I have a buddy who has a bar in his basement. As a gift to him I want to take the drivers and xover out of an old, cheap but decent sounding pair of 3 way speakers whose cabinets are close to the same size and put them into beer kegs, making the kegs into speakers. I have figured out what to do to insulate and deaden the inside of the kegs but.........

What is giving me fits is trying to figure out how to mount the flat drivers onto a round surface. Without ruining the beer keg look. I want them to sit on the floor in their natural upright position and I want them to remain looking like beer kegs as much as possible.

The drivers are a 10" woofer, 4" mid and a 3" tweet.

Any ideas or sugggestions???????

Thor,

Well first off you will need help emptying two kegs. Just let me know where and when. :)

Rob

LOL! I already have one empty one to "experiment" on you are more than welcome to come up and help me empty the next one :D

Hello Thor

You could cut a window in the keg to mount a flat baffle out of wood. Know any welders?? You shoild be able to still have the basic shape. Great idea he is gonna love them!!

This topic was previously discussed at AU. Who was it that wanted to do just this very thing?


Mike

That was me :D But I figured I would post it here too since we got some new folks. The project is on hold until I find a full time job tho ;)

That was me :D But I figured I would post it here too since we got some new folks. The project is on hold until I find a full time job tho ;)

That was me :D But I figured I would post it here too since we got some new folks. The project is on hold until I find a full time job tho ;)

That was me :D But I figured I would post it here too since we got some new folks. The project is on hold until I find a full time job tho ;)

Yah that was me, since we got new peeps here I thought i would post it again, even tho the project is on hold until I get a full time job ;)

Deja vue all over again!

Thatch I thought you would at least tell me to use solid silver wiring in my crossover or to fill the bottom of the keg with bleached sand or lead shot ;) :D

I think you should get those never stop pouring into a mug beer taps at Spencers for the tops.
Thatch

Thor...have you thought of any way to mount the drivers yet?

What size drivers are they?

I suggested to Thor that he take the kegs to an auto body shop to have the hole for a baffle cut out with the air shears and check out a truck mechanics shop for the perferated mesh that covers the huge air filters to cover the baffles and drivers after construction. Any thoughts or ideas on that? I am of the opinion that the drivers need to be mounted on a baffle made of MDF to keep direct contact of the drivers baskets from contact with the metal of the beer keg. And though I believe he wants to do a 3 way with a 10" woof I recommend because of the curve and the need to cover the drivers that a 10"er could be impratical.
Thor, a pic of a keg would be a big help. I know there are a number of shapes.
Thatch

Perhaps a good idea given the keg shape would be to install the woofer in the bottom down-firing and elevate the keg on 3 pointed standoffs. The mid and high could be on the front side. This would look like the layout of those marble top Empire speakers from the 60's.

Rob

Rob, would the sound be as good as with the typical 3 way configuration??

Thor,

I am afraid that you are compromising the speaker design by making it a novelty item. It has to look like a keg first and sound like a speaker second. I think the aluminum keg will have nasty resonances, one especially in the several hundred Hz range, and that will be a real problem unless you damp it internally with a conformal coating of something like lead shot mixed with short strand aurobody filler and thinned with polyester resin, or some other materials, perhaps even cement if you can get it to stick to the aluminum, and then line the inner walls with absorber too. As far as a bottom firing woofer, no problem there really if the crossover point is low enough that directivity isn't an issue. I've never experimented with such ideas yet, so all I can do is guess.
I'm sure if beer kegs made really good sounding speakers they would be all over the place by now eh?

Rob

Well damping the keg will be the easiest part, I am gonna spray the inside with about 3" of that sticky ass expanding foam stuff then while it is still tacky press 6" of polyfill insulation into it, that should dampen it enough I think, what do you think?

Originally posted by THOR
Well damping the keg will be the easiest part, I am gonna spray the inside with about 3" of that sticky ass expanding foam stuff then while it is still tacky press 6" of polyfill insulation into it, that should dampen it enough I think, what do you think?

Thor,

I think that will reduce the internal volume of the keg so much that you will lose the ability to make bass.

Why not give your friend real speakers, paint 'em white and include a 35mm slide projector with a picture of a beer keg that he can project onto the speakers.

