Metal speaker box?

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Is there a good reason you don't see any metal speaker boxes?  I'd like to build some for a set of 12's.  I figured it would be because of vibration but it shouldn't vibrate if it was built from 10ga.  It would be 2 separate boxes and fairly small.  Where's the audio guys?  I know yall are there.DewayneDixieland WeldingMM350PLincoln 100Some torchesOther misc. tools
Reply:Even in 10ga. you'll get standing waves, and resonance, if not vibration. I'm not an expert at all, but I would guess that whilst it might work, it would have an effect - rather like the difference between a wood bodied acoustic guitar and something like a Dobro. It might not necessarily be bad, but I'd lay money it'd be "different"!M
Reply:Might just have to build one a see, I was hoping someone would know a definate answer if it sounded like crap or not.DewayneDixieland WeldingMM350PLincoln 100Some torchesOther misc. tools
Reply:Goals with the case for the speaker are massive and no resonances. Particle board has the benefit of mass and being a good damping material. Metals tend not to be lossy enough to sound good, and also tend to clatter and buzz when they vibrate at joints. Other potential issue (though I doubt it will matter much in the real world with a little care) is magnetization, if steel is used, and reactive effects if nonmagnetic materials are used. Though, the reactive effects might damp out vibration.... All of that said, probably the biggest reason is cost. Particle board is cheap. Metals arn't, by comparison. Now you have me curious. Curses....
Reply:A while back, I built four small (6.5”w x 9”h x 5”d) speaker enclosures using some .100” wall aluminum light fixture housings.   You can see one in the attached picture above my left shoulder.    The fronts and backs are 1/8” thick aluminum sheet.     I used a 5” midrange car speaker and a small Delco tweeter with a crossover cap in each.   The boxes are fully welded and there is a pad of fiberglass insulation inside.    I’m not into music at all so I don’t know good sound from bad, but the sound from the speakers was very “tinny”.    Even with the bass cranked up, it still sounded lousy.     I added a tube port to each speaker and it improved the sound a lot.   I also had to add rubber washers between the speaker boxes and the mounting brackets because they seemed to vibrate with the volume turned up Attached ImagesThere are no small projects
Reply:Reasons why speaker enclosures typically aren't made of metal:- cost (as stated above) of materials and labor- resonance/vibration (as stated above)As an experiment, if you have a welding or shop table with a nice thick slab of steel on it, pick up a BFH and smack the middle of the table pretty hard.  The racket the impact made is loud and also 'ringing' and also LOUD.  Take a typical higher-end speaker enclosure and hit it and you would hear "thud".  Not all that loud and there is no ringing or resonance.  All that ringing and resonance will 'color' the sound of the speaker and make it sound tinny.  And because the metal will be vibrating all over the place, it will be buzzy as well.You could maybe make a pretty massive tube subwoofer for a 12 inch driver with a 6 foot piece of 18inch Schedule 80 pipe.  You'd need a shop/engine crane to lift it though, and make sure the building's floor can handle the weight (1000+ pounds, driver and endcaps and wiring and misc not included).  Adire Brahma 12 driver, 30 % fill, and 55 cm long 12 cm diameter flared port in that pipe would give you within 5 db smoothly dropping off response from 200 Hz down to about 20 Hz, and then a slight kick-up from 20Hz down to 14 Hz ( up 2 db), and then falling off below that.  You could -shake- the house with that.
Reply:Partical board is best for all of the reasons stated above.  Nice cart Imagineer!Hobart 140 Handler w/ gasHyperTherm Powermax 380 Plasmaoxy/acetylene
Reply:Originally Posted by Rick MoranPartical board is best for all of the reasons stated above.  Nice cart Imagineer!
Reply:Originally Posted by MoonRiseReasons why speaker enclosures typically aren't made of metal:- cost (as stated above) of materials and labor- resonance/vibration (as stated above)
Reply:that is one of the coolest tool chest I have ever seen! very nice!
