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

[JonMarsh]

Very nice Jon. No one would guess those were just prototypes. Nice collection of routers! I've been thinking of getting another but my DW621 does so well at everything but its nearing 20 yrs old. :E

DW621's are the best! :T. IF I could only have one router, that would be it. But I'm a lazy SOB and like to have a collection of routers on the shelf setup for specific jobs with the right attachments and bits so that all I have to do is pick up the router off the shelf... I have over a dozen now. The only other things I'm that bad about are computer bags and guitars...

Yeah, apart from my mediocre/hurried execution and so-so craftsmanship, the cabinets have turned out as expected with regards to the appearance due to my plan for which type of LBL I'm using and how I'm using it... From horseback, they'll look pretty good when finished. I'm just planning to use General Finishes Wipe on poly or perhaps the water based lacquer I used on GF's sub boxes.

But then, these "are" the design for any one in the future that wants to build a table saw version, and doesn't have access to Translam stuff like Ergo's build or the co-build Steve is doing with me.

[JonMarsh]

Here's a htguide site question.

I noticed when I reply to an embedded message with an image attached within htguide the image is reduced like a thumbnail. This also happened when I replied to a message that had an image hosted by photo-bucket. The last message the images were full size when I replied and they are hosted by flickr. I hate to clutter the thread with redundancy, is there a setting or procedure other then removing the pics....just a curiosity.

Thx,

Scott

Not that I know of. Sometimes I use the embedded server, but it annoys me in the same way as Photo-bucket does, in that it applies extra compression and size and quality reduction. Particularly on engineering graphics that's an issue, which is why I use my favorite, Flickr, a lot, lately, because it doesn't mess with your stuff at all. Note, with a Flickr picture, it's not a conventional image embed, it's actually a little HTML program that brings in the image at the chosen size from the Flickr server.

[JonMarsh]

Ok - I've gone to use "bigger guns" - ie replaced ARTA based setup with CLIO 11 FW. The only negative with CLIO is that I can't get it to behave together with my laptop running win 10 and PC-card FW interface.
It does work on my HP desktop PC which also runs win 10..... anyhow, due to this I had to do measurements in my listening room instead of a bigger family room. The gating needed to be 4.1ms due to that

I think levels wise this setup is getting it very close. There is still a discrepancy especially in 500...3k range even though this time I did not use any protection cap.

My measurements are with
ARTA + GRAS 40AM mic
CLIO + GRAS 40AM mic
CLIO + LinearX M53 mic
With M53 I'm pretty confident that CLIO has a bug and never applies the mic cal file. I tried all tricks and copied the MICA.cal file to the Clio.exe folder etc - I never see any change. The plot also indicates that mic cal has not been enabled.

Still my two mics give resonable good match - so the conclusion I guess is that the baffle shape and maybe a bit of unit to unit variance must be the cause here.

[ATTACH=CONFIG]25589[/ATTACH][ATTACH=CONFIG]25590[/ATTACH]

A lot of good detailed work, there, Ero! :T

I'm hoping/planning to have the test box together (without PR, though) and be able to get some new data on the different size cabinet baffle this afternoon. I'm pondering whether to proceed directly to the AP setup or use my usual setup again. Probably I'll try the AP stuff first, as I really want to get some experience with it, and it directly support the microphone calibrator. If things look "good" or "reasonable", and I can extract the design data needed, then all will be well. At least I have a backup plan...

[Steve Manning]

You feeling better now that you got a sawdust fix Jon? Sounds like the new router is a keeper.

[augerpro]

How's the downtown Denver lifestyle these days? For me, it's really hard to imagine living without a garage or some kind of shed/storage/work space. A lot of people do that, though...

I love it. Everything is walking distance, great food, lively entertainment. But I can't turn the music up much due to having neighbors, even with the concrete construction. IF I move I'll probably get a house near one of the new/future light rail stations so I can always hop on and be downtown in minutes. Denver should be pretty fantastic when all the light rails are done. As it is right now traffic is getting just absurd.