Rob

No, No, No Rob the point is that these speakers are going in the basement pool hall/bar of a bunch of raving lunatics, as long as they pump out good and loud they will be fine, this is not science! This is art! They must look like beer kegs they simply must! Now Professor tell me how you would make this dream come true in an easy to understand fashion :D I have the kegs, I have the drivers and xover, I am just gonna take them out of an old 3 way speaker set I have that sounds good and loud but look crappy. 10" woofers, 4" mids and some tweets. No rocket science no equations just good ole practical madness ;) The cabs of these old speakers are roughly prolly the same volume/size as the kegs so my biggest challenges are mounting the drivers (while maintaining the keg look) and now that you shot down my dampening plan, dampening the keg. Pretend its junk yard wars! Pretend we're in the A-team, this is what we have to work with now how do we do it Soldier!

Thor,
I thought of the down firing woofer after I posted and I agree that that is going to be your best bet for bass. An idea that I had was that there are some really good mini speakers you could put inside for the mids and highs and only worry about the damping for the woofer. I suggest for quality size and price that you get a pair of Minimus 7s on Ebay for around $25. They are in cast aluminum cabs. You could tap the cabinets and use some mini L brackets bent to go inside the kegs and attach the speakers with the same nuts and bolts used to attach the perferated metal cover that hides them. You do this through the hole in the bottom used for the woofer. As far as the Minimus 7s go I would replace the cap that is the high pass for the tweeter. That is the only crossover part in it. I would also solder my cable to the speaker instead of relying on those spring loaded wire holders they have.
I have an idea on the damping material but I can't remember the name right now. It is basically what was used to line the inside of airplane cabins for noise and temp insulation. A layer of that glued inside, with egg crate covering that ought take care of your woofer. I don't know the SPL of the Minimus 7s but you match that up with a sub woofer that runs from around 100 Hz and down and then all you have to do for a cross to the Minimus 7 is a 6db high pass at around 80 Hz and let the woofer run free.
What do you think?
Thatch

ooooooooooooooooh thats a snappy idea! I understand how you mean to attach the min 7's to the inside I got a little confused on the "cap" part tho :confused: And what about a crossover? I don't know about matching a woofer but I will have two rat shack 12" woofers available when I get all my woofers refoamed and can put the original woofers back into some cabs.

The only drawback is this is a more expensive solution to using the drivers and the crossover out of my old 3 ways that I got sitting around.

THOR will have to think about this ........hmmmmmmmmm argh! THOR head hurt! THOR will think later!

Thor,
The biggest draw back is if you don't do this very carefully it will sound worse than a sack full of cats. It might take a while but not counting the kegs you might get out of this at around $200 to $250 with the best sounding kegs in the world.
Well,....if you don't do it right they will still be the best sounding kegs in the world but you might loose your friend. Graduating number one in a class of one can be simple or difficult. The results will speak, pound, sing, blast and dazzle according to what goes in them.
I hope this is going to be a Xmass gift. This Pete's Wicked Red Rush sure is tasty.
Thatch

I really don't have anything else to add other than the Minimus 7's have somewhere in the neighborhood of 87/89 db meter range. Max power somewhere around 40 watts. Brad

Thor,
Not counting sound proofing and damping materials, kegs and construction I figure you can get all you need besides cable for approx $150. That is with a pair of Minimus 7s, Dayton 12" woofers that go down to 28 Hz and crossover parts. And the great part is that the hole for the mid/tweet can be as small as 6" tall and 4" wide. And they should sound good enough for you to get orders to make some for your other Old Style chugging buddies.
Thatch

Brad, thanks for the SPL info!

Ok I will drain the other keg so that I have two empties :D To start off with.

Is my idea for dampening them good enough?? Just spray the inside with that expanding foamy stuff?

Also does the woofer have to fire out of the bottom? Could it fire outta the top? That way it wouldn't have to have legs and could sit on the floor in a natural keg fashion?

