Hi Marc,
The combined response model was significantly improved with the release of Version 40.60 - see Post #7383 linked below, and also Post #7387.
http://www.diyaudio.com/forums/subwoofers/119854-hornresp-739.html#post5087339
Note that it is no longer necessary to specify positive or negative offsets, only the direct straight-line distance separating the two outputs (which are treated as point sources).
Kind regards,
David
Hi USRFobiwan,
This is no different to how things worked originally, when there was only a 10 - 20000 Hz frequency range
.With the 10 - 20000 Hz range selected, the filter and loudspeaker wizard charts show 10 - 2000 Hz by default. Double-clicking on the 'Frequency (hertz)' label at the bottom of any chart changes the range from 10 - 2000 Hz to 100 - 20000 Hz.
With the 1 - 2000 Hz range selected, the filter and loudspeaker wizard charts show 1 - 200 Hz by default. Double-clicking on the 'Frequency (hertz)' label at the bottom of any chart changes the range from 1 - 200 Hz to 10 - 2000 Hz (see attachment).
Kind regards,
David
Attachments
Hi USRFobiwan,
Thanks for the feedback. You are correct, the frequency is out by a factor of 10. I noticed the same thing myself a few days ago, and have already updated the code
. It will be fixed in the next release - see attachment.Kind regards,
David
Attachments
I am curious how you are doing the calculation now. It seems like you need more information to be able to calculate the far field response. For example, if the port output is lagging the horn output by 90 degrees of phase at a particular frequency, and the straight-line distance is one quarter wavelength at that frequency, the output could be 6 dB higher than either output alone if the port is in front of the horn, 3 dB up if they are equidistant to the far field listener, or complete cancellation if the port is 1/4 wavelength behind the horn.
Am I missing something or is there a reference I should read?
Thanks. Marc
Hi dipolar,
The "SPL Response - Constant Directivity" chart is now called the "Acoustical Power" chart.
The title was changed quite some time ago. The information presented on the chart remains the same.
Kind regards,
David
Hi Marc,
Remember it is combined power that is being calculated, not combined pressure. The reference is given in Post #7387, mentioned in my previous message.
Kind regards,
David
Hi 3ll3d00d,
Thanks for the feedback.
I am pretty sure that it worked originally - I will investigate and see what has gone wrong
.Kind regards,
David
My bad,I thought there was some hidden key somewhere.
______
By no means I am able to make the response smooth shown in figure below. I have been trying various values for last one week.
Is this driver not suitable for Horn or TH enclosures?
My goal is to get a flat response from 25 to 100hz without filters or minimal fillings.
regards
Attachments
Not a comment about HR, but you have 23 -100 +4/-3dB. A notch filter at or otherwise crossed below 130, depending on taste and or design criteria. Does not look bad.
Besides, once in the room it'll murder a flat response
I have achieved this in below pic with lot of tweaking but the spl output in such a configuration for a 100+ litre enclosure is poorer than a Ported enclosure with half volume.
And I guess the below figure is not a tapped horn but some kind of tappered QW tube?
I am afraid if a such a tapered tube makes sense when goal is to design Tapped Horn ( higher efficiency is requirement).
A horn should have a Incrementing mouth Dia I believe.
Attachments
I was mistaken - the feature was never provided. I will see if it can be added.
Hi tkroeker,
The Cms value of 0.24 mm/N given by Eminence needs to be converted to units of m/N for entry into Hornresp.
Conversion: 0.24 mm/N = 2.40E-04 m/N
If you double-click the Sd input box you can directly enter the Thiele-Small parameter values instead (see attachment). The T-S values will be automatically converted to the equivalent electro-mechanical parameter values.
Kind regards,
David