[5th element]

Must have been amplifier going to oscillation to do that sort of damage, but yes odd that no input was able to still trigger that.

With these C18 units it does make me bit itchy as they seem to really be 'all gone' and no new productions coming available. So I don't want to loose my only pair. Jon probably has bought a few extra knowing him

Agreed and I thought something similar but this was an isolated event and only ever happened the once with no system changes after the event took place. Whatever it was the protection cap didn't help!

[JonMarsh]

You feeling better now that you got a sawdust fix Jon? Sounds like the new router is a keeper.

Mongo like router... router work well... Mongo make lots of sawdust... wood shed is a mess!

[JonMarsh]

I love it. Everything is walking distance, great food, lively entertainment. But I can't turn the music up much due to having neighbors, even with the concrete construction. IF I move I'll probably get a house near one of the new/future light rail stations so I can always hop on and be downtown in minutes. Denver should be pretty fantastic when all the light rails are done. As it is right now traffic is getting just absurd.

Sounds like what I like about Munich. Question is, how long to "finish" the build out of Light Rail? They've done a piddly ass job of it in San Jose. And in Munich they are frequency adding stuff on to the S-Bahn...

[JonMarsh]

BTW, for anyone that cares, the empty weight of the table saw version is about 54 lb. Still working on loading it up, several delays, including GF & doggie related stuff and a flurry of emails with my Munich cohort- I may wind up having a PS Audio DirectStream DAC here to test for him.

It also occurred to me that an interesting short cut instant gratification might be to play it with the V2 crossover, and measure that in this cabinet. (Not the same specific drivers- the other side of this pair)

[Steve Manning]

BTW, for anyone that cares, the empty weight of the table saw version is about 54 lb. Still working on loading it up, several delays, including GF & doggie related stuff and a flurry of emails with my Munich cohort- I may wind up having a PS Audio DirectStream DAC here to test for him.

It also occurred to me that an interesting short cut instant gratification might be to play it with the V2 crossover, and measure that in this cabinet. (Not the same specific drivers- the other side of this pair)

That's still a pretty stout cabinet for what it is ....... Cool on the DAC, I'll be curious as to what you think of it.

[JonMarsh]

Let's just say we have the formula for building adequately stiff cabinets pretty much down cold- two layers of LBL, or LBL+BB Ply, and BB ply bracing, definitely gets the job done! :T :B

The routed out hole for the C18EN was just a skosh too big at the strut points, (I must have misinterpreted the drawing) and that took a little saber saw work to correct at those points. Now I'm working on temporary wiring routed through the rebated cut out for the PR which hasn't actually been removed- so I won't leave any temp scars on the box, but I don't want three sets of cable ingress with permanent connectors (crossovers internal)

[JonMarsh]

Where did Sunday go?!?

Slow work takes time, especially when there are a lot of other tasks one needs to do but would rather not be doing (laundry, for example).

so, I finished setting up for measuring the Cambridge Audio 851D, answered a variety of questions and discussed possible paths with my cohort in Munich, and I DID get to the hardware store and pick up bits, and get the cabling and hardware for testing done for the cabinet. But I didn't have time to actually hook it up to anything... but I got real close!


Nothing like having the right tool for those occasional difficult tasks- I should have a promo deal worked out with DeWalt, if I was smart.... in this case, drilling some through holes in the center baffle separating the woofer and midrange/tweeter.





No, everything didn't go smoothly, I must have been optimistic interpreting the frame dimensions, that or they didn't take into account the struts, as we needed a bit of relief to get things together...





But together they did go- I will put in inserts before finishing and final assembly, but for now, a 7/64's bit gives you a great pilot hole for a Special drywall screw, that locks down solid once you run out of travel.




And here we have two views of the Minerva TS, shown on the optional tall maple stand.

