Minerva Monitor: "Patience my ass, I'm going to go build something!"

[Steve Manning]

Continuing on with stands today, specifically a crossover compartment. Glue clean up and sanding and then worked on more inserts.









One down ..... three more to go ......

[JonMarsh]

Slow work takes time.... lots of slow work takes even more time! :B

[Steve Manning]

Bit of an update ....

Spent a lot of hours removing this stuff and sanding .......





Got all of the inserts in place for the 4 crossover sections and then started on beveling the edges of each section. All four are now done.







Some voids and tear out areas will need addressing prior to finish going on.

[JonMarsh]

These are a happening! You're the man, Steve- though I shudder to think about how much time you've spent getting that glue off!

I'm hoping to get back to the acoustic prototypes soon... I'm under low activity orders for now, and not doing a bunch of heavy lifting. Better get some stuff done in the lab then, this weekend!

[Steve Manning]

These are a happening! You're the man, Steve- though I shudder to think about how much time you've spent getting that glue off!

I'm hoping to get back to the acoustic prototypes soon... I'm under low activity orders for now, and not doing a bunch of heavy lifting. Better get some stuff done in the lab then, this weekend!

I can attest to how well the glue sticks and not only to the wood ..... during the glue up process I had the occasional dab or two get on my arms. I now have some areas that are healing from the skin coming off with the glue :E

[JonMarsh]

I can attest to how well the glue sticks and not only to the wood ..... during the glue up process I had the occasional dab or two get on my arms. I now have some areas that are healing from the skin coming off with the glue :E

Damn, that's really putting it all on the line- blood, sweat, tears, and skin in the game! :B

[5th element]

Damn, that's really putting it all on the line- blood, sweat, tears, and skin in the game! :B

Sounds like what happens whenever I get my hands on some cyanoacrylates. I always end up glueing some skin to skin >.<

[Steve Manning]

Ass Kicking 101 &amp; Lessons Learned

Well after successfully performing a test cut of the PR cutout with mdf, I set about repeating the process on the first cabinet. It did not go well, I had the router bushing come loose. This led to crunching noises and brass shavings be thrown around :E. The obvious thought, was what did I do wrong? The brass bushing though a little worse for wear, was still usable, so I tried again, making sure everything was aligned and tight. The bushing did not survive the repeat performance of the crunching noises!! Fortunately through this the router bit was fine. I then ordered two replacement bushings and went on to other tasks.

With the arrival of the new bushings I wrapped the threads of the bushing with teflon tape and cinched things tight with a pair of channel locks and gave it another whirl. I made it ~ 30 seconds this time before the crunching started, managing to save the bushing before terminal failure.

So we did some research ....... First I ordered some of these from MLCS ......



Why these do not come standard with bushing sets in beyond me, they are a must. They put constant pressure on the lock ring helping it stop it from coming loose. Also I came across some information about the selection of bushing sizes. To make these cuts, I'm using a 1/2" straight bit, I'm hogging through 2 - 2.5" of lbl. Typical choices for this size are a 5/8" or 3/4" bushing. Me having little experience using bushings, I typically use flush trim or pattern bits, I picked the 5/8" dia. bushing. This worked fine for the mdf. Once I moved on to the lbl I got large chips instead of dust and they clogged up the small clearance gap between the router bit and the bushing. This in turn loosened the bushing and crunching, etc. .........

So for round three ...... I went to the 3/4" bushing (the templates were all made for 5/8" so I had to go back with the 5/8" for a final cleanup), put in the locking spring and hooked up the shop vac to the router to help pull out the chips. The result ...... no more crunching

This is the initial set of cuts







The 2" thick drop out.

[Steve Manning]

Before removing the inner ring of the template and cutting the outer section of the cutout, I needed to chamfer the backside of the driver cutout. Since that could not be done in the typical fashion, I got to try out a custom bit setup from Whiteside.






Instead of the standard chamfer it gives a nice round over which ought to do the trick.

