advice on concrete subwoofer enclosure

[natedb]

Hi guys!

I just joined the forum! I am looking for some advice on the construction of a concrete speaker for a design project. In short I am studying engineering and for one of my courses I want to design a speaker using concrete. I already know how to create curved surfaces in concrete but I also want the speaker to sound somewhat decent, or at least design the shape that way. The choice of a subwoofer is based on the sole fact that there are less variables to consider. It would be a passive subwoofer and the budget for the driver is less than 100€.

Any help on specific parameters i should take in account for my build? I want to collect some theoretical background on sound engineering to support my design choices. I'm all ears!

cheers, Nathan

 

[waxx]

To be able to answer your questions, we need to know what the goal is (frequency spectrum, efficiency, max volume desired)

To start, learn about Thiele & Small (TS) parameters and how that dermines wich driver is fit for what: Thiele/Small parameters - Wikipedia

 

[natedb]

Well, my technical know how of speakers is rather limited. Would it help if i said that I own a pair of older B&W LM1 speakers and it would be nice if i could pair this sub with them?

 

[Indigent Audio]

Selecting a speaker will determine the box size/shape/type of box which the speaker needs, you can do this by using the t/s info, the manufacturer recommendation or software such as bass box pro etc...Since weight of the enclosure and cost of the speaker are issues you will probably want to choose an 8-10 inch speaker in a ported enclosure. Using concrete as your material will be challenging, if you make it too thin the output of the sub will eventually break it, if you make it too thick it will be too heavy to move. I would recommend a thin wood form with chicken wire to reinforce, then only remove the outside of the form leaving a wood lined reinforced concrete enclosure. If you want something different you could use sonotube of different diameters as your forms. You can look up cider block bookshelf speakers for inspiration, good luck

 

[KaffiMann]

Beyma 12BR70 fits the budget and does not need a huge box, sealed 50-60 liters works fine. No earth shattering bass, but very good, and high value for the money!

Build two!