Just trying to think of a fun little project to try. I am already working on some DML styrofoam panels but I want to make another set of speakers for the outdoors. I'd pair these with some kind of subwoofer. Only pain with exciters is they need a ton of EQing to sound good. Has anyone done this?
I have not done it, but since response is slow I'll speculate a bit. You may need a relatively thin, hollow sphere of decent size to get significant output down to a range where you can hand off to a sub. I'm not sure if you were thinking of using a solid foam sphere.
Tethering the non-driven end and/or the exciter may be beneficial also, but I'm guessing. What I'm imagining is something similar in layout to a Radialstrahler, but driven with an exciter.
Summer Project - Replication of MBL loudspeaker 101mkII
One other thought: plain Styrofoam isn't UV stable, so long term you'll need to protect it for use outdoors.
Tethering the non-driven end and/or the exciter may be beneficial also, but I'm guessing. What I'm imagining is something similar in layout to a Radialstrahler, but driven with an exciter.
Summer Project - Replication of MBL loudspeaker 101mkII
One other thought: plain Styrofoam isn't UV stable, so long term you'll need to protect it for use outdoors.
I have cut my foam boards to the correct size, but has to work them over, sanding off the shiny surfaces. Waiting for the exciters - Dayton DAEX32EP-4. According to the shop, coming in by the end of July.
From some of the YT videos it apperas you don't need equalizers, but maybe it is all depending on how, or rather WHERE the exciter is positioned.
I wanted to build a pair of cheap panels. jost for the fon of it and also to have something out of the ordinary to bring to our DIY/HIFi meeting in October.
Instead of , try to use two fabric tweeters with domes cut off , on both poles , northand south , use a rod between them for stable mechanics .
Related to DML/BMR , you may need a stiffer matrix material und also stiff outer/Inner skin for more bandwith ...
Nice hobby idea but certainly no hifisound ...
Related to DML/BMR , you may need a stiffer matrix material und also stiff outer/Inner skin for more bandwith ...
Nice hobby idea but certainly no hifisound ...
I had suggested in the:
A Study of DML's ... thread
to take an aluminum cylinder -- maybe even a pretty large diameter one -- fill it with spay-in urethane foam and figure a way to attach an exciter.
I got dissuaded from pursuing the idea, but I still wonder about it.
Even a very thin wall aluminum tube filled with foam would have incredible rigidity.
I still think the key to DML's follows from weight vs rigidity.
Maybe one could even cut the tops off of a couple of large (gallon) beer cans, fill them with foam and attach an exciter to the bottoms.
Strange ideas but, who knows?
A Study of DML's ... thread
to take an aluminum cylinder -- maybe even a pretty large diameter one -- fill it with spay-in urethane foam and figure a way to attach an exciter.
I got dissuaded from pursuing the idea, but I still wonder about it.
Even a very thin wall aluminum tube filled with foam would have incredible rigidity.
I still think the key to DML's follows from weight vs rigidity.
Maybe one could even cut the tops off of a couple of large (gallon) beer cans, fill them with foam and attach an exciter to the bottoms.
Strange ideas but, who knows?
I actually made one of these.
wow cool someone actually asked about something I actually did sweet!
I actually made a set of these a few years back and yeah I did them with Dollar Tree Parts in fact or Dollar General or poundland whatever you guys have or wherever you are.
The Voice coils were still good in these two inch speakers that were from my Chrysler minivan and traditionally used in the dash or rear speakers.
problem was is that the foam surround had gone the way of the dodo.
so what I did is I took some latex gloves and stretched it over and put a Styrofoam ball in the middle and glued it there.
I didn't have much luck using the glove as a surround so I used Saran Wrap as a suspension in place of the rotted foam surround.
the problem was actually trying to get it and have it centered around the actual ball. and of course the cone which had no phone service around anymore so as you can imagine they didn't last long.
I found a way to actually make it work and it's pretty ingenious especially since I came up with it all myself.
I pretty much made it so I could have some of the kids play with it and they had a good time until it died.
I don't think I would use an Exciter but I guess you could they are cheap enough. just stick it out and you're done.
personally I would just use any old speaker that you could find and just glue it on to the cone . just don't use super glue because as I found out it's not really good for the polystyrene.
I like to experiment with outdoor speakers a lot and I find that having these large spherical speakers actually is kind of nice for things like background music in your garden or pathway. you can also install LED lights inside of them and it makes them look very pleasing at night.
the perfect material would be something like an aerogel sphere.
if you happen to have one of those piezoelectric Mist making devices, you can really get some cool effects.. or fog machine but that's more expensive. and water is cheap.
I was thinking about making some solar powered outdoor speakers with this kind of arrangement. I was just going to use a basic radio tuner and some circuit that would work to turn on when the solar lights would normally turn on at night.
I was going to ask big Clive to chime in on this because I'm pretty sure he could come up with the circuit in about 5 minutes. I was thinking about just tuning the radio dial to the local classical radio station and I think that should work out pretty well. that way I don't have to muss and fuss with things like Bluetooth or Wi-Fi audio or anything like that.
I see someone mentioned the balloon idea well I actually did that once where I got some large mylar balloons and stuck a greeting card speaker on to the balloon it was kind of neat because it would just keep looping the same little jingle and it was decently Audible.
really one of the best ways to do this as a spherical speaker would be to use something like mylar and blow it up into a rigid and high-pressure sphere. it would be cheaper than aerogel and I think it would work quite well.
if you filled them with hydrogen gas , then technically if you mounted the sphere facing upwards the sphere would have the same mass but in theory should be more efficient to drive. (I will let you physics engineers geniuses scratch your heads on this one)
realistically the balloon application for the Exciter would probably work best for something like a inflatable holiday decoration.
it would make a pretty neat set of Bluetooth speakers. lower frequency response however would be somewhat limited and buy some what I don't think there would be very much at all. but there are ways of course.