[Steve Manning]

With the round over complete, the inner template ring was removed and the final routing was done.



Test fit of the PR ....







Back shot of the cutout .....



Now on to the other cabinets ....... tomorrow.

[5th element]

When these are finished you could see them selling for crazy $$$ on the audiophile market.

[JonMarsh]

Live and learn- everyone take notes! Pretty exciting to see the driver holes start to appear- and it even fits!

I wasn't any where near that physical, but still was too physical for my condition. (No point in giving you folks more information than you want or need...) But I did get a bunch of stuff organized in some binders for project work & planned development. Still, not the satisfying feeling you deserve today, Steve! :T

[dar47]

Hey, Steve glad you made it. That's a lot of torque running that wide a bit. I have used 1/4" up cutting spiral bit as deep as convertible. 1/8" pass depth not all the way through the material. Drill a whole in the slot on 2 sides and finish cut with a saber saw. From there I flush trim the hole. Takes more time but a little more controllable with a hand held router with bushings. Maybe 1/16" pass would put less vibration on the bushing. Great work so far.

[JonMarsh]

Hey, Steve glad you made it. That's a lot of torque running that wide a bit. I have used 1/4" up cutting spiral bit as deep as convertible. 1/8" pass depth not all the way through the material. Drill a whole in the slot on 2 sides and finish cut with a saber saw. From there I flush trim the hole. Takes more time but a little more controllable with a hand held router with bushings. Maybe 1/16" pass would put less vibration on the bushing. Great work so far.

Basically my standard technique too- not flashy, but easier for someone with my limited skills. It's definitely pucker time, though, when you get those grinding crunching events!

Great to see that the Whiteside router bit is working out the way we hoped.

[ergo]

Hang in there Steve! With this complex projects it's seems inevitable that there are some hurdles on the way regardless of amount of planning.

I have now oil/waxed the boxes. Added the felt to walls and doing the driver mount jobs....

I was saying how nice is is to make the driver holes with CNC - well I did got a surprise also. On CNC bed I fitted the woofer to the cutout upside down and tuned it for a nice snug fit. BUT it appears that Wavecor has made the edge ever so slightly off the 90 degree angle, so diameter is actually increasing towards the back. I probably have to do some manual sanding now to help it fit.

I'm hoping to get far enough by next weekend that I can do the acoustic measurements. Planning to do a 0..180 degree for both horizontal and vertical. The VituixCAD plotting of that would be fun to see.
I have an idea how to make the "contraption" to do that. I do have a DIY manual turntable, but that allows only horizontal off axis without major hassle. If I want to do the verticals too then my box being tall enough is much harder to mount sideways and turn at same time. So I'll be attempting to rotate microphone instead.

[cochinada]

I've been following this thread and have to say the bamboo looks really beautiful. :T

I was saying how nice is is to make the driver holes with CNC - well I did got a surprise also. On CNC bed I fitted the woofer to the cutout upside down and tuned it for a nice snug fit. BUT it appears that Wavecor has made the edge ever so slightly off the 90 degree angle, so diameter is actually increasing towards the back. I probably have to do some manual sanding now to help it fit.

This has also happened to me with drivers from Scan Speak and SB Acoustics, so I would say it is a rather common thing. I too had to manually sand the whole and what I did was wrap a piece of sand around a 'virgin' pencil to give me enough grip and make it possible to sand from the edge because if you just use your finger this won't be possible as you will soon find out. I'm sure there must be some other way to do it but without a proper tool I couldn't find a better way. It takes time though and it is a real pain in the ***. Good luck!

[cochinada]

These are a happening! You're the man, Steve- though I shudder to think about how much time you've spent getting that glue off!

I'm hoping to get back to the acoustic prototypes soon... I'm under low activity orders for now, and not doing a bunch of heavy lifting. Better get some stuff done in the lab then, this weekend!

