Poor Man’s Planets
Some time ago, in a grey November day I decided to do something about the sound of music in our bedroom. We used a Bluetooth speaker located in the top shelf of our bedroom commode/sideboard, which was neat but no real stereo.
Since I’m a bit of an audiophile naturally I would prefer a (cheaper) alternative to Duevel’s Planets, which are superb sounding omnis with a decent amp, but meanwhile around 1k €/$ a pair and quite large for such a small room - hence the name for the project.
Disclaimer: For me the greatest motivation to build something, whether it is artwork, music, software, home improvement, bikes or this speakers is to create and get something new, which wasn't there before and cannot be acquired otherwise – the days I was poor in any meaning are long gone.
Searching the internet and some retailers I found out about a building kit for classic omnis – as satellites with optional sub woover which would be a basis for some modifications but still 600 to 700 a pair – with unknown sound quality, and no builder or user feedback available … the idea was to use the shelf board as kind of box volume / semi open back solution for the “satellites”…
During searching for wood materials to make the base board from, the Focal Performance Expert Flax PC165F dual speakers came along since I was searching parallel for posibillities to simplify the design, and they are two way speakers and have a near perfect wood-color fabric membrane, and so the idea of simpler “Planets” with only one diffusor/reflector was born.
As they arrived I got my first headwash during this project: “No, you will not build such ugly color-mismatching wood extensions to the shelfboard!” and… much more later “Perhaps in white*, and I don’t want to see any black from the bed!” harsh conditions – I was speechless for some time – because I introduced the project some time ago – and it was wood the whole time.
*which is the second base color of the sideboard
So… time to redesign the materials and composition, from a straight plywood multiplex composition to a plywood – white plastics composition with white ironed edge-Tape around.
I changed the planet holder bows to chromed copper pipe, and bought white Christmas balls in 10cm diameter and a collection of 2 to 3cm diameter ones because it wasn’t possible to figure out the size of the sockets without buying and dismounting them.
And the main board to precoated white shelf boards from the hardware store.
After Christmas (I ordered my own present – a 200W Douk Audio ST-01 PRO Mini HiFi-tube amp)
…all materials had arrived I started to build.
As built plan (after) first build:
In a first step we cut the 125mm Sewage elbows parallel to the shelfboard in my father’s workshop.
I had to remove the inner section later.
I made several cut outs from the plywood until it fits.
Two layers of plywood were glued together/laminated and screwed+glued to the parallel boards, which have been screwed to the sewage-elbows before,
and the upper bows filled with brick-layered cut wood strips – I was not able to saw out the exact needed shape with the electric jigsaw, and was not enthusiastic enough to do so with the manual saw.
I had changed the width of the horizontal ear boards because the planned width seemed too narrow during building. In the effect I had some trouble with cutting and glueing the plastic board because I had to mirror one side to minimize waste and gaining enough area.
Turns out copper plumbing-Ts are eighter too large or too small, such I ended with screwing a short section/ring of 30mm plastic pipe to a wooden peg which perfectly fits in the chromed copper pipe bow. In the larger glass balls I put a wooden strip with a hollow nut in the middle, and in the smaller glass balls I glued a fitting mechanical bolt/screw and screwed it through the plastics ring together.
First test of the setup was sobering, I was disappointed, the sound was telephonic with a lot of resonances and nearly no bass. I had to ad to add additional wood bars behind, and wood strips to the front board to eliminate resonance of the boards and sound damping layering in the pipe-elbow ends, the elbow itself and a squared absorber foam block in elongation to the front board
– And to finally get some bass I added a passive bass reflection absorber box in the middle of the shelf.
And I added another wood block as support beam for a furniture foot used as a clamp to press the upper side of the speakers’ boards against the top board of the side board.
Now I was satisfied with the sound for some time – real good jazz speakers for soft to medium volume, with very precise stereo position and depth… And with some SciFi finish…
In May or June I built additional front boards from new 60cm long shelfboards (and remainders from the building process as support in the back) to increase the volume of the boxes mainly for bass…
It got more bass, but lowered brilliance and a second “headwash”, she didn’t want to see the new fronts again – too large!
