This is my first post, i'm a product designer, i have some modeling skills and i want to realize a teardrop like enclosure for a fullrange speaker. I've been reading around and my two references for now are the B&W 800D midrange enclosure and the norh speakers "drum style" speakers.
Drivers i was considering for this project: w5-1611 or the w5-2106 variation and the w4-1337SDF
My idea is to realize the front portion of the sphere where is sitting the driver in plywood, and the rest in a concrete compound (portland concrete, marble dust and sand) made whit a rubber mold. then join the tow parts with a strong resin. Using two different materials is a problem?
The thing is that the B&W approach is a closed enclosure and is the combination of a sphere with a tapering tube, instead the Norh design is a sort of inverted horn bass reflex from what i've read...
I'm a total noob in acoustics and loudspeaker design and my aim is to have decent bass, so what's the best compromise in your opinion?
If i make the B&W enclosure open at the end it becomes a bass reflex port or is an inverted horn design? I'm a bit confused...😕
here i found a detailed paper on the B&W 800, look at page 16:
http://www.gramophone.com/sites/default/files/wysiwyg/VendorLogos/800_Development_Paper.pdf
Thank you!
Giulio
Drivers i was considering for this project: w5-1611 or the w5-2106 variation and the w4-1337SDF
My idea is to realize the front portion of the sphere where is sitting the driver in plywood, and the rest in a concrete compound (portland concrete, marble dust and sand) made whit a rubber mold. then join the tow parts with a strong resin. Using two different materials is a problem?
The thing is that the B&W approach is a closed enclosure and is the combination of a sphere with a tapering tube, instead the Norh design is a sort of inverted horn bass reflex from what i've read...
I'm a total noob in acoustics and loudspeaker design and my aim is to have decent bass, so what's the best compromise in your opinion?
If i make the B&W enclosure open at the end it becomes a bass reflex port or is an inverted horn design? I'm a bit confused...😕
here i found a detailed paper on the B&W 800, look at page 16:
http://www.gramophone.com/sites/default/files/wysiwyg/VendorLogos/800_Development_Paper.pdf
Thank you!
Giulio
Follow up the designs of Derek Wilson and his "Overkill Audio" mid range chambers
The 'tail' on the B & W mids is actually called a 'tapered resistance tube' - thye Nautilus version has an hole/port at the rear altho hard to make out in their 'white paper'
There's quite a bit of material here in the archives about spherical/teardrops and because of the manufacturing difficulty, it's usually seen only in the more expensive products.
The material/shape design should contain a method to stop any ringing (usually higher mass and damping material (ie 'AudioSpheres) or a design that uses unequal acoustical sections (Overkill one)
Their is still info on the French speakers of the 80's called "Epsilon' - very clever engineering indeed.
... all the best
The 'tail' on the B & W mids is actually called a 'tapered resistance tube' - thye Nautilus version has an hole/port at the rear altho hard to make out in their 'white paper'
There's quite a bit of material here in the archives about spherical/teardrops and because of the manufacturing difficulty, it's usually seen only in the more expensive products.
The material/shape design should contain a method to stop any ringing (usually higher mass and damping material (ie 'AudioSpheres) or a design that uses unequal acoustical sections (Overkill one)
Their is still info on the French speakers of the 80's called "Epsilon' - very clever engineering indeed.
... all the best
Tear drops look cool from a design standpoint, but are a pain to make. If you want the sonic benefits of a non-parallel wall enclosure, try a 3-sided pyramid (or tall tetrahedron) that I call the 'Dagger'. It can be made sealed or with a small vent for an aperiodic TL. It has essentially zero coloration to the sound as there is essentially no back reflections onto the cone. A round tear drop has rotational symmetry and thus, there is the symmetric tangential ("whispering gallery") mode of resonance that will have a peak and show up as coloration.
More info on the Dagger here:
http://www.diyaudio.com/forums/full-range/273524-10f-8424-rs225-8-fast-ref-monitor.html
Here is the frequency response of the Dagger in a 2-way. No EQ was used - and you can see the flatness of the response with a ScanSpeak 10F/8424 driver. The Dagger sounds "open" like it was an open baffle, but provides additional cone motion control not available with OB.