Reply:Well I guess that's a definate enough answer   Sucks though, I think it would look good in my truck.  Oh well, I guess I'll get me a sheet of MDF.  BTW, that is a sweet toolbox imagineer!  Where's the thread on it?DewayneDixieland WeldingMM350PLincoln 100Some torchesOther misc. tools
Reply:i was in many bands in my life..5000 watt 4 way PA systems and such..we had no road crew...wood speakers weigh enough..god help anyone with metal ones...and they'd probably feed back badly when you got around to 1 hz... ...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:1hz!? Or did you mean 1khz? I don't think anyone has to worry about 1hz. This is probably the only time I'll ever get to correct you...
Reply:Originally Posted by gimpyrobb1hz!? Or did you mean 1khz? I don't think anyone has to worry about 1hz. This is probably the only time I'll ever get to correct you...
Reply:I went to a consumer electronics show (C.E.S.) in Chicago a few years ago. Clark Audio was working (displaying) subs that ran off of servo motors. Two 18" drivers moved by a motor could produce frequencys that were low enough to rattle the Sh_t out of the building, and they didn't get below 10hz. I love loud and clear audio, and that trip I saw some gear that I will NEVER forget. Oh to have more money than sence. Some of the connecting cables were like, 25.00 a foot.
Reply:Very cool tool box. Have plans to share? John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Originally Posted by gimpyrobbI went to a consumer electronics show (C.E.S.) in Chicago a few years ago. Clark Audio was working (displaying) subs that ran off of servo motors. Two 18" drivers moved by a motor could produce frequencys that were low enough to rattle the Sh_t out of the building, and they didn't get below 10hz. I love loud and clear audio, and that trip I saw some gear that I will NEVER forget. Oh to have more money than sence. Some of the connecting cables were like, 25.00 a foot.
Reply:Originally Posted by MicroZoneVery cool tool box. Have plans to share?
Reply:Originally Posted by littlefuzzI'd like to see the 18"  I've never even heard of anything like that.  I remember on Pimp My Ride they installed a big sub.  Yeah here it is. http://www.mtxaudio.com/caraudio/pro...jackHammer.cfmYeah, that's big!
Reply:Make the boxes out of particle board then skin them with whatever type of aluminum you want, just be sure that it is tightly secured to the boxes to keep it from ratteling.
Reply:i was just going to say, that you could skin the MDF, but rice burner beat me to it by 4 and a half hours lol. It would look pretty cool. the MDF would absorb most of the sound and the skin would reflect back whatever escapes the MDF, thus further isolating the inside box from the outside box... at least, thats what i think.. but i'm no sound engineer.
Reply:wakeboard tower speaker enclosures are almost always made of metal and they are super spendy!  get your technique down and they go for 500 and up per pair.check out  http://www.wakeside.com/page/w/PROD/...tower_speakers________________________________________millermatic 130 XPspectrum 125 Cgas gas gascan you tell how much I need a 220 outlet in the garage?
Reply:If I'm gonna use MDF I might fiberglass over it with some kind of design.DewayneDixieland WeldingMM350PLincoln 100Some torchesOther misc. tools
Reply:just pick up a can of expanding foam to fill the speeker cabenet with and go for steel. summer is here, plant a tree for mother earth. if you dont have time or space, sponcer some one else to plant one for you.feel free to shoot me a PM or e-mail me at [email][email protected] i got lots of time.
