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  • andy19191
    replied
    Originally posted by dlr View Post
    A good web site doesn't have to be fancy. Consider how john k published his tech papers and studies. Heavy on the math, but also including explanations to go along with it. I have his web site archived at mine.
    The subjects in the "Tech Studies" section is close to the sort of thing I am considering but with a more general 3D focus rather than OB and, if I can work out how, with some community involvement to direct what is of interest and possibly grow things. Subject to sufficient interest of course . The archived status of John's work has been noted. The website design will be basic github pages (whatever that turns out to be) which I do not expect to sink much time. What is sinking time is understanding the practical side of how the web works in order to determine what I can and cannot do. It doesn't help that I have a low level of interest in the subject and tend to take every opportunity to do something else.

    Apologies to the OP for wandering off topic on what is an interesting question. I don't have any useful answers at present but hope to in the future.

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  • analogkid455
    commented on 's reply
    Wow, a lot of good info you got there on your page, Augerpro. I just went through it all but will have to go back over it to digest it all. Thank you for all your hard work!

  • dlr
    replied
    Originally posted by andy19191 View Post
    Given the time soaked up trying to sort out html/css/js for a website I think youtube videos will have to wait a year or two in my case. Not sure it is the best format though for making a case based on science and engineering since such cases rely on the application of scientific and engineering knowledge which most DIY folk don't possess. To introduce the laws and principles, skimp a lot on how those laws and principles are applied (lots of maths and computation) but with enough depth to convey what is or is not in the model and then to discuss the results in an understandable way requires both significant length and the ability for the reader to easily access what wasn't quite fully absorbed in the first pass.
    A good web site doesn't have to be fancy. Consider how john k published his tech papers and studies. Heavy on the math, but also including explanations to go along with it. I have his web site archived at mine.

    Archived musicanddesign

    dlr

    Leave a comment:


  • billfitzmaurice
    replied
    I try to keep the free area between braces at six inches, never more than eight. I don't use typical window braces, I do use window grille braces. The former is shown below left, the latter below right. Full window braces put material in the cabinet corners, where it's not needed, while the pieces that connect the grille sections aren't thick enough to be worthwhile.



    With less material the grille method connects the opposing panels at more points, making it much more effective. I don't cut the grilles from a sheet of material, as that creates a lot of waste. Instead I use either dowels as shown below, or even better, scrap cutoffs.



    I also use ports as braces when possible. I especially like corner ports for that reason, like so:

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  • augerpro
    replied
    BillF> given the dimensions of my box, I only used 1 brace, since that mimics a brace every 8" or so in large speaker. Next time I do some testing I'll try 2. I need to try a window brace anyway, and some other ideas, so maybe another round of experimenting is in order.

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  • augerpro
    replied
    andy19191> if Sir Roger Penrose can talk physics on podcasts on Youtube, I think our field of interest will do just fine there too. Unless you think panel resonance is more difficult to explain than quantum gravity

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  • andy19191
    replied
    Originally posted by augerpro View Post
    Well since we have BillF in one corner and andy19191 in the other, I might as well jump in the ring!
    Given the time soaked up trying to sort out html/css/js for a website I think youtube videos will have to wait a year or two in my case. Not sure it is the best format though for making a case based on science and engineering since such cases rely on the application of scientific and engineering knowledge which most DIY folk don't possess. To introduce the laws and principles, skimp a lot on how those laws and principles are applied (lots of maths and computation) but with enough depth to convey what is or is not in the model and then to discuss the results in an understandable way requires both significant length and the ability for the reader to easily access what wasn't quite fully absorbed in the first pass.

    I had a go at starting a group project a few years ago which didn't attract interest mainly due to misjudgement on my part I suspect. In this case I don't expect wide interest in a lot of "school" stuff for a hobby but there might be enough to continue and grow. We will see.

    Leave a comment:


  • billfitzmaurice
    commented on 's reply
    I totally agree that moving the panel resonance above the passband is a red herring. While it may occur as a by-product of bracing that's not what prevents panel sourced coloration. The taming of panel vibration is. You can accomplish the same thing with pure mass, for instance, making the cabinet of six inch thick reinforced concrete. That sucker isn't going to vibrate, and the lack of panel sourced coloration isn't due to the panel resonant frequency being above the passband. Using damping and bracing in tandem may give a better result than bracing alone, but if it does IME that indicates that the bracing was too widely spaced and/or the panels too thin. Even with four inch spans between braces 1/8" plywood panels are going to vibrate...unless you bend them.

  • a4eaudio
    replied
    analogkid455 - although Augerpro says his website is a "wall of words" I suggest reading his page​​ (wall of words) on box construction methods since you are interested in the topic. (Go to the Soma Sonus link in his signature).

    Leave a comment:


  • augerpro
    replied
    Well since we have BillF in one corner and andy19191 in the other, I might as well jump in the ring! I made a brief summary of my testing here https://www.diyaudio.com/community/t...2#post-7090874. Bottom line to me, as shown by my testing, bracing has only partial effect on the primary panel resonance region, and something more should be done. There must be some form of damping, not just stiffening. My CLD method is stupid simple. There is no support for the idea that you can stiffen a wood box so the primary panel resonance region is above the passband of the midrange. It's not happening. Since the results on my website are a wall of words, I've decided to start a YT channel to better communicate what I've found so far. The first two videos are just about my method, no results, but I'm on vacation for 3 weeks and hoping to put out the bracing and panel material testing.


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  • analogkid455
    commented on 's reply
    Thanks for the comment. Something to consider.

  • billfitzmaurice
    commented on 's reply
    It's a constrained layer when sandwiched between two higher density layers.

  • Billet
    commented on 's reply
    The 3 layer Sonic Barrier has a solid sheet of material with a thin layer of foam sandwiched between the solid sheet and the enclosure panel. I believe it actually is a constrained layer.
    Last edited by Billet; 09-08-2022, 07:48 PM. Reason: clarified some details about the solid sheet of material

  • Billet
    commented on 's reply
    I think that constrained layers and damping are intended to absorb vibrations. Bracing pushes the resonant frequency of the panels higher, possibly to a point where the wood internally absorbs the vibrations.

  • djg
    replied
    My current build. Transverse windowpane, rear panel one stiffener plus a brace to the weakest part of the baffle,

    Click image for larger version

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