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Shoebox enclosures - aluminium or steel?

chrisn

chrisn

pfm Member
As Andrew's sleeves are no longer available (I should have supported the manufacturer better!)
I need to make something to cover two sleds

Which is better from the point of view of the electronics inside, aluminium or steel?
 
No difference whatsoever. Why would there be? Alloy vastly preferable from most other perspectives such as machinability, finish etc.
 
Ally's easy to work but difficult to weld. Steel is easy to weld but hard to work. It's technically easy, but steel is hard.
 
Steel may give better magnetic screening but if you really need this you are better off using a purpose made material such as Stalloy or, if you have the means to work it and the enclosure is small, Mu-Metal.

Aluminium gives good RF screening but most alloy enclosures are made of thicker material than the steel equivalent so there may be more to the choice than just material.

The point about welding is valid and steel is easier to spot weld brackets to but there are always other techniques, self clinching studs, for instance.
 
If I were going to make an enclosure, rather than buying one off the peg, I'd emulate the "bolt-up" means of manufacture. This would be very easy, I'd use angle brackets to make the basic structure and flat heavy aluminium plates to make the sides. You can then choose the way that you wish to paint/polish the various panels, and flat ally plates are easy to cut, finish and work. Something like M4 domed hex headed machine screws would do the job, an M4 tap would allow you to thread up the angle brackets so that you didn't have to worry about captive nuts and the like. I'd avoid self tappers because they end up looking cheap.

Don't underestimate the time that this will soak up. You probably imagine that given a limitless supply of ally sheet, angle, fasteners and all the required hand tools along with a workshop you could knock this off in an afternoon. Guess again. I've made any amount of things, usually to a lower standard than anyone would accept for audio, and they take hours and hours, spread over several days.
 
You can glue aluminium very effectively with something like Araldite. Especially it you use L-shaped bits inside or outside 90 degree joints. The thing is to lightly roughen the mating surfaces and use heat and clamps to set the adhesive.
 
stevec67 said:
If I were going to make an enclosure, rather than buying one off the peg, I'd emulate the "bolt-up" means of manufacture. This would be very easy, I'd use angle brackets to make the basic structure and flat heavy aluminium plates to make the sides. You can then choose the way that you wish to paint/polish the various panels, and flat ally plates are easy to cut, finish and work. Something like M4 domed hex headed machine screws would do the job, an M4 tap would allow you to thread up the angle brackets so that you didn't have to worry about captive nuts and the like. I'd avoid self tappers because they end up looking cheap.

Don't underestimate the time that this will soak up. You probably imagine that given a limitless supply of ally sheet, angle, fasteners and all the required hand tools along with a workshop you could knock this off in an afternoon. Guess again. I've made any amount of things, usually to a lower standard than anyone would accept for audio, and they take hours and hours, spread over several days.
Click to expand...

+1!! I've just spent several days doing the drilling, cutting, filing etc etc to make a pre amp for a customer to a very high standard. The electronics should be dead easy and take a day...
 
Just thinking that if it is something like a pre-amp that does not produce any heat, you could make it out of wood. Much nicer to work with than metal.
 
I'm not so convinced. Wood moves and splits, it's a pain. At least when I've made something in metal it stays the dimensions that I built it. Wood does look nice. It makes great front panels.
 
I`m not keen on the idea of pre-amps in unshielded wooden boxes but if you like the idea of wood why not build the electronics in a cheap ugly and easy to work die cast box and then fit it into your smart wood enclosure?
 
I thought that aluminium enclosures have less inductive effect on the cables / circuits within, and so I'd imagine a wooden box would be a 'good thing' apart from screening. A friend did run a NAP72 in a perspex enclosure, in a very revealing system (Wilson WATTs etc) and we were convinced that the perspex sleeve sounded better.
 
If you have a friend with a workshop that has metal folding/bending gear......(I don't any more) - things can become much easier. Access to a wide selection of punches also make the job easier, but not many of us do.

Back in my school days I made a pre-amp / amp combination. A rough metal box inside was finished with a nice wooden casing (top and sides). Wood can hide some sins....
 
And people baulked at £100 for a case and sled.
100s of hours spent on development and production.

We sold the whole lot at a loss!
Still a batch of undrilled, unpainted sleeves but I’m not prepared to loose ££££s again.
 
flatpopely said:
And people baulked at £100 for a case and sled.
100s of hours spent on development and production.

We sold the whole lot at a loss!
Still a batch of undrilled, unpainted sleeves but I’m not prepared to loose ££££s again.
Click to expand...
Sell as is then, unfinished? I’d take 2 or 4 :)
 
Can’t.

Need to buy them at a loss, not happening.
Supplier is holding them for us but can at anytime recycle.
 
JemHayward said:
I thought that aluminium enclosures have less inductive effect on the cables / circuits within, and so I'd imagine a wooden box would be a 'good thing' apart from screening. A friend did run a NAP72 in a perspex enclosure, in a very revealing system (Wilson WATTs etc) and we were convinced that the perspex sleeve sounded better.
Click to expand...

Nah.... A few companies do try to con people into thinking this is relevant though...
 
It is always an issue for the very small manufacturer that people don't "get" that an empty box, at trade price, will often cost more than a finished brand new 40WPC budget amp from the likes of Richer Sounds! Unfortunately it's the way of the market.. supply and demand and all that...
 
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