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Homemade speakers/Headphones
- Thread starter R6MGS
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swift6
Yoda
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R6MGS said:
Try this company Parts Express . I get their catalog and they have different speaker building projects all the time in their catalogs/flyers. They also sell all the stuff needed to build them at very reasonable prices.
GregW
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I’ve built a couple home theater systems and I found the book “ Advanced Speaker Design ” quite helpful. I don’t know how involved your son wants to get. Figuring out the best volume (LxWxH) for a given driver involves a fair amount of math and then there is designing a crossover network. There are some programs that can do the math for you. Here is a site that has some to download. Linear Team Here is a shot of a center channel speaker I made.
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Nunyas
Yoda
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nice enclosure!
but I'm thinking that since it's a physics class he may be wanting to build the drivers them selves? meaning assembling the cone, spider, voice coil, magnet and all that... am I right? Or is it just building the speaker cabinet and dropping the drivers into it?
Either way, it'll be a fun project /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
but I'm thinking that since it's a physics class he may be wanting to build the drivers them selves? meaning assembling the cone, spider, voice coil, magnet and all that... am I right? Or is it just building the speaker cabinet and dropping the drivers into it?
Either way, it'll be a fun project /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
Nunyas
Yoda
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crossover networks have plenty of physics in them when you analyze whats going on with the components and how connecting them in different ways makes it function differently. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
But the actual math involved with some of the simpler crossovers may only take trig. Then again, a lot of physics equations aren't much more difficult than Algebra, IIRC. Still, it's all mind tingling stuff IMO. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
But the actual math involved with some of the simpler crossovers may only take trig. Then again, a lot of physics equations aren't much more difficult than Algebra, IIRC. Still, it's all mind tingling stuff IMO. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
cjm
Jedi Trainee
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maybe this link is useful?
https://www.physicsforums.com/
also how about maplin, don't they sell electronic projects?
https://www.physicsforums.com/
also how about maplin, don't they sell electronic projects?
PC
Obi Wan
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R6MGS, what grade is you son in? What sort of math (if any) is he expected to provide to support his project?
quick sidebar:
The bits that have the wires hanging off them that make noise when you apply an electrical signal are usually referred to as drivers.
In any field of physics/engineering a device that transforms one form of energy (such as electricity) into another (say, acoustic) is called a transducer. So a driver is a form of electroacoustic transducer.
The whole system, box, drivers and crossovers (usually) is called a speaker.
So I take it your son is expected to build a driver?
I'm not surprised you didn't find much on the web about building drivers. It's like saying "I wanted to learn how to build an engine but everything I found was about assembling engines, re-building engines and a little about machining engines, nothing about casting blocks." It's rarely done by hobbyists.
Making high performance drivers is a rather involved process, usually requiring quite a bit of precision manufacturing equipment and specialized tooling. Most hobbyists are either after something that works as well as or better than commonly available product or just don't have the capacity. So they buy the drivers and put their energy into the boxes (where commercial manufacturers have less of an inherent advantage).
If your son just needs to make something that works, but not necessarily well, you can just start with the most basic diagram of a generic driver and make a version of it. It won't perform anything like a commercial unit but it will make noise.
PC.
quick sidebar:
The bits that have the wires hanging off them that make noise when you apply an electrical signal are usually referred to as drivers.
In any field of physics/engineering a device that transforms one form of energy (such as electricity) into another (say, acoustic) is called a transducer. So a driver is a form of electroacoustic transducer.
The whole system, box, drivers and crossovers (usually) is called a speaker.
So I take it your son is expected to build a driver?
I'm not surprised you didn't find much on the web about building drivers. It's like saying "I wanted to learn how to build an engine but everything I found was about assembling engines, re-building engines and a little about machining engines, nothing about casting blocks." It's rarely done by hobbyists.
Making high performance drivers is a rather involved process, usually requiring quite a bit of precision manufacturing equipment and specialized tooling. Most hobbyists are either after something that works as well as or better than commonly available product or just don't have the capacity. So they buy the drivers and put their energy into the boxes (where commercial manufacturers have less of an inherent advantage).