I really need application of this is to get a bunch of those regular round if spiracle shaped balloons and glue them together and make a large stock of them with something like an Exciter on the bottom and have them float at an event while producing sound. it would be like a very odd distributed mode loudspeaker.
or a very poor man's version of a German omnidirectional speaker.
I think if you put a piezoelectric on one of those floating balloons would make a very interesting omnidirectional microphone. technically it would be close to immune to overloading. so that would be an immediate benefit.
and if you really want to go Hog Wild they've already created a graphene balloon which would probably work really well in this instance if you could get your hands on it. if you were able to orient the carbon nanotubes in a certain position you could attain performance to something like a flat panel speaker like a magneplanar.
you're tuning or resonance frequency of the balloon speaker will be dependent on the amount of pressure it would have on its interior dictating the speakers frequency response. but something like this is a pipe dream. simulating something like this in Mathematica or some other kind of program that does actual simulation testing would probably be the best place to start but again it's just an idea.
I was thinking about something similar as the ballon speaker by using a laser to create a high frequency Tweeter or super Tweeter.
it's just something I've been kicking around in the back of my head for years.
I'll see if I can cook one up sometime in the next week and if I get around to it I'll post in this thread.
wow cool someone actually asked about something I actually did sweet!
I actually made a set of these a few years back and yeah I did them with Dollar Tree Parts in fact or Dollar General or poundland whatever you guys have or wherever you are.
The Voice coils were still good in these two inch speakers that were from my Chrysler minivan and traditionally used in the dash or rear speakers.
problem was is that the foam surround had gone the way of the dodo.
so what I did is I took some latex gloves and stretched it over and put a Styrofoam ball in the middle and glued it there.
I didn't have much luck using the glove as a surround so I used Saran Wrap as a suspension in place of the rotted foam surround.
the problem was actually trying to get it and have it centered around the actual ball. and of course the cone which had no phone service around anymore so as you can imagine they didn't last long.
I found a way to actually make it work and it's pretty ingenious especially since I came up with it all myself.
I pretty much made it so I could have some of the kids play with it and they had a good time until it died.
I don't think I would use an Exciter but I guess you could they are cheap enough. just stick it out and you're done.
personally I would just use any old speaker that you could find and just glue it on to the cone . just don't use super glue because as I found out it's not really good for the polystyrene.
I like to experiment with outdoor speakers a lot and I find that having these large spherical speakers actually is kind of nice for things like background music in your garden or pathway. you can also install LED lights inside of them and it makes them look very pleasing at night.
the perfect material would be something like an aerogel sphere.
if you happen to have one of those piezoelectric Mist making devices, you can really get some cool effects.. or fog machine but that's more expensive. and water is cheap.
I was thinking about making some solar powered outdoor speakers with this kind of arrangement. I was just going to use a basic radio tuner and some circuit that would work to turn on when the solar lights would normally turn on at night.
I was going to ask big Clive to chime in on this because I'm pretty sure he could come up with the circuit in about 5 minutes. I was thinking about just tuning the radio dial to the local classical radio station and I think that should work out pretty well. that way I don't have to muss and fuss with things like Bluetooth or Wi-Fi audio or anything like that.
I see someone mentioned the balloon idea well I actually did that once where I got some large mylar balloons and stuck a greeting card speaker on to the balloon it was kind of neat because it would just keep looping the same little jingle and it was decently Audible.
really one of the best ways to do this as a spherical speaker would be to use something like mylar and blow it up into a rigid and high-pressure sphere. it would be cheaper than aerogel and I think it would work quite well.
if you filled them with hydrogen gas , then technically if you mounted the sphere facing upwards the sphere would have the same mass but in theory should be more efficient to drive. (I will let you physics engineers geniuses scratch your heads on this one)
realistically the balloon application for the Exciter would probably work best for something like a inflatable holiday decoration.
it would make a pretty neat set of Bluetooth speakers. lower frequency response however would be somewhat limited and buy some what I don't think there would be very much at all. but there are ways of course.
I really need application of this is to get a bunch of those regular round if spiracle shaped balloons and glue them together and make a large stock of them with something like an Exciter on the bottom and have them float at an event while producing sound. it would be like a very odd distributed mode loudspeaker.
or a very poor man's version of a German omnidirectional speaker.
I think if you put a piezoelectric on one of those floating balloons would make a very interesting omnidirectional microphone. technically it would be close to immune to overloading. so that would be an immediate benefit.
and if you really want to go Hog Wild they've already created a graphene balloon which would probably work really well in this instance if you could get your hands on it. if you were able to orient the carbon nanotubes in a certain position you could attain performance to something like a flat panel speaker like a magneplanar.
you're tuning or resonance frequency of the balloon speaker will be dependent on the amount of pressure it would have on its interior dictating the speakers frequency response. but something like this is a pipe dream. simulating something like this in Mathematica or some other kind of program that does actual simulation testing would probably be the best place to start but again it's just an idea.
I was thinking about something similar as the ballon speaker by using a laser to create a high frequency Tweeter or super Tweeter.
it's just something I've been kicking around in the back of my head for years.
I'll see if I can cook one up sometime in the next week and if I get around to it I'll post in this thread.