I've posted a few other times asking for design help on this project and recieved very helpful feedback. Now I'm asking for a "ROAST" please give me any pros or cons, likes or dislikes to this 26 sided enclosure shape (rhombicuboctahedron) when used for a sub.
Rule out any complications in construction, I created a Excel program that will determine the exact exterior dimensions for all sides of this shape given any internal volume I plug in. And I own a cabinet shop to build them in.
So far I've built blank .75"MDF enclosures in the following sizes: 1.3cu.ft (10" baffles) , 1.62 cu.ft (10.5" baffles), 2.8cu.ft (11.5" baffles) and 3.2ft (13" baffles)
This enclosure will comfortably hold between 2 and 6 drivers.
Please fire away at this design...I asked for it!
thx...Chris
http://ncd296.spencer.netclusive.de/speakerworld/bauvorschlag/trilo_urps/trilo_urps.jpg
Rule out any complications in construction, I created a Excel program that will determine the exact exterior dimensions for all sides of this shape given any internal volume I plug in. And I own a cabinet shop to build them in.
So far I've built blank .75"MDF enclosures in the following sizes: 1.3cu.ft (10" baffles) , 1.62 cu.ft (10.5" baffles), 2.8cu.ft (11.5" baffles) and 3.2ft (13" baffles)
This enclosure will comfortably hold between 2 and 6 drivers.
Please fire away at this design...I asked for it!
thx...Chris
http://ncd296.spencer.netclusive.de/speakerworld/bauvorschlag/trilo_urps/trilo_urps.jpg
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My $0.02
Why such a complicated shape? In many cases people mention diffraction and reducing standing waves inside the enclosure - without realising that the wavelength is likely to be in the range of 3 to 17 metres and the shape of the box won't make much difference. If each woofer requires a box volume of say 20L, well then the combined volume should be 120L, unless appearances are deceptive and that box is bigger than it looks. I assume the huge black boxes that look like amplifiers will power this beast to keep you warm in winter
?
I'm assuming your sub is designed for "SPL" - high volume, lot's of stress on each woofer, and if one of them were to stop working, then that wouldn't be particularly good for other 5 woofers either....Unless you made 6 separate enclosures in anticipation of failure. Ok I tried being harsh, but that's the best I could do.
CM
Why such a complicated shape? In many cases people mention diffraction and reducing standing waves inside the enclosure - without realising that the wavelength is likely to be in the range of 3 to 17 metres and the shape of the box won't make much difference. If each woofer requires a box volume of say 20L, well then the combined volume should be 120L, unless appearances are deceptive and that box is bigger than it looks. I assume the huge black boxes that look like amplifiers will power this beast to keep you warm in winter
?I'm assuming your sub is designed for "SPL" - high volume, lot's of stress on each woofer, and if one of them were to stop working, then that wouldn't be particularly good for other 5 woofers either....Unless you made 6 separate enclosures in anticipation of failure. Ok I tried being harsh, but that's the best I could do.
CM
While it's aesthetically interesting looking it's complexity serves absolutely no practical or functional benefit that I can determine. In fact the shape poses somewhat of a drawback in that the fairly large amount of living space it consumes is compounded by the fact that nothing can be set on top of it in any way to allow it to at least serve some double utilitarian duty... not even a book... but then I guess it's meant to stand out alone as it's own loud artistic decor statement. I assume you intend to include a grill to protect the woofers (especially the upward firing from falling objects.)
It gets a major thumbs down from me for practicality & functionality but I suppose the average person with no knowledge of acoustics & speaker design might find it a pleasing piece of decor.
It gets a major thumbs down from me for practicality & functionality but I suppose the average person with no knowledge of acoustics & speaker design might find it a pleasing piece of decor.
Erm.... not quite true, the shape is inherently
more rigid than an equivalent plain box.
This is only due to the choice of the base mounting, a
standard box cube could be set onto a base this way.
Personally think it would look quite nice with a
single driver face down and 4 feet on that face.
The well known Linkwitz Transform would need to be used,
isolating each driver is also a choice needed for plain boxes.
Personally I can't see any wrong with the box design
at all, as long as getting the pieces cut is not a hassle.
In a normal orientation it will look small for its size.
Has some similarities with Tannoy's six
sided truncated triangular speakers.
sreten.
Thank you all for the replies. My response to a couple things mentioned.