So I only tested them from time to time but was never satisfied myself…
Some weeks ago I had another “sting” and sat down to redesign the speakers in terms of used volume and resonance prevention – I ended up with larger, slightly downward pointing front board - preventing steady front to back and “circular” reflections. Second topic was a slightly backward aimed /”opening” back board to prevent in phase front to back reflections – but both would require a real wood workshop for milling straight flush egdes – better tools and a complete disassembly and nearly total rebuild of the speakers… both a bit out of reach…
But since I got the “sting” I decided to do it half way! I used the electric saw to remove half of the back boards and the wood strips to the front. Then I added the 60cm front board which I cleaned from the supports and did it in a slide angle as planned and shifted so only 12cm longer, as long as the added absorber foam block before, connected / supported with wood glue, wood strips and 6 wood screws. Layered with flooring fabric at the ends – the absorber turned 120 degrees inwards. So there is a nice slight bass reflex horn like design (including the passive box) now.
The appearance changed a bit from technical (visual pipe elbows) to clean Bauhaus style.
The sound is brilliant, precise stereo position (i.e. Yosi Horikawa – Bubbles), room filling – great depth esp. in ambient (like) productions (i.e. Pink Floyd – nearly any Intro, esp. High Hopes [from the division bell], Hattler – Sand am Meer [from Warhol Holidays]; Carbon Based Lifeforms – M [from Interloper], Massive Attack – anything from Mezzanine, Dan Gibsons Solitudes – Rocky Mountains Suite), decent bass – I am very happy and satisfied …
…awaiting the final “headwash” when she notices the larger front boards, if, ever…
probability sinks, weeks in the aftermath … 😉
in the moment i'm writing this i'm lounging on the bed, listening to Moby and Two Lanes and simply enjoying the great sound...
Some time ago, in a grey November day I decided to do something about the sound of music in our bedroom. We used a Bluetooth speaker located in the top shelf of our bedroom commode/sideboard, which was neat but no real stereo.
Since I’m a bit of an audiophile naturally I would prefer a (cheaper) alternative to Duevel’s Planets, which are superb sounding omnis with a decent amp, but meanwhile around 1k €/$ a pair and quite large for such a small room - hence the name for the project.
Disclaimer: For me the greatest motivation to build something, whether it is artwork, music, software, home improvement, bikes or this speakers is to create and get something new, which wasn't there before and cannot be acquired otherwise – the days I was poor in any meaning are long gone.
Searching the internet and some retailers I found out about a building kit for classic omnis – as satellites with optional sub woover which would be a basis for some modifications but still 600 to 700 a pair – with unknown sound quality, and no builder or user feedback available … the idea was to use the shelf board as kind of box volume / semi open back solution for the “satellites”…
During searching for wood materials to make the base board from, the Focal Performance Expert Flax PC165F dual speakers came along since I was searching parallel for posibillities to simplify the design, and they are two way speakers and have a near perfect wood-color fabric membrane, and so the idea of simpler “Planets” with only one diffusor/reflector was born.
As they arrived I got my first headwash during this project: “No, you will not build such ugly color-mismatching wood extensions to the shelfboard!” and… much more later “Perhaps in white*, and I don’t want to see any black from the bed!” harsh conditions – I was speechless for some time – because I introduced the project some time ago – and it was wood the whole time.
*which is the second base color of the sideboard
So… time to redesign the materials and composition, from a straight plywood multiplex composition to a plywood – white plastics composition with white ironed edge-Tape around.
I changed the planet holder bows to chromed copper pipe, and bought white Christmas balls in 10cm diameter and a collection of 2 to 3cm diameter ones because it wasn’t possible to figure out the size of the sockets without buying and dismounting them.
And the main board to precoated white shelf boards from the hardware store.
After Christmas (I ordered my own present – a 200W Douk Audio ST-01 PRO Mini HiFi-tube amp)
…all materials had arrived I started to build.
