Glass Speakers

Intro: Glass Speakers

This set of speakers resonates glass to produce sound. While this may seem complicated, the technical explanation is actually rather simple.  Each speaker has a tactile transducer attached to the center, which is a device that vibrates the glass to produce sound waves. This simple mechanism allowed for the design of stereo speakers which are a departure from the standard bulky floor speaker. These glass speakers - by comparison - are obviously sleek, lightweight, and almost invisible. They can also be collapsed and easily moved, making them good for a nomadic lifestyle.

Of course, the big questions is, "how do they sound?" Well...These speakers sound a lot better than you would imagine, but still not as  great as your average stereo speaker. They tend to cut a little from both the high end and low end of the audio spectrum. Nonetheless, they have a very unique and somewhat warm sound to them. There is also the added bonus of truly feeling the music resonate through your feet when you crank up your stereo really high and stand near them.

STEP 1: Ode to Noah

Noah is a man
Who helped me build these speakers
He did all he can
To make sure this project was a keeper

We went to his shop in the East Bay
Metalwork he did teach
We worked for many a day
To make a set of speakers for both of us each

I told him I would honor him with this verse
For his ego I set out to tame
Because I knew he would get terse
That I wanted to publish this project solely under my name

So I must thank Noah for showing me how to do this
On this project he truly saved the day
I would give him a great big kiss
But I really don't swing that way

STEP 2: Go Get Stuff

You will need:
(x2) tactile transducers
(x2) 29-1/2" x 14" x 1/4" glass panel
(x1) 1-1/4" x 3/16" x 10' steel flat bar
(x1) 1/2" x 12" steel L-extrusion
(x1) 12" x 12" sheet of adhesive backed silicon rubber (or similar)

STEP 3: Mark and Cut

Measure and mark every 48" along the steel bar.

Cut four 48" sections along the the steel bar.

STEP 4: Bend

Measure about 16" from the edge of the flat bar and make a bend of about 100 to 110 degrees.

The metal bender we used is basically a rotary lever with a central pin and an adjustable outer pin (for different stock sizes). To make it work, you just set the outer pin as tight as possible and push on the lever until you have the bend you want.

Repeat this process making certain all of the bars have identical angle bends. It is better to undershoot to begin with than overshoot. You can always easily bend it slightly further, but it is difficult to undo a bend.

STEP 5: Trim

After making the bends, make certain all of the rods have the same end measurements. Mark and cut as necessary until they are all identically sized.

STEP 6: Weld

Cut four 1" long L-brackets. Sand a slight angle off one of the outer edges to allow for a better weld.

Weld one bracket at the top of your flat bar on the inside of the bend, such that it forms a U-shape to hold the top of the glass.

Measure 29.75" from the inside of this top bracket and weld the other bracket to form a U-shape to hold the bottom of the glass.

STEP 7: Grind

Grind away the welding bead, and use a file in some of the harder to reach places.

STEP 8: Sandblast

Before finishing the metal, you are going to need to sandblast it. We didn't have a sandblaster, so we outsourced it to some guy. I forget how much he charged us, but it was relatively cheap.

STEP 9: Bluing Metal Finish

Be sure to wear gloves and appropriate eye protection.

Metal bluing is a process that produces a controlled rust on a piece of metal and turns it a natural black.

The mixture I used was made by a friend and I really don't know enough about preparing it to advise on mixing up your own batch. Nonetheless, you can find all kinds of recipes for this online. Here is a page that seems to have some promising recipes. Definately do your own research before taking any steps to copy any recipe for this found online. This processes typically uses dangerous acids.

That said...

Rub this mixture onto your sandblasted parts. Make sure to cover all surfaces well and not get the mixture all over the place (its relatively expensive and a bit caustic). You may want to put on more than one coat to ensure a nice black finish. This mixture will probably eat away at your rag as you apply it. Don't worry too much about it. That is normal.

Leave the metal bars to dry for 30 minutes when you are done.

STEP 10: Wash Off

Spray off your metal parts with a hose to wash off the gunmetal mixture. Leave the parts to dry fully before proceeding. Don't worry if they start to fade and turn funky colors. That is a normal part of the process.