Reply:almost every car door is steel and they stick speekers in them. summer is here, plant a tree for mother earth. if you dont have time or space, sponcer some one else to plant one for you.feel free to shoot me a PM or e-mail me at [email][email protected] i got lots of time.Hi all,I've built 14 speaker systems over the years, so I have some experience.Metal cabinets are used - typically Radio Shack (or whatever they are called now) marketed the famous small book-shelf acoustic suspension (no ports) 'Minimus 7' speakers that used a 4 inch woofer and 1 inch tweeter.  The Minimus boxes appeared to be cast aluminum and were stuffed with fiberglass.  They also released a larger unit of similar design using a 5 inch woofer.  These units were great - there was no 'ringing' or metallic sound.  However, the Minimum 7 speakers were small - about 9 inches high x 5 inches wide x 5 inches deep... with walls of about 1/10 inch thick aluminum = these metal boxes were very, very rigid.The problem comes when you want to use larger bass drivers like your 12 incher.  There is going to be a lot more air compression/expansion in a speaker enclosure that has much larger panels.  In the wall remain about 1/10 inch thick, the wall panels are likely to flex out/in as the woofer moves in/out of the enclosure - especially with a sealed enclosure.Short of using 1/2 thick metal walls for rigidity, what can you do?1 - make the metal panels rigid - perhaps welding to each panel a backing lattice of angle iron/aluminum.  Making the walls rigid is the most critical item.e.g. The RS Minimus series worked well because their aluminum boxes were RIGID!!  (I stood on them to change ceiling light bulbs.)2 - port the enclosure - porting depends upon the speaker parameters.  Note: The problem is that ported enclosures are usually way bigger - exasperating #1.  If you do a good job on 1, 3 and 4, you should be fine with an acoustic-suspension type woofer.  [There are ways to calculate what volume enclosure you require from the speaker parameters.]3 - damp the panels - apply a layer of self-adhesive felt (or glue with silicon sealant regular felt to the panels).  Alternatively, you could smear a couple of tubes of caulking compound (acrylic, silicon, plastic roofing, etc.) over all the internal surfaces - trying to get about at least 1/8 to 1/4 inch layer of rubberized goop over everything.  This will remove any metallic 'ring' or tendency to resonant.4 - fill the enclosure with fiberglass insulation as damping material.Note: I don't think using expanding foam is a good idea.  Unlike fiberglass insulation (attic stuff), solidified expanding foam is 'solid' enough to reduce the 'open' volume of the enclosure - reducing the bass response.Just my 2 cents...Good LuckRick V
Reply:Originally Posted by fun4now.almost every car door is steel and they stick speekers in them.
Reply:I have been building speaker enclosures for years It is best if you use particle board or MDF Medium density fiber board. Its hard enough to keep the car from rattling let alone a metal box all tho an all aluminum box would look cool for a custom install.Will   Supports Autism Awareness                            My ToysBobCat 225 PLusMillermatic 130Miller Spectrum 300 CutmateEverlast Power Tig 185 Micro April is Autism Month .
Reply:so fill it with expamding foam and cut out the air space you want, this should alow you to have a nice 1" or so of foam all around the inside of the box and prevent the rining. it would be a lot easyer to fill the box with expamding foam and cut it to the thickness you want than it would be to try to build up 1/4" of caulking. you could even make a smaller box the size of the opening you wanted inside the box, wrap it in a plastic bag, fill the box with foam and insert the smaller bof to creat a inside mold. let it dry and remove the iner box, walah you have a shaped iner cavity for the speeker. and no resinance problem with a steel box.if it were me i would get out there and start making some and see how it works out with diferent shapes and or packings. never let them tell ya it cant be done, just do it and show them it can after all what do ya have to lose but a little steel and maybee a can or 2 of $4 foam ??? or caulk if you prefer.lets see some progress, now ya got me wanting to build one just to do it. man i realy need help.......wheres my Jack and coke i got work to do. summer is here, plant a tree for mother earth. if you dont have time or space, sponcer some one else to plant one for you.feel free to shoot me a PM or e-mail me at [email][email protected] i got lots of time.
Reply:Well I already bought a sheet of MDF before hearing these other ideas.  The MDF box is almost already done now.  It's turning out very nice so far, I like working with wood too.  I just need a bigger table saw.  I do have another truck that needs a box in it, I might try the metal in it.  I got to get the gas tank out from behind the seat first   Or maybe the gas tank could be the box  I'll at least post some pics of the MDF box when it's done, I know we all like pics.DewayneDixieland WeldingMM350PLincoln 100Some torchesOther misc. tools
Reply:oh ya, every one loves pic's i gotta get to work on my 51 this summer so i can try out my expanding foam in a metal box therie, got lots to do on the old girl but some day she wil be all purdy and back on the roads, summer only now that im in NY insted of AZ though. summer is here, plant a tree for mother earth. if you dont have time or space, sponcer some one else to plant one for you.feel free to shoot me a PM or e-mail me at [email][email protected] i got lots of time.
