[Peter J]

Built pair of those also with Oak veneer over Mdf/Baltic birch and then when my boss let me have a damaged sheet of Japanese Tamo Ash
I rebuilt them using just Baltic Birch. Did not sound any different to me. Still regret selling them because they were the most beautiful
speakers I have ever built, but they could not compete with the Wedgies/Wedge base sonically.

This will be my first foray into open baffle, I'm excited. What sort of work do you do, Keith? Sounds like you might be in a cabinet shop.

[lacro]

Peter, As always, your work in impeccable!

I don't like pronged T-nuts in MDF either, but I do like Hurricane nuts.
http://www.parts-express.com/parts-express-10-32-hurricane-nuts-50-pcs--081-1082. In your case where they will show on the back side, you could counter bore the heads with a forstner bit so they would be flush with the surface. They could be pre-painted black or you could use a gasket hole punch to make stick on covers using the 3M carbon fiber look vinyl you have used in the past.

I have use these on MDF speaker stands with good results:  http://www.globalindustrial.com/p/fasteners/Threaded-Inserts/thread-inserts-for-wood/m6-10-insert-for-soft-wood-flanged-900610-20?infoParam.campaignId=T9F&gclid=CNu8yJrZuMoCFYqPHwodFJEGAg

Your idea of tapping the MDF hardened with Super Glue is a good one. I carry the method a little further with something I learned in boat building to hold screws in soft woods. Over drill the hole, and fill it with epoxy. You then have a very hard plug to hold the screws, either tapped hole machine screws or wood/tapping screws.

Another method I have had good luck with in MDF is using plastic screw anchors with tapping/wood screws.

[nickd]

http://www.audiocircle.com/thumbnails/user/52624/2968/45591_thumbnail.jpeg

I have found inserts to work quite well with reasonable labor. The threaded, super glued MDF however is a really cool idea.

[Peter J]

Got some photos of the leg base prototype.  Black headed bolt would look better, methinks, but overall design looks promising.

[Plund]

Wickedly good info in your build thread(s)!  Thanks for documenting and sharing!   I look forward to seeing your finished product!

Pete

[ebag4]

Wickedly good info in your build thread(s)!  Thanks for documenting and sharing!   I look forward to seeing your finished product!

Pete

X2
Always great ideas in your threads Peter, thanks.

Best,
Ed

[Peter J]

As much as the audio geek world eschews grills, I sorta like them. Don't get me wrong, I like staring at naked drivers as much as the next geek, but in the real world with guests, curious fingers and non-naked-speaker loving significant others, some compromise is needed. 
From my perspective, most grills look a lot alike. Black cloth stretched over a frame looks OK, but I'm shooting for something a little different that still embodies the pragmatic aspects but doesn't follow the conventional esthetic. Overthink? Probably, but I like pushing boundaries, so why not push a little here?

So here's my foray into what I'll call OCD sheer and sexy floating grills.

These were test mules to prove concept and explore some options




Frame stock en masse




Staple channel close up




Mitering Sled


 

The cut parts




And the glue. With the accelerator, this stuff goes off almost instantly. Perfect for fussy stuff like this




Ended up with these



Added cross pieces




And corner blocks




Ended up here



Drilled 1/8" holes in the corners of frames, centered the grills where I want them and drill a pilot in baffle






Drilled 1/4" hole 7/16" deep




Epoxy and 1/4" x 3/8" N52 magnets




End result




Because upper and lower grills gotta be aligned to satisfy my OCD, a little wax paper to keep things from gettin' stuck together




Drill out 1/8" hole in frame to 5/16", retape grills in position, add epoxy from top. Guarantees alignment just so...




End up with this after epoxy dries




And now for the final touch so they don't look so blocky




My "keep it from chattering" jig




And here's the result








Waiting for some epoxy filler for the holes, then they'll get sprayed in black and covered in no-see-up net like first photo


More later...

[Early B.]

Peter J -- that's ridiculously awesome!

[gregfisk]

I really like it Peter, the best of both worlds. Do you think the raised grill going to cause any issues with the drivers dispersing the sound?

Greg

[Peter J]

I really like it Peter, the best of both worlds. Do you think the raised grill going to cause any issues with the drivers dispersing the sound?

Greg

Thanks Greg, it's a little different than what I originally wanted (wire frame), but I think it will look interesting when all is said and done. My reasoning concerning reflections is that a conventional grill for these surface mounted drivers needs to be 1/2" thick for clearance. Total height on these from baffle to top of frame is just a bit more  @ 9/16" so I doubt it will be any worse than that.

