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DIY concrete stands

I've been fooling around with DIY stands made of concrete block.

I first made two speaker stands for my gf. Each stand was 3 blocks, sealed together with white grout. I used a thin wood veneer on the bottoms, to which I attached felt sliding feet. On the top, so far, I just have a thin cardboard piece, and the speaker resting on that.

I planned on wrapping a fabric around the stands to hide the concrete block work. The funny thing is, they look really cool. They're on wood floors, with rich tapestry burgundy/gold curtains behind them. And with almost no gap between the blocks, and black Paradigm Studio 20's resting on top, they look more stark-modernist than white-trash. Weird. My gf won't let me cover them with fabric.

I also made myself an amp stand out of two solid concrete blocks. I have the blocks sitting on a thin cardboad pice (so they don't scratch the floor) and my amp sitting on styrofoam peanuts (crushed beyond visibility) on the blocks. I don't know for sure if there is a difference in the sound (it's a ss integrated, after all) but it's kinda cool. Again, it's sitting in a refined and polished surround. In that setting, with a pretty amp on top, the raw concrete slabs actually make a blunt aesthetic statement.

Anyway, the only thing that's cheesy about the speaker stands is the feet (the felt sliders) and the top (cardboard, right now). They look cheap (and they were!). I'm wondering what I should do. I'm thinking of getting thin steel plates, which I paint black and attach to each end, then fixing adjustable feet to the bottom, and mounting the speaker with blu tack on the top. But where do I get adjustable feet? Especially cones or spikes?

Even with the felt sliders, these stands are solid! And total cost was $25 bucks and about 2 hrs of labor (me... clueless at that).

Is there anything wrong with using conrete to stabilize gear? Mass is resistance to acceleration, and it's a lot of mass... cheap.
qualia8
qualia8 OP
49 posts
 
Thanks everyone for the replies. Rich, your stands look *way* cool. I did check out the glass blocks as well, but I was thinking of wrapping them in fabric at the time. (I had in mind just a satin-y type of fabric pinned in the back, and maybe black.)

I also thought about a slab of slate for the ends. Cap block is a good idea. As is rubber. And I'll check out the cement stains. I didn't even know that existed.

A trip to the local mega-hardware store is really enlightening. Mass, in the form of sand or cement, is so darn cheap! I can't see (with my salary) paying hundreds of $ for an amp stand that doesn't weigh as much and isn't as steady as $3 worth of cement block.

I've just made an offer on a tube pre, so I think I'm going to check try to fit some cones to the bottom of that solid concrete block and make that an amp stand.

I'm also going to talk to my dad over Christmas about a wooden amp stand. He makes banded cutting boards out of eucalyptus. They're pretty thick, but I'm guessing he could make them thicker. I'll suggest that extra thickness and mounting it on cones. I'll let you know how it goes. Maybe there would be a market for it here on Audiogon. The cutting boards are really beautiful.
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arcticdeth's avatar
arcticdeth
1,572 posts
 
Should be fine.

picked up a 4 inch granite square from a home improvement shop for my TT.
IF IT GETS rid of vibration, don’t know, but looks nice.

also a pair of matching butcher blocks for my amps, they look nice on a nice hunk of cherry stained wood stands.
williewonka
3,082 posts
 
One way to improve on the performance of any "stand" is to incorporate a "sandwhich" of materials having different densities
e,g, - my speaker rest on a sandwiched platform...
  1. my speakers spiked feet rest on a ceramic tile so there is a very small area of "connection"
  2. the ceramic tile lays on a thin layer of rubberized drawer liner
  3. and the final bottom layer of the sandwich is a granite tile
NOTE: my listening room has carpet with thick heavy duty underlay, over a concrete floor, so my challenge was how to make the speakers stable without punching a hole in the vapor barrier under the underlay
  1. each tile is 18" square which went a long way to aid speaker stability - had the same effect as outrigger feet
  2. each tile has those plastic "carpet saver" multi-spiked foot at each corner so the carpet has little impact on stability
  3. it took about 1 month for the underlay to compress enough so that the speaker stopped "rocking"
  4. I could have used two ceramic tiles, but I felt I needed some extra mass in order to anchor the platform and the different density aids vibration suppression

I take a similar approach on my component stand
  1. the components spiked feet rest on a granite tile
  2. same rubberized drawer liner is used under the granite tile
  3. and supported by an MDF shelf
I have a VTI metal stand with MDF shelves, which has the same "carpet saver" spiked feet on the section of the stand

The problem with very dense materials like concrete and granite is that they can "ring" and they transmit vibration very easily - once those vibrations start it is difficult to stop them.

Adding a layer of rubberized drawer liner between two dense materials make the resulting "sandwich" much less prone to vibration and transmission

This is a very affordable method of providing a very solid and vibration free platform for both speakers and components

I have tried sorbothane in place of the rubberized drawer liner in the past, but it is too spongy for this application.

Another approach it to make a laminate of a single material e.g.
  • my turntable plinth is made from three layers of 3/4" mdf
  • They are all the same density of MDF
  • but it seems that the extremely thin layer of glue used to bind them together acts very much like the rubberized drawer liner
  • the result is a very dense plinth that is vibration free
  • The plinth has large 2.5" bronze cone feet that sits on a granite tile.
Hope you find this useful

Regards - Steve
millercarbon's avatar
millercarbon
12,531 posts
 
My turntable rack is solid cast concrete. https://systems.audiogon.com/systems/8367 The hardest part was making the mold with curves so it doesn't look like concrete. The thing about concrete, it is massive and stiff but not very well damped. So it should be combined with something to damp out the ringing. In my case the bottom and top shelves have a depression molded into them, filled with sand, so integral sand bed shelves. The whole thing was maybe $50, plus $150 for the granite top plate, awfully good for the money.  

Even 750 lbs of concrete is not enough to insure absolute stability. Now recently this whole rack was put on Townshend Pods. Not easy but a real nice improvement. The equivalent budget move would be Nobsound springs. Awfully good for the money. Do not use cones. For only $30 Nobsound will be better than any cone. Use directly under the component, not under the concrete. For turntables you can try both ways and even both together. Which will be best depends on the situation.
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