[cochinada]

Let's just say we have the formula for building adequately stiff cabinets pretty much down cold- two layers of LBL, or LBL+BB Ply, and BB ply bracing, definitely gets the job done! :T :B

Why two layers of LBL? Isn't it the same as one layer only with the same thickness as two?

[JonMarsh]

I'm drawing a blank on exactly what you mean this time- two layers is 3/4" + 3/4" = 1-1/2" -

Tops, bottoms, and front panels are pure LBL, made from the edge wise 12" board planks, glued up to 1-1/2" thick. The sides, though, are a combination of one layer of tooling grade BB Ply + 3/4" LBL, covered with LBL (edgewise boards, epoxied together to make a wider board).

It's not two thin layers of LBL making up 3/4". (That's possible to obtain with the right vendors, but I don't see any benefit). And one can't buy 1-1/2" LBL around here...

So, you might say, that for a smaller cabinet like this, 1-1/2" thickness of LBL or LBL with BB Ply works fine- especially with this type of LBL board.

The only place I "cut corners" is the rear baffle, which is just 3/4" LBL, becuase it's mostly full of holes (such as for the PR) or it's well braced by the front to rear BB ply baffle separating the midrange and woofer compartments.

[Steve Manning]

Lest Jon think I've been slacking ....... here's what's been going on of late.

Ran into issues with the aluminum trim for the cabinets not fitting well at all. I'm certain this was due to the parts being bent by hand and not a machine. I ran into additional issues with the welds not holding up to "tweaking" when I tried to get the shape of the rings to fit. So I came up with plan "B", which required a number of days to work through the mods required for the trim.

Essentially I removed a section of the trim at the weld area (this is at the bottom of the cabinet), some more "tweaking" and drilling of 26 holes in each trim piece for nails to hold things where I want them. If any more of these get built, solid plate is a must over the route taken, the time alone is just not worth it, lesson learned.

[Steve Manning]

Additional clean up and sanding on the stand vertical sections as well as installing inserts ....



Installed inserts on the bottom of the crossover compartments for spike attachment ......





Spikes Installed ....

[Steve Manning]

A few more of the spikes ...... love the look and quality of the Via Blue spikes .....

[sdl2112]

You have a lot of patience there Steve...How do you plan on finishing the aluminum trim. Same time as the bamboo or mask it off...other?

[JonMarsh]

Lest Jon think I've been slacking ....... here's what's been going on of late.

Ran into issues with the aluminum trim for the cabinets not fitting well at all. I'm certain this was due to the parts being bent by hand and not a machine. I ran into additional issues with the welds not holding up to "tweaking" when I tried to get the shape of the rings to fit. So I came up with plan "B", which required a number of days to work through the mods required for the trim.

Essentially I removed a section of the trim at the weld area (this is at the bottom of the cabinet), some more "tweaking" and drilling of 26 holes in each trim piece for nails to hold things where I want them. If any more of these get built, solid plate is a must over the route taken, the time alone is just not worth it, lesson learned.


[ATTACH=CONFIG]25598[/ATTACH]

[ATTACH=CONFIG]25599[/ATTACH]

[ATTACH=CONFIG]25600[/ATTACH]

[ATTACH=CONFIG]25601[/ATTACH]

One short comment: Time consuming... I feel your pain! Experience is a b*tch of a teacher, sometimes...


BTW, which model of Viablue are those, and what vendor do you get them from?

[Steve Manning]

You have a lot of patience there Steve...How do you plan on finishing the aluminum trim. Same time as the bamboo or mask it off...other?

Thanks Scott ..... the plan at this point is to clean up any scratches, etc. and then polish the visible side of the aluminum trim. Then spray a clear coat on it to prevent oxidation. Apply the finish on the cabinets and stands and then install the trim prior to final assembly.

[Steve Manning]

One short comment: Time consuming... I feel your pain! Experience is a b*tch of a teacher, sometimes...


BTW, which model of Viablue are those, and what vendor do you get them from?

Ain't that the truth ....

