Concrete Audio Speakers...Speaker Enclosures made out of Concrete ?..

No. They will ring like a bell. And not thick enough. 

NO! Too much resonance!

You also have Rauna. Very good but not very practical to ship somewhere.

https://rauna.com/

Concrete, granite, cast iron... Companies try, but really, how practical is this?

Its not a question of practicality. They sound bad. 

I once saw a demonstration about concrete boat hulls. At one point the speaker struck the side of the concrete hull (it was an unfinished boat out of the water) with a pipe or bar and it rang like a giant bell. We actually sailed a concrete hull sailboat. Beautiful boat.

To say one material is always superior to another and another material is always inferior is an over simplification of what's involved in the designing of any product. The implementation is just as important as the material used.

For example, some people here argue that aluminum is the best material to use for speaker enclosures. Which alloy are you referring to? 6061, 2024, 7075...? What cross section? What shape? Pick up a piece of 0.5" thick 7075 and strike it with a bar, it will ring big time. I'm not saying aluminum isn't good for use in speaker enclosures, it can be great if used properly. BTW, properly designed aluminum extrusions can be economical and practical for speaker enclosures if you sell enough product.

I tried concrete, and the sound was weighty and too hard. I wanted something more airy. So now trying styrofoam.

BAD idea it will sound like bricks  are you joking?

Ideas, ideas, ideas!  This leads me to think of horn speakers.  Have someone cup their hands around their mouth and talk to you - it doesn't sound ANYTHING like them talking to you without their hands cupped around their mouth!!!  WHY, WHY would you want that effect in your hi-end audio system???  TOTALLY UNNATURAL!!  Horns are fine if accuracy is not a requirement or you just want to fill an auditorium with sound - but, to me, NOT for music!  Another concept from the past that has fueled a company to be a "great seller" is Amar Bose and his direct-reflecting speaker concept.  When have you EVER been to a concert/music presentation where the performer(s) and their equipment were turned around to face the back of the stage, save for one or two pieces of equipment for direct play to the audience - NEVER!!!  We won't get into the ridiculous 901 speaker design here! the unconscienable joke that it was!  But yet Bose is a top-selling brand!      Sorry for the divergent rant - all this talk about speaker cabinets set me off!  and these are IMHO only!

Everybody is saying no good...but who here has heard them ?

Could’ve sworn thiel had some kind of a concrete driver. 

More feedback..

https://www.theaudiobeat.com/blog/concrete_audio_n1.htm

https://www.youtube.com/watch?v=pk0H-xahxA4

So if I design a piece of junk speaker but enclose it in concrete what will make it sound better?  Lets 

What about acora's granite speakers? Lot of people swear by them!

https://www.acoraacoustics.com/src-1

How to make your own concrete speaker boxes...five part video
 
 https://www.youtube.com/watch?v=kf2zkd5SAZU&list=PLycL7IZk1IZk1IfKmUbsd4870ooVKHcIhdt  
 

 

Rauna from Norway or Sweden made transmission line speakers made from Concrete about 40 years ago, they did sound pretty good for their time. Danish Advance Loudspeakers also made concrete enclosures back then. Both companies used a fiber filled concrete and  the walls were about 2" thick,  so very little "ringing". I'ts all in the implementation. The biggest issue both had was the the alkaline that constantly seep out of the concrete would cause any finish applied to them to peel off. I think this was the main reason they quit doing it.

Good Listening

Peter

Has anyone heard these?  I would find opinions intriguing.  I moved my system from our main room which has polished concrete floors into another area where I put down an engineered product over the concrete with immediate improvement in sound quality.  Just trying to think about how to abstract one into another.  Not sure.  I suspect the book shelf on stands vs the floor standers vs the wall mounts would all sound completely different given the contact points but uncertain.  Very interesting concept. 

"...the alkaline that constantly seep out of the concrete would cause any finish applied to them to peel off."

Having "any finish" on them is blasphemy. We, the purists, would want them in "natural concrete".

here's the videos on how to make your own concrete speakers 
 
https://www.youtube.com/watch?v=xCPMxgY_ZN4
 
 https://www.youtube.com/watch?v=LsegJY347dE&t=126s
  
https://www.youtube.com/watch?v=8XLqTvL51t4
 
 https://www.youtube.com/watch?v=CIGmRkhFjIQ&t=78s

Very very small concrete speakers SOUND TEST...put some GOOD headphones on and listen to this.. 
 

  
https://www.youtube.com/watch?v=BuQK82Fwb1U&t

They do sound quite bad to me. 

