEasy, CrossoverShop, etc.

All calculated results can still also be exported using the standard *.txt or *.csv bulk data files.

Kind regards,

David

 

[Kravchenko_Audio]

Now we are getting into some serious capabilities. Muchly appreciated David.

Mark