Austrians build concrete cast 5.1 speaker set

We've seen a bevy of interestingly designed speaker systems come our way, and we've even caught a few glimpses of concrete-based gizmos, but a few crafty Austrians decided to create their own nearly immovable 5.1 surround set by casting each speaker in pure cement. By measuring out the dimensions and constructing molds using wood and wax, the speaker enclosures were then placed in a wire cage and doused with concrete. After solidifying, the internal molds were removed and a custom etched logo was carved on the side, only to be further decorated with a few dashes of paint. Eventually, the electronics and drivers were all installed and sealed up, leaving a surround system that would be quite a burden if any thieves tried to relocate them. While there's no specific step-be-step guide available, the entire process was fairly well captured in photographs, so be sure and hit the read link if you're interesting in killing gobs of time creating a very bizarre set of speakers, or click on through for a few more snapshots.

[Via HackADay]

[pyro @ Jan 23rd 2007 9:47PM]

Maybe it's just me, but I don't think giving a cement subwoofer spikes for feet is the greatest idea.

[Matt @ Jan 23rd 2007 9:51PM]

Awesome now instead of them cinder blocks holding up my bed i can use speakers!! Talk about killing 2 birds with 1 stone!!!!

[chaser24 @ Jan 23rd 2007 9:52PM]

Cement is only an ingredient of concrete. So these are not made of "pure cement" because that would just be a pile of powder, which wouldn't resonate all that well. This is a cool project, I'm curious about sound quality though. Sound absorbing insulation inside?

[ScOObyDoo @ Jan 23rd 2007 9:55PM]

I'm no audiophile, but somehow I suspect cement speakers just don't sound all that much better. If they did then Bose would have been marketing them as the worlds best speakers ages ago.

[... @ Jan 23rd 2007 9:58PM]

Umm, concrete isn't pure cement... It is has rocks/sand mixed in. Get your facts strait!

I also think that the feet of the sub looks sorta dangerous/painful with that block of concrete on it...

Also, I am pretty sure that a concrete casing won't help the midrange speakers... The sub maybe, but not the satellites.

[gene f @ Jan 24th 2007 12:52PM]

Yes, you are SO right. Using the term cement and concrete interchangeably, is like using the term flour and cake interchangeably.

[Karl @ Jan 23rd 2007 10:03PM]

Very nice DIY project, but I'm not too fond of the paint job. I think plain concrete grey speakers would look awesomely retro.

Karl

[saq @ Jan 23rd 2007 10:04PM]

This is neat. Concrete is a nice material because it is very heavy and vibrates very little. This dampens the harmonics of the speaker cabinet itself almost completely, which is very important.
There are companies that make speakers out of marble (both synthetic and natural) they have practically 0 cabinet vibration.


Bose does NOT make good audio products WHATSOEVER. They make very poor, very gimmicky, very slickly marketed crap. There is NOTHING special about ANYTHING they make at all.

[ScOObyDoo @ Jan 23rd 2007 10:06PM]

Uh, yeah. Hence the sarcasm in my post. I'm fully aware of the marketing behind Bose and their lackluster performance.

[I LOVE THE CAPS LOCK KEY @ Jan 24th 2007 1:01AM]

"Bose does NOT make good audio products WHATSOEVER. They make very poor, very gimmicky, very slickly marketed crap. There is NOTHING special about ANYTHING they make at all."

MR. BOSE probably got his start by selling his speakers out of the back of a WHITE VAN.

[BatteryAcid @ Jan 23rd 2007 10:15PM]

Comeon, "nearly immovable", you guys cant lift a few block. JJ. Nice article. I love "well built" speakers, but i'd perfer metal over concrete. I bet there's solid metal speakers out their also. I saw rock speakers at a mall once, the sound sucked though.

[Chris @ Jan 23rd 2007 10:27PM]

there's a fair bit of science in building a speaker cabnet that produces good sounds, so if you are wanting to try something like this be sure to pick up a book on speaker cabnet design or you won't be impressed with the sounds you get vs the original cabnets. And just duplicating the original cabnet won't really work because different materials behave differently.

[Nipponese @ Jan 23rd 2007 11:06PM]

Actually, the importance is the volume of the cavity within and (if it's a ported design) the size and the length of the port that really matters. If you duplicate the original cabinet (which this clearly is not) in a different material, as long as the original design had their Thiel-Small parameters correctly calculated to come up with the correct volume for the particular driver used for the cabinet, there should be no problem. One other benefit of this construction approach is that you can determine the internal volume even if it's an odd shape before you construct it. For example, you could make an egg shaped cabinet by carving a foam core in an egg shape and dunk it in water to measure the volume till you get it right. It is interesting they chose to use the lost wax method though.