Are you going to use Bud straight edged kegs ot the type that has a thicker middle than ends? And if you and your Buds are emptying kegs while you listen to them then I doubt a upward firing woofer would be at all safe. Another thing is that if these are sitting in corners the downward firing would give you a big bass boost. Using bolts for legs to raise a keg off the floor a few inches should not detract from the beauty of the keg and if you put those light up never stop pouring beer into a mug taps on top the bottom will be hidden in shadow. As to the idea for insulation I doubt it. I think you need to go for a soundproofing method first. That will trap the sound in between layers and then do the damping. That is an opinion only.
Thatch

So what do think to do for soundproofing?

The kegs are straght sided not bigger in the middle.

That makes it easier since it already has a raised bottom and handholds.Raising that 2" more ought to do the trick. I will make a run out to Home Depot and get the name of the company that makes this insulation stuff. It is made out of a dence layer of shredded rags and has a foil outer side. Way I figure is with a spray adhesive you line the keg with this stuff. Sound will penetrate the foil, slow down in the padding, bounce off the keg,and when it goes through the padding on the way out it hopefully has lost enough power to penetrate the foil again. After that is installed you spray adhesive on the foil and attach the bubble wrap with the smallest bubbles. That can absorb some sound but better yet it can defract sound waves so that you don't get standing waves. Then you take a real cheap pillow and use the dacron fibers inside it to stuff the keg. Simple and cheap and should do the job of that expensive Black Hole acoustic foam.
Thatch

Cool cuz I have a whole can of spray adhesive left from redoing some speaker grills ;)

I went to Home Depot and bought a 4'X6' piece of the insulation for $20. It is made by Quality Heat Sheild Sound Deadener. The phone is (800) 252-7901. If they are on the net do a search at <www.metacrawler.com> and you will find them. I am going to use this and bubble wrap to line a subwoofer cabinet. The bubble wrap comes in rolls for $10 at Target. Just the bubble wrap by itself defeats standing waves big time. A very good DIY speaker builder's cheap but very effective tweak.
Also I have been thinking and will send you a pair of very good EMIT ribbon tweets (not for free) from some Infinity speaks and do another search on Parts Express for some wider range woofer so you can do a 2 way and not have to cut such a big hole in your kegs. I'll even toss in some light up beer signs if you want. I don't think I have any beer clocks left but will check in the attic. A beer/pool hall has to have the right ambience.
Thatchmo

Sweet thatch lemme know on that stuff ;) I have tons of bubble wrap from all the stuff I got from the grumpster :D

It has to be the small bubble- bubble wrap Thor. The large stuff is just good for packing. I did a search an did not find a web site for this group but the $20 I paid was less than 1/3 the price for the same stuff at the aviation supply and that was at 40% off! Let me know if you are interested in the ribbons. They run at around 88 db so I think a woofer that runs at 92 db will give you a lot of extra bass for the same wattage and if you turn the ribbons sideways then you can avoid the sweet spot syndrome and help with everybody hearing it. Any woofer that runs to at least 5K will do as these ribbons should go down to 3.5K. By the way these tweeters are what got Infinity into the big time. I will post on Vintage, brave soul that I am, for comments on them. Also as an aside they were designed by Janszen who had his own company making speakers of which the most popular were and are still today the Elecrostat Tweets of which I have a pair of the 2 pannel jobs. They are around 25 years old which put them in the middle of the heyday of vintage SS gear.
Are there Home Depots in the land of the frozen Bush? If not I guess a care package will have to be put together for you.
The tweeters are 3 1/2 " circular and have to be flat so you are going to have to mount them on plywood and attach them to the inner wall of your kegs.
Thatch

Yes we have a Home Depot, how much are ya wanting for the tweets??

Try and get some of the sound deadener, make arrangements on the keg surgery for the woofers( I am hoping 12"ers will fit) and we can worry about the cost of the tweeters later. I would tell you now but don't know the rules about posting prices outside of the For Sale part of the site. Rest assured they are very reasonable and ought to be a simple solution for keeping your kegs as keglike as possible. Are you resigned to the fact that a downfiring woofer is the most practicle and best sounding alternative? Not knowing what speakers your 3 ways are I am firmly of the opinion that spending $50 or so on woofers just for this project are worth it simply because knowing the numbers and having more data will allow for better speakers 1st time out. By pairing the tweets with more efficiant woofers will give you more bass before the tweeters really kick in. This will allow you to get higher volumes before starting to overdrive the tweeters. It will aslo make low volume listening not as good. A way to even it out is a simple horn. Are you good with wood and have access to the tools. The big problem here is the curvature of the inside of the keg. If you have the ribbon sideways firing for greater mid/high spread then the horn must be sideways to the curve of the keg. The hole in the keg is small but the engineering is way up. And it must be air tight. Given the right curve I probably could get somthing close enough that a lot of silicone calk could handle it. I need to check on those truck air filters too.
I saw a chromed Bud keg hanging from the ceilind of a liquor store the other day. Maybe you should take a trip to the brewery in NH and talk with some PR people. If nothing else you get the free beer at the end of the tour.
Thatch