The foot print that this enclosure takes up is surprising. if set on one of the larger sides like a typical sub enclosure would sit the dimensions of the pictured box is 18" x 18" x 18" Whent the cube si truncated in this fashion and set on one of the small corners (like the one in the pic) its footprint turns into 19.5 x 19.5 x 19.5. So it really does not consume much more space than a box.
Admittedly this enclosure was built based on aesthetic. While it may not fit the design aesthic of most homes I wanted something that would work in my home (modernist architecture).
This enclosure allows for great flexibility. You could, if crazy enough place drivers on all 6 sides.
I will gladly provide the exterior dimensions for people if they provide me with a target interior volume.
Can you guys recommend any driver arrangements. I have a bunch of these enclosures to experiment on.
thanks for all the great ideas & help
cg
The foot print that this enclosure takes up is surprising. if set on one of the larger sides like a typical sub enclosure would sit the dimensions of the pictured box is 18" x 18" x 18" Whent the cube si truncated in this fashion and set on one of the small corners (like the one in the pic) its footprint turns into 19.5 x 19.5 x 19.5. So it really does not consume much more space than a box.
Admittedly this enclosure was built based on aesthetic. While it may not fit the design aesthic of most homes I wanted something that would work in my home (modernist architecture).
This enclosure allows for great flexibility. You could, if crazy enough place drivers on all 6 sides.
I will gladly provide the exterior dimensions for people if they provide me with a target interior volume.
Can you guys recommend any driver arrangements. I have a bunch of these enclosures to experiment on.
thanks for all the great ideas & help
cg
Stephen D said:
The exact same statement could be applied to any number of objects found in a typical art museum !!!
And I think this creation pretty much qualifies as art. To make it practical - How about a single Peerless XLS with the matching passive radiator? That would be just about perfect in ~2 sq. ft. version - and it would preserve the aesthetics as well...I give it two thumbs up - no, make that THREE thumbs up (as in a Picasso I once saw where the guy actually HAD three thumbs)...
But that was art too! 
Very Nice...
I’m a big fan of unconventional and unique enclosure designs, so I love the looks and the design. However since you asked for critiquing I will have to mention the one drawback I see, Price, 4 to 6 woofers and the power required to move them to reference levels would be IMO too much considering you can do the same thing with a single woofer and 2 passives in the same size and shape box.
I really like the way the box looks and the stand shows it off nicely, but the cost must be astronomical.
I’m a big fan of unconventional and unique enclosure designs, so I love the looks and the design. However since you asked for critiquing I will have to mention the one drawback I see, Price, 4 to 6 woofers and the power required to move them to reference levels would be IMO too much considering you can do the same thing with a single woofer and 2 passives in the same size and shape box.
I really like the way the box looks and the stand shows it off nicely, but the cost must be astronomical.
Thank you all for this great input!
Please recommend some more driver configerations. I mentioned 4 or more drivers but 2 are fine or even 1 plus a PR is absolutely fine. I agree that the cost is too high for practical applications if you load this sub with so many drivers. However, the way the sub sits really screams out for at leats 2 of the exposed side to be occupied by either a driver or PR.
I might not have been too clear about my goal.
My total target budget for this project is $600
The cost I can produce this enclosure for is $275 out the door
What driver + plate amp configeration might work well on a budget or $325 (not including the prefinished enclosure) in your opinion?
Thanks again for all the input!
Chris
Please recommend some more driver configerations. I mentioned 4 or more drivers but 2 are fine or even 1 plus a PR is absolutely fine. I agree that the cost is too high for practical applications if you load this sub with so many drivers. However, the way the sub sits really screams out for at leats 2 of the exposed side to be occupied by either a driver or PR.
I might not have been too clear about my goal.
My total target budget for this project is $600
The cost I can produce this enclosure for is $275 out the door
What driver + plate amp configeration might work well on a budget or $325 (not including the prefinished enclosure) in your opinion?
Thanks again for all the input!
Chris
"serves absolutely no practical or functional benefit that I can determine."
What exactly is that supposed to mean?! So what if you can't put a lamp or book on top of it.
Do you have a lamp or book on top of your computer monitor?! Probably not. Why? Who cares?!
This subs was built to do the same thing as any sub was, to reproduce bass frequencies. And it's probably better than a traditional box for the simple fact that all the sides are as small as possible, making it more rigid than most, unless their built with 1" or 1.5" MDF. Even then, this one is probably still more rigid, due to all the bracing for all those corners.
