Official Build Thread - MIC

[meb46]

Jon - Was just looking at this and I think I can create the right sort of curve/chamfer out of 30/45/60 degree straight edge bits. These are typically a lot easier to find in this part of the world... I think my next step will be to have a trial run at things.

[JonMarsh]

Just remember to remove small amounts of material each pass, building up to the full cutaway you need- should go smooth! I have a big Hitachi router that works great for those kinds of jobs- 3-1/2 HP, and butter smooth!

[benchtester]

...Anyone know if you can get 1" or 1.5" radius router bits on a 1/2" chuck?

I have a 1.5" round over bit with a 1/2" shank. Work fine in a mill, but it doesn't fit in my Ryobi router. The cutter tips would hit tabs on the base casting.

+1 on multiple passes.


BTW: I got mine on Ebay. I just looked and found an example of a vendor that will ship worldwide. I don't know these guys, but their feedback rating is pretty good.

http://www.ebay.com/itm/1pc-1-2-SH-1...item1e6ae097b7

[meb46]

Finally some serious progress... funny turn of events, I thought when I received the bracing that it would take me a week or so to assemble the two Bass Cabinets. I was expecting to have to custom fit each piece together with some sand-paper edging and fitting... this was not the case!

Thus far, I have received all of the 2D CNC cut pieces, which are essentially the internal bracing of the base cabinets. On arrival, this is how they looked...





Armed with nothing... I thought I would test fit a few of the pieces together to see what find of work I have in fornt of me trying to assemble these... approximately 2.5 minutes later... this is how they looked...







The cabinets essentially "fell" together. The bracing machining is perfect, and my assumption of resistance fits and clearances were spot on. I had thought I would need some "resistance" fit matrix's, but these proved to be absolutely perfect in their matching and fit. HUGELY happy with the result, I couldn't have expected anything better. BIG thumbs up for CNC machining yet again!!!!

Tonight I will try and get all of the radii machined into the bracing and then get these ready for gluing. I think looking at the MDF, I will definitely need to glue the bracing together and then seal all of the MDF that doesn't get fixed/glued to the other sides/baffles etc. Especially since I am in a humid climate, I think this will probably mean Zinsser Seal Coat... another upside of doing this before the sides and baffle goes on is simply access. Things will get tight to work on soon.

Updates after all the radii are machined in...

[Hdale85]

Wow that's awesome...can't wait to see the main event

[JonMarsh]

Slick!

This is the way it SHOULD work! :T Looking good, Mike!

[BBLV]

Is it weird that your CNC'd wood turns me on?

Your build is looking AWESOME.

[cjd]

That's what happens with good CAD. Just remember to take it all apart before you start final assembly so you don't accidentally forget a piece.

You need a wine bottle or something in the pics so we can get a better sense of scale on those.

C

[meb46]

A few more pictures after the addition of the internal radii... and a picture for CJD for scaling

Unfortunately... now I must patiently wait for the front baffles before I can start and glue these all together... oh the temptation of it all...











The wine-bottle photo is a bit decieving, as the bottom chambers are actually much larger. If it helps, these brace frames stand 1150mm x 330mm x 470mm(deep but not including angle). Thus far, the Brace Frames weigh in at 18kg... These are going to be some heavy beasts...

Fingers crossed I get my Baffles back next week and I can then start to glue them up and then seal the MDF etc...

[cjd]

Mmmmm, see, I'd now be distracted from the desire to assemble more thoroughly. A nice Cab Sauv it seems.

[meb46]

Yes... i'm fighting the same tendancies... but I had envisaged I assemble them from the baffles backwards. The Bracing structure, while square and now complete, does need the fit with the Baffles to ensure complete accuracy. As I dont have the baffles yet, I am sitting on my hands paitently until they arrive. My thoughts are to Build/Glue them starting with the Baffles and the main vertical braces and then slowly glue in the horivontal braces etc. I'm trying to be thorough, and avoid any "cock-ups" with these "expensive" machined parts. These are not parts I would want to pay for a second time

[meb46]

I caved... started assembling the internal braces and gluing. Point to note... 30 G-Clamps required to clamp it all together while drying. Will post some further photos later tonight...