As built plan (after) first build:
In a first step we cut the 125mm Sewage elbows parallel to the shelfboard in my father’s workshop.
I had to remove the inner section later.
I made several cut outs from the plywood until it fits.
Two layers of plywood were glued together/laminated and screwed+glued to the parallel boards, which have been screwed to the sewage-elbows before,
and the upper bows filled with brick-layered cut wood strips – I was not able to saw out the exact needed shape with the electric jigsaw, and was not enthusiastic enough to do so with the manual saw.
I had changed the width of the horizontal ear boards because the planned width seemed too narrow during building. In the effect I had some trouble with cutting and glueing the plastic board because I had to mirror one side to minimize waste and gaining enough area.
Turns out copper plumbing-Ts are eighter too large or too small, such I ended with screwing a short section/ring of 30mm plastic pipe to a wooden peg which perfectly fits in the chromed copper pipe bow. In the larger glass balls I put a wooden strip with a hollow nut in the middle, and in the smaller glass balls I glued a fitting mechanical bolt/screw and screwed it through the plastics ring together.
First test of the setup was sobering, I was disappointed, the sound was telephonic with a lot of resonances and nearly no bass. I had to ad to add additional wood bars behind, and wood strips to the front board to eliminate resonance of the boards and sound damping layering in the pipe-elbow ends, the elbow itself and a squared absorber foam block in elongation to the front board
– And to finally get some bass I added a passive bass reflection absorber box in the middle of the shelf.
And I added another wood block as support beam for a furniture foot used as a clamp to press the upper side of the speakers’ boards against the top board of the side board.
Now I was satisfied with the sound for some time – real good jazz speakers for soft to medium volume, with very precise stereo position and depth… And with some SciFi finish…
In May or June I built additional front boards from new 60cm long shelfboards (and remainders from the building process as support in the back) to increase the volume of the boxes mainly for bass…
It got more bass, but lowered brilliance and a second “headwash”, she didn’t want to see the new fronts again – too large!
So I only tested them from time to time but was never satisfied myself…
Some weeks ago I had another “sting” and sat down to redesign the speakers in terms of used volume and resonance prevention – I ended up with larger, slightly downward pointing front board - preventing steady front to back and “circular” reflections. Second topic was a slightly backward aimed /”opening” back board to prevent in phase front to back reflections – but both would require a real wood workshop for milling straight flush egdes – better tools and a complete disassembly and nearly total rebuild of the speakers… both a bit out of reach…
But since I got the “sting” I decided to do it half way! I used the electric saw to remove half of the back boards and the wood strips to the front. Then I added the 60cm front board which I cleaned from the supports and did it in a slide angle as planned and shifted so only 12cm longer, as long as the added absorber foam block before, connected / supported with wood glue, wood strips and 6 wood screws. Layered with flooring fabric at the ends – the absorber turned 120 degrees inwards. So there is a nice slight bass reflex horn like design (including the passive box) now.
The appearance changed a bit from technical (visual pipe elbows) to clean Bauhaus style.
The sound is brilliant, precise stereo position (i.e. Yosi Horikawa – Bubbles), room filling – great depth esp. in ambient (like) productions (i.e. Pink Floyd – nearly any Intro, esp. High Hopes [from the division bell], Hattler – Sand am Meer [from Warhol Holidays]; Carbon Based Lifeforms – M [from Interloper], Massive Attack – anything from Mezzanine, Dan Gibsons Solitudes – Rocky Mountains Suite), decent bass – I am very happy and satisfied …
…awaiting the final “headwash” when she notices the larger front boards, if, ever…
probability sinks, weeks in the aftermath … 😉
in the moment i'm writing this i'm lounging on the bed, listening to Moby and Two Lanes and simply enjoying the great sound...
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Thanks, great documentation!
I guess you will get some comb filter effect and several strong early reflections from the dual diffractor and the very nearby wall.
Did you take any measurements?
I guess you will get some comb filter effect and several strong early reflections from the dual diffractor and the very nearby wall.