One of the reasons I made two grills was to accommodate taking the top one off easily if I'm critically listening. The tweeter would be most susceptible to refraction but I needed the center brace to beef up overall stiffness with so little structure. I played around with a center diamond shape brace around tweeter and even considered a circle, but in the end went with what you see for simplicity and also to be consistent with bottom grill.

[AKLegal]

PeterJ, what type of drill press are you using there?  I have this one http://www.amazon.com/Wolfcraft-4525404-Attachment-4-Inch-8-Inch/dp/B000JCIMEA/ref=sr_1_4?s=power-hand-tools&ie=UTF8&qid=1453898636&sr=1-4&keywords=drill+press. Yours looks a whole lot sturdier.

[Peter J]

PeterJ, what type of drill press are you using there?  I have this one http://www.amazon.com/Wolfcraft-4525404-Attachment-4-Inch-8-Inch/dp/B000JCIMEA/ref=sr_1_4?s=power-hand-tools&ie=UTF8&qid=1453898636&sr=1-4&keywords=drill+press. Yours looks a whole lot sturdier.

I had to go look and see! I've had it for years, but it gets little use. Seen more action lately than in the three years prior. It's a General. Looks like they've added a handle on the side which might be handy.
http://www.amazon.com/General-Tools-Instruments-36-37/dp/B00004T82L

[mresseguie]

I am slack jawed in stunned amazement, Peter.

You do beautiful work.

 

[Peter J]

More futzing with the minutia while I wait for epoxy to cure.

I started to wonder what the grills would look like with a faux fastener in the corner so I hacked my test mule for a real world look. Appreciate your thoughts on this one, I'm on the fence. Bear in mind the finished grill frame will be mo betta looking and have radiused edge. Might tie in with the sort of industrial theme on the leg mounts.

Copper rivet might look nice with the copper dust cap on upper drivers







Or button head screws






Of course there's always the option of nothing, which was my original intent. But then I got to thinkin....



I messed around with the sample leg clamps to explore possibilities of different ways to use them. The base has clearance holes for metric M3 screws which would take nuts on the opposite end. Looks like anything 1"(25mm) diameter would be workable. That's a walnut dowel on the right. In my experimenting I discovered a happy accident. The clearance hole for the M3 screw is just the right size for running a 6-32 tap which opens up all kinds of options for mounting and different looks. My mind's eye sees these on amp stands or racks, maybe adornment on DIY electronics boxes....many possibilities.

On right is M3 nut and bolt, left is #6 button head machine screw threaded into base. Sharpie is there for scale


 

[gregfisk]

I like the copper and I do think it would stand out and look good with the dust cap. IMO the black makes it look like your trying to hide it so at that point why put it on?

I think the machine screw head would look good on the grill in copper and also the same copper on the black leg would look great. All just my opinion of course but you did ask

Greg.

[Peter J]

I like the copper and I do think it would stand out and look good with the dust cap. IMO the black makes it look like your trying to hide it so at that point why put it on?

I think the machine screw head would look good on the grill in copper and also the same copper on the black leg would look great. All just my opinion of course but you did ask

Greg.

Thanks for your thoughts, Greg, I really am soliciting them and like input from a different perspective...don't be shy y'all!
 Kinda funny when I think about it. Bury the magnets to conceal the fastening mechanism and then add a fake...hmmm.  In the end, I decided against either, seemed too busy, despite the copper tie-in. There'll be plenty going on, I probably don't need to add yet more detail, but my mind just doesn't go there without some coaxing.

Got the frames filled, primed and lacquered.






And the baffles sealed and ready for gilding






 


FWIW, you did spark another idea, though. I was planning on black fasteners for drivers, but then got to wondering what copper might look like. Yeah, yeah, I know that's a rivet, just imagine it's a screw and tell me what you think.

[mlundy57]

Peter,

The copper dust cap/phase plug stands out by itself. I think adding copper fasteners would make it too busy and detract from the effect. Less is more ...

Mike

[Folsom]

I like it, a lot.

[gregfisk]

Peter,

The copper dust cap/phase plug stands out by itself. I think adding copper fasteners would make it too busy and detract from the effect. Less is more ...

Mike

I'm with Mike on this one, but I think using them on the legs would be a really good way to tie everything together.

[Captainhemo]

Looking great peter.

I agree with Gregg and  Mike....
If you are thinking  of  going with the fake fastners on the grills,  I like the copper  idea, it wouldn't be over kill but I think it would add a little  "extra" to the  appearence.

With regards to the driver mounting screws,  I too think they'd be a  bit too much... I had actually considered  doing the same thing myself with the NX-Otticas but  again, felt it was  just  too much and took away from the  "pop" of the NQ's copper  phase plug

jay