[meb46]

Yes, believe it or not, under the maze of G-Clamps resides the Internal Bracing Structure. Baffles and all other panels are due Friday, so looks like i'm in for an exciting weekend of assembly

[Evil Twin]

Most impressive!

[5th element]

You can never have enough clamps

[cjd]

I worry that a weakness may be found. . .

should we prepare your shuttle?

(looks like it's coming along nicely! Hopefully it's also fun and rewarding.)

[meb46]

Progress has been made over the weekend and I will post some updated photos shortly... however... I have some questions on stuffing and materials. Here in Singapore I have a limited source of Acousta-Stuf and similar type products, hence I am trying to decide what sort of product I should use to stuff my Bass Cabinets with. I can get Mineral Wool, or Rock-wool, but I havent heard a lot of people using this. Anyone have any feedback on this type of amterial for stuffing?

[Hdale85]

You can't get polyester pillow stuffing out there? I'd be surprised by that. All acousta stuff is is the Poly-Fil stuff. They use it in pillows and what not.

You can use Rock-wool type stuff, generally if you don't have access to products from PE though people use fiberglass insulation. Seems a lot of the world doesn't use that either though?

[meb46]

Yep, I can get standard Poly/dacron stuffing easily... I was always of the opinon that the Acousta-Stuf was a little more specialized than that? I could be wrong...

[Hdale85]

Nope, most of us don't even use the acousta-stuff brand we just run to the local Wal-mart or similar and get the poly-fill bag for like 3 bucks.

[JonMarsh]

Progress has been made over the weekend and I will post some updated photos shortly... however... I have some questions on stuffing and materials. Here in Singapore I have a limited source of Acousta-Stuf and similar type products, hence I am trying to decide what sort of product I should use to stuff my Bass Cabinets with. I can get Mineral Wool, or Rock-wool, but I havent heard a lot of people using this. Anyone have any feedback on this type of amterial for stuffing?

Rockwool is not all that stable physically, and I recall seeing tests showing poor damping properties compared with fiberglass. Dacron and Acousta-Stuff has better midrange than bass absorption, but that's not necessarily bad- in many systems, particularly small two ways, that's exactly what you want, so that the back wave through the mids is tamed, but the port coupling is not over damped.

For your bass cabinets, you'll probably want to experiment with the amount and placement of stuffing selectively on one cabinet to figure out the optimum in room response profile at your intended placement and listening positions, then replicate that stuffing in the second cabinet. I suggest you don't put stuffing near the port; concentrate on the center of the cabinet behind the woofers to start.

[Carl V]

Can you get loose Wool? Layers of thick Wool Felt?

I have used loose fiberglass which I have
stuffed into nylons/aka panty hose. I have also used
those ditty bags which are used to launder delicate silk
clothing stuffing Fiberglass into those as well.

What you will have is various sizes of " fluffly fiberglass Balloons".
I can then place them where I want, tape them down, hot
glue them or whatever. Wool felt on walls or Braces with
these balloons midway to break up resonances. It's clean, neat
& repeatable.

[Bear]

Yep, I can get standard Poly/dacron stuffing easily... I was always of the opinon that the Acousta-Stuf was a little more specialized than that? I could be wrong...

If worst comes to worse, you could always hop a flight on SQ down to AU/NZ. Rumor has it those guys have decent quality wool just lying around. ;-) (I was in Australia a decade ago, and remember hearing about the challenges with Australia's 'strategic wool reserve'. The controversy was that it was a large stockpile of nearly commercially useless quality -- only good for making low-grade blankets and other bulk market items...)

Rock-wool is often a by-product of steel manufacturing (slag). It's good for housing insulation in certain uses (compare to XPS and EPS panels), but I'd echo Jon's caution about its use acoustically. In readily available commercial products, my guess is that it's density would be such that it would just reduce volume (i.e., reflect), rather than acting as an acoustically beneficial damping barrier. However, that is a guess that would need to be validated with testing.