Did you take any measurements?
An original idea, an almost invisible extension to a shelf (largely due to the lower section a similar colour to the wall). I wonder if a simple cone diffuser would work better. .
@stv
from my experience with the original Duevel Planets, which i own for 16ys now, i can say that omnis are very comfortable with every environment you can place them like you want to and get no strange effects in phase (opposite to open baffles) or sweet spots or muffled spots. As long as the diffusors can freely radiate and are not enclosed in furniture gaps or something. The only downside with the original planets is that there are 2 diffusor planets and you can get in fact muffled treble if you manage to "shadow" the treble horn "planet" with the bass "planet" (they are approx. 10cm spaced apart), but thats really hard to manage
Unfortunately in spite to my university time i have no access to high quality measuring equipment - so i go by golden (or not so golden) ear and listen to many types of music, and distinct titels for specific topics and compare to my other setups (see my introduction). I would definitely say you get no noticable comb filter effect or any other downside from reflection, Omnis (and these as well) sound a bit like a audio type hologram. You record something at two points is space recording every incoming sound from any direction, and you play the thing to two points in space, radiating it to any direction again.
@cracked case
i don't think so, the original planets use sheet metal balls, and sound fantastic without any direction problem in vertical listening position, and without noticable resonance effects.
I did some experiments during the build and setup process - outcome: you can even use unregular bodies as diffusor, as long as there is enough reflection to the listening position - a flower pot will do too. but you have to use the right size, i.e. with the large ball alone, there is not enough treble reflection around, or no omni effect.
i.e. these use a pipe and another speaker:
So in my case dual cone meets dual ball (or similarly) - the distance between cone and ball is adapted loosely from the originals, but the balls placed together.
And even if i had to bend my mind a bit to find a useful construction method to put these parts together, it is in the result much more easier to get good looks and sound like this, as if you have to mill different wooden cones with no milling equipment, not knowing if the picked/designed shape will sound fine in the end (with cones i really have no experience). Looking at the high class range of i.e. Duevel you come around very different cone shapes...
from my experience with the original Duevel Planets, which i own for 16ys now, i can say that omnis are very comfortable with every environment you can place them like you want to and get no strange effects in phase (opposite to open baffles) or sweet spots or muffled spots. As long as the diffusors can freely radiate and are not enclosed in furniture gaps or something. The only downside with the original planets is that there are 2 diffusor planets and you can get in fact muffled treble if you manage to "shadow" the treble horn "planet" with the bass "planet" (they are approx. 10cm spaced apart), but thats really hard to manage
Unfortunately in spite to my university time i have no access to high quality measuring equipment - so i go by golden (or not so golden) ear and listen to many types of music, and distinct titels for specific topics and compare to my other setups (see my introduction). I would definitely say you get no noticable comb filter effect or any other downside from reflection, Omnis (and these as well) sound a bit like a audio type hologram. You record something at two points is space recording every incoming sound from any direction, and you play the thing to two points in space, radiating it to any direction again.
@cracked case
i don't think so, the original planets use sheet metal balls, and sound fantastic without any direction problem in vertical listening position, and without noticable resonance effects.
I did some experiments during the build and setup process - outcome: you can even use unregular bodies as diffusor, as long as there is enough reflection to the listening position - a flower pot will do too. but you have to use the right size, i.e. with the large ball alone, there is not enough treble reflection around, or no omni effect.
i.e. these use a pipe and another speaker:
And even if i had to bend my mind a bit to find a useful construction method to put these parts together, it is in the result much more easier to get good looks and sound like this, as if you have to mill different wooden cones with no milling equipment, not knowing if the picked/designed shape will sound fine in the end (with cones i really have no experience). Looking at the high class range of i.e. Duevel you come around very different cone shapes...
Important Update:
today I finally managed to partially fill the big white christmas balls with small white decoration grit, which was left from Christmas preparations. Fill level approx 2cm, weight gain of the balls assembly approx 150%.
Intention was damping of possible glass resonance in certain frequencies.
