Ikea Salad Bowl 4" full range speakers

[chris12345]

Hi All, I was going to have a go at making a pair for spherical speaker cabs using some wooden salad bowls from ikea

IKEA | Serveware | Serving dishes & bowls | BLANDA MATT | Serving bowl

Is it simply mounting the speaker on the flat part of the wood, guleing two bowls together to form a ball and adding speaker posts?

I want to keep it as simple as posible. I already have my drivers


Any info greatfully recieved

Chris

 

[joe58]

Hi

When your getting them make sure you check the sizes of them up against each other as when I got some one was significantly bigger than the other. Just a tip.

I have built domes with just one bowl, I have a build thread and currently doing a massive overhaul of them making them ten times better.

 

[joe58]

Also the leading edge is beveled which is a pain as you spend quite a bit of time with the filler trying to remove this and create a smooth finish.

 

[joe58]

Quick pictures to show what I mean by the bevel. Not finished but getting there. It's on the second pic and the white filler filling it in.

 

[chris12345]

Hi Joe - thank you for your reply.

Thanks for the tip about choosing the two bowles carfuly so they are the same size.
I can see what you mean about the leading edge and how I might need to use filler to make the seam smooth. I will work that bit out when I get the bowls glued together - I think i can probably live with the fit without any filler.

I like the simplicity of simply gluing two bowls together!

Chris

 

[buzzforb]

I have a question. On Olson's famous page 23 of the different baffle shapes, the sphere clearly produces the best response, with the hemisphere coming in third behind the chamfered baffle. Considering that an incomplete sphere does not perform as well as a perfect sphere, what performance do you expect from your reverse hemisphere. Are you hoping that the second half of the sphere is the one that more greatly defines the response? As it stands, unless you round over the leading edges, don't you have one of the worse case scenarios of round baffle with abrupt baffle edges? No offense intended, just trying to learn.

 

[planet10]

Indeed you do.

dave

 

[joe58]

Well I'm know expert. I chose the hemisphere because I thought it was one of the better shapes to choose, plus I also saw the Focal Domes. I'm learning like you, I'm not 19 yet and have a long way to go. I wanted the full sphere, but couldn't quite afford an extra two bowls and seeing the Focals I thought I could get away with it like it is. At the time I originally built the Mk1 versions(see my threads) I didn't really understand the concept diffraction/ Baffle step loss(correct terms), but now I'm starting to get the hang of the concept after reading many threads. The above mk2's are currently being built (as a much better quality finish and construction) now for when I go back to uni on saturday.

So how do I improve them? How much rounding off of the front edge would they need. A simple 1cm in from the edge and curve to the side if you can understand what I mean. No doubt when I come back for Easter or when ever i'll be busy again.

Thanks

Joe

 

[buzzforb]

I have only learned knowledge and have yet to buld anything, but from what little I do know, you need as smooth and large of a roundover as possible. Dave sent me the page to the pictoral representations of the different baffle shapes along with the responses they generate. Check my posts and you should easily find it. Lot's of great advice to be had here. Ask questions and follow the leads that people give you and you will learn more than most who listen to music daily will ever know. Another option is to get rich and buy extremely expensive designs and not worry about this diy stuff. WARNING! DIY IS ADDICTIVE!

 

[joe58]

I think I've seen them diagrams before. The ones with the many different type of baffle and a graph next to them. Thats what I based my decision on. I know how addictive it it. I originally built the Zigmahornets and then along came a new T-amp and then a sub. Next i'm building the mk1 domes and a pair of Fonken to bench mark them against. And now the mk2 facelift is being done. Very addictive for someone who likes to build stuff and then you get to see and listen o the results.

 

[tomchr]

As it stands, unless you round over the leading edges, don't you have one of the worse case scenarios of round baffle with abrupt baffle edges?

That's where the DSP-based baffle step compensation filter comes in...
Sorry. Could not resist.

~Tom

 

[planet10]

Olson's famous page 23 of the different baffle shapes

Most recently posted here for buzz.

dave

 

[tomchr]

This is Olson's original paper:
http://www.aes.org/aeshc/pdf/how.the.aes.began/olson_direct-radiator-loudspeaker-enclosures.pdf

~Tom

 

[planet10]

DSP-based baffle step compensation filter comes in...

No filter can compensate for, but for the ripple in the baffle step transition.

dave

 

[planet10]

This is Olson's original paper

Thanx for that. It is more comprehensive than what is in The Book

dave

 

[joe58]

Thank you for the links, but is it possible to round the edges off by an amount and remove the right angle edge? and therefore just create one seamless shape? Would it make much difference? I don't mean just take a bit of sandpaper and take a couple of mm of the edge I mean doing a good round over like this quick example.

 

[chris12345]

guys - I am a bit lost now - I was hoping to just glue two bowls together to form a ball, chuck in a 4" and a binding post, use some filler to get the optimial volume for my driver ( 5-6 liter) and lineten.

Have you got links to others who have done this design - with good pics and explanations/


Chris

 

[joe58]

Sorry about that, heres a link of a build and theres also a few other pics on the last pages in the thread of other peoples salad bowl speakers I believe. Page 22 has something you may want to do, and work your way back to the beginning. Which bowl was you thinking of getting? As I've just measured the flat space of my 20cm bowls and its about 5.5/6cm. On the original build from that thread you can see how he made the hole bigger.

http://www.diyaudio.com/forums/multi-way/159151-ikea-spherical-speakers-first-build-done.html

 

[vitalstates]

Have you got links to others who have done this design - with good pics and explanations/


Chris

audio-talk :: View topic - martians

 

[buzzforb]

How do the B&W nautilis designs kill the standing waves with their elongated sphere? In their 802 speaker, is the sphere design on top really effective considering that it terminates into a box. The dual bowl idea is really intriging if you can kill standing waves inside somehow. Wonder fi you could vent out the back or build a neck that forms a sort of horn or transmission line.