"They do sound quite bad to me."

Get better headphones.

Another concrete speaker build 
 
 https://www.youtube.com/watch?v=E1ZaGwqJ9i4

Patented array-technique of the Fraunhofer IDMT – 41 electrodynamic mini-speakers act like one large membrane, allowing for a total depth of only 32 millimetres and giving a convincing performance.

But do they sound Tektonical?

I don't know, I am sure someone said pre 1939, "don't underestimate the skill of a German's engineering" - maybe?

There are marble speakers also.
Find a statue of Cicero or Demosthenes.  

I don't know how concrete enclosures sound. I do know that cinder blocks make decent speaker stands. I used some, back in college, for my large Advents. Cheap, minimal resonance and meets a certain post-industrial chic.

I've heard a round (actually grout) underground vault. It had 4 18" pipe intersections. It was bell shaped. Two were blocked, top was a manhole cover. No bottom, just sat in the sand. This was not concrete, no rock, just fiberglass strands about 4-6" long and an epoxy/grout mix.

2 pro 15" drivers. It had an interior of 20 CF and 1500 pounds or so. It rang so bad, I had to spray the interior with expanding foam.  It bassed  up the whole 2 acre yard. 

A column of Corian at 5/8 thick 18" x 20 x 72" with little bracing will hit a 1/2 ton.. pretty quick. Just a front baffle of @Corian and sides of MDF 550-600 lbs

I'm dealing with 410 lb each, NOW.. With HDF/MDF 

Concrete is the heaviest because of the BIG rock, a lot of weight. Also tough to pump. Light grout mixes that are made with accelerators, can fluff to about HALF concretes weight. Fiberglass, Stainless all kinds of stuff go in the mixes.

Regards

Huh???

For some inexplicable reason, Jern has not ventured yet into making 3-way floor-standing speakers.
http://jernspeakers.com/

The easy way to do this is use a router and cut out very large slots into the wood at a depth of 32 millimetres and fill them with concrete.. 

I seem to recall Jamo and Thiel using concrete in some of their products.

ACTUALLY BOTH PAUL HALES AND JIMTHIEL MADE CONCRETE FRONT BAFLES FOR THEIR SPEAKERS

BOTH SPEAKERS SOUNDED VERY GOOD

THE ISSUE IS WEIGHT AND ABILITY
TO CHIP

WE ARE WAITING FOR SAMPLES FROM JERN JERN http://jernspeakers.com/jern12-xf-loudspeaker/ ARE REVOLOUTIONARY COMPACT MONITORS EITH PROBABLY THE MOST NON RESONANT CABINET ON THE MARKET SO THE SPEAKERS JUST DISSAPEAR


THEIR NEW LOUDSPEAKERS ARE MADE OUT OT CAST IRON AND GRAPHENECOMPOSITE

https://www.tonepublications.com/review/jern-14eh-speakers/

BASICCALLY WHEN USED WITH A PAIR OF SUBS YOU HAVE A MODULAR MAGICO KILLER AT A FRACTION OF THE PRICE

https://www.bing.com/videos/search?q=jern+speakers&docid=608022865000202871&mid=6C69E90ADD95EBE4B2D96C69E90ADD95EBE4B2D9&view=detail&FORM=VIRE

LRM is our technology flagship and one of the most important factors when it comes to reducing vibrations within the cabinet. The cabinet of JERN14 has an ability to reduce vibrations 50 times better than other conventional speaker materials.

Sandcasting by the Cronig method makes it possible to craft the cabinet in one piece with no assembled parts. The one piece cast cabinet made from our low resonance material gives the speaker a stiffness that conventional cabinets, assembled from several parts will never achieve. The cabinet of JERN14 is so strong that it can withstand a load of 5 ton. The toughness and durability of the cabinet make it impossible for even a heavy metal track to generate any vibrations in the cabinet. This means that there will never be any vibrations from the cabinet that can interrupt the output quality.