I planned this for longer, but the in house available grit was too large, and there was enough work to do otherwise and no urge...
The sound is much more natural / amazing now, hard to describe, even the bass is more pronounced, the more resonant reproduction of already "wood resonant" tracks (I.e. "particles" from Olafur Arnalds & Nanna Bryndís Hilmarsdóttir) is gone now, the improvement is in the same range as the enlargement in November. I didn't think it would be this much better, since the original planets have light balls too, perhaps even thinner, from stainless steel sheet.
Now I am thinking of filling them too, maybe replacing the balls, since they are seamless welded with 2x 2mm screw holes only... No fine sands available in the moment...
today I finally managed to partially fill the big white christmas balls with small white decoration grit, which was left from Christmas preparations. Fill level approx 2cm, weight gain of the balls assembly approx 150%.
Intention was damping of possible glass resonance in certain frequencies.
I planned this for longer, but the in house available grit was too large, and there was enough work to do otherwise and no urge...
The sound is much more natural / amazing now, hard to describe, even the bass is more pronounced, the more resonant reproduction of already "wood resonant" tracks (I.e. "particles" from Olafur Arnalds & Nanna Bryndís Hilmarsdóttir) is gone now, the improvement is in the same range as the enlargement in November. I didn't think it would be this much better, since the original planets have light balls too, perhaps even thinner, from stainless steel sheet.
Now I am thinking of filling them too, maybe replacing the balls, since they are seamless welded with 2x 2mm screw holes only... No fine sands available in the moment...
Update of update, i measured and weighed a little bit, with different fill grade / mass.
The aforementioned filling got 110±4 g (3.9 oz) for the total ball assembly including filling, i tried more and found more is less, and vice versa.
So i ended up with fantastic sounding 85g (3 oz).
The aforementioned filling got 110±4 g (3.9 oz) for the total ball assembly including filling, i tried more and found more is less, and vice versa.
So i ended up with fantastic sounding 85g (3 oz).
During the holidays i got another idea - how about an almost free standing column-like design?
i read a bit and put some figures in the back loaded horn calculator: https://bgaudio.org/horn_en.php
The first sketches were multiple folded all along, but i fanally ended with this almost 1/8 lambda design
- meant to "Eckhorn style" "load" into a room corner or furniture gap - the smaller face (left in the sectional, bottom in horizontal) is the front, the wider face with the horn points to the wall.
both, the angled not parallel walls and the inner walls should provide low resonance, but front back resonance still have to be damped...
Unfortunately this is maybe a nice idea (what do you think?)
but since i miss the appropriate room this will stay a paper dream for a while...
In the meantime a built something totally different in the living room....
i read a bit and put some figures in the back loaded horn calculator: https://bgaudio.org/horn_en.php
The first sketches were multiple folded all along, but i fanally ended with this almost 1/8 lambda design
- meant to "Eckhorn style" "load" into a room corner or furniture gap - the smaller face (left in the sectional, bottom in horizontal) is the front, the wider face with the horn points to the wall.
both, the angled not parallel walls and the inner walls should provide low resonance, but front back resonance still have to be damped...
Unfortunately this is maybe a nice idea (what do you think?)
but since i miss the appropriate room this will stay a paper dream for a while...
In the meantime a built something totally different in the living room....
You might take inspiration as well from Stu Hegeman's 1a from the '70s (right) and the Don Morrison interpretations as the inheritor of Stu's vision (left).
The one on the left looks interesting, I guess a mid/bass cone, and dome tweeter, both at around 45deg, should work well against at wall, HiFi world were certainly impressed by the Kibri Naima speakers when they reviewed them.
That's a Hegeman Model 1(a). Aluminum driver handmade by Hegeman factory, driven full-range (no low-pass filter). Philips tweeter hi-passed at 5kHz. The mounting angle is 20º.
Amazing speakers for the price, have the tightest most articulate bass of any speaker I've heard (no all that many tho). Produce an outstanding 3D sound-stage with optimal placement. Work well flush to the wall, but better pulled out 8-12" plus.