Got them here, http://www.avoutlet.com/index.php?di...roduct_id=1577 half the price of anywhere else I've seen them.

[cochinada]

Those Viablue spikes are nice indeed. The thing I would change is the size of the protection plate which is too small and easily slides out of place when you try to move the speakers, specially if they are very heavy. This happened to me more than once and it caused some holes in my floor which was not very pleasant to say the least.

I'm considering purchasing some after market plates, like in eBay for instance where the offer is plenty, although it is too late for me that the damage is done.

EDIT: these are the biggest I saw so far, although they are made of aluminium and not steel. Most don't mention if they have some felt protection underneath it or no, which is a pity.

[cochinada]

On a side note I found this HiFi rack very appropriate for aesthetic matching your electronics to these speakers.

[JonMarsh]

Made in the UK, I can't get them to list from my USA eBay account. Found retailers in the UK- I expect the problem is shipping, and shipping weight! But they do look nice, especially the natural bamboo with silver aluminum posts.

[cochinada]

Made in the UK, I can't get them to list from my USA eBay account. Found retailers in the UK- I expect the problem is shipping, and shipping weight! But they do look nice, especially the natural bamboo with silver aluminum posts.

On eBay they say that shipping to USA is 25EUR only! Of course I imagine you have to pay extra taxes. If it was the other way around, that is form USA to Portugal we were talking about an extra 40%. :M

[Steve Manning]

Those Viablue spikes are nice indeed. The thing I would change is the size of the protection plate which is too small and easily slides out of place when you try to move the speakers, specially if they are very heavy. This happened to me more than once and it caused some holes in my floor which was not very pleasant to say the least.

I'm considering purchasing some after market plates, like in eBay for instance where the offer is plenty, although it is too late for me that the damage is done.

EDIT: these are the biggest I saw so far, although they are made of aluminium and not steel. Most don't mention if they have some felt protection underneath it or no, which is a pity.

I agree with you they ought to be a little bigger ...... if one had access to a machinist, that could be easily solved with a small amount of work.

[Steve Manning]

On a side note I found this HiFi rack very appropriate for aesthetic matching your electronics to these speakers.

I'm set for a while on the equipment rack side, http://www.htguide.com/forum/showthr...Equipment-Rack, made my own. I don't know about Jon ..... It would be rather straight forward to make something like you linked to though.

[JonMarsh]

Found a similar rack with natural bamboo shelves, also for EUR 25 shipping! Same vendor, slightly lower price. Also found a bunch of different spike floor protectors from this British company. Interesting... too bad I've got so much other stuff going on, can't really afford this right now. Have to keep an eye on it though...

[flamethrower1]

I'm set for a while on the equipment rack side, http://www.htguide.com/forum/showthr...Equipment-Rack, made my own. I don't know about Jon ..... It would be rather straight forward to make something like you linked to though.

That is a REALLY nice rack, impressive

[JonMarsh]

That was a very nice job you did, Steve... straightforward, yes... time consuming... yes. I have to think very carefully these days about time consuming... and where to put the time!

[Steve Manning]

That is a REALLY nice rack, impressive

Thank you .....

[cochinada]

Nice rack Steve. You are indeed a master carpenter. :amen:

Found some huge spike shoes made of steel. I'm not so sure if these aren't overkill though... Moreover they also don't mention if they have felt on the bottom.

[Steve Manning]

Stand work continues ...... put together some jigs for stop points so I could cut the rabbets for the aluminum trim on the vertical stand parts. I think doing that and making some test cuts took twice as long as the real parts.







Once they were cut spent some time squaring things up with some chisel work ......

[Steve Manning]

Quick Update ....... finished fabricating the trim pieces for the stands this afternoon, after the lawn got mowed. Clean up, scratch removal and polishing remain on all of the trim, as well as applying a clear coat.

[JonMarsh]

Good progress, Steve!

now, isn't that the problem with being able to do cool looking renders from SketchUp models, making them "real" is DEFINITELY a bit more work!