[Evil Twin]

Don't let anyone pull the wool over your eyes on this one- with the expenditures you're making, you must not "settle" for any aspect of the build or construction materials...

[meb46]

Updates on the Bass Cabinets - Bottom Panel with reinforced Port Hole. Should enable me to secure the port and tube a little better. The port will be epoxied in and will also have the top flared port epoxied to the internal brace.

[meb46]

Bass internal bracing is now sealed with a layer of Poly and the rear panel has has 3mm Bitumen pads cemented to them and then the internal planes have 30mm acoustic Foam. I will be adding more bitumen pads to the top and bottom, and I am still to decide if I will use these on the side panels.









Obviously these cabinets are gaining weight with the Bitumen...

[meb46]

The Mid/Top Cabinets are a little tricky to put together as I have no right angle planes to clamp and work from. This has been a bit of a trial and error process, but I now have the cabinets assembled, bitumen lined and acoustic egg-shell foam on the internal Mid Driver Enclosure. Even without the Front Baffles, the enclosures sound/feel very rigid. All of the cabinets will get a 3mm MDF skin over them, so will tidy the look up a lot before veneering. I ended up having to use a few screws to hold things together during gluing. Subsequently, these screws have now been removed and the holes plugged.









Re-machined/corrected Front Baffles for all of the cabinets are being delivered this afternoon... maybe some photo's later today...

[JonMarsh]

Looking very good-

I expected the top modules would be tricky because of all the angles, but with the high accuracy fabrication you paid for, I'd expect it to go reasonably smoothly- and it looks like it has. How do the front panels match up? Do you have them yet?

[meb46]

Baffles have finally arrived... after much discussion and rework, I have got the baffles which I had designed and are pretty happy with. there is some minor finishing to do on them, which is more of a case of my assembly accuracy and not the machining. I will also need to seal/poly the inside faces to slow moisture absorption.

[meb46]

Mid/Top Baffles...



And finally... a picture of the full cabinet...



Jon - all the baffles match up and I have just glued the first Bass Baffle to one of the brace structures. Once this has dried I will then seal the internal structures... fun stuff!!!!!!

[madinaudio]

Hello
Very beautiful loudspeaker !!! INCREDIBLE
So, you use in the bass, two Aurasound subwoofers NS12-513-4A . There are 4ohm version with re=2.86ohms !!!! You want to use these drivers in series or in parallel ?

[JonMarsh]

Hey Mike-

It's so cool to see this coming together this slick and as planned- of course, a lot of effort and money on your part went in to getting to this point!



I'm off to Monterey early this morning for a trip long promised and delayed to my girlfriend- next weekend, back to work. It's a sign of how sick I am that I'd be more excited about doing what you're doing, in all likelihood!

Those Aurasounds will be wired in series unless Mike goes active with a brute of an amplifier- I know mine will be.

[baniels]

Time for an update!

[Hdale85]

Looks good, I think I would of went LBL on the baffle and left it raw and either cabinet ply for the rest or just veneer the cabinet and then poly the baffle/cabinet. Would of looked awesome Veneering all that seems like a pain lol, I bet you'll get it though.

[meb46]

Agreed, Raw Ply would have been nice and really emphasized the baffle cuts... alas, this is not to be. I am going to finish these in a Paper Backed Veneer and I am leaning towards a more rough grained style. I have normal Maple, a reconstituted Maple but neither are really taking my fancy for this. On that topic, I am back in the Bay Area next week, and I thought I might take a look at some Veneer Suppliers there to see if anything really lloked nice... and suggestions on suppliers in this area? There are only a few suppliers in Singapore, so keen to see if I can find something in SF/Bay Area.

After travelling for a few weeks and then my wedding last week, I haven't had much time to make any progress... further downside is that I leave this Monday for another 2 week trip so the dust is collecting on the top of the speakers due to lack of activity... and this is the wrong kind of dust, not MDF dust!!!! Hopefully I will get back onto them after I return early May.

