Walt's Stepped Horn

Dear Dark matter,

Sketchup file, can't guarantee correctness though!
http://members.lycos.co.uk/darkmatterdnb/WaltsSteppedHorn.skp

Nice to hear you like the performance of the Stepped Horn. I was also impressed the first time I fired it up. Too bad it was a little to big for the room, so I had to sell it. The stepped horn is also an easy build, no strange angles to cut.

Jake - only thing is sketchup won't calculate volumes for you. It can do cross sectional areas and you can go from there, or I guess you could export the file and import into a cracked autocad. I guess what I'm getting at is I don't think it's brilliant for refolding horns etc. There's no easy way to group objects and tell them how to behave when another connected object is stretched 10cm for example, so it's good for doing a mockup but more difficult when you want to have a quick play with the dimensions as you go along.

Pics...

Did plenty of dry fits to make sure I wasn't making stupid mistakes along the way:



Here you see I smoke too much - I thought the tee nuts went on the other side first of all so I routed little spaces round the driver cutout, then realized ten minutes later that this was completely unneccessary. Ah well :D


If you're routing 18mm rebates, get an 18mm bit. I used a 10mm straight cutter and had to do two cuts for each rebate to get the 18mm - loooong. Was too impatient to wait for an 18mm bit to arrive.


Air gaps? What air gaps!?


High quality wiring when I'm ere - maplins standard mains cable no less.


I didn't have any safety goggles so I innovated:

ok cool, because i really need to graduate from using mspaint for my technical drawings!

sketchup is veeeerrry easy mate, you'll get to grips with it straight away, you seem to have a good eye for 3d space. it can really help to inspire you to get on with building when you see the mockup :) its made calculating volumes for the 12+1s i'm planning easier, and helped me avoid some very stupid mistakes with the stepped horn too!