Overall response with woofer:
At higher vertical resolution:
Example of Dagger outside by itself:
I know it doesn't look like a teardrop, but you can always add material on the outside of the Dagger to shape it like a teardrop externally.
More info on the Dagger here:
http://www.diyaudio.com/forums/full-range/273524-10f-8424-rs225-8-fast-ref-monitor.html
Here is the frequency response of the Dagger in a 2-way. No EQ was used - and you can see the flatness of the response with a ScanSpeak 10F/8424 driver. The Dagger sounds "open" like it was an open baffle, but provides additional cone motion control not available with OB.
Overall response with woofer:
At higher vertical resolution:
Example of Dagger outside by itself:
I know it doesn't look like a teardrop, but you can always add material on the outside of the Dagger to shape it like a teardrop externally.
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I think you should see this thread: http://www.diyaudio.com/forums/full-range/167744-fe168e-sigma-teardrop-enclosure.html
Pictures weren't showing on the first page but there is a lot of info, also from Derek (Overkill): http://www.diyaudio.com/forums/full-range/167744-fe168e-sigma-teardrop-enclosure-28.html
Pictures weren't showing on the first page but there is a lot of info, also from Derek (Overkill): http://www.diyaudio.com/forums/full-range/167744-fe168e-sigma-teardrop-enclosure-28.html
Hmmm Good luck with that.
A few years Back I had a Client who got talked into a Set of B&W Nautilus speakers.... the Shiny Snails.
Part of the Bespoke AV system for his several Million $ "reno" on his Whistler 'cabin' .
I was there for the inaugural.. Fire up.
Hey I like Nifty gear too. Unlikely I would miss it..
Frankly they were unimpressive, surprisingly so, given their 16$ k price tag.
And the Cost no object upstream gear to drive the things.
Mediocre sounds was a charitable descriptor.
Client was less than pleased or impressed.
Red faces on the AV sales guys
Lotsa Hype in Audio Weenie land. NEVER lose sight of that small factoid.
But hey! the client bought into the Hype and graciously accepted the consequences.. significant $$ losses on returning the things for an Upgrade to Wilson's.
Caveat Emptor
A few years Back I had a Client who got talked into a Set of B&W Nautilus speakers.... the Shiny Snails.
Part of the Bespoke AV system for his several Million $ "reno" on his Whistler 'cabin' .
I was there for the inaugural.. Fire up.
Hey I like Nifty gear too. Unlikely I would miss it..
Frankly they were unimpressive, surprisingly so, given their 16$ k price tag.
And the Cost no object upstream gear to drive the things.
Mediocre sounds was a charitable descriptor.
Client was less than pleased or impressed.
Red faces on the AV sales guys
Lotsa Hype in Audio Weenie land. NEVER lose sight of that small factoid.
But hey! the client bought into the Hype and graciously accepted the consequences.. significant $$ losses on returning the things for an Upgrade to Wilson's.
Caveat Emptor
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Are you saying Nautilus speakers were not impressive sounding? I thought they were $80k speakers not $16k?
Thank you all for your suggestions, i had already seen the design of Derek Wilson, really impressive...
xrk971 thank you for the dragger internal shape suggestion.
What you think about this vividaudio design?
http://www.vividaudio.com/images/docs/making-giya.pdf
They used bass reflex and a tapered tube to eliminate resonances for a the woofer enclosure, look at page 19/20. Could this work for a fullrange driver?
What a bout the TB drivers, i read w4-1337SDF to be a bit "cold" and analytical and the w5-1611 softer and warmer, any experience?
xrk971 thank you for the dragger internal shape suggestion.
What you think about this vividaudio design?
http://www.vividaudio.com/images/docs/making-giya.pdf
They used bass reflex and a tapered tube to eliminate resonances for a the woofer enclosure, look at page 19/20. Could this work for a fullrange driver?
What a bout the TB drivers, i read w4-1337SDF to be a bit "cold" and analytical and the w5-1611 softer and warmer, any experience?
xrk - B&W's "Nautilus" technology encompasses a series of models, and I think that most of us will have only had opportunity to hear various models in the 800 series (6 or so at last count?) - the current top models of which are in the $16K (USD) range. I've heard those in a local dealer, and frankly if I had that kind of money to burn would probably go for something like the Sonus Faber Elipsa or Stradivarius.