Reply:Usually when you buy sub woofers they come with a spec sheet for a closed or a ported enclosure for them to work at there best the box has to be a certian cubic feet it should have the cubic displacement on that spec sheet. Thats what I go by when building a box for a subwoofer. The last box I build was what they call a band pass box it liked frenqucies between 25 and 100 hz. that thing would set off car alarms at the mall.Last edited by Steelwill; 01-07-2007 at 11:59 PM.Will   Supports Autism Awareness                            My ToysBobCat 225 PLusMillermatic 130Miller Spectrum 300 CutmateEverlast Power Tig 185 Micro April is Autism Month .
Reply:Originally Posted by SteelwillThats what I go by when building a box for a subwoofer. The last box I build was what they call a band pass box it liked frenqucies between 25 and 100 hz. that thing would set off car alarms at the mall.
Reply:Better?  A bigger driver can move more air, so it can be louder and reproduce lower frequency sounds better than a smaller driver.  But a lot of 'better' is not just the size of the driver but the QUALITY!And sometimes the size of the driver is dictated by other things, like cost or space.So the answer is "It depends."Is your usage for in a vehicle or in a building?  If it's for in a building, look up "infinite baffle speaker" in google or whatever search-engine you want to use.  Look here http://home.comcast.net/~klone-audio...-12Shiva1.html for one example.I still think you should get that 6 ft piece of 18inch Schedule 80 pipe and make a tube subwoofer out of that.  It was only ~1000 pounds of pipe.  You can weld feet and brackets to it, since this is a welding site.For speaker enclosures, rigid is better and solid is better and rigid and solid is what you want.  A chunk of expanding foam inside a sheet metal enclosure is neither.Although maybe you could start a new design in speakers with an exterior metal box and a smaller interior metal box and the gap between totally filled with expanding foam.  You just made a foam-filled composite panel.  Stuff the inside box well with poly-fill or other acoustic batting as needed and mount your driver.  Post pics, we love pics of stuff.
Reply:Well here's the box that I decided on.  I still go to get some carpet and maybe cut some flames out of stainless   Should I port?  Is that decision dependent on the driver?  Sorry my questions have turned more toward audio.  I'm still gonna try a metal mox later though. Attached ImagesDewayneDixieland WeldingMM350PLincoln 100Some torchesOther misc. tools
Reply:Nice box. And depending on the frequency and type of bass you want will determind if you port the box or not.Will   Supports Autism Awareness                            My ToysBobCat 225 PLusMillermatic 130Miller Spectrum 300 CutmateEverlast Power Tig 185 Micro April is Autism Month .
Reply:Originally Posted by SteelwillNice box. And depending on the frequency and type of bass you want will determind if you port the box or not.
