[Menisk]

I've had this idea for a while and have no idea why I have taken so long to post it...

Headphones and Speakers are all about moving air and we've done this in a whole bunch of different ways. Do you think it could be done in a similar way to the ion lifter things that many people have made such as this one: HVLabs.com

I'd have thought you could do it by having the thin wire in the middle and having the two larger electrodes where air is attracted to on either side. Then you could be constantly creating thrust, but changing the direction in which it's going by having the two attracting electrodes being activated at different times to move air back and forward.

I have no idea if this would actually work but I'd have thought it'd sound pretty good considering you don't have a driver that has inertia and you'd be able to move more air than a plasma arc so you'd actually be able to get some bass out of it.

I don't have the knowledge or the skills to build something like this but I'm sure someone here would be able to build such a device and the required driving circuitry. Anyone think this could actually work?

 

[Bilavideo]

That's a cool idea if you could work out the logistics.

 

[Uncle Erik]

You mean something like this plasma tweeter? You'll find a few projects for plasma or "singing arc" speakers out there. In a recent thread, someone even posted a little information about plasma headphones.

There are a few major problems with these kinds of speakers. One, they consume their electrodes over time. You'll need to keep opening them up to replace the electrodes. Two, they generate ozone. You have to have constant fresh air exchange if you're going to use them. Three, high voltage. 'Nuff said there.

But yeah, if you get plasma to work, it apparently sounds amazing. I'm seriously tempted to build those tweeters. I'd probably pair them with a couple of servo driven woofers in an open baffle dipole configuration like that used in the Orion+. I think that's the only way you could get bass close to the speed of plasma short of building an electrostatic woofer the size of a sliding glass door. Which would be pretty damn cool, but I don't have the 'nads to take on a gigantic 'stat with attendant frightening stator voltage.

 

[hopeless]

Why don't you build one and show it to us with some pics?

 

[Bilavideo]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif You mean something like this plasma tweeter? You'll find a few projects for plasma or "singing arc" speakers out there. In a recent thread, someone even posted a little information about plasma headphones. There are a few major problems with these kinds of speakers.

I think he's talking about something else. If I understand it correctly, he's talking about moving air itself, without a physical material of any kind. He wants to use the same technology as the lifter to puff air the way a conventional speaker modulates to achieve the same effect. I'm no engineer but it seems like the success of such an endeavor would depend on frequency, amplitude and decay. How fast could he puff this air? How much punch could he give it? How quick could he stop it on a regular basis? (By the way, I realize "puff" is likely the wrong word to use. I'm just having a vocabulary crisis.)

Every medium has its strengths and weaknesses. Paper, for example, is cheap enough, easy to mass produce and capable of being modulated fast enough to produce audible sound. But its stiffness slows it down, both in terms of maximum speed and rate of decay. It's not so very fast and it's not so very durable. Titanium is more durable and its abiliy to be fabricated nice and thin makes it a better material for tweeters. It has a better frequency rate. But its strengths are also a weakness. Lower mass means it has a harder time being brought to rest. There's more of an issue with ringing and more of a need to dampen things down. Then there's silk and other fabrics. They have greater mass than titanium but less of it than paper. They make some sweet-sounding tweets and some decent midrange domes but you won't get that sharpest treble. They're mellower and, to many ears, more euphonic, but they can't compete, at the very top of that stinging treble, because they're too heavy and too slow for that particular race.

The most expensive material I can think of, apart from those diamond tweeters, is aluminum, particularly aluminum ribbon. It's super lightweight. It can be driven super fast, to produce HF up through 40 kHz (so you can torture your dog). If I'm not totally mistaken, the decrease in mass gives it less momentum, sort of like a paper airplane with insufficient balast. Unlike titanium, which just rings back and forth against the seemingly massless air, aluminum acts more like a sail. Deprived of its energy source, it's easier to be stopped by the wind resistance of the air around it. This gives aluminum a better decay rate, which makes it better, not just at hitting those high frequencies but at stopping fast enough to preserve the finer details.

So, what if you could go even finer? That's the point of a plasma tweeter, but for plasma, you have lots of side effects making it impractical (and illegal for importation from abroad). What Menisk is proposing isn't a plasma. It's an ionic driver. He doesn't want to move a feather through the wind. He wants to move the wind. If this could be done, without a physical medium you could see, it would be quite the feat. Logistical issues would have less to do with dampening than with generating the right frequencies and amplitude.

The biggest hurdle may be in providing the amplitude. This isn't going to be the most efficient means of producing amplitude. It will take greater power to produce the same amount of output. It certainly won't compete with other drivers at the low or even mid level. But at the high end, where buyers will pay a premium to "go where no man has gone before," you may be on the cusp of something great. Don't think of it as a series of problems. Think of it as an opportunity to be realized by responding to all-new challenges.

 

[Uncle Erik]

Quote:

Originally Posted by hopeless /img/forum/go_quote.gif Why don't you build one and show it to us with some pics?

I will, eventually. I might even start buying and putting the parts away.

Though it'll probably be four or five years before I can get to it. Work has had me around from morning to midnight lately, including weekends. Coming here on the iPhone between projects is one of the few things I get to do that I enjoy.

 

[Menisk]

Quote:

Originally Posted by Bilavideo /img/forum/go_quote.gif I think he's talking about something else. If I understand it correctly, he's talking about moving air itself, without a physical material of any kind. He wants to use the same technology as the lifter to puff air the way a conventional speaker modulates to achieve the same effect. I'm no engineer but it seems like the success of such an endeavor would depend on frequency, amplitude and decay. How fast could he puff this air? How much punch could he give it? How quick could he stop it on a regular basis? (By the way, I realize "puff" is likely the wrong word to use. I'm just having a vocabulary crisis.)

Bilavideo is spot on there. I'm just curious to know if using that technology might actually work and whether anyone here has the time, knowledge and curiosity to try and make some kinda proof of concept.

 

[Ynis Avalach]

Hehe sounds amazing! But wouldn't you get a lot of free ions?Or am I not understanding this? Greetz Ava

 

[Menisk]

Quote:

Originally Posted by Ynis Avalach /img/forum/go_quote.gif Hehe sounds amazing! But wouldn't you get a lot of free ions?Or am I not understanding this? Greetz Ava

Well they end up bonding back together but a big problem is that when you ionize oxygen with a hot arc it seems to bond back together as a different allotrope called ozone which is bad stuff. Not quite sure why so I'm gonna have a read.

 

[El_Doug]

the main problem i see with using an ionic air-mover is simply the low volume of air these things move. to get any appreciable sound at all, this would probably need more voltage than... something that needs a lot of voltage

im not feeling very creative at 3am, feel free to insert your own quippy noun

 

[Menisk]

Quote:

Originally Posted by El_Doug /img/forum/go_quote.gif the main problem i see with using an ionic air-mover is simply the low volume of air these things move. to get any appreciable sound at all, this would probably need more voltage than... something that needs a lot of voltage im not feeling very creative at 3am, feel free to insert your own quippy noun

Well, if it needs lots of voltage then feed it a heap.