I also heard the pain from this kidney stone thing is on top of the scale so I wish you recover as quick as possible BUT since I'm also an advocate for DIY in terms of health maybe you want to take a look at this article with some advice about your condition.

[Steve Manning]

Cabinets are looking nice Ergo ........ That's a bit rude on the Wavecor. I made my templates to give me a hole 1/16" over size on the diameter, just to deal with finish build up. On my Jensen project I had to sand paint to get the drivers to fit the hole after the cabinets were painted. Hopefully that will be enough to compensate for the issue you found.

[JonMarsh]

Thanks for the article- I do follow DIY practices in this area. Though I must say, a half gallon of cranberry juice per 100lb of body weight per day sounds a little over the top! :W

[Steve Manning]

Great to see that the Whiteside router bit is working out the way we hoped.

The new bit worked out great Jon ..... I dropped the speed on the router and the thing just zipped right through the lbl. With the extended shaft their was plenty of reach, even though at 2" this was the "thin" side.

[Steve Manning]

Thanks for the article- I do follow DIY practices in this area. Though I must say, a half gallon of cranberry juice per 100lb of body weight per day sounds a little over the top! :W

I'd think your skin would start taking on a purplish hue drinking that much of the stuff.

[JonMarsh]

Hang in there Steve! With this complex projects it's seems inevitable that there are some hurdles on the way regardless of amount of planning.

I have now oil/waxed the boxes. Added the felt to walls and doing the driver mount jobs....

I was saying how nice is is to make the driver holes with CNC - well I did got a surprise also. On CNC bed I fitted the woofer to the cutout upside down and tuned it for a nice snug fit. BUT it appears that Wavecor has made the edge ever so slightly off the 90 degree angle, so diameter is actually increasing towards the back. I probably have to do some manual sanding now to help it fit.

I'm hoping to get far enough by next weekend that I can do the acoustic measurements. Planning to do a 0..180 degree for both horizontal and vertical. The VituixCAD plotting of that would be fun to see.
I have an idea how to make the "contraption" to do that. I do have a DIY manual turntable, but that allows only horizontal off axis without major hassle. If I want to do the verticals too then my box being tall enough is much harder to mount sideways and turn at same time. So I'll be attempting to rotate microphone instead.




[ATTACH=CONFIG]25481[/ATTACH][ATTACH=CONFIG]25482[/ATTACH][ATTACH=CONFIG]25483[/ATTACH]

The cabinets are looking very nice, Ergo! You've chosen a nice way to work with the grain pattern of the LBL.

Now you're making me antsy with your progress, and I'm thinking whether I can get a way with ignoring the doctors "suggestions" and while GF is away on a hike this afternoon go out to the storage shed/wood shop and get a little more progress in on my 2nd level test cabinets.

I have a manual turntable and will use it, but only plan to do horizontal polars, as the midrange/ tweeter should be fairly symmetrical, and I'm not overly worried about off axis flare with the crossover work I've done so far. Problem is, I want to use VituixCAD, and just bought a second license (for my 2010 Mac Pro; first is on the new XPS15 Dell), but I'm not sure if I can figure out a way to get the crossover topology the way I've realized it into VituixCAD, in spite of the clever things he showed us.

I've also got to dig in to the APx500 software documentation and be sure I can export data in a usable format for design, using their R&D Acoustics package. This is all going to be interesting, but I've got a lot of new learning curves this year to conquer.

[JonMarsh]

I obeyed my various "medical advisors" and did not go out to the shed to tote and lift cabinets and work on real man stuff- instead, I was a CAD weanie all day except when we went out for Easter Brunch. which was good.

Among the things accomplished was a sort of "proof of concept" for working with VituixCAD on the Minerva, both importing and scaling and filtering my Fuzzmeasure FRD data, and working out a network topology that got basically the same results but was doable in VituixCAD. Pretty much mission accomplished.




Note- yes, there are some values tweaked, and it's possible this is a little bit better version of the crossover - for the OLD TEST CABINETS. What this really establishes is a process baseline for bringing in the data and working on VituixCAD, with a network that accomplishes the acoustical targets I want for now.