[granny down east @ Jan 23rd 2007 11:07PM]

erm, i once made a speaker cabinet and used kotex for insulation.
soopoib sound.

[threEchelon @ Jan 23rd 2007 11:35PM]

I can vouch for the fact that there was no sarcasm in your post. Maybe you should employ emoticons.

[SnowB @ Jan 23rd 2007 11:47PM]

Just Google "Ron Arad concrete stereo" to see the origin of this idea, done in beautiful raw concrete in 1983.

Still wish I'd bought it back then from One Off in London. It's estimated at $30k now. Oh well.

[DiedFamous @ Jan 24th 2007 1:43AM]

If he calculated his volumes and the measurements on the flared port for the sub correctly then I would be willing to bet that these speaker enclosures have quite good harmonics. Thats pretty easy given all the nice programs out there for such things these days, like WinISD Pro, my personal favorite. Its a bit difficult to say at first glance what the quality of drivers that he employed might be, but if the Visaton tweeters are any indication then the overall sound quality of the system should be rather excellent. Concrete would serve as a great material for enclosures, chaser24 has the right idea about there being minimal vibration. Usually, the denser/stiffer the medium, the better. It would be at the very least better than the crappy medium density fiberboard that most OEM speakers are made with. I've done a number of DIY speaker projects over the years, in most of which I have employed solid wood, either Ash or quater-sawn white/red Oak. My father and I have been milling solid wood boards ourselves for years now using STIHL chainsaws (we currently run an 088) and an Alaskan style milling rig. After a little planing, mitering, and sanding these boards have proven to be some of the best speaker building material I've ever seen in use, worlds better in terms of quality than anything employed by OEM speaker builders, especially BOSE :p This is due to the tremendous density and rigidity of solid woods when compared to traditional MDF, and I can see no reason why concrete wouldn't behave very much the same way, though I think my wood boxes are prettier than that slightly garrish paint job. (for those interested, a shot of my current running project can be seen here: http://tinyurl.com/3666j8 )

Kudos to this DIYer, my hat goes off to him for some innovation in the world of acoustics. Oh, and pyro, those scary spike-feet are pretty traditional subwoofer mounts, they are meant to transfer as much vibration as possible into the floor instead of resonating the cabinet. (though with a concrete enclosure and a relatively small driver I think that might be a little overkill, nothing wrong with that though)

[Wellcraft19 @ Jan 24th 2007 1:54AM]

Concrete is nothing new. I have a pair of Rauna Leira II (or Balder as the model was called for a while) speakers that are built out of concrete. They were manufactured in Sweden and caught the eyes of audiofiles in during the mid-to-late 80ies. I got mine shipped over from Sweden to Texas back in the mid 90ies, just before the company folded. Not cheap back then, think retail was a bit north of $1,000.

They are painted in a high gloss white, and the closest they resemble is a pair of submarime pericscope, poking out of the floor. Each speaker is about 3' tall and weighs in at about 80 lbs (hence, you do not move too often). Dual woofers and a tweeter, all on a cement/conrete baffle where the "optics" are found on a periscope.

And, no I have not had any troubles with them ending up just as a pile of powder. Assume they are the cement is poured over a "shape" with chickenwire before they are "cast" and the speakers get the final shape.

[adam @ Jan 24th 2007 3:40AM]

DiedFamous, that's great looking flake on the white oak cabinet.

[lionsroar @ Jan 24th 2007 4:09AM]

"There are companies that make speakers out of marble (both synthetic and natural) they have practically 0 cabinet vibration."

I have a set of speakers from Green Mountain Audio that are cast in marble...it's actually a cool process and I had the privilege of watching Roy and his crew make their magic while I was going to school in Colorado. The Europas sound fantastically clean and the cabinets are bomb-proof. Highly recommended from my audiophile-wannabe-point-of-view.

[Tom T. @ Jan 24th 2007 9:33AM]

now *that's* some heavy bass.

[Richard @ Jan 24th 2007 10:47AM]

Hi,

as the one who made the Homepage for my mate Markus' project, I'd like to add that while wo do indeed speak the german language we are actually from AUSTRIA. :-)

Cheers
-Richard

[macona @ Jan 24th 2007 12:24PM]

No Highs,
No Lows,
Gotta Be Bose!

[topcat @ Jan 25th 2007 4:52AM]

The speakers may be cool, but not so sure about the A/V receiver in the background, looks like the cheap Yamaha I've got at home.