STEP 11: Seal

Make a 50/50 mixture of linseed and mineral oil.

Mix in a dash japan dryer.

STEP 12: Wipe

Once coated, wipe off the metal with a clean rag.

Leave it to dry for a few hours before handling.

STEP 13: Center

Find the center of the glass sheet.

The easiest way to do this is to draw an "X" from corner to corner with an impermanent marker. Where the two lines meet will be the center of the panel.

Repeat for the second sheet of glass.

STEP 14: Transducer

Flip the glass sheet over so that the marker is on the underside of the glass sheet.

Peel the adhesive covering off of the tactile transducer and center it upon the side of the glass without the center markings.

Make certain it is attached nice and firmly.

Repeat for the second sheet.

STEP 15: Clean

Wipe the marker marks off of the two glass panels.

STEP 16: Padding

Cut small adhesive silicon squares and affix it to the front and back of the U-brackets on the metal bar. These will hold the glass snugly in place and keep it from rattling.

Repeat for the other three U-brackets.

STEP 17: Assemble

Slide the glass between the silicon padding in the U-brackets.

STEP 18: Solder

Solder speaker wires to the tactile transducers. Be mindful of the positive and negative terminals.

STEP 19: Setup

Attach these speakers to your stereo amplifier like you would any other speaker.

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Comments

[MississippiMan]

The best possible transducer to use for this application can be found at www.invisibleStereo.com

The HAS Model 801

I personally created a pair of six foot tall X three foot wide double laminated glass speakers (1all the way back in 1979, using a rubber grommeted wood frame work on a supportive stand. The transducer I used back then was the original Rolen Star #308...a 30 watt 8 ohm unit. using four of them on each panel in a vertical array and driving them with a good old Yamaha Stereo receiver (100 wpc ) Allowed me to create an expansive on the directional sound field that had the ability to fill a 1000 square foot room. Not even a pair of Dahlquist electrostatics could accomplish that back then.

These days I use them for critical listening environments as well as home theater installation and it they can easily be designed to be as proficient and as effective when applied to a variety of services as almost anyone could hope to imagine.

The important thing to always remember is not to send a boy to do a mans job. If higher listing levels and critical listening are desired traits then you have to design and install the project with that criteria in mind

I would be more than glad to assist anyone in any type of project they could dream up, Austin the 39 years I've been involved with audio transducers I have pretty much "been there done that" along every conceivable line.

Please, everyone understand I am only making that statement because I have seen a great many posts that allude to the limitations of this application. And while there are indeed some design and performance considerations that must be taken into account, that in no way restricts the creativity, desirability, and affordability of using a product such as Audio Transducer to create something unique and special to be proud of. that is to say, when one uses the right audio transducer for the application desired.

I personally advise all branches of the US Military, government, industry, education, and the artistic community in the use of this product, so I know full well the complete range of its potential. In this instance what are hoping I can do this to simulate some creativity and productivity among do-it-your selfers.

[Fred the Minifig]

Mississippi man, you said you know 'bout this stuff.
Could you point me in the directions of some good data sheets or other reference material?
Thanks. -Fred

[Arghus]

would love to hear how that sounds

[VladM3]

I love seeing more people experimenting with transducers. You hit the nail on the head with the "usable" frequency range of the glass, so I would add the following: Use Cork or Styrofoam for the low-end and use heavy-gauge art board from Michael's for the highs. In fact, that art board is almost the right kind of material to be full range. If you want that glass to be more effective, try pasting about 2-4 transducers to your glass panes. You might get better frequency response that way.

[jessica.herman.10]

Love this idea, and I think this would work to turn my shop window (here in SF) into a speaker, but could use a little help. The sound woukd be coming from my computer...how do I connect the transducers and is there one you would recommend? The linked one is out of stock...thanks!

[Lee Wilkerson]

They're in stock again.

[daniel.stillmunks]

Hello, sir. I'm 65 y/o and ever since I first laid eyes on Altec-Lansing speakers--I wanted a pair (I was 13) It took me 52 years but I finally got both the 604-E Super Duplex 15 or 16 inch speakers and AND the Famous Altec V.O.T.T.= Voice of The Theatre. LARGE horn up top; large woofer below it and mucho bass reflex. These babies are as big as a medium sized refrigerator! I LOVE IT. But good going and kudos on your little glass speakers experiment. (They're just not for me.) BOOM BOOM BOOM and no I do not own ANY subwoofers!

