sphere shaped speakers

[rokr]

I've been asked to build sphere shaped speakers (passive). I did some research and found out that some consider this shape as the worst and some thinks it’s the best… anyway, I decides to move on with this project knowing that this one won't win any audiophile awards but hopefully will look good and have a decent sound.

I also found that one of the easiest ways to create a sphere is using Ikea's bamboo salad bowls (I was initially thinking of using concrete), but I couldn't find plans for it.

So, I'm going to have a 27cm inner diameter, about 9 liters internal volume sphere.

A full range driver seems like the obvious choice (I know about the disadvantages of this type of driver).

So, my questions are, are there specific drivers (3.5-4") you recommend for this project, about up to 100$ for pair (I was thinking about Mark audio chr70, or dyton audio rs100) ? Should it be sealed or ported?

Any information will be appreciated.

 

[voodooless]

I also found that one of the easiest ways to create a sphere is using Ikea's bamboo salad bowls (I was initially thinking of using concrete), but I couldn't find plans for it.

There are a few projects out there:

IKEA Blanda Bamboo Bowl Speakers

Hi all, I was hoping I could get some advice on routing. I’m looking to build a pair of speakers with the IKEA blanda bamboo bowls. Now I’ll be the first to admit I’m somewhat challenged when it comes to wood working ( and that’s been somewhat kind). :( I’ve just got a plunge/fixed router and...

www.diyaudio.com

Ikea Salad Bowl speakers with internal amp, battery, and bluetooth - Techtalk Speaker Building, Audio, Video Discussion Forum

Show off your speaker projects by posting the details and images of your creations. We encourage you to discuss with the speaker project designer his methods and results.

techtalk.parts-express.com

Drivers from Markaudio can be nice, FaitalPro 3 and 4" drivers, Scanspeak 10F... a few more

Here are some of them tested: https://www.dibirama.altervista.org/le-prove/full-range.html

 

[Killingbeans]

I did some research and found out that some consider this shape as the worst and some thinks it’s the best…

It's the best external shape, and the worst internal shape.

 

[JPA]

It's the best external shape, and the worst internal shape.

Yes. However, if you keep it sealed and stuff it with fiberglass you won't have any internal resonances.

 

[voodooless]

Yes. However, if you keep it sealed and stuff it with fiberglass you won't have any internal resonances.

Adding some braces inside would also work in breaking resonances.

 

[rokr]

There are a few projects out there:

IKEA Blanda Bamboo Bowl Speakers

Hi all, I was hoping I could get some advice on routing. I’m looking to build a pair of speakers with the IKEA blanda bamboo bowls. Now I’ll be the first to admit I’m somewhat challenged when it comes to wood working ( and that’s been somewhat kind). :( I’ve just got a plunge/fixed router and...

www.diyaudio.com

Ikea Salad Bowl speakers with internal amp, battery, and bluetooth - Techtalk Speaker Building, Audio, Video Discussion Forum

Show off your speaker projects by posting the details and images of your creations. We encourage you to discuss with the speaker project designer his methods and results.

techtalk.parts-express.com

Drivers from Markaudio can be nice, FaitalPro 3 and 4" drivers, Scanspeak 10F... a few more

Here are some of them tested: https://www.dibirama.altervista.org/le-prove/full-range.html

Thanks. There are no actual plans, but some good information.
Looking at the drivers web-site measurements, seems like the manufacturers are having difficulties with measuring their own drivers...

 

[rokr]

Adding some braces inside would also work in breaking resonances.

Hoe would you brace this shape? maybe a pole from the top to the bottom.

 

[highender]

Spherical outside, cylindrical inside perhaps? Like these.

 

[Mr. Widget]

I've been asked to build sphere shaped speakers (passive). I did some research and found out that some consider this shape as the worst and some thinks it’s the best… anyway, I decides to move on with this project knowing that this one won't win any audiophile awards but hopefully will look good and have a decent sound.

It seems this is a perfect project for 3D printing. You can build a 3D model of almost any size desired with internal bracing, speaker and crossover mounting bosses, and every feature you need. If you use a commercial service instead of the inexpensive home DIY printers, you can even choose your material to give you an inert nonresonant shell. Proto Labs offers an impressive array of material options to choose from.

Edit: As a former professional prototyper I was focused on the "how to" side of the problem. In re-reading your original post I now noticed your asking for $100 pair driver recommendations. Based on that I guess you have an extremely limited budget so you will likely need to stick with IKEA salad bowls. The Photo Labs solution will allow you to develop a next level spherical loudspeaker, but not at an "Amazon Basics" price level.