But this is just a proof of concept for that. Next step will be to get new measured data in one of the new table saw built test cabinets, which is similar enough in layout and front panel dimensions that it can be used for the final cabinets which Steve is working on. Heck, I'll probably just have two sets of these when I'm done, as I have all the parts cut out for two of the 2nd gen prototype cabinets.

Next round of data taking will be another experiment, as I'll be trying to do that with the AudioPrecision- see if there's any benefit to that over Fuzzmeausre, besides the logo on the graphs. :W :lol:



Yeah, it does CSD's and other groovy things that aren't mentioned on this page- this is just a page off the data sheet for the Acoustics software package, which is an option for APx500 compatible analyzers.

[sdl2112]

Ergo, your cabinets are really coming together :T. I like the diverse construction techniques you used to minimize waste. The wider bamboo pattern looks good too. What do you plan for the final finish?...I see you mention oil/wax and lacquer?

Hang in there Steve! With this complex projects it's seems inevitable that there are some hurdles on the way regardless of amount of planning.

I have now oil/waxed the boxes. Added the felt to walls and doing the driver mount jobs....

I was saying how nice is is to make the driver holes with CNC - well I did got a surprise also. On CNC bed I fitted the woofer to the cutout upside down and tuned it for a nice snug fit. BUT it appears that Wavecor has made the edge ever so slightly off the 90 degree angle, so diameter is actually increasing towards the back. I probably have to do some manual sanding now to help it fit.

I'm hoping to get far enough by next weekend that I can do the acoustic measurements. Planning to do a 0..180 degree for both horizontal and vertical. The VituixCAD plotting of that would be fun to see.
I have an idea how to make the "contraption" to do that. I do have a DIY manual turntable, but that allows only horizontal off axis without major hassle. If I want to do the verticals too then my box being tall enough is much harder to mount sideways and turn at same time. So I'll be attempting to rotate microphone instead.


[ATTACH=CONFIG]25481[/ATTACH][ATTACH=CONFIG]25482[/ATTACH][ATTACH=CONFIG]25483[/ATTACH]

[sdl2112]

Steve, your attention to detail is off the charts...:T I enjoy watching this come together.

With the round over complete, the inner template ring was removed and the final routing was done.

[ATTACH=CONFIG]25475[/ATTACH]

Test fit of the PR ....

[ATTACH=CONFIG]25476[/ATTACH]

[ATTACH=CONFIG]25477[/ATTACH]

[ATTACH=CONFIG]25478[/ATTACH]

Back shot of the cutout .....

[ATTACH=CONFIG]25479[/ATTACH]

Now on to the other cabinets ....... tomorrow.

[sdl2112]

Jon...I don't even know what thread to respond to... you are on a real tear with info on this forum. I don't see how you do it with your schedule...but we much appreciate it :B. I do want to say good luck with your kidney stone procedure :T.

I obeyed my various "medical advisors" and did not go out to the shed to tote and lift cabinets and work on real man stuff- instead, I was a CAD weanie all day except when we went out for Easter Brunch. which was good.

[JonMarsh]

Jon...I don't even know what thread to respond to... you are on a real tear with info on this forum. I don't see how you do it with your schedule...but we much appreciate it :B. I do want to say good luck with your kidney stone procedure :T.

Thanks! Much appreciated... :T

I'm not expecting any surprises Wednesday. :W

[Steve Manning]

When these are finished you could see them selling for crazy $$$ on the audiophile market.

Thanks Matt ...... we're taking orders

[Steve Manning]

Steve, your attention to detail is off the charts...:T I enjoy watching this come together.

Thanks Scott ....... as the saying goes "It's all in the details". Some of us worry about them (OCD, I think they call it) and others don't, I might be one of the former. Hows you project coming these days?

