Spherical Speakers

Ironhead

Member
2007-12-10 5:43 am
Hi,

I am planning on building a pair of spherical speakers using W3-871SC Full Range drivers. I know a sphere front and a tapered tube for the back is better than a sphere but I'm going with the sphere because of how I want it to look. I want to know if porting it would be practical instead of leaving it sealed. Also what method should I use to reduce resonances? The internal diameter will be 8-1/2 inches. I will use Tuf Cal plaster as the enclosure material.
 
I used Jordan JX92s in a sealed 3 litre enclosure to create my spheres. Though I got the enclosures hand turned out of American Black Walnut [beyond my skill]

They sound excellent when positioned near a wall, and with a matching sub woofer do justice to any CD or DVD !

I found that porting wasn't really necessary [and would have been difficult in such a small enclosure]

The shape itself tends to reduce any sort of problem with resonance, and stuffing it lightly with polyester wool gives good results with the mid range.

Good luck with your spheres, post some images when your done !!!
 

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Ironhead

Member
2007-12-10 5:43 am
Beautiful speakers smallangryboy. And thanks for the advice from both of you. I used win isd to get the Vb of my enclosure then I used a calculator I made to calculate the same size sphere that would need to give me that internal volume. I asumed that this program was accurate but I don't know. I noticed that win isd takes into acount measurements from small speakers more accurately than many online calculators that just aproximate the measurements for smaller speakers based on some kind of size limit. ex. smaller than 4 or 5 inches.
 

Ironhead

Member
2007-12-10 5:43 am
Nice!

Made out of bowls from Target eh. I thought about using some bowls from under our sink today as making them with plaster would take too long (because of waiting for the plaster to be delivered). And cost much more than I really want to spend. I'm sure someone would have been angry if I did.lol
 

TNT

Member
Paid Member
2003-04-26 10:25 pm
Sweden
Thanks - I enjoy them every day and at times I push them (and neighbours) quite hard and they are up to it (the spheres that is!). I feed them 500w/ch from B&O Icepower.

Sorry, no building instruction but most of it is in the thread really. If you have questionss I'd be happy to answer them.

BOM: for 1 pc.

2 Ikea blanda blank
2 Seas H1208 http://www.seas.no/index.php?option=com_content&task=view&id=113&Itemid=135
Plastic / metallic tube
Cable
Glue (Sika)
Glute (2 comp glue)
Metallic band
Nerves ;-)
Noisekiller

I would really liked to have had som proffesional cutting support but it was not at hand. It shall be noted that on my prototypes, the holes are not made as per below drawing - there is no flat edge to mount the driwers from inside. On my next pair, I will cut these with laser.

See some simulation and more pics here:
http://www.hififorum.nu/forum/topic.asp?ARCHIVE=true&TOPIC_ID=52671

Drawings:

[IMGDEAD]http://hem.bredband.net/filmtva/bboll1.jpg[/IMGDEAD]

edit: smallangryboy, congrats to extreamly nice execution of both speakers and stands !!!

smallangryboy said:
TNT

Lovely ! I wanted to make a matching sub woofer fro my spherical speakers, but couldn't get over the logistics , do you have some instructions about how you went about making your metal enclosure, and a parts list :)
 

TNT

Member
Paid Member
2003-04-26 10:25 pm
Sweden