Of course coming from the mighty populous nation of Canada.California I believe is a little larger in population of our mighty 36 million!
My mother lives in Los Angeles!
All these years later and you are still looking for superstitious reasons to explain the BC line of subs? You can forget about inertia and momentum. And if you don't want to forget about them, Akabak will simulate force, acceleration, pressure, etc at any node, these will easily show the effects of inertia and momentum.
But you don't use Akabak, do you? You haven't even simulated a BC sub accurately yet, have you? If you had you would not be looking for radical ideas to explain it's behavior still.
Nothing in the BC line is new or groundbreaking or even special. It uses physical size to create a boundary large enough to give a diffraction boost.
I've made a horn in the past with a very small mouth, much smaller than the cross sectional area of the flare up to that point. It operated exactly as expected. High velocity through the mouth, lots of air flow and a lower tuning compared to a full size mouth. It operated exactly as the sim suggested it would.
I am not a paid corporate shill trying to pounce on your ideas and squash them so my employer can patent these ideas unimpeded as you suggested in another thread. Your ideas are simply shockingly bad and you would realize this if you bothered to perform proper accurate simulations in the first place instead of inventing ludicrous phenomenon to try to explain the behavior of the BC series of subs. There's no genius or magic in this series, it's simple good design following a small set of basic rules that Danley always uses.
The problem is you are going to build a parabolic enclosure. I see you are not modeling the ROAR as a TH like Martinsson' blog and diyaudio thread.
http://publications.lib.chalmers.se/records/fulltext/61697.pdf
A great article about nonlinear acoustics.
They are talking about sine waves that are transforming into steep nonlinear shock-waves at 10kPa (174 dB) and with modern drivers like the B&C IPAL series we are getting there.
I guess Chalmers university is all into "superstitious reasons" and "inventing ludicrous phenomenon" since they are publishing a master thesis on the subject.
For someone used to working with acoustic levitation and active noise cancellation at rocket launching platforms nonlinear acoustics must seem very superstitious and probably even magic.
Nonlinear Sound and Acoustic Levitation - How Acoustic Levitation Works | HowStuffWorks
Nonlinear acoustics - Wikipedia
A great article about nonlinear acoustics.
They are talking about sine waves that are transforming into steep nonlinear shock-waves at 10kPa (174 dB) and with modern drivers like the B&C IPAL series we are getting there.
I guess Chalmers university is all into "superstitious reasons" and "inventing ludicrous phenomenon" since they are publishing a master thesis on the subject.
For someone used to working with acoustic levitation and active noise cancellation at rocket launching platforms nonlinear acoustics must seem very superstitious and probably even magic.
Nonlinear Sound and Acoustic Levitation - How Acoustic Levitation Works | HowStuffWorks
Nonlinear acoustics - Wikipedia
Simulating Bass Loudspeakers Requires Nonlinear Acoustics — a Second Order Correction to the Helmholtz Equation | SpringerLink
At least I am not alone in my madness, wanting to explore the nonlinear behavior of loudspeakers.
Regards,
Johannes
At least I am not alone in my madness, wanting to explore the nonlinear behavior of loudspeakers.
Regards,
Johannes
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http://publications.lib.chalmers.se/records/fulltext/61697.pdf
A great article about nonlinear acoustics.
They are talking about sine waves that are transforming into steep nonlinear shock-waves at 10kPa (174 dB) and with modern drivers like the B&C IPAL series we are getting there.
I guess Chalmers university is all into "superstitious reasons" and "inventing ludicrous phenomenon" since they are publishing a master thesis on the subject.
For someone used to working with acoustic levitation and active noise cancellation at rocket launching platforms nonlinear acoustics must seem very superstitious and probably even magic.
Nonlinear Sound and Acoustic Levitation - How Acoustic Levitation Works | HowStuffWorks
Nonlinear acoustics - Wikipedia
Simulating Bass Loudspeakers Requires Nonlinear Acoustics — a Second Order Correction to the Helmholtz Equation | SpringerLink
At least I am not alone in my madness, wanting to explore the nonlinear behavior of loudspeakers.
Regards,
Johannes
You still have not accomplished a single accurate sim yet and you want to change the simulator so that it can accurately assess the impact of making noises so loud they act more like a shockwave followed by a near vacuum than a wave? Come on now, let's actually think about this for a minute.
How many of your designs are getting anywhere near shockwave level spl inside the box?
What do you intend to do about this phenomenon if you can simulate it?
How are you going to account for the fact that most of the issues are going to be due to factors like high aspect ratio ducts and materials (cones, walls) being less than perfectly rigid and Hornresp can't simulate those at all?
Since you already have articles that should give you a pretty good idea of what spl level nonlinear behavior should be a problem and since Akabak can simulate spl at any node inside the enclosure, wouldn't it make sense to just make sure that your power density inside the horn simply does not exceed atmospheric tolerances? This seems like an incredibly easy solution. Changing the simulator to account for non linear behavior (something it was never meant to do) seems like a ridiculous approach since it would never work accurately anyway.