Personally, I like it. However, it makes me kind of mad that my woodworking skills aren't up to par.
What exactly is that supposed to mean?! So what if you can't put a lamp or book on top of it.
Do you have a lamp or book on top of your computer monitor?! Probably not. Why? Who cares?!
This subs was built to do the same thing as any sub was, to reproduce bass frequencies. And it's probably better than a traditional box for the simple fact that all the sides are as small as possible, making it more rigid than most, unless their built with 1" or 1.5" MDF. Even then, this one is probably still more rigid, due to all the bracing for all those corners.
Personally, I like it. However, it makes me kind of mad that my woodworking skills aren't up to par.
Hey wait a minute fellas... I think you misunderstand my reply totally. I think it's a beautiful piece of art to, & also applaud the skill it took to match up that many angles, but the guy specifically asked for a "ROAST" ... get It.... . 
He wanted cons as well as pros. It was hard enough coming up with what measily critic I could. If you read correctly you will se I also couldn't help but acknowledge it's a nice work of art.
I've never had a problem getting a conventional box design to be plenty rigid with bracing so while true in theory the shape inherently lends itself to greater rigidity I think the end benificial result compared to a well constructed box would be minimal to moot.
"Do you have a lamp or book on top of your computer monitor?!"
No, but I have an amplifier & a book on top of my subwoofer.
Of course it doesn't have to serve any more functionality & practicality than to sound good (which I'm sure it can & never criticized it for not) but any time you can add or maximize functionality to a design I think it's a plus.
I still think I correctly pointed out that this is 1st & foremost a work of art decor with the added function of being a subwoofer, so in that respect it is multifunctional . I did fail to point that out.
Sonically & structurally I can find nothing wrong with it compared to conventional designs (Just don't see any real benefit in this department either).
Aesthetically it excels over conventional designs ( as I initially inferred)
He asked to be roasted... not just patted on the back. Sorry, but not being able to set something on top of it is the only negative I could come up with. I agree that's a minor complaint but I haven't seen any of you come up with a better one yet.
Christof;
Any idea what the internal volume calculates out to be? That might help with driver recommendations.
He wanted cons as well as pros. It was hard enough coming up with what measily critic I could. If you read correctly you will se I also couldn't help but acknowledge it's a nice work of art. I've never had a problem getting a conventional box design to be plenty rigid with bracing so while true in theory the shape inherently lends itself to greater rigidity I think the end benificial result compared to a well constructed box would be minimal to moot.
"Do you have a lamp or book on top of your computer monitor?!"
No, but I have an amplifier & a book on top of my subwoofer.
Of course it doesn't have to serve any more functionality & practicality than to sound good (which I'm sure it can & never criticized it for not) but any time you can add or maximize functionality to a design I think it's a plus.
I still think I correctly pointed out that this is 1st & foremost a work of art decor with the added function of being a subwoofer, so in that respect it is multifunctional
. I did fail to point that out.Sonically & structurally I can find nothing wrong with it compared to conventional designs (Just don't see any real benefit in this department either).
Aesthetically it excels over conventional designs ( as I initially inferred)
He asked to be roasted... not just patted on the back. Sorry, but not being able to set something on top of it is the only negative I could come up with.
I agree that's a minor complaint but I haven't seen any of you come up with a better one yet. Christof;
Any idea what the internal volume calculates out to be? That might help with driver recommendations.
It is a gorgeous piece of woodwork, and i am a big fan of enclosures that aren't just plain boxes... funcionaly thou it is pretty much just a cube, which would be easier and less expensive to build.
As to drivers -- i always like to use pairs in push-push (ie opposite sides). To maximize the visual potential you would need to use 4 smallish drivers with relatively small Vas. Perhaps 4 of the ApexJr 8" subs. You could get away with 1.35 ft^3 net volume.
Excluding shipping costs that would leave you $185 for a plate amp -- enuff to get Steve's big plate amp (with $25 left over for shipping).
dave
As to drivers -- i always like to use pairs in push-push (ie opposite sides). To maximize the visual potential you would need to use 4 smallish drivers with relatively small Vas. Perhaps 4 of the ApexJr 8" subs. You could get away with 1.35 ft^3 net volume.
Excluding shipping costs that would leave you $185 for a plate amp -- enuff to get Steve's big plate amp (with $25 left over for shipping).
dave
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