So... after a bit of thinking, a bit of research and a bit of playing around in Hornresp it appears that these two graphs actually can be used for the purpose of reactance annulling (or determining if reactance annulling is even possible for any given design), which obviously makes these two graphs incredibly important.
I still think the "Driver (diaph) Driver" graph is important to find actual pressure stress on the cone and probably should be available in Hornresp.
Hi just a guy,
Hopefully both will be available in the next release.
Kind regards,
David
Hopefully both will be available in the next release.
Kind regards,
David
Hi just a guy,
In an earlier message you referred to "the summed pressure on the cone itself". Just to clarify, I assume that "Driver (diaph) Driver" is actually the vector difference between the pressures exerted on each side of the diaphragm, and not the vector sum. Is this correct?
(AkAbak won't run on my current computer, so I can't check for myself).
Thanks.
Kind regards,
David
Hi sebDIY,
Set to OD and Fr in the main Input Parameters window, and then use the Loudspeaker Wizard.
Kind regards,
David
Woah, slow down with the fancy math talk, man, lol. I don't know what a vector is. All I know is the definition I posted previously from Akabak Help.
"This simulation displays the pressure across the acoustical poles, i.e. between the front and rearward side of the diaphragm."
Beyond that Akabak Help is not very helpful at all.
Maybe "vector difference" is a better description than "summed pressure", I don't know.
I don't even know for sure that this graph is showing what I think it is (but I'm pretty sure it is), nobody ever told me how to do any of this stuff. I've been using the "Driver (diaph) Driver" graph to determine the amount of pressure stress on the cone. I never really looked at any of the other pressure graphs before a couple of days ago.
Anyway, here's a picture for you. This design is pretty bad from the POV of the recent conversation but maybe you can see what you need here.
Top line - Duct Throat chamber
Middle line - Duct Rear chamber
Bottom line - Driver (diaph) Driver
(And btw, Akabak won't run on my computer either and I don't have an OS that will support Microsoft Virtual Machine, so I have to use Oracle VirtualBox. It works well but it's a major pain getting files back and forth between Win7 and VirtualBox.)
An externally hosted image should be here but it was not working when we last tested it.
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Very nice.
As far as tapped horns go we won't be able to sim Danley's stuffing method exactly (due to Hornresp's limited amount of segments) but we should be able to get a fairly good idea of what's going on.
Hi sebDIY,
Sorry, no.
The Loudspeaker Wizard is limited to SPL response, electrical impedance and diaphragm displacement to prevent the tool from "locking up" due to excessive calculation times. Just adding the absorbent filling material feature slowed things down considerably because of the extensive "number crunching" required - try a design with four filled Par segments to see what I mean. The time delay in this case is close to the maximum acceptable.
Kind regards,
David
Hi just a guy,
Thanks for the screenprints. Would you have the input parameters for the design so that I can simulate it in Hornresp? This will then allow me to establish what the AkAbak results represent.
Thanks again.
Kind regards,
David
Hi just a guy,
Extensive coding modifications will be required to the Hornresp tapped horn model to accommodate absorbent filling material. I'm not sure at this stage how long it will take me to get everything working properly.
Kind regards,
David
Just to be clear since I don't know exactly what you need and I haven't got much experience with Akabak's throat and chamber pressure graphs, the previous screenshot showed "Duct (1) Throat Chamber" and "Duct (1) Rear chamber". Each chamber has a Duct (1) and a Duct (2).
Since everything in Akabak flows from left to right, upon further reflection I probably should have showed "Duct (2) Rear chamber", that is probably the side closest to the cone. BUT I just did a quick check and I can't see any noticeable difference between Rear chamber duct 1 and 2. And it probably doesn't matter anyway since Hornresp will show you whatever you need when you run this sim. Anyway, just trying to be as accurate as possible to give you what you need.
So here's the screenshot of the inputs. Like I mentioned, this might not be a good design for this purpose since the goal of this design was to have ruler flat response above all else. If you need any other info or would prefer to study a completely different design let me know and I'll see what I can do.
An externally hosted image should be here but it was not working when we last tested it.
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If you want to skip this completely I certainly won't be upset. Like I mentioned, due to Hornresp's limited amount of segments it wouldn't be possible to use this feature in an ideal fashion anyway. Stuffing between S1 and S2 isn't quite far enough down the line and stuffing the entire last segment is a bit too much compared to Danley's stuffing method.
It would be a neat feature but it's probably not worth it if it's a lot of work.
Hi just a guy,
The information you have provided is all that I require, thanks.
AkAbak calculates "Driver (diaph) Driver" as follows.
Given:
P1R = Real component of pressure on front side of diaphragm
P1X = Imaginary component of pressure on front side of diaphragm
P2R = Real component of pressure on rear side of diaphragm
P2X = Imaginary component of pressure on rear side of diaphragm
Then "Driver (diaph) Driver" = ((P1R + P2R) ^ 2 + (P1X + P2X) ^ 2) ^ 0.5
It is a relatively simple matter to include this information in Hornresp as another chart, if considered worthwhile.
Kind regards,
David
Hi just a guy,
Thanks for the "escape clause"
.Out of interest, I will probably investigate the required changes a bit further, but if it all gets too difficult, I won't proceed.
I will let you know the outcome, either way.
Kind regards,
David
Sorry, it's not going to happen
Hi David_Web,
Further to my comment above, rather than having separate force charts, would it be sufficient to show the loading on the diaphragm in kilograms as an additional output in the diaphragm pressure chart Sample results?
Kind regards,
David