Well, that's kind of you, but I'm the one that didn't bother to learn your language! The burden of understanding is on me, since you are making an effort on my behalf.
I understand what you (and Dave) are saying, but you're assuming that the source of excitation is the same frequency as the resonance. If I play a low E (82Hz on guitar), my cabinet will not resonate at that frequency, but several octaves up.
What do you mean by easier? If a thinner panel vibrates more than a thicker panel, wouldn't it stand to reason that the thinner panel would require more damping than the thick one in order damp out those vibrations?
Find something in your house that vibrates (..no, not that), and test out your theory.
Only if the note has harmonics with energy at the same frequency as the resonance.
dave
Actually it's your theory.Find something in your house that vibrates (..no, not that), and test out your theory.
Hey I'm here to learn, and you were the one that stated that thin (lighter mass) panels are easier to damp than thick (higher mass) panels, so why don't you go ahead and explain what led you to draw that conclusion.
Actually it's your theory.
The BBC did some research on that leading to thin ply with bituminum damping panels.
dave
If I cut the wood the way you suggest i waste everything inside the square because I need hollow squares ... all the inside goes to waste and that's the problem.
That's right; take a subwoofer enclosure of say 600hz resonance frequency (rigid and relatively small); if the lowpass fr is fixed at i.e. 80hz with a slope of 24dbs, what kind of music you are playing the box will absolutely not vibrate, you will even feel nothing if you place your hand on it.
All of the input I have read seems valid in many ways from possible to probable! I read an article back 2003-4? SpeakerBuilder that studied this very subject. They touched on all aspects mentioned here by the repective opinions of members. At the time of testing MDF was still King as prefered building material and was suggested using MDF for bracing as well. However it was hinted to experiment by including the sound that the cabinet produces as part of your design rather then chasing the Fr. up or down. The article also showed if full length hardwood brases were benefitial if gluing to the front and or back panel vertically in a fashion where it terminated attached to the bottom panel directly and if it could be coupled by a cones or spikes under the cabs. The idea is to send the fibrating enomoly through the brace into ground much like a electrical circuit! Surprised? Me too! The artical stated that it was taking advantage of the sound conductivity of the HardWood characteristics....! So may I suggest Maple strips 3/4" by 1" glued vertically played with top end of braces close together and bottom of braces in the mounting ring of woofer terminating, as suggested into the base panel coupled/decoupled by spikes! NOTE: The artical also suggested to damp the panels with some sort of Butimine type substance which would transform the vibrations into heat, (low level heat I would think!) If I could add, the cabinets I have built with this type bracing have (to these ears) benefited over other methods and I now use an asphalt type damping material purchased at Solen... solen.ca!
Francis
Francis
That's the "mechanical grounding", an analogy with the electrical grounding (some of the electrical and mechanical/acoustical propagation laws are equivalent).
Goldmund was one of the first manufacture to use this kind of damping, notably through their coupling cones. They had a white paper, mainly explaning with simple words, but no more available on their new site.
This doesn't make any sense to me.
I'm talking about cutting strips (like the bracing you have on your first sketchup) and laminating them together.
ScottG? Care to offer some support for your statement?Actually it's your theory.
I think more bracing is good, if you can afford it. It's like somebody else said " can you ever be too rich or thin type of question" PA speakers have serious tradeoffs when it comes to weight vs performance. The primary effect of weak or lighter enclosures is reduction in bass output. The stuff you guys are discussing is mainly secondary effects IMO. In DIY audio we can do things to an extreme, so if you can carry it by yourself through the workshop doors then does it really matter.
This doesn't make any sense to me.
I'm talking about cutting strips (like the bracing you have on your first sketchup) and laminating them together.
like building a brick wall ?
..like building a log cabin.
(..or like a brick wall with out cutting up the lengths for each individual "brick".)You can also go a bit further than the Mini, beyond increasing panel thickness, by making top and bottom panels that are *also* "lam'ed" with the "lam" edge of the plywood facing the interior and exterior.
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I did (by way of experimentation), and other than that an CLS's comment - no.
..you can of course always google "damping" and see what turns up.
ScottG , Do you mean somthing like this ?
I never seen anyone build a cabinet like that before ... But it appears to be solid with 30mm wall thickness and all the gluing that needs to be done .. but , well it's weird
Anyone approves ? The problem is I dont see a way to chamfer the inside circles , Only by sanding it by hand a bit .. also incorporating braces that interlock with the design is a pain.
edit : nevermind , the solution to the braces came naturally ... just made x2 squares with an X shape brace inside connecting the sides ... kinda like the magico mini
Also building it like that would require 192 "flanks" for 2 cabinets ... can you say labor cost hehe
I never seen anyone build a cabinet like that before ... But it appears to be solid with 30mm wall thickness and all the gluing that needs to be done .. but , well it's weird
Anyone approves ? The problem is I dont see a way to chamfer the inside circles , Only by sanding it by hand a bit .. also incorporating braces that interlock with the design is a pain.
edit : nevermind , the solution to the braces came naturally ... just made x2 squares with an X shape brace inside connecting the sides ... kinda like the magico mini
Also building it like that would require 192 "flanks" for 2 cabinets ... can you say labor cost hehe
An externally hosted image should be here but it was not working when we last tested it.
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This is the final design , the top and bottom will be sealed with 36mm boards.
The braces are as shown in the picture , I could place more but i believe it's enough. ( Edit: Actually I decided to put 4 braces in each box , Figured might as well go totally insane.. )
"All" I need is x192 birch "flanks" sized 300mm x 30mm x18mm.
I suspect this is the most insane box design I have ever seen or thought about ...
The braces are as shown in the picture , I could place more but i believe it's enough. ( Edit: Actually I decided to put 4 braces in each box , Figured might as well go totally insane.. )
"All" I need is x192 birch "flanks" sized 300mm x 30mm x18mm.
I suspect this is the most insane box design I have ever seen or thought about ...
An externally hosted image should be here but it was not working when we last tested it.
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