Jern14 is prepared and shaped in one piece before the casting. A CNC machined model is used for producing a sand mold which is assembled around a core that provides the inner geometry. Gray iron is melted at 1450 degrees celcius before it is cast into the mould. The quality of the casting is checked with a spectrometer. After cooling, the cabinet is cleaned and its dimensions and tolerances checked. After checking, the cabinet is ready for processing.
The cast iron cabinet makes it possible to mount the drive units solid to the cabinet which is very important for the ability of the speakers to deliver clean audio, free of vibration

THE JERNS ALSO USE VERY GOOD DRIVERS AN TOP OF THE LINE MUNDORF CROSSOVERS

EVERY REVEW HAS STATED THE JERNS ARE RAMARKABLE AND CONSIDERING WE PRIDE OURSELVES IN FINDING UNIQUE CLASS LEADING PRODUCTS FROM ALL OVER THE WORLD WE HAD TO GET THE JERNS

DAVE AND TROY

AUDIO INTELLECT JERN DEALERS

More info on the Jern speakers
  
https://www.youtube.com/watch?v=CuPaobyfjLM
 
 https://www.youtube.com/watch?v=GUTk3Jw7Yvg

WE ARE WAITING FOR SAMPLES FROM JERN JERN http://jernspeakers.com/jern12-xf-loudspeaker/ 

They are unfortunately made of iron so they will ring like a bell. The speaker is even shaped like a bell so not very good design. 
Theres no response curve provided on their site, they have -6db @65 hz which is terrible and are overpriced. Best to be avoided. 

If you wanted to make big concrete speakers, the way to do it would be to make them modular.  Stack 6" high sections on top of each other separated by thick gaskets. They need to be something that is assembled in place.  You don't want to try to move 500lbs of concrete in one piece.  I don't know if concrete by itself is great idea but it could certainly be a big part of a great box.  It's incredibly dense and won't resonate at low frequencies.  Maybe some high frequency damping is in order but that's certainly doable.

@jpwarren58 ha! 
@roxy54 ha! 

Kenjit Not having heard them your blather is one of ignorance.... naturally.

I have  a system of CNC’d aluminium billets incorporating 6 x 2” full range speakers in each module, 6 modules per channel. Custom amplifiers drive them and I dare anyone to say they ring. The sound is top quality! I compare these to my other system (250k) and yes there is a difference naturally but the solid aluminium speakers are in the high quality sound range.

I’ve spent time listening to Acora’s granite enclosed speakers at the 2019 CAF and they sounded great, even in the minimally treated hotel room. 

StoneBjelk Concrete speakers... Sounds LIVE
  

  

 
https://www.youtube.com/watch?v=TB6V9yxW4P8

I did not know those Acora speakers were granite, but they did sound fine.

Rauna Concrete speakers with a tube amp... LIVE
  

 
 
https://www.youtube.com/watch?v=bbt8moHmvZ4

You would think aluminium billets would ring like a bell but they are used often. Concrete is a too general term for a number of different mixes which obviously have different characteristics. Which would be best for speakers, I don't know. As previously stated concrete has been used in transmission line speakers. I still rate concrete as a great idea for speaker plinths and equipment stands, as for speakers I think it certainly would be worth investigating further

"I don't take anything for granite..."  (Sorry, and Yes, too easy...)

I made a pair of ceramic speakers (porcelain) a long while ago....fun concept, lousy in use....*shrug*  Resonates...but they were small....

Fibre concrete will allow thinner walls, saving weight.  Flip side requires very careful design as the stronger structure will start to resonate.

Foamed concrete hasn't been tried to my knowledge.  But may have the same issues as ceramics.  The mass reduces, the weight as well....allowing for the excitation of the enclosure.....

...and foamed materials generally require casting.....big$....

Kenjit

So if a speaker is shaped like a bell it will ring like a bell?
Does that imply a speaker shaped like a tuna fish will sound in tuna? 

"Does that imply a speaker shaped like a tuna fish will sound in tuna?"

How will the speaker shaped by kenjit sound?

So if a speaker is shaped like a bell it will ring like a bell?

It IS a bell. Its a bell with drivers in them. Not a good idea. 

How will the speaker shaped by kenjit sound?

If I had a speaker company my speakers would have to be perfect. No ringing or resonances. Just pure music. 

Glass Fiber Reinforced Concrete ..... 
 
https://www.youtube.com/watch?v=gRJZTITp15Q

YUK!!! It's a squished Tekton Moab! 21st century Bose 901?

I have heard of concrete subwoofers. The enclosure was poured in the basement and the drivers mounted in the floor. It was an infinite baffle design. Theoretically it should work! 

"The enclosure was poured in the basement and the drivers mounted in the floor."

Didn't kenjit already propose something similar?