If your son just needs to make something that works, but not necessarily well, you can just start with the most basic diagram of a generic driver and make a version of it. It won't perform anything like a commercial unit but it will make noise.
PC.
Nunyas
Yoda
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let's see... chicken wire for the basket, toilet paper tube for the voice coil former, sheet aluminum for the cone, bicycle inner tube for the surround and spider (suspension parts) a roll of wire to make the coil from. Dunno where to find a magnet big enough to hold a 1.5 to 2" voice coil.
hmmm... maybe go smaller, you can use one of them ferro-ceramic fridge magnets (you know the type that they attach to the paper clips to hang on the fridge?).
MythBusters made a driver that was 56" out of 1/4 aluminum plate and car inner tubes for the suspension, and used energy from the transmission to power the driver. They hit something like 156Db before the device ripped itself apart. They were attempting to prove/disprove that you can make a car explode/fall apart by playing music too loud.
----
back to the topic. I'm not sure about driver kits, but the basic components to build one should be easy enough that you can find some bits at an electronic components store or be able to fabricate a rudimentary part from 'cheap' material.
a basic representation of a driver and its components should get ya on the right track to making a rudimentary one.
Here's a Wikipedia article (with diagrams and cut-aways of the different parts) on them:
https://en.wikipedia.org/wiki/Loudspeaker
hmmm... maybe go smaller, you can use one of them ferro-ceramic fridge magnets (you know the type that they attach to the paper clips to hang on the fridge?).
MythBusters made a driver that was 56" out of 1/4 aluminum plate and car inner tubes for the suspension, and used energy from the transmission to power the driver. They hit something like 156Db before the device ripped itself apart. They were attempting to prove/disprove that you can make a car explode/fall apart by playing music too loud.
----
back to the topic. I'm not sure about driver kits, but the basic components to build one should be easy enough that you can find some bits at an electronic components store or be able to fabricate a rudimentary part from 'cheap' material.
a basic representation of a driver and its components should get ya on the right track to making a rudimentary one.
Here's a Wikipedia article (with diagrams and cut-aways of the different parts) on them:
https://en.wikipedia.org/wiki/Loudspeaker
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Check Wikipedia under "Loudspeaker." Also do a Google search under "speaker driver design" or "loudpeaker design." There is plenty of info on the web--you just need to know how to find it. Also, how to use it. You won't find step by step instructions, so your son will have to take what info is there, and figure out some things for himself. I'll bet anything that this is what the teacher is trying to force him to do.
It's important for a young student to learn how to reasearch information, so, as a former college professor, I strongly encourage you not to accept "I can't find anything," and to send him back onto it. Also, to the library; rooms full of books have all kinds of useful stuff. Young people these days need to learn that the web isn't the only resource.
Back when I taught at UCLA (pre-internet days), I'd send a classroom full of students off to research something fairly easy, and always--ALWAYS--quite a few would come back telling me they couldn't find anything. I'd ask if they checked periodicals, reference section, searches under similar terms, ask the librarian for suggestions, and I'd get a blank stare. If I told them to research pie baking, they'd go to the library, look in the catalog under "pie baking," find nothing, and have no clue as to what to do next. Learning to research a subject is like learning anything else--you have to work at it a bit to learn it.
Good luck; this will be a great learning experience for your son!
It's important for a young student to learn how to reasearch information, so, as a former college professor, I strongly encourage you not to accept "I can't find anything," and to send him back onto it. Also, to the library; rooms full of books have all kinds of useful stuff. Young people these days need to learn that the web isn't the only resource.
Back when I taught at UCLA (pre-internet days), I'd send a classroom full of students off to research something fairly easy, and always--ALWAYS--quite a few would come back telling me they couldn't find anything. I'd ask if they checked periodicals, reference section, searches under similar terms, ask the librarian for suggestions, and I'd get a blank stare. If I told them to research pie baking, they'd go to the library, look in the catalog under "pie baking," find nothing, and have no clue as to what to do next. Learning to research a subject is like learning anything else--you have to work at it a bit to learn it.