The one keg I have now is dead on mint, looks brand new, nice bright stainless steel finish I will get a matching one, I have racked my brain for some time on this project and don't see how to mount the woofers any other way without ruining the "keg" look. What suggestions do you have for woofers?? Try to find some as inexspensive as possible that will work good, since these will be an experiment and a gift I don't wanna spend too much money on them, mebbe if they work good I'll build an even better pair of "audiophile" kegs ;)

I was wondering tho will just a 12" woofer and some tweets give us enough midrange sound?

I do have woodworking skills, I have a AS degree in Building Construction Technology, and I think I can get to some tools.

Thor,
You could pull that down firing woofers out of those big ugly;) CVs you have collecting dust.
The price of drivers will differ little for what we (you) are looking for. Will a 12" fit or does it need to be 10". You are still going to have to get someone to cut the holes out for the speakers. I will find you a pair of woofs at a good price that give the sound you want. If there are some that go up to 5K then a simple high pass for a crossover would be all that is needed. I'll see what I have lying around as far as caps go. If you don't want to go for the $20 for the sound deadener then buy some car under coat, do a few coats, attach bubble wrap and get a $5 pillow at K-Mart and pull the dacron out of it to stuff the keg.
You could get by with a 3" hole for the EMITs, so that you might be able to do your self with a hole saw. If you can't do it you sure will scratch that nice keg up.
Thatch

Thor, Thatch-ear

Would this woofer work for this project?

10" PAPER CONE 8 Ohm
Size: 10-3/4" Square
Hole cut out: 9"
Power: 100W
Response: 45-5500 Hz
Magnet: 25 oz.
Sensitivity: 92 dB

http://www.simplyspeakers.com/graphics_products/10%20Square%20Frame.jpg

It's available at www.simplyspeakers.com

Chris

"You could pull that down firing woofers out of those big ugly CVs you have collecting dust."

Thatch I know you kidding so I won't have to track you down and wear your head as a hat ;) :D

I think a 12"er will fit ooooooooo mayhap even a 15"er I haven't done any measuring yet but a 12" will definetely fit. I can cut the holes myself ;) My GF's mother has a nice Makita Sawzall that will do nicely :D

I will go measure the keg now ;) Dammit I can't :mad: All my tape measures are out at the GF's mothers's house being used in the rebuilding after the fire.

The sawzall will do the job!

I agree with Thatch about finding a woofer with a reach up to about 5K Hz, that would be able to blend with an EMIT nicely.
Thor, pop over to http://www.partsexpress.com and poke around. Over on the left lower part of the screen they have several very decent help links for diy'ers along with several calculators and such. They've also got a lot of drivers, you could get some ideas, and Thatch has pondered this infamous kegger speaker and has had some really neat ideas. Use that guy! :D
We should get an idea of the internal volume of the keg. We should be able to do that by translating the gallons to cubic inches dived by 1728 (is that right?) to get cubic feet.
Etc.
Let's get crackin'!! ;)

sneaky pete

The EMITs are 4 ohms but that is nothing a resister won't fix if there is a better buy on an 8 ohm. Parts Express also has some good buys on planers if the EMITs are too old. The EMITs are probably around 88db SPL so if you put in a 92 SPL woofer you aught to blow it first and it will be much easier to replace. Youll get a bit more head pounding out of it too.
Thatch

Go borrow a ruler from one of your kids!