[Lee Wilkerson]

I agree with you about the 604-E. I heard a pair in 1971 which were connected to a 60W/channel Dynaco tube amp. You could actually hear them easily and clearly across the (Army) parade field. Right, also, about the V.O.T.T. going BOOM, BOOM, BOOM but in a narrow range of frequencies.

I built a pair of cabinets once which were 4' 3 3/4" tall x 13" x 13" and used Sylvania (Eminence) 12" woofers P/N 12-22112-2 in an air suspension enclosure of 3/4" high-density particle board. The top third of the cabinet was sub-divided for midrange where I used Utah full-range 8" speakers crossed over for midrange only. I had 3" cone tweeters (brand ?) and used Sylvania Mylar-dome super- tweeters 12-22112-4 for everything above 15 KHz. They were fed bi-amplified with active crossovers before the amplifiers. Extremely hard to beat for the < $100 each I invested in them.

[Monty^]

A Canadian company made a flex-membrane speaker back in the 80s with a centrally driven transducer, much like a speaker attached to a stretched Mylar. The membrane vibrated like a ripple in the pond to produce full range sound. The low frequency limit was determined by the membrane/frame size as it was a dipole subject to front/back cancellations, but the thing sounded just like large electrostatics or ribbons but without the beaming high frequency responds.
http://www.museatex.com/planar1.htm

One problem with the speaker was temperature and humidity sensitivity of the Mylar membrane causing the central suspension point within the voice coil to be prone to rubbing.

The glass speaker described here is interesting and similar in concept but the rigidity of glass won't allow it to vibrate freely except at its dimensional resonance; as an improvement one might try suspending the transducer to cross members attached to the metal frame in order to decouple it from the glass.

[Blue Hawaii]

Yes, I remember some of those models back in the day. I had a pair of Magneplanars in the early 80's. Mylar sheets and ribbon tweeters. http://www.magnepan.com/ They were similar to the MG12's pictured on the website but were just called Magnepans. They were as tall as I was. They were really sweet sounding too. I've always thought of trying to build a pair of various sized panels that would hang from one another from the ceiling, suspended only by their audio cables, positive running down one side, negative on the other, larger panel for bass on top and smaller in the middle for, well mids and a smaller or even some sort of ribbon tweeter on the bottom for the highs.

This instructable really is pulling at my dream of over 30 years ago.

[Lee Wilkerson]

Magnepan is still building their speakers and I have yet in the 30+ years since I heard the Magneplanars to hear ANYTHING which comes even close to the purity of sound I heard that evening. Paper cone speaker=10%THD because the paper flexes varying amounts depending upon the frequency and power fed to them. After auditioning the Magneplanars, everything else sounds muddy.

[amclaussen]

Good comment, Monty, there was another (I believe was an american company with an Italian sounding name) that produced another similar design, but using Styrofoam flat diaphragms that were large and gave some bass. Treble was obtained by mechanically decoupling the smaller, center section by using a ring of soft pliable compound, so that bass was reproduced by the whole large diaphragm, and the treble by the center part only. Theh didn't last for long, and disappeared from the market. (I guess that those styrofoam speakers were much better than any glass one, but this Instructable is for fun, and appearance is novel and nice enough! Just lets don't expect any fidelity from these! Amclaussen.

[Razor 911]

this must be the coolest speakers ever you should build them and sell them

[David the R]

NIce project. I wonder if you could put two holes near the top, put in rubber grommets, and simply hang them up?

Again, nice job.

[frostystones]

Wireless. maybe parts from wireless headphones?

[BartP2]

I happen to work in a glass plant. I can cut glass up to 8 ft wide by 7 ft tall. How would a wall of glass sound?

[makeshiftmech]

won't the glass shatter if the resonance matches the frequency of the glass.

[mb-j]

yes, but it is unlikly to reach that frequency. sorry if I'm late to the party

[NovoStar]

that, is very, very unlikely

[jkuchera]

Tempered glass vs non tempered glass? Will it make a difference in the sound quality?