Good luck; this will be a great learning experience for your son!
GregW
Yoda
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Hi Rob,
I followed your Wiki link and found something extremely cool and had no idea existed. A plasma tweeter, basically discovered in 1900 by mistake when William Duddell was trying to get carbon arc street lights to stop humming. Look at the bottom of the link you provided under “plasma arc loudspeakers”. Eventually they were made commercially for sound reproduction. Apparently, it is the same type of technology that NASA uses for their Ion drive on the new deep space probes. Here is a link to more information including some DIY projects. The Audio Circuit If the link doesn’t take you straight there, click at the top Loudspeakers: Ionic Speakers: DIY projects: PS-UH. A very cool project that should have the Physics teacher scratching his or her head.
I followed your Wiki link and found something extremely cool and had no idea existed. A plasma tweeter, basically discovered in 1900 by mistake when William Duddell was trying to get carbon arc street lights to stop humming. Look at the bottom of the link you provided under “plasma arc loudspeakers”. Eventually they were made commercially for sound reproduction. Apparently, it is the same type of technology that NASA uses for their Ion drive on the new deep space probes. Here is a link to more information including some DIY projects. The Audio Circuit If the link doesn’t take you straight there, click at the top Loudspeakers: Ionic Speakers: DIY projects: PS-UH. A very cool project that should have the Physics teacher scratching his or her head.
kennypinkerton
Yoda
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Another interesting variant, and there are free plans on the web for them (Warning - they use very high voltages - enough to kill a few times over) are electrostatic drivers. Do a search. /bcforum/images/%%GRAEMLIN_URL%%/grin.gif I built one once, but never completely finished it.
PC
Obi Wan
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Since he only has to build something that makes noise I'd suggest keeping it as simple as possible.
A dynamic (electromagnetic) driver is probably the way to go. Alternative technologies like electrostatics and plasmas require additional high voltage supplies and such.
A piezo driver may be easy to build, if you can find a source for piezo material.
I wouldn't even bother trying to make a traditional cone woofer. Why go to the trouble to build something for low frequencies when you're not going to build a cabinet that can actually produce the sound.
I'd keep it to a midrange driver. That'll keep the size reasonably small and easy to work with while giving more perceived sound for a given electrical input.
Will he also be providing the electrical drive or will it need to hook up to something the teacher has?
PC.
A dynamic (electromagnetic) driver is probably the way to go. Alternative technologies like electrostatics and plasmas require additional high voltage supplies and such.
A piezo driver may be easy to build, if you can find a source for piezo material.
I wouldn't even bother trying to make a traditional cone woofer. Why go to the trouble to build something for low frequencies when you're not going to build a cabinet that can actually produce the sound.
I'd keep it to a midrange driver. That'll keep the size reasonably small and easy to work with while giving more perceived sound for a given electrical input.
Will he also be providing the electrical drive or will it need to hook up to something the teacher has?
PC.
ok, I'll have a go at this.
What I would do is take an oatmeal box (those big round ones) secure a sheet of tissue paper on one open end. (the kind used for wrapping gifts) it should be fairly taut. You will also need a very small very strong magnet. Radio Shack probably has them. they will be called something like rare earth magnets. glue one in the exact center of the tissue paper.
Now you will need an electrical coil. get a spool of very fine wire at RS. you need to mount this in the center of the oatmeal box, close, but not touching the magnet.
connect to the radio. you should be able to get a fairly decent sound out of a simple device like this.
This is basically a giant version of a headphone speaker.
to get it to work, you will need to play with the distance between the magnet and coil, size of the coil, and tension on the diaphragm. It might also be worth trying a sheet of mylar, (like what the silvery helium balloons are made out of) This is what most headphones use.
You pretty much want to create a drum surface, and then a motor to push it. The magnet / coil will attract and repulse each other when a sound signal is sent to them, and force the drum surface back and forth.