I spent almost three hours this morning looking for my NOS Aurasound NS10-513-4A woofers, I did finally find them, though not in the unit I expected, but one with much newer stuff. but then I'd been moving a lot of the "good stuff" over to it, so I should have remembered... Maybe I need an inventory system.... my nephew Josh runs the IT for a college, maybe I could get him to whip me up something!

Seriously, I'm getting setup for acoustics measurements with the Audio Precision, and as a backup, with Fuzzmeasure 4 and a TC Konnekt Impact twin interface that I've had for years and haven't used... yet.

Also, last night I finished the bench measurements on the Cambridge Audio 651W. That's a pretty clean little guy- turns out there's even a firm in Germany that does hotrod jobs on them, mostly because it's so good to begin with.

Teaser:



Yes, that's 0.005% at 1W output through balanced inputs (has to be quiet to hit that low a number at 2.83VRMS out) and under 0.0008% at 50W out. Rated 100W/ch 8 ohms, 150W/ch 4 ohms. It's not an AHB2, but it's not $3K, either. $999.00

[ergo]

Loudspeaker companies have some way to go to improve the speaker units before your new test setup starts to be a limiting factor for measurements 8)

[ergo]

Good progress Steve. Lots of work done and to be done but I'm sure the mental image (and the renders) of the end product help drive it.

[Steve Manning]

Good progress, Steve!

now, isn't that the problem with being able to do cool looking renders from SketchUp models, making them "real" is DEFINITELY a bit more work!

What knucklehead would do that? Oh wait that was me wasn't it ..... :yesnod:

[Steve Manning]

Good progress Steve. Lots of work done and to be done but I'm sure the mental image (and the renders) of the end product help drive it.

Thanks Ergo .... your right on the driving factor ..... I might even be seeing a glimmer of the finish line if I squint a little.

[JonMarsh]

Thanks Ergo .... your right on the driving factor ..... I might even be seeing a glimmer of the finish line if I squint a little.

Nah, that's just probably glare from the oncoming headlights! :W

[Steve Manning]

Nah, that's just probably glare from the oncoming headlights! :W

Maybe it's a shinny new NSX .....

[JonMarsh]

I wish! Though realistically, in my more mature and mellower current incarnation with a stronger technology bent, I think a Tesla Model S in Ludicrous mode would be more appropriate... :W

[ergo]

After redoing the measurements with ARTA, then CLIO and then Fuzzmeasure in end it seems I get best correlation with Jons measurements and simulation with Fuzzmeasure data. Which in a way is not surprising as Jon's V1 measurements were also with Fuzzmeasure I would guess.
Anyhow, after some trials it seems the V1.1 crossover with tiny modifications works better with my data (I can't get equally good phase alignment or response with v1.3 voiced XO.

I've now assembled a candidate part list to order. Based on Janzen stuff. If Jon or anyone else would like to chime in on my choises I would be happy for feedback. I did try to choose the better stuff for the series parts and just good for some parellel parts and compensations paths.

[ergo]

Hmm, forum software does decrease jpg quality a lot. I shared the excel file here too.

https://onedrive.live.com/redir?resid=73B3DF257C874FF5!16236&authkey=!AGr3j48RbN0vRkc&ithint=file%2cxlsx

[JonMarsh]

Hmm, forum software does decrease jpg quality a lot. I shared the excel file here too.
https://onedrive.live.com/redir?resi...nt=file%2cxlsx

Yeah, that's why I use Flickr a lot. Nice work, Ergo, glad to see you're making headway- I'll download that Excel file and make a clean jpg and post via flickr. Looks like you're back in LspCAD- are you seeing any correlation issues between it and VituixCAD? Thats' something else I should check as a point of tool verification, right? :W


I've just got my first measurements with the AP setup going this AM, the 64,000 Euro question is whether I can get data out in text files for design, need to figure that out soon, but now that I'm up and going, I figure just running the tests is a good idea.