[Hdale85]

I think most of us shop online, I'd have to say I would think that you'd be able to find all sorts of veneer MFG's out where you are. Most of that stuff is probably made over seas. I'd go for something pretty exotic on the baffle or sides, then something not so exotic on the opposite. These type of speakers always look nice like that, birds-eye maple, or burl, or something.

[JonMarsh]

You might try the Woodcraft store in Dublin, or the Rockler store in Pleasant Hill.

Unfortunately, I'm leaving for Europe on business this weekend, for two weeks, or I'd show you around myself!

[meb46]

Jon, many thanks for the offer... travel schedules are all a bit hectic at the moment, but makes for interesting times

I'll check out Woodcraft tomorrow some time, but I suspect going by website prices, my Singapore sources are considerably cheaper... just need to find the right style. Most of the maple I have used previously are not light enough for my taste.

I have another issue at the moment whereby my 6mm MDF skin has been glued on, but I have found a few air bubbles between the 25mm MDF wall and the 6mm thick skin. I may have to try and remove two sides of the 6mm skin and replace... not happy! On the upside, I ahve my mids and tweeters on-route to me... FINALLY!!!

More soon...

[JonMarsh]

Jon, many thanks for the offer... travel schedules are all a bit hectic at the moment, but makes for interesting times

On the upside, I ahve my mids and tweeters on-route to me... FINALLY!!!

More soon...

Good news about the mids! I've been in Villach Austria since Monday evening, had a surprising experience making my connection in Vienna for the flight to Klagenfurt- my flight from Frankfurt was late and I didn't think I had a chance at the connection, since the plane was unloading on the tarmac, but a guy in one of these little airport mini vans met me on the Tarmac and drove me directly to the turboprop on the Tarmac going to Klagenfurt. That was a pleasant surprise!

Other work issues since Friday haven't been, though. My boss is pulling his hair over what to do because he realizes he can't have me working 7 days a week for the next two quarters, something which DID happen this time last year and resulted in discussions with HR and the division VP. Oh well.. It will get sorted eventually.

Stay safe in your travels!

[Hdale85]

Did you ever find another person to hire on Jon?

[JonMarsh]

Hello again from Villach,

We did succeed in hiring a new guy on the West Coast, but due to my schedule, I've had very little time free for coaching him. Smart guy from Denmark that's married to a US gal, been working in different areas, including CLASS D amplifiers. He's got a lot of potential, I think- but it doesn't happen overnight.

We also have a newish guy since December on the East Coast, who'll be joining me over here later this week. Another sharp guy, this one piled higher and deeper.

In my second week in Villach, heading back to the US briefly this Friday, then headed back to Vienna the following Monday. Things have been going pretty well here, but as usual, there are unforeseen issues and some delays in accomplishing key tasks. Oh, and I hate using Microsoft Word for writing App notes, especially when it has to go back to the PC version (which is less capable graphics wise- can't use PDF in tables or images).

May 1 here, a so called holiday in Europe, just means I can work in the hotel room instead of going into the office!

[meb46]

Oh the excitment... returned from weeks of travel to a few boxes on my desk... Finally they have arrived...

C30-6-358 CELL Tweeter from Accuton





C173-6-090 Mid/Base from Accuton

[meb46]

For comparative purposes...





I will have a test fit of thesse tonight in the cabinets and get some photos after the weekend of progress. I am still working on the MDF skin and also have just started to get some veneer on the top Cabinets. A long way to go, but the arrival of the Mid/Base and Tweeter Drivers will spur the project on

[JonMarsh]

Cool! You've got the good stuff in house!!

I was looking at these online just the other day while packing.

We're in Vienna now, here a couple more days before taking off for the Czech republic. Don't tell Bev, but I'm missing doing Speaker Camp!

[meb46]

Well... yet another delay on progress... I have another 3 weeks of travel ahread of me so not much progress on the project in the last few days. I have enarly finished the MDF skin on all cabinets and just got a couple of sides of the Mid/High Cabinets covered with some veneer. Have decided to go with a Birds-eye Maple which is starting to look quite good. No more photos yet... but will get these up on my return...