I would not hook it up to my Ipod. to great a risk that it will kill it, and the power output is minuscule so you probably won't hear anything. I would get one of those old boom boxes, the type that says something like 190Watts of power! one it (salvation army thrift store!) and hook it up in place of the original speakers.
Let us know how it turns out. sound like a great project.
Yisrael
Edited to add a few more ideas
since this is essentially building a drum and them forcing it to vibrate, it would be possible to build this using a toy drum as the starting point. Also if you are going to take apart an old radio, that would be a good source for a decent coil. I would still glue a very strong magnet onto the drum surface. Using a strong magnet will increase the efficiency of the speaker. the output from the amplifier is usually AC, so part of the time, it will pull the speaker drum, and part of the time push.
What I would do is take an oatmeal box (those big round ones) secure a sheet of tissue paper on one open end. (the kind used for wrapping gifts) it should be fairly taut. You will also need a very small very strong magnet. Radio Shack probably has them. they will be called something like rare earth magnets. glue one in the exact center of the tissue paper.
Now you will need an electrical coil. get a spool of very fine wire at RS. you need to mount this in the center of the oatmeal box, close, but not touching the magnet.
connect to the radio. you should be able to get a fairly decent sound out of a simple device like this.
This is basically a giant version of a headphone speaker.
to get it to work, you will need to play with the distance between the magnet and coil, size of the coil, and tension on the diaphragm. It might also be worth trying a sheet of mylar, (like what the silvery helium balloons are made out of) This is what most headphones use.
You pretty much want to create a drum surface, and then a motor to push it. The magnet / coil will attract and repulse each other when a sound signal is sent to them, and force the drum surface back and forth.
I would not hook it up to my Ipod. to great a risk that it will kill it, and the power output is minuscule so you probably won't hear anything. I would get one of those old boom boxes, the type that says something like 190Watts of power! one it (salvation army thrift store!) and hook it up in place of the original speakers.
Let us know how it turns out. sound like a great project.
Yisrael
Edited to add a few more ideas
since this is essentially building a drum and them forcing it to vibrate, it would be possible to build this using a toy drum as the starting point. Also if you are going to take apart an old radio, that would be a good source for a decent coil. I would still glue a very strong magnet onto the drum surface. Using a strong magnet will increase the efficiency of the speaker. the output from the amplifier is usually AC, so part of the time, it will pull the speaker drum, and part of the time push.
PC
Obi Wan
Offline
70herald's oatmeal can design is great but I would do it the other way around, gluing the coil to the diaphragm and fixing the magnet in place. You generally want to keep the moving mass as a light as possible.
Be aware that headphone outputs can be very different on different pieces of gear. Something that works ok on a home stereo might not work at all with an iPod. Small portable equipment typically has less drive capability when compared to large benchtop units. So if the teacher will be grading students by hooking it up to his iPod your son should be using a something similar while developing his piece.
Back in the eighties when Sony came out with the first Walkman everybody assumed that shrinking the tape transport was the tricky part. The reality was that the hard part was coming up with high fidelity headphones that would not overload tiny, battery-powered electronics. By developing ultra high efficiency rare-earth magnet headphones Sony opened the door to a whole new world of miniaturized gear.
PC.
Be aware that headphone outputs can be very different on different pieces of gear. Something that works ok on a home stereo might not work at all with an iPod. Small portable equipment typically has less drive capability when compared to large benchtop units. So if the teacher will be grading students by hooking it up to his iPod your son should be using a something similar while developing his piece.
Back in the eighties when Sony came out with the first Walkman everybody assumed that shrinking the tape transport was the tricky part. The reality was that the hard part was coming up with high fidelity headphones that would not overload tiny, battery-powered electronics. By developing ultra high efficiency rare-earth magnet headphones Sony opened the door to a whole new world of miniaturized gear.
PC.
kennypinkerton
Yoda
Offline
If all the students are making these - the teachers ipod is gonna fry on at least one of them. Someone will use heavy guage low resistance wires for the coil, and it'll pop the output transistors.