It'd be interesting to audition the full snail version as a curiosity, but extrapolating on both the 800 Diamonds, and the last big full zoot Linn active system ( Keltik or some such), for me the threshold for diminishing returns is at least 2 decimal points to the left of what any of these "serious" systems cost.
As for the Vivids, they bear more than a few similarities to the driver, enclosures and materials /production engineering demonstrated by the B&W Nautilus, but I guess aesthetic beauty is in the eye of the beholder. They gave both myself and wife a very distinct initial impression - for me the Smurf hat, and for her the DQ soft ice cream cone curly top
Her opinion of the B&W was less appreciative.
All are gorgeous examples of form following function, extensive acoustic and electronic engineering and artful production design.
It'd be interesting to audition the full snail version as a curiosity, but extrapolating on both the 800 Diamonds, and the last big full zoot Linn active system ( Keltik or some such), for me the threshold for diminishing returns is at least 2 decimal points to the left of what any of these "serious" systems cost.
As for the Vivids, they bear more than a few similarities to the driver, enclosures and materials /production engineering demonstrated by the B&W Nautilus, but I guess aesthetic beauty is in the eye of the beholder. They gave both myself and wife a very distinct initial impression - for me the Smurf hat, and for her the DQ soft ice cream cone curly top
An externally hosted image should be here but it was not working when we last tested it.
Her opinion of the B&W was less appreciative.
All are gorgeous examples of form following function, extensive acoustic and electronic engineering and artful production design.
I've been on the lookout for a suitable teardrop shaped 'anything' like light fittings, hairdrier covers, aircraft nacelles, fishing net floats, etc but unsuccessful so far - I'm told I can get well finished metal spinnings for an exterior mold, possible in 2 parts (front speaker & rear teardrop/taper) and possibly use an internal 'plug mold but a recent change in driver has meant starting again ...
Tapered resistance for bass drivers is a bit of a 'hit & miss' exercise without a measuring mike and display, as the benefits are determined by the rate of increased density down the decreased X section area of the tube, the length of the tube, and the pressure (volume) also - too many variables that don't seem to behave in any program I've tried but this also might mean that I'm just not smart enough to make it work or to simplify things enough - the longer wavelengths in the bass region make realistic compromises another challenge - subwoofers look a lot easier in comparison, even distributed subs like Floyd Toole suggests
I'm told that Epsilon speakers (from years gone by) had worked out a really neat way of controlling the back wave without overdampening the cone but alas, the designs aren't available any more - I've only seen a cursory glance inside a small Gallo sphere which seem to require just basic damping material, but their driver behaviour could easily be built to work this way as they're an 'old hand' at this sort of chamber.
A few years ago, I was quite surprised by the sound that the Avantegarde Solo speakers - perhaps not their top of the range audiophile model, but ...
I didn't take to the Vivids at all - could have been the unfavourable room at an audio show maybe or the associated system.
Tapered resistance for bass drivers is a bit of a 'hit & miss' exercise without a measuring mike and display, as the benefits are determined by the rate of increased density down the decreased X section area of the tube, the length of the tube, and the pressure (volume) also - too many variables that don't seem to behave in any program I've tried but this also might mean that I'm just not smart enough to make it work or to simplify things enough - the longer wavelengths in the bass region make realistic compromises another challenge - subwoofers look a lot easier in comparison, even distributed subs like Floyd Toole suggests
I'm told that Epsilon speakers (from years gone by) had worked out a really neat way of controlling the back wave without overdampening the cone but alas, the designs aren't available any more - I've only seen a cursory glance inside a small Gallo sphere which seem to require just basic damping material, but their driver behaviour could easily be built to work this way as they're an 'old hand' at this sort of chamber.
A few years ago, I was quite surprised by the sound that the Avantegarde Solo speakers - perhaps not their top of the range audiophile model, but ...
I didn't take to the Vivids at all - could have been the unfavourable room at an audio show maybe or the associated system.
I have tested 3" TB in a 1,5 liter soft drink bottle after some sims with MJK models. Some stuffing was needed ti smooth out the 170 Hz ripple.
This was mosly for fun, but it worked. No low bass of corce, but not bad.
Bjørn
This was mosly for fun, but it worked. No low bass of corce, but not bad.
Bjørn
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