We had them (FARO) into our plant last year -- to check film build on various substrates -- very neat but for now we will rely on a guy with a micrometer.
My dad would give me discarded patterns from the grey iron foundry he ran -- some of these folks would have found work in Tilman Reimenschneider's 16th C workshop the stuff they made on the side was so beautiful.
My dad would give me discarded patterns from the grey iron foundry he ran -- some of these folks would have found work in Tilman Reimenschneider's 16th C workshop the stuff they made on the side was so beautiful.
The use of these materials are not new , with the exception of composites. In the 70's we experimented with aluminium (alcoa), concrete, marble and we keep going back to wood. Each material had their own subjective sonic character and you could pretty much get all of them inert , subjectively wood was felt to sound the most natural, marble the most difficult to work with...
I guess those favoring electronic music may feel otherwise ...
With these you do have to worry about how close the innerwall of the box isto the cone and reflections back thru the cone. There is too narrow,
Your box construction description sounds much like the design of out miniOnken, except that instead of a superthick baffle, there is a driver brace that shunts driver reactive force to the back/top/bottom panel spreading & dissipating the energy across multiple panels. These boxes have proven to produce little noise.
dave
Planet10,
Somewhere in another thread I think I have seen those enclosures before. I like the way you did the vents up the sides, a great use of the space. I have some two way enclosures that look similar to yours in shape except they have a stepped front and have a dome tweeter above the bass mid range speaker.
Somewhere in another thread I think I have seen those enclosures before. I like the way you did the vents up the sides, a great use of the space. I have some two way enclosures that look similar to yours in shape except they have a stepped front and have a dome tweeter above the bass mid range speaker.
You should try multiple small ports in a circular fashion around the bass driver , a derivative of when we used to use honeycomb construction when porting with tubes ....
Nuff moons back .... 🙂
Nuff moons back .... 🙂
The vents are borrowed from theOnken, the 1st picture i saw of one in a late 70s Audax publication.
A 3D visualization of the 1st example we built,
Later development of a "trapezoidal" version further reduces diffraction signature.
Here is a thread with pictures of actual builds. http://www.diyaudio.com/forums/planet-10-hifi/214897-minionken-fonken-gallery-pictures-only.html
dave
They look nice. I have done some trapezoids myself, a bit more complex than what you did with tapering in both the x,y,z axis, they were a real pain to build though. They were horn loaded enclosures though, I have pictures of them I would have to scan. Nice Carpathian Elm Burl wood, real expensive veneer, over $500.00 a sheet at the time and that was moons ago.
The vents are borrowed from theOnken, the 1st picture i saw of one in a late 70s Audax publication.
A 3D visualization of the 1st example we built,
Later development of a "trapezoidal" version further reduces diffraction signature.
Here is a thread with pictures of actual builds. http://www.diyaudio.com/forums/planet-10-hifi/214897-minionken-fonken-gallery-pictures-only.html
dave
Didnt Jensen have a model like this too late sixties /early seventies..?
hello, i would agree that the resonance of the front panel is important during the design phase, but could you explain its usefulness for a finished product? at the point that things are being measured by a magazine its to late to do anything about it, so why measure it? at this point it is a part of the finished product's sound.
From what I have read in the past of Stereophile testing of speaker enclosures this is only done to show what is contributing to the sound and why something may have a contribution to the overall sound. They never tell you to change anything, just show any panel resonances that may be contributing to a particular sound quality. As Myhrrhleine has stated this would be useful information when developing the speaker but after the fact it is just a tool to tell you why it ended up sounding the way it does.
Actively venting
Great looking cabs. Are these vents tuned like a port, or is the idea they act as a trap for diffracted sound?
I wonder too if they provide a little out of phase noise cancelling to isolate the cabinet from side wall reflections.
As for quieting a cabinet , once tried an M & K S1C driver arrangement, but wired the lower woofer out of phase and with an inductor to roll it off at 120 hz.
The idea was to lower midbass cabinet pressures and not put a cap on the driver that mattered.
Worked very well, clearer sound , better integration with the sub, kind of expensive for non buyout woofers though.
The vents are borrowed from theOnken, the 1st picture i saw of one in a late 70s Audax publication.
A 3D visualization of the 1st example we built,
Later development of a "trapezoidal" version further reduces diffraction signature.
Here is a thread with pictures of actual builds. http://www.diyaudio.com/forums/planet-10-hifi/214897-minionken-fonken-gallery-pictures-only.html
dave
Great looking cabs. Are these vents tuned like a port, or is the idea they act as a trap for diffracted sound?
I wonder too if they provide a little out of phase noise cancelling to isolate the cabinet from side wall reflections.
As for quieting a cabinet , once tried an M & K S1C driver arrangement, but wired the lower woofer out of phase and with an inductor to roll it off at 120 hz.
The idea was to lower midbass cabinet pressures and not put a cap on the driver that mattered.
Worked very well, clearer sound , better integration with the sub, kind of expensive for non buyout woofers though.
Still venting
Forgot to mention, this gave the effect of highpassing the upper woofer while leaving it direct coupled to the amp.
Forgot to mention, this gave the effect of highpassing the upper woofer while leaving it direct coupled to the amp.
The vents are distributed ports, the high aspect ratio adding an R term to the vents which makes them less sensitive to dynamic changes in T/S parameters.
The construction of the walls make them VERY stiff, dissimilar material for the vent spacers minimizes energy transmission from inner, to outer walls.
dave
I was thinking, I realize that stiffening only changes the resonant frequency of the panel, but wouldn't raising the resonant frequency potentially reduce the annoyance of resonances by narrowing the amount of frequencies that can get the panel resonating. Of course as you get into higher frequencies, there is less power output to excite the resonance and you may get into the region where our ears are somewhat less sensitive?
Also, if the bass resonates the cabinet, the entire audio band is compromised. If the panel only resonates above 5kHz, the frequencies below this point will not be affected.
Also, if the bass resonates the cabinet, the entire audio band is compromised. If the panel only resonates above 5kHz, the frequencies below this point will not be affected.
Thanks. Are the individual vent sizes critical? If not, I guess you could distribute wall resonances by varying the spacers... spacing?
But wouldn't this still be preferable to lower freq fundamental vibrating the whole front panel. The higher the resonant frequency, the less panel flex you will get, reducing the amount it affects ALL other frequencies. Then, on top of this, as an added bonus, wouldn't a higher freq resonance have far less of an effect on the frequencies below it than vice versa.
This is all just pure speculation on my part of course.
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