Now I think I understand a bit better why you are constantly attacking Hornresp, saying it is way too theoretical, saying a successful sim is only 10 percent of the design process, even when Djim's sim of your design was almost a perfect overlay. Your comments seem to be based on extreme high spl situations in which the atmosphere cannot act in a linear fashion.
If you studied Danley's works you would see how he designs. The subs are all pretty similar, there's nothing going on in the higher spl cabs that isn't happening in the lower spl cabs. He uses quality drivers, keeps the aspect ratio of waveguides and ducts in a reasonable range and he uses a compression ratio usually around 2:1. That's why his cabs behave at high power levels, not because he knows something about acoustic levitation.
Pill time I believe.
If you need pills you can go ahead and take them, you don't have to tell everyone.
The response I wrote that you quoted has technical information to back up my viewpoint and perspective. If you can counter it with technical information then go ahead. You haven't posted any technical information for years now, since your measuring t/s in a car fiasco, so this should be interesting.
Hey, let's keep David's Hornresp thread to discussions about Hornresp, thanks. The thread is long enough as it is, without adding flaming to it
I promise to behave.
I've been working on a few jobs that have proved out some of the newer features of Hornresp. Pretty snazzy really.
I like the power input graphs as it is very quick to show the design and amplifier limitations.
Pretty much exactly as requested.
Thanks again David.
Hey, let's keep David's Hornresp thread to discussions about Hornresp, thanks. The thread is long enough as it is, without adding flaming to it
This thread is long for sure... but many of us (I do anyway) read David's Hornresp thread almost every day. It doesn't seem long to me at all and I hope to still be reading this thread 30 years from today!
I learn something almost every visit here, plus I am getting to know and understand a very fine and generous human whom I admire and respect, along with his exceptional works.
I learn from each technical contributor as well. Those that contribute technical information (and correct irrelevant nonsense, point out mistakes or identify myths) are very important persons in this thread, because without them daring to chime in from time to time to challenge, many of us would be swimming in a sea of useless information in complete confusion! Or worse, we may become victimized by an incompetent salesman with a fancy sig!
I just don't see any flaming going on here. I see relevant conversation. Sure, words occasionally become strong and pointed like a sharp stick, but those are generally deserved and healthy. Truth is not always comfortable... It can be cold and sharp and bite. Reality is necessary though, no matter how it must come.
I learn more from smart knowledgeable guys armed with facts and carrying sharp sticks than I do posers or dreamers who contribute nothing of value. I'm really glad they're all here though... the posers, the dreamers AND the really smart guys... I learn who they really are, whom can be trusted, whom to respect... so I learn from them all!
I'm confident you are learning from them all too Brian. Thanks for allowing me to voice my 2 cents...
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Sometimes my wacky sense of humor getts under Anthony's (just a guy) skin.
But I'd be the first to admit he has good comments and suggestions. He knows hornresp better than I do.
Our opinions differ but deep down the majority of posters in this thread are very knowledgeable people on what they post.
As for me posting technical info. What would you like to see Anthony?
May I interrupt for a post?
Finally, after all these years - I've learned to use Hornresp. The rather "curios" interface had always put me off, but yesterday I forced myself to learn it - and I like it!
Here's a newbie question: In simulating front loaded horns, what causes the low pass behavior? I can see slight changes if the throat area/compression ratio is changed, but how else is the roll off calculated?
Finally, after all these years - I've learned to use Hornresp. The rather "curios" interface had always put me off, but yesterday I forced myself to learn it - and I like it!
Here's a newbie question: In simulating front loaded horns, what causes the low pass behavior? I can see slight changes if the throat area/compression ratio is changed, but how else is the roll off calculated?
throat filler
I'm curious about this comment. I've seen some horn designs where a type of filler (wood or molded foam) is placed on the baffle so that when the driver is attached the filler sits inside taking up space in the cone. This is used to reduce the volume in front of the cone. I've read that this helps improve midrange, but I'm sure it has more of an effect than just midrange frequency. And I wonder if this somehow affects fidelity.
Can anyone explain what effect this has of reducing the enclosed volume of the speaker cone in horn-loaded designs?
And how is this accurately simulated using Hornresp?
Here is an example of a 3d-printed plug being used as a throat filler on the SynTripP enclosure by weltersys.
I'm curious about this comment. I've seen some horn designs where a type of filler (wood or molded foam) is placed on the baffle so that when the driver is attached the filler sits inside taking up space in the cone. This is used to reduce the volume in front of the cone. I've read that this helps improve midrange, but I'm sure it has more of an effect than just midrange frequency. And I wonder if this somehow affects fidelity.
Can anyone explain what effect this has of reducing the enclosed volume of the speaker cone in horn-loaded designs?
And how is this accurately simulated using Hornresp?
Here is an example of a 3d-printed plug being used as a throat filler on the SynTripP enclosure by weltersys.