Spheres , Balls , and such

Nicholas_23

Have any of you messed around with spheres for your enclosure ? I know Curt built some awhile back and did the whole enclosure as the cabinet. I found some foam balls at the hobby store and mounted a ND16FA in it . Just sitting down now to mess with it. I have just the one tweeter mounted now but may put a second one in the back just out of curiosity. Also curious , do any of you know if foam with dissolve if you tried to fiberglass it?

jr@mac

If you glass it, might as well make it into a form and cast something. Could be fun.

dcibel

I remember watching "James May's Toy Stories" where they were building a life size Airfix model. It turns out that Styrofoam will dissolve in most epoxy resins, so make sure you use the stuff for surf boards. I'm sure a google search will tell you what will and won't work.

Nicholas_23

Ok , thanks for the info guys , maybe I can find some wood spheres similar in size if this turns into something. 

Nicholas_23

Various measurements off axis horizontal and vertical , the picture shows the greatest off axis and is the bottom FR response in the picture. 6.8 cap on the tweeter. 

PWRRYD

What's your impression of the Tang Band full range with the funky surround sitting below it.

Nicholas_23

I just started messing with it , Its currently in one of PE's micro cabinets sealed. I think its starting to roll of a little above 150 ish ? Acoustic music sounds good if that matters , still putzing around with it. Its the 2141 the little guy.

Nicholas_23

I was going to do a compact bluetooth build but I think these will turn into a 2.1 micro system. The woofer will be the W5-2053 , odd thing . I need to figure out how Im going to do the enclosure for it. Im thinking passive radiators might be the best , the ports get whicked long.

 

jr@mac

I have two of those weird RBM drivers myself. I'm thinking maybe plate amp with some boost, instead of figuring out a pr or port system.

D1PP1N

I am pretty happy with the 3 inch. I always liked the cheaper ones but the frame is really shitty on the $18 one. This one is like $32ish so your getting into coax territory. 

Silver1omo

If you do not mind an extra step, you might papier-mâché it like a cheap piñata and fiberglass the resulting sphere if you want additional strength.

Silver1omo

Something like:

R-Carpenter

https://deluxeacoustics.eu/en/acustic_systems

D1PP1N

The video is cool Roman thanks for sharing. Looks like resin and molded enclosures. Pretty cool either way. 

Nicholas_23

Thanks for the link Roman, some inspiration . Onto round two , using the AMTPOD. This is the tweeter I was originally going to go with. I kind of like that little ND16 though . At any rate , a couple pics , I need to tinker some more and see if I can tame the rising response on the AMT. Not bad though but I think it can sound better. 

Nicholas_23

Getting there ....

PWRRYD

Have you tried a simple RC in parallel with the tweeter?

Nicholas_23

Craig, went back and brought the xover up on the TB. Still messing with them , wish I had the drivers in something more permanent but , hey .... proof of concept at this point I guess. I think I might drop the TB back a little bit. Hearing something in 3k and up range I believe . Maybe pad the tweeter some too. 

Nicholas_23

near field measurements FWIW , mic distance is the same distance away as the baffle width ... 4.5"

Nicholas_23

last one , enough for tonight . Ill mess with it some more tomorrow . 

Nicholas_23

Round two , I hooked up the miniDSP 2x4 I had laying around. Im getting more familiar with it and its starting to grow on me. Onto measurements. 

JasonP

This is a really interesting project, can't wait to see more measurements!

Nicholas_23

I also tried this config for shits and giggles but found that I liked the sound of the spheres vertical . What I would really like to do, is lay the cabinet on its back so the TB is shooting up with the spheres on top of the cone but I havent figured out a way to mount the spheres above the TB ? The dispersion of the top end is great , but when you move far off access of the flat front baffle , you start to loose the midrange and its very noticeable . 

Nicholas_23

Light bulb just went off or is that on , bamboo skewers as the front baffles is just some foam board for now. I should be able to use the same idea as the foam balls , just poke some skewers threw the balls then stick those into the baffle of the mid and lay it on its back as mentioned above. Should work .... right ?

Nicholas_23

Not pretty but should work? For science and DIY.

Nicholas_23

How does one measure stuff like this? I can't do polar response

jhollander

Measure off axis by rotating the speaker and leaving the mic fixed.  Those FRDs could be used to create a polar response by anyone with omnimic.  If the speaker would hold together such that you could place the box on it's side you can rotate that (horizontally) to get the vertical response.

I think on axis will tell you a lot about the response as you adjust the mountings

Here are some ideas https://www.duevel.com/home/loudspeaker.shtml

Nicholas_23

LOL "If the speaker would hold together such that you could place the box on it's side you can rotate that (horizontally) to get the vertical response" love it , yeah that probably wont happen with this "proof of concept" . So , one meter out and start rotating ?

Nicholas_23

focused the mic in between the two spheres at one meter and rotated 

Nicholas_23

Nicholas_23

I wonder how the "stereo effect" would work with omni speakers? Less effective? More?