Glad you responded! I think we all feel that the speaker kit as in the first post is seriously flawed.
I thought we’d moved on and we’re just discussing speakers made from concrete blocks, which I think have
plenty of potential. There’s been discussion of concrete cabinets resonating. In a cabinet this size
thre walls are so relatively thick that I don’t think it will be a problem. And unreinforced concrete
should be the best as if it has steel bars or mesh it would actually be springier, which we don’t want
I’ve got my blocks. And I do think that some people will appreciate a speaker design pair that can be made
with 2 blocks and a piece of shelving in an hour! . No clamps or power saw required….
Also I have had some luck finishing cabinets textured like these in an appealing way…
I thought we’d moved on and we’re just discussing speakers made from concrete blocks, which I think have
plenty of potential. There’s been discussion of concrete cabinets resonating. In a cabinet this size
thre walls are so relatively thick that I don’t think it will be a problem. And unreinforced concrete
should be the best as if it has steel bars or mesh it would actually be springier, which we don’t want
I’ve got my blocks. And I do think that some people will appreciate a speaker design pair that can be made
with 2 blocks and a piece of shelving in an hour! . No clamps or power saw required….
Also I have had some luck finishing cabinets textured like these in an appealing way…
Oh absolutely. The basic concept has plenty of potential. I was referring specifically to the kit when I said I didn’t get it. The comment about a 20 year old having no idea how to use them brought me back to the kit specifically. If somebody that legitimately understands this stuff gives this a shot, I’m interested to see where it goes. Simple DIY is great if the results are positive, whether that be in terms of aesthetics, performance, or price (or any combination of the three). The original just seemed likely to fail at all three. Some may disagree on the looks…
Anyway, it probably wouldn’t be overly difficult to put a solid finish on something like this (even a smooth one) without too much struggle. I’ve never tried that hard to make block look especially good. But that’s a pretty standard element of diy speakers. They’re pretty rarely just left completely bare with whatever the wall material is. I don’t think the material is impossible to finish well at all. I do think it needs something beyond just the screw together and done approach though. If nothing else, rough concrete will wreck the finish on my stands…
Anyway, it probably wouldn’t be overly difficult to put a solid finish on something like this (even a smooth one) without too much struggle. I’ve never tried that hard to make block look especially good. But that’s a pretty standard element of diy speakers. They’re pretty rarely just left completely bare with whatever the wall material is. I don’t think the material is impossible to finish well at all. I do think it needs something beyond just the screw together and done approach though. If nothing else, rough concrete will wreck the finish on my stands…
Great! I guess at worst this sort of project is harmless fun, but we agree it has some advantages. I don’t think the concrete wall will vibrate at all compared to the partical board or thin MDF usually used in small speakers.
I’ve had some luck with similar textures by first scraping a dark colored filler over it then sanding and finally
Staining it with a dye. Might look a bit “like granite”. Also the main thing people, will see are the front baffles, which will be stained plywood or partical board with melamine finish. Yeah, partical board isn’t the best in many cases but the largest span is going to be about 4” .
Probably I’ll first use a small full range Fostex driver to keep things simple. It requires about 6 liters for a ported cab and the 2 cavities of the block, before knocking out the center wall add up to about 6 liters exactly, leaving room after removing the wall to adjust it to be exact.
Hmm, I might have to start another thread in the full range driver forum!
Those drivers work well with the Amp Camps Amps I have sitting around…
I’ve had some luck with similar textures by first scraping a dark colored filler over it then sanding and finally
Staining it with a dye. Might look a bit “like granite”. Also the main thing people, will see are the front baffles, which will be stained plywood or partical board with melamine finish. Yeah, partical board isn’t the best in many cases but the largest span is going to be about 4” .
Probably I’ll first use a small full range Fostex driver to keep things simple. It requires about 6 liters for a ported cab and the 2 cavities of the block, before knocking out the center wall add up to about 6 liters exactly, leaving room after removing the wall to adjust it to be exact.
Hmm, I might have to start another thread in the full range driver forum!
Those drivers work well with the Amp Camps Amps I have sitting around…
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For finishing off the block I'd be looking to try what in France is called "ciment prompt" or quick cement. This dries quickly and can be got in black or grey.
Tarmac Blue Circle Mortar Grey 5kg | Ready Mix Cement | Screwfix.com
Silver Man quickly Mortar 10 "Black", Cement, 1000 ML | eBay
Speedy vicat cement 1 kg | eBay
Tarmac Blue Circle Mortar Grey 5kg | Ready Mix Cement | Screwfix.com
Silver Man quickly Mortar 10 "Black", Cement, 1000 ML | eBay
Speedy vicat cement 1 kg | eBay
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I think the finishing options are more of a “feature rather than a bug” type thing. Would be fun to see what people come up with. I like the tech/homemade look of the raw block with light stained and matte finished front and rear baffles,, but am curious about cool colors, textures, and pre-finished baffles
I have a rule though: the entire speaker pair should be able to be made in an afternoon with hand tools!
Not that you must use hand tools!
Blocks often have imperfections also, ie a flattened corner, etc. Locally, people use regular premixed drywall “mud” to get a smooth exterior finish on stucco. It’s then easy to sand flat, and once it’s painted it resists weather and impact surprisingly well. Certainly you’d want to use something more substantial on corners. Perhaps Bondo or epoxy. Bondo is probably an excellent filler overall and plenty tough I’d think, and easy to work with until it starts to set up. Seen various vids on painting cars using Rustoleum oil paint and a roller. On a well prepped surface it dries slowly enough to level very smooth.
I have a rule though: the entire speaker pair should be able to be made in an afternoon with hand tools!
Not that you must use hand tools!
Blocks often have imperfections also, ie a flattened corner, etc. Locally, people use regular premixed drywall “mud” to get a smooth exterior finish on stucco. It’s then easy to sand flat, and once it’s painted it resists weather and impact surprisingly well. Certainly you’d want to use something more substantial on corners. Perhaps Bondo or epoxy. Bondo is probably an excellent filler overall and plenty tough I’d think, and easy to work with until it starts to set up. Seen various vids on painting cars using Rustoleum oil paint and a roller. On a well prepped surface it dries slowly enough to level very smooth.
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I just used that Rustoleum hammertone rattle can paint last week on a steel table base I made. It looks cool, but not very “hammered”
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