[Steve Manning]

To illustrate what I was talking about with saw dust and chip build up earlier ....... this pile of chips is from just one driver cutout. It's 3 inches deep and that is the drop out from the 10" PR as a reference .....



All the PR cutouts are done .....

[JonMarsh]

Yeah, when you're going through a couple of inches or more of baffle, the chip out really stacks up fast!

Three more done- that's definitely progress! :T

[Steve Manning]

Small update ..... moved to the front of the cabinet and got the jig modified for the coax template ...... that extra 1/2" of thickness seemed to take forever to get through.


Now that's a plug of wood .....







At least the cabinets are getting a little lighter .....

[JonMarsh]

Nice looking rebates and holes! So, just HOW MUCH lighter are the cabinets getting? :W

[Steve Manning]

Nice looking rebates and holes! So, just HOW MUCH lighter are the cabinets getting? :W

Well the plug and chips that came out of this hole should be ~2 lbs.

[dar47]

Nice work Steve, take some out put some back in it's all good you don't have to move them that much, haha.

[Steve Manning]

Thanks Darrell ...... the fun comes when I have to get things boxed up for UPS, then they get the surprise when they go to move them.

[JonMarsh]

Thanks Darrell ...... the fun comes when I have to get things boxed up for UPS, then they get the surprise when they go to move them.

Yeah, that part is likely to be a stone cold b*tch!

You've gotta admit we're not cutting corners in our "evolution" of the TAD Compact Evolution One...


These are pretty, but bottom line it's just a ported 6-1/2" woofer on the bottom end....

[ergo]

Wau, that front panel is something indeed. I can imagine how many passes it takes to get through that with a router.
And this bamboo stuff if pretty tough material. I made a small improvised sanding block from leftover material and getting staples into it was a challenge. The leftover blocks you got Steve would make something more than a sanding block though

I have solved my woofer fit issues also. It turned out to be more of an issue with inner rim. The spider legs and the small rim were not sitting into the hole, so I ended up chamfering it a bit. Now it fits.... Hopefully I can get the other drivers in and impedance measurements started today/tomorrow.

[ergo]

I used this oli/wax mixture for the finish

http://www.amello.ee/et/moeoeblivaha.html

They have an english page too, but this product is not on it. It is a mixture of natural oils and waxes. Smells like a fresh squeezed orange juice. It's a pleasure to use something like this instead of toxic vapours. My wife joked that now I have the 'best smelling speakers' one can find.

Aha Google Translate does make it into sort of readable

https://translate.google.com/translate?sl=et&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.amello.ee%2Fet%2Fmoeoeblivaha.html&edit-text=

[Steve Manning]

Glad you got the fit issue worked out Ergo ..... I had to make a sanding jig and do the same on the Jensen's, though mine was from paint build up. This is what mine looked like ......



I used carpet tape to hold the sandpaper and stuck a 3/8 threaded insert in the disk and used the handle from another jig to control things. Took a while but it worked.

[JonMarsh]

You guys keep working away- I'm admitted to the surgery center, in the prep area, and not exactly dressed for public exposure! At least they let me keep my iPad Pro a while longer....

[Alaric]

Best of luck and a speedy recovery , Jon.

[wkhanna]

:agree:
what Lee said +1

[sdl2112]

Thanks Scott ....... as the saying goes "It's all in the details". Some of us worry about them (OCD, I think they call it) and others don't, I might be one of the former. Hows you project coming these days?

Steve...your nice work continues. I haven't done much on my project lately but I will post a small update shortly.

It's funny...not really "ha ha" funny but the day after I wish Jon good luck with his procedure...I ended up in the ER Monday. I had an atrial fibrillation event with high heart rate. I had a similar episode earlier in the year. Everything is going good and we have a plan to get things sorted out. It's just a dose of reality the older we get.8O

[ergo]

Lets hope all these nice speaker projects bring some relaxations and tranquillity through music after the completion. Seems too much work and not enough play is a general problem.

Best of luck for both of you with recoveries.