The idea for this project came up when I knew I was going to get my pair of extra CSS EL70 back from my father since he doesn't use them anymore. Right now they are in a center channel speaker but I would like to build something for a kitchen stereo in my apartment. I had a look at some Ikea hacks and found the Variera storage boxes made from 7mm bamboo. I couldn't decide whether I wanted to build with the smaller ~4L box or the larger ~9L box so I bought a pair of both sizes since they were on sale.
I took some more detailed measurements today and the smaller one has a volume of 4.12L and the bigger one 8.88L. I plan on using a 19mm MDF board as baffle mounted flush on the inside of the box and that will bring down the volumes to 3.56L and 7.66L.
The walls are 7mm thick and very light but they are surprisingly stiff for their size. I guess bamboo is a very hard material. I am planning on lining the inside walls with 2mm silent coat sound absorber panels (will buy in bulk and treat my car as well). This should help make the boxes less likely to ring. However, this will also decrease the volume. The volumes with 2mm bitumen panels and the baffle (no bitumen on the back of the baffle) 3.18L for the small one and 7.06L for the big one.
I don't know really if a brace will be needed since the walls are quite stiff already and we're talking pretty small drivers. Sure, a brace is always good in one way but since the volume here is quite limited it might be a better trade-off not using one to gain some extra cabinet volume.
Now back to the driver choice. The EL70 wouldn't be too happy in a ~3.2L enclosure so I guess I will use them in the bigger box instead. I don't know how much volume is displaced by the EL70 and I don't know how to simulate with/without port volume in WinISD and how to calculate with a port that's narrowing towards the end. But a the EL70 in a 7L box tuned to ~45-50Hz seems reasonable I think.
Then for the smaller boxes... What driver should I use there? I assume I wont be able to find a 4" driver that's happy with such a small box so I would have to step down to 3-3.5" drivers. Do you have any recommendations?
I took some more detailed measurements today and the smaller one has a volume of 4.12L and the bigger one 8.88L. I plan on using a 19mm MDF board as baffle mounted flush on the inside of the box and that will bring down the volumes to 3.56L and 7.66L.
The walls are 7mm thick and very light but they are surprisingly stiff for their size. I guess bamboo is a very hard material. I am planning on lining the inside walls with 2mm silent coat sound absorber panels (will buy in bulk and treat my car as well). This should help make the boxes less likely to ring. However, this will also decrease the volume. The volumes with 2mm bitumen panels and the baffle (no bitumen on the back of the baffle) 3.18L for the small one and 7.06L for the big one.
I don't know really if a brace will be needed since the walls are quite stiff already and we're talking pretty small drivers. Sure, a brace is always good in one way but since the volume here is quite limited it might be a better trade-off not using one to gain some extra cabinet volume.
Now back to the driver choice. The EL70 wouldn't be too happy in a ~3.2L enclosure so I guess I will use them in the bigger box instead. I don't know how much volume is displaced by the EL70 and I don't know how to simulate with/without port volume in WinISD and how to calculate with a port that's narrowing towards the end. But a the EL70 in a 7L box tuned to ~45-50Hz seems reasonable I think.
Then for the smaller boxes... What driver should I use there? I assume I wont be able to find a 4" driver that's happy with such a small box so I would have to step down to 3-3.5" drivers. Do you have any recommendations?
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Nice project. I use the small variara with Faital pro 3fe22. They sound incredible for the money.
Initially I lined with plywood but they started to rattle loose. They are lacquered so you have to remove this to glue to the bamboo.
Now I just have them lined with bitumen and wool and a bit of polyfil.
Look forward to your progress
Initially I lined with plywood but they started to rattle loose. They are lacquered so you have to remove this to glue to the bamboo.
Now I just have them lined with bitumen and wool and a bit of polyfil.
Look forward to your progress
Thanks for the tip! Will sand the insides to remove the laquer.
I have a pair of desktop CSS EL70 already, these speakers will go to the kitchen.
Any idea on how to do a TL in that box?
I was thinking about that but I decided that a white baffle would probably look cooler and since I'm going to paint it I might as well go with cheaper MDF.
A while ago my dad helped me cut the baffles for me.
He also let me borrow his router so I could finish the rest on the baffles. I have never used one before so I figured I'd try on some scrap wood first. I was planning to make a circle jig but the router base plate is too big for the ~62mm radius circle I need so I had to think of something else. I realised that by using one of the holes in the base plate I should be able to make such a circle anyways. It took me a couple of tries with different sized bolts but with a 4mm bolt in a 8mm hole and using the big router bit I was able to get a pretty good sized circle.
This is with the driver pushed all the way to the right. The circle is a little too big but not by much.
How do you guys do it when you need to make a circle that smaller than your router base plate? Is there any other clever way of doing it? For the inner circle that goes all the way through the board I used another hole in the base plate that's close to the center. Turned out it was just the right radius for the cutout.
He also let me borrow his router so I could finish the rest on the baffles. I have never used one before so I figured I'd try on some scrap wood first. I was planning to make a circle jig but the router base plate is too big for the ~62mm radius circle I need so I had to think of something else. I realised that by using one of the holes in the base plate I should be able to make such a circle anyways. It took me a couple of tries with different sized bolts but with a 4mm bolt in a 8mm hole and using the big router bit I was able to get a pretty good sized circle.
This is with the driver pushed all the way to the right. The circle is a little too big but not by much.
How do you guys do it when you need to make a circle that smaller than your router base plate? Is there any other clever way of doing it? For the inner circle that goes all the way through the board I used another hole in the base plate that's close to the center. Turned out it was just the right radius for the cutout.
read this Ikea box idea.
Last time I went to Ikea I looked for these Bamboo boxes.
Welll It turns out they are s9old as pairs One large and one small box for ~25$ .
So that's 50$ to buy two (well actuaLLY 4) thin bamboo boxes ...open on their large side.
Not nearly as attractive in the flesh as in print
Last time I went to Ikea I looked for these Bamboo boxes.
Welll It turns out they are s9old as pairs One large and one small box for ~25$ .
So that's 50$ to buy two (well actuaLLY 4) thin bamboo boxes ...open on their large side.
Not nearly as attractive in the flesh as in print
CRB7 Combination Router Base Jig | MPOWER Tools
Not cheap but it fits most routers (not Triton) and is available on Amazon. It allows a circle from 1-1/2” - 17-1/2” diameter. The web link has a compatibility chart and a retailer finder (including Sweden).
SONOS or Symfonisk. Wi-fi and/or Bluetooth. And prices look reasonable too (in USA, this statement may not apply in W. Europe ). Maybe IKEA will make flat-pack kits for some great speakers?
Must be different over there then. Here in Sweden it is possible to buy them one at a time.
Looks nice but I get a 404 error for the retailer in Sweden and importing it would end up being way too expensive.
No need to import!
CRB7 MK3 Universalbas/frasfot - woodworking
A little searching and here it is. I don’t read Swedish but it looks like it’s on sale.
CRB7 MK3 Universalbas/frasfot - woodworking
A little searching and here it is. I don’t read Swedish but it looks like it’s on sale.
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