Reply:a ported will make louder sound ( at tuned frequency )...  Tune too low, bass is boomy... tune too high, and you could damage the speakers at high volume, low frequency ( don't ask me how I know this )There are several ways to figure out box/port frequency... A book "loudspeaker design cookbook" has a ton of 'em, or a program called 'blaubox'A sealed box is more forgiving, however,... you want to rattle some stuff at ultra low freq's so low you can't hear it, but can feel it... you want a tuned ported box.  ( basically what music do you listen to? )
Reply:Originally Posted by slamdvw ( basically what music do you listen to? )
Reply:New tread   http://www.weldingweb.com/vbb/showthread.php?t=8454  Kinda the same project.DewayneDixieland WeldingMM350PLincoln 100Some torchesOther misc. tools
Reply:Just stumbled across this thread.  I'm not going to get in the middle of a cockfight about enclosure design.  There are lots of good books on that topic.  But I am going to get into the foam discussion.Basically, expanding foam is useless for acoustical purposes EXCEPT for sealing leaks.  It is definitely NOT a substitute for glass fiber or "acoustical" foams.  The reason is that the cells are closed.  That is, they do not communicate with each other.  That is a desirable property for sealing leaks in your house.  It is a very undesirable property for an acoustical absorber.  The result of the closed cells is that the acoustical waves cannot pump air through the pores in the material. That pumping action is the way energy is dissipated and sound energy is absorbed."Acoustical " foams are closed cell foams that are made porous by "zapping the bun."  When a polyurethane foam is produced at the factory, the cells are filled with the flammable gas used for expanding the liquid into a foam.  By lighting off the gas, the thin membrane walls of the cells are burned away, producing a porous foam.  You can distinguish "acoustical" foam from insulating foam by blowing through it.  If you can't blow through it (or if you don't feel any resistance to your blowing through it), it will have negligible acoustical properties.One of the calculations we acoustical consultants make is the resonant frequency of building wall constructions.  That resonant frequency is related to the frequencies at which the wall is an effective sound barrier between adjacent rooms.  A rule of thumb is that a wall filled with acoustical absorption (like glass fiber batts) has 50% more effective airspace between the wall faces and is, therefore, more effective as a sound barrier at lower frequencies than a wall without sound absorption.While I have not been involved in speaker enclosure design for about 4 decades, I think a good rule of thumb would be that the effective volume of an enclosure is increased by about 50% by packing it (loosely) with glass fiber.  Conversely, filling an enclosure with expanding foam will REDUCE its effective volume by roughly the volume of foam in the box - not a good thing.  You might as well make a small box to begin with and put a lot of stiffeners on the outside of the walls.  An enclosure filled with houshold expanding foam conforming to the speaker shape will have the approximate acoustical characteristics of an enclosure built to conform closely to the speaker shape.This ignores the aspect of damping and rigidity of the enclosure walls - both desirable.  But filling the box with expanding foam is not the best method of achieving either damping or rigidity.  The most effective way of maximizing rigidity (for a given thickness of material) is to install struts between opposite walls and to have deep ribs integral with the walls.  The most effective way of providing damping in the walls is to employ naturally damped materials (not metals) and "constrained layer damping."Constrained layer damping means that an energy dissipating material (and its selection of properties is heavily involved in theory) is fully bonded in a sandwich between the metal wall and another piece of metal of similar thickness.  This configuration maximizes the shearing strain of the energy dissipating material for a given bending of the wall, thus maximizing energy dissipation.  You can actually buy panels of constrained layer damped sheet steel for fabrication of products by conventional means (other than welding).awrightLast edited by awright; 01-09-2007 at 03:46 AM.
Reply:Well with that being said, would fiberglass insulation work?  I got a pile of that laying around.  I did build my box out of MDF, should I put something else in it?  Will that change the sound?  My filter on my amp is set for low frequencies.DewayneDixieland WeldingMM350PLincoln 100Some torchesOther misc. tools
Reply:Glass fiber building insulation is fine.  Your speaker sound will almost always be better with absorption in the box.awright
Reply:Just to add fire to this.  How about putting a thin Metal shell on it.  This way you have the sound from the MDF box, but it looks like it was made from all metal.Just something to think about.
Reply:Originally Posted by partagasJust to add fire to this.  How about putting a thin Metal shell on it.  This way you have the sound from the MDF box, but it looks like it was made from all metal.Just something to think about.
Reply:You can tig weld the edges.  That will give you a nice look.
Reply:Originally Posted by partagasYou can tig weld the edges.  That will give you a nice look.
Reply:yea so dose the magnet, just go for it. come up with some thing realy artsy and sell it to some fool with more $$ than brains.now thats not a bad idea. summer is here, plant a tree for mother earth. if you dont have time or space, sponcer some one else to plant one for you.feel free to shoot me a PM or e-mail me at [email][email protected] i got lots of time.
Reply:Originally Posted by fun4now.yea so dose the magnet, just go for it. come up with some thing realy artsy and sell it to some fool with more $$ than brains.now thats not a bad idea.
Reply:Originally Posted by littlefuzzHow do I go about figuring all that out.  What type of bass does a ported box give vs. a sealed box?