I missed out on the fact that the emits are 4 ohm,

I dunno if this woofer could work, but it looks very good to me:

10"
TREATED PAPER CONE
Size: 10"
Hole cut out: 9"
Power: 110W
Response: 40-5000 Hz
Magnet: 20 oz.
Sensitivity: 90 dB

#GW-210/8
LIST $54.95
OUR PRICE $44.95

http://www.simplyspeakers.com/graphics_products/GW-212.jpg

Chris

I put the 12" woofer from my Altec Model 15 upside down on the keg and it is a perfect fit! I took some pics but I had to install a driver and restart to post them so i will post them later tonite.

The bottom of keg:

http://www.printroom.com/_vti_bin/ViewImage.dll?userid=hellianthor&album_id=53107&image_id=51&courtesy=1

With 12" woofer on top:

http://www.printroom.com/_vti_bin/ViewImage.dll?userid=hellianthor&album_id=53107&image_id=50&courtesy=1

Thet 12"er looks about right. Get on partexperess and check out the 12"ers in your price range and remember the higher in Hz it will go the better for crossing the tweeter, and get high SPL. The driver is going to be pushing against a lot of air in that keg and low efficiency can mean thicker wire in the voice coil which means less turns which leads to a stiffer spider to keep it from overextending etc...Higher SPLs typically mean better motors in the drivers. Higher watts means thicker wire in the voice coil and that gets us back to where we were before. I will pull one of the ribbons and double check the impedence. If it is 4 (Ithink it is) and the best driver for the $$ for you ends up an 8 ohm there is no worries as you just use 4 ohm calcs for the tweet xover.
Most all soft,and hard domes are basically 4" wide as are the ribbons. You have to have something flat to attach the ribbon and something curved to fit the inside of the keg. I suggest 3/4 to 1" ply in a approx 5 '' circle to attach the ribbon. If you make a rectangular slot that only the ribbon part of the tweeter and curve that out you will be making a simple horn mouth and raising the decible to power ratio. If you mount it sideways in the keg up at the top then this will send out the upper mids and highs sideways and keep them from creating that sweet spot syndrome. That is good for lots of space and people. And since it is firing side ways you also might be able to get it to fire out one of the hand grips on the top off the keg. Don't forget those same grips on the bottom will help you in the amount off height you have to raise them off the floor. For that if you can drill 3 holes and arc weld nuts on then you can use different length bolts and also adjust the height by turning the bolts. Then you and you friend can spend hours optimizing them!
Have you ckecked out truck air filters for the metal screens yet?
Thatch

We aren't going to put a port in? It's gonna be a sealed enclosure? Could we modify one of these horn lenses http://www.partsexpress.com/webpage.cfm?DID=7&WebPage_ID=3&Start=3&Filter=horn&searchorderby=1&sm=1&so=1 for the tweeter?? Why do I need a metal screen? If the woofer is facing the floor it will be fine right?

We aren't going to put a port in? It's gonna be a sealed enclosure? Could we modify one of these horn lenses http://www.partsexpress.com/webpage.cfm?DID=7&WebPage_ID=3&Start=3&Filter=horn&searchorderby=1&sm=1&so=1 for the tweeter?? Why do I need a metal screen? If the woofer is facing the floor it will be fine right?

Nah, an acoustic suspension system will give y'all a tighter sound. And simplify things a bit.
The Pioneer woofer i suggested previously is at partsexpress, p. 200, they have a 12-inch version, too. I'll see if I can find it on their website.

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=290-118

Modifying the wood to fit the inside of the keg is so that the keg can be sealed and to give the tweet a flat surface to attach it to. The EMIT will be fine in the keg and the screen is to kind of hide the hole for the tweet. Keep the kegs looking more keggy and the little metal screens will impress your friends when you tell them that they are from a diesel rig. After all you have a rep to uphold. Am I right?
Thatch

Ah sooo true, I get what you mean now, any pics of those screens anywheres? Just so happens my brother work at a Truck Stop ;)

Give your brother a holler and see if he can find you a used filter that has round holes in the screen. If you can get one of those you can drill the holes out a bit more before you cut the sections out. I think the one I saw was about 2/3 the size of a bud keg, so the curve of the screens should be easy to deal with.
If you find out that you can't get this I will bother a friend for a piece of a large screen of this type stuff I saw at his place a couple of months ago. I would prefere not to have to do this even though I know he would give it to me.
Thatch