 

[rokr]

Spherical outside, cylindrical inside perhaps? Like these.

This is interesting, i can cut a cylinder out from a dense sponge ball which is slightly bigger then the internal sphere and use the the ball as dampening and the hole as a cylinder.
The pressure will give a little bracing, the sponge will give dampening and the cylinder shape is better then the sphere.
Making a wood cylinder to match the spheres contour is way over my woodworking skills.

 

[rokr]

It seems this is a perfect project for 3D printing. You can build a 3D model of almost any size desired with internal bracing, speaker and crossover mounting bosses, and every feature you need. If you use a commercial service instead of the inexpensive home DIY printers, you can even choose your material to give you an insert nonresonant shell. Proto Labs offers an impressive array of material options to choose from.

Edit: As a former professional prototyper I was focused on the "how to" side of the problem. In re-reading your original post I now noticed your asking for $100 pair driver recommendations. Based on that I guess you have an extremely limited budget so you will likely need to stick with IKEA salad bowls. The Photo Labs solution will allow you to develop a next level spherical loudspeaker, but not at an "Amazon Basics" price level.

While a printed speaker could definitely be better, it will be a lot harder to design (tinkercad is as far as I've gone in 3d design...), a lot more expensive, and will never be as beautiful as real bamboo.

 

[jaakkopetteri]

I would try a coaxial driver instead of a full-ranger - we're on ASR, after all
The budget is rather restricting (quite impossible if crossovers are accounted for) but the SB Acoustics SB12PFCR25-4-COAX gets pretty close

 

[ppataki]

I've been asked to build sphere shaped speakers (passive). I did some research and found out that some consider this shape as the worst and some thinks it’s the best… anyway, I decides to move on with this project knowing that this one won't win any audiophile awards but hopefully will look good and have a decent sound.

I also found that one of the easiest ways to create a sphere is using Ikea's bamboo salad bowls (I was initially thinking of using concrete), but I couldn't find plans for it.

So, I'm going to have a 27cm inner diameter, about 9 liters internal volume sphere.

A full range driver seems like the obvious choice (I know about the disadvantages of this type of driver).

So, my questions are, are there specific drivers (3.5-4") you recommend for this project, about up to 100$ for pair (I was thinking about Mark audio chr70, or dyton audio rs100) ? Should it be sealed or ported?

Any information will be appreciated.

I would use a Markaudio CHN110 driver - it sounds great even without serious DSP (not sure if you will have DSP capability)
In a 9 liter well-stuffed sealed box it will have a Qtc value of 0.6 and will produce 89dB SPL at 1 meter at 30Hz (95dB for two + room gain) with 55W max power (xmax limited)

 

[rokr]

I would try a coaxial driver instead of a full-ranger - we're on ASR, after all
The budget is rather restricting (quite impossible if crossovers are accounted for) but the SB Acoustics SB12PFCR25-4-COAX gets pretty close

We definitely don't want to get Amir angry especially after the Towelgate
I was thinking about a coaxial and after building Neil Blanchard's MLTL6 speakers I really like SB acoustics, so it's a great idea.
As a speaker that puts looks as a priority, I wish coaxial drivers would look as cool as point source (Kef did it).

 

[rokr]

I would use a Markaudio CHN110 driver - it sounds great even without serious DSP (not sure if you will have DSP capability)
In a 9 liter well-stuffed sealed box it will have a Qtc value of 0.6 and will produce 89dB SPL at 1 meter at 30Hz (95dB for two + room gain) with 55W max power (xmax limited)

You're right and they are actually cheaper in some places then the chr70.
I saw this guy using the Alpair 7 in his sphere speaker, but its an overkill for this project.

 

[jaakkopetteri]

I wish coaxial drivers would look as cool as point source (Kef did it).

What do you mean with "point source" here?

 

[rokr]

What do you mean with "point source" here?

something like this

 

[jaakkopetteri]

something like this
View attachment 328869

Right, I guess you're referring to the phase plug? Coaxials are a point source too

 

[rokr]

Right, I guess you're referring to the phase plug? Coaxials are a point source too

For some reason those phase plug drivers are always referred as point source drivers while coax as coaxial drivers, but yeah, both radiate from one center point, I guess.

 

[gaz]

Here are some tests of small, full-range drivers you may find helpful:

Timothy Feleppa's Pages: Speaker Measurements - Midrange/Fullrange Speakers 4" and smaller

Zaph|Audio