Hornresp

Yes - to me it seems to be the same results - just that I cant do overlay as you show

max_spl_comp.png


Thanks for making "tab" available..

Michael
 
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Hi David, one more question

Regarding diaphragm displacement its said in the HELP that it is for a specified input signal.

Can this input signal be selected - or if not - what value is it?
Could you possibly add an option to relate displacement to an specific output SPL of desire as well ?
This would give me a clue on how THD and IM distortion alter relatively, when opimizing overall design.
Just a thought...

By the way capture feature does not work with displacement plot either - maybe its on my system as I run Hornresp under XP in Virtualbox ? - though didn't experience any troubles until now...

Michael
 
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Michael, I would say that 120 dB is somewhat unrealistic with OB-speakers. May be Stig-Erik could comment on this, his setup, which you know I think, would be closer to achieve it. But really even with large conearea I think you will have trouble reaching these levels also with IB speakers.

Effeciency-wise with OB, plain panels will be more efficient than H- and U-baffles which in turn will be more effecient than Ripole and N-baffles, but these last variations can be constructed to go lower in frequency.

/Erling

I've now run a couple of Hornresp simus and IMO it was quite interesting on that subject.

Sure you are right - max SPL depends on type of OB - but with two of the Ripols each side (+9dB in summ) Hornresp tells me that 120dB *free field* can be accomplished roughly up from 60Hz.

Thats for a displacement of 5mm and full AES input of 700W for each double (and all four double 15" in mono-operation assumed) - still an impressive figure I'd say - though it does not tell us anything about the SPL outcome *in room* - and - would burn past 2kW amp power :eek:

The most interesting part is that low frequency for full max SPL of 120dB can only be lowered marginally to roughly 40-50Hz when the front to back distance would be doubled (80cm). And what a surprise: infinite baffle wouldn't perform any better than those 80cm !!!

So - *if* one decides to go OB sub, a Ripol isn't any bad ;)

This I very much like from simus - quick guesstimation on optimization trade offs - big thanks to David for providing such a versatile tool !!!
:) :) :)

Michael
 
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Just to complete:

With a good 18" we could reach with same config (4 pieces of double Ripol) 120dB free air up from roughly 30Hz
- and with 21"" woofers Beyma 21SW1600 in same config free air 120dB would go up from slightly below 20Hz :crazy:
Amp power needed is more or less the same in all cases.

I guess I have to ask Stig Erik doing a free air measurement. ;)

Michael
 
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Yes - to me it seems to be the same results - just that I cant do overlay as you show.

Hi Michael,

This is very strange indeed. To capture results it should simply be a matter of:

1. Right-clicking the mouse on any chart to open the 'Capture current results' pop-up menu.
2. Clicking on the 'Capture current results' pop-up menu command to save the data. A red 'Current results captured' message should then be temporarily displayed in the top left corner of the chart to confirm that the information has been stored - see Attachment.

Captured results can then be subsequently compared to other results by selecting the 'Tools' > 'Compare Captured' menu command, or by pressing the F4 function key.

Kind regards,

David
 

Attachments

  • Captured.png
    Captured.png
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Is there any chance that, in some future version, it will be possible to include some active filtering?

Hi Khron,

Sorry, but I have no plans to add incoming signal filtering functionality to Hornresp.

My interest lies with the performance of the loudspeaker itself - not with how the signal is processed prior to reaching the loudspeaker :).

Kind regards,

David
 
Hi Michael,

Regarding diaphragm displacement its said in the HELP that it is for a specified input signal. Can this input signal be selected - or if not - what value is it?

By default Hornresp assumes a sinusoidal constant voltage input signal. The root-mean-square value of this voltage is given by Eg. When the Maximum SPL tool is used, the voltage level at a particular frequency is derived from the specified value of Pmax or Xmax, depending upon which parameter is the limiting factor.

Could you possibly add an option to relate displacement to an specific output SPL of desire as well?

Sorry, it's not going to happen :).

By the way capture feature does not work with displacement plot either - maybe its on my system as I run Hornresp under XP in Virtualbox?

I suspect that the problem may be with your system :). No-one else has reported similar issues and as you can see from my earlier attachment, the capture feature normally also works with the Diaphragm Displacement chart.

Kind regards,

David
 
I suspect that the problem may be with your system :). No-one else has reported similar issues and as you can see from my earlier attachment, the capture feature normally also works with the Diaphragm Displacement chart.

No wonder - I have to apologize - its all been me, myself and I
:( :( :(

Thanks for the answers to all other questions.

Michael
 
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David,

Hornresp appears to vertically scale the calculation result graphs automatically. While this is very convenient, it can lead to problems. For example, if the speaker has a high inductance, the electrical impedance can rise to a very high value at 20 KHz. This means the LF resonance impedance peaks are tiny bumps at the bottom of the graph. To see what I mean, pick any speaker and add 10 mH to its Le value. Then Calculate and display the electrical impedance graph. It's particularly bad on Volvotreter's Tang Band 38 Hz Tapped horn.

In my opinion, a solution that should suit novice and power users alike would be a slider beside the graph, allowing adjustment of the vertical scale. Just a suggestion...

... or maybe an option to limit the frequency range. I notice that the Loudspeaker Wizard graphs only go to 2 kHz or so, reducing the effects of the aforementioned impedance rise.
 
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Have the results been plotted after the software has divide by 10 or as David suggests, the user divides what is shown by 10?

Hi Andrew,

For the example you quoted, the user should divide Y-axis displacement values by 10.

When in doubt the Sample tool can always be used to check actual values. See the screenprint below and the Diaphragm Displacement description on page 6 of the Help file.

Kind regards,

David
 

Attachments

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