OB "omni" experiment

[dewardh]

When does an Open Baffle become and Open Box?

When the "baffle" is warped around enough to have five sides?

 

[Kjeldsen]

When the "baffle" is warped around enough to have five sides?

Or maybe someone could define the minimum required open area vs. the surfaced area in order to ba an open baffle.

 

[Kjeldsen]

Just bought 4 sheets of particleboard. Within the next year I should be able to cut some nice curves 🙂. I'm not always fast, but I almost always get's my projects done.

 

[Kjeldsen]

Little progress- yes I know I'm not as fast as some other OB builders😀

Fired up the router yesterday

 

[Kjeldsen]

Pictures

I know I'm not fast, but some progress have been made.

I now have two raw cabinets. Here just the one

 

[tinitus]

I know I'm not fast, but some progress have been made.

you will get there, eventually 😀

I now have two raw cabinets.

looks cool

how many divers are you going mount in that .... thing ?

 

[Kjeldsen]

There will be four identical 10" woofers from Peerless, and one Mark Audio CHR-70 fullrange in each speaker. It will be two way. The side woofers could be a problem, and I will consider to cross them at 80 Hz or so, and then just let the two front woofers cover the full range up to the Mark Audio

 

[tinitus]

There will be four identical 10" .....
..... side woofers could be a problem, and I will consider to cross them at 80 Hz or so....

or maybe try 2.5way

 

[Kjeldsen]

That is 2½ way I suggest. I will have two in front to cover full range to the Mark Audio driver, and then the two side firing woofers only to 80 Hz.

But, it seems to work in the RAAL loudspeaker, so I hope that the four woofers will work with the same input

 

[Kjeldsen]

more pictueres

A bit closer to be done for testing. Need to find som felt now. They will have black felt and red speaker grill cloth.

 

[adason]

Kjeldsen, are you sure that sound pressure changes generated by those four woofers will not negatively affect sound from that poor little fullrange just above them?

 

[Kjeldsen]

I honestly don't know. But putting a divider in between will be fairly easy

 

[Don Bunce]

You will definitely need to isolate the full range.

 

[Kjeldsen]

Finally found a supplier of felt. 10 mm soundabsorbing felt, and 2 mm black felt for the looks. Most suppliers only sold small sheets, and I needed much longer runs.

 

[Kjeldsen]

First try with the 10 mm thick sound absorbing felt. This will be used inside and outside and will be covered with a thin 2 mm layer of black felt.

 

[Kjeldsen]

You will definitely need to isolate the full range.

But, this is open baffle - will there so much sound pressure?

 

[tinitus]

But, this is open baffle - will there so much sound pressure?

if it moves more than it should you will notice it 😉

I'm quite sure a single woofer would not cause any real big problem ... but with 4 woofers cramped into a very small space might be different than just a single woofer

btw, not sure I would call it open baffle, but more like folded, slotted, or open back, or something

 

[Kjeldsen]

The closest to any official term is a u-frame I guess. But the sidefiring woofer might be closer to som slottet types like slot loaded open frame.

Hybrid U frame slot loaded open frame
HUFSLOF

 

[Kjeldsen]

getting closer

Getting closer. It's looking very close to what I had in mind.

Now I need to find someone with a sewing machine. I think I will add a zipper on the back for easy removal

 

[Squeak]

First try with the 10 mm thick sound absorbing felt. This will be used inside and outside and will be covered with a thin 2 mm layer of black felt.

WHERE!!! did you get that gray felt?!! 😱

I have to import mine for a kings ransom from Sweden. I've been looking for years for a suitably cheap outlet for the stuff in Denmark (it really should cost next to nothing as it is a waste product).

It is the only other obtainable alternative to mineral wool in EU but seemingly impossible to get hold of unless you are a car manufacturer or furniture factory.