OHM Acoustics "Walsh F" Speaker remakes

[planet10]

Originally posted by rcavictim
I have not removed a driver from it`s cardboard tube cabinet yet to look at the underside of the cone.

Be very careful if you try. The last set i tried to dissassemble had the cardboard tube glued to the edge of the surround (where you would find the cardboard gasket on a normal woofer) and the surrounds were destroyed when i attempted separation.

dave

[rcavictim]

Originally posted by planet10


Be very careful if you try. The last set i tried to dissassemble had the cardboard tube glued to the edge of the surround (where you would find the cardboard gasket on a normal woofer) and the surrounds were destroyed when i attempted separation.

dave

Thanx for that potentially day saving advice Dave! I`d hate to damage these.

[c2cthomas]

Hi Bud

Any idea on how the pattern was applied and what material was used? Conformal coating should not be a big problem but gluing on all of those little squares is really going to take some time!!

How in the world did they do it?

Could not find any other development of the concept - did / has anyone employed the design?

Interesting idea (the pattern) - but I think that mamboni has allowed for this with his design of the felt pads applied to the cone material - but he is the one to pose an answer to that question. His design looks doable in the DIY sort of way - so I'm headed that way 1st.

But the science looks very interesting! I can feel my mental gears turning - but then there is a lot of rust there!

[c2cthomas]

Hi Bud

Reading your bio I see that we share magnetics in common - but thread isn't about those sort of things. Perhaps I will PM you about a couple of thoughts there. I was thinking about baffles and the use of some paint mixed with fine sand silk screened on with a finish similar to fine sand paper. Silkscreen might also be a method with which to apply your pattern onto a speaker or other surface. I can feel the old mental rust beginning to break free. Retirement - I love the freedom - but it's a bit of a drag to not have all of my technical toys around to play with.

[BudP]

Thomas and Mamboni,

Please do email me with thoughts we can share.

Thomas, I have literally cracked the code on E/I transformers. I can build a push pull output that does not exhibit hysteresis induced remanence, no zero crossing distortion nor loss of micro dynamic coherence. This has allowed me to explore coil construction formats and dielectric barriers with an eye to matching core material B field permitivity to coil E field / D field permitivity. First results are "voiced" guitar outputs. But now I have really hijacked the thread and apologize to all.

Bud

[c2cthomas]

Hi Bud & Mamboni

I'm thinking: 1) design pattern for 10" cone (for use in this project using mamboni's existing speaker development). Designs or patterns could be developed for other cones as required. 2) print pattern on thin paper using large format printer. You could use a regular printer but large cones would require printing on more than one sheet of paper - or being broken into segments if printed on a single sheet of paper. Those segments would need to be joined and aligned. (Well maybe not - if you only did a section of cone at a time.) 3) remove paper material where printed leaving a stencil pattern in the paper. (Where is my 10KW laser CNC when I really need it!) 4) apply a "tacky" type of spray adhesive to the back of the paper. 3M makes one that I have used to tack up plastic sheeting when spray painting my rooms during remodeling - available at hardware stores. If applied to the paper stencil - not the speaker cone - it should leave little if any residue. 5) apply stencil to speaker cone. 6) mask off areas not to be painted 7) air brush on chosen material (paint, speaker dope, etc.) 7) remove stencil. 8) hook that bad boy up and let it GO - GO - GO!!

BTW - Bud - Got anything that will do 8 T's for 100ms at 5cps and not require cryo cooling?

[c2cthomas]

Hi Bud

Hemp paper or cardboard (thin) is great stuff - very though and friendly to the environment. I checked ebay and about the closest I could get was hemp rolling paper - and if we start using that stuff it'll take like 5 or 6 years to get things finished - if we remembered what we started doing in the 1st place. I think the combo of felt and hemp would be a natural - I was checking into Gore-Tex but it looks to be hard to get unless I want to destroy a $160.00 jacket from REI. But if you think that felt has some fibers in it then the fiber count in Gore-Tex will blow you away. But this approach gets us into the area of speaker cone replacement - which while doable can be tricky. Plus we would need to fabricate the cones. That could be done but would present problems to others that follow and want to duplicate this project. Might be tempted to do a prototype for personal use tho

Visited Seattle on my trips to Boeing - loved it - loved the seafood. Have some buds in VC/BC. So what's the latest odds on Mt. R blowing it's lid? My buddies would always throw things at me when I asked them that one

[c2cthomas]

Hey BudP:

These guys are up in your neck of the woods and do laser and dye cutting. http://www.mag-knight.com/diecutting/

I don't have your pattern so really can't talk to them about a bid - plus - it's your pattern and your patent so for me to discuss anything without your permission would be way out of line

But I'm thinking that if enough interest in your EnABLE pattern is generated it might be worth considering having a pattern cut on to a vellum mask that could be applied to the speaker cone and removed once the pattern is applied with chosen material - say adhesive and powered felt - or paint, ink, speaker dope - whatever. These guys might be able to cut the lam's for your xformers too.

Just a thought

BTW - your xformer ideas could be a big hit with the tube and power supply forums - ya might want to check 'em out.

[c2cthomas]

Hmmm,

Come to think of it - we are going to need to deal with that spider. Mr. Mamboni (Dr. Mamboni?) have you had any negative sound refractions in your speakers due to interference caused by the spider? Have you tried any sound treatments of it?

[c2cthomas]

Aint nothing that a couple of cases of jello pudding dumped into the base enclosure wouldn't take care of!! Yum