DIY Speaker Build - Troels Gravesen's Poor Man's Stradivari

Thanks Graeme I thought it was all coming to an end too quickly.
I will be tuning in for future episodes :+1:

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Aaaaaand finally, we’re back to the cabinets…

First edge sanded down:

My apprentice keeping a watchful eye as ever:

The plywood piece has locating pins to ensure alignment with the aluminium after carbon skinning. Cabinet and end pieces with be skinned separately then glued together with the aluminium sandwich. The aluminium will then be embedded in the intermediate resin coats:

Sanding is much faster now - grabbed some 40 grit Abranet HD sanding discs. Gloves are essential when working with these. The edges are lethal:

Gratuitous inclusion of this afternoon’s ā€œlubricantā€ especially for @Gadnoz_Seek. Cheers Kees!

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Great post again Graeme! And Stan watchful as ever!
I reply with a Dutch haze from Kompaan in the Hague:

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Great project, excellent work! :+1:

Very entertaining to follow. :beers:
First topic I put on ā€œwatchingā€.
Don’t want to miss any updates. :smile:

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I am so in awe of this build. I look forward to watching and drolling over the completed project.

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Thanks. I’m having a ā€œdecompressionā€ week off work next week to preserve my sanity. My boss is having this week off! Should be able to make some serious progress over the 9 days I’m not at work :slightly_smiling_face:

I just have to survive tomorrow now…

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Good luck tomorrow. I have every other Friday off with my compressed schedule. New pup arrives Saturday so tomorrow is committed to getting ready.

Thanks. SWMBO is properly putting her foot down at the moment. Pushing me to either drop to a 4-day week or just quit altogether and wait for my pension in 22 months’ time…

Good luck with Angus! I don’t think I asked which breed Ferg is, but he looks like a Collie? If you’re used to herding breeds, a GSD pup will be pretty easy to integrate into your home/family.

When Katy was adamant that she wanted a Border Collie, I thought she was mad. They can be a challenging breed and lots of them end up in rescue centres. Having done our best to start, and continue our journey as a good ā€œparentsā€, Stan has turned out to be the most awesomely quirky, cheeky, adoreable and affectionate pooch. He’s also a handsome little b’stard and exploits that to the max, especially with young ladies (of the 2, rather than the 4-legged kind). He’s only 3, but when his time comes, he’ll rip our hearts out. Never in my life have I loved a dog so much as I love him.

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Well I must admit that we are both lucky. The wife is a college professor/dept head after many years in research, so she is off all summer.

Fergus actually (according to the dna profile) is mostly husky with some Great Pyrenees to give him the drop ears. We were amazed there was no Collie. As stubborn as this guy is, I look forward to a real working dog.

I hope the upcoming week brings us as many photographs of your build as i am sure there will be over on the critter thead.

No idea what they are, but I must have some redeeming qualities - my wife is 13 years my junior, has been at director level for the last 6 years and no matter how badly my life is car-crashing, she sticks by me.

Well, I’ll be darned! I had him pegged as a Collie/Aussie sheepdog based on his looks.

Herding breeds are a peculiar bunch - intelligent, stubborn, with an overwhelming desire to please, acutely sensitive to their environment, emotionally astute, in need of a degree of physical exercise, but more importantly, in need of a great deal of mental exercise. After 45 minutes in a training class, Stan is as wrecked as he would be on a 4 hour walk. As Barbara Sykes (one of the foremost experts on Border Collies in the UK and owner/operator of a large BC rescue centre) said - if you only focus on physical exercise, you’ll end up with a badly behaved athelete! Discipline has to be administered with a very gentle hand. A change in voice tone, or even a look is sufficient chastisement for less than desireable behaviour. If Katy and I raise our voices at each other, not even in disagreement, but just in animated conversation, Stan runs and hides.

A family member has a GSD with pretty significant behaiour issues. Sadly, the root cause lies with the owners, not the dog…

I’m sure you’ll have done your research. A GSD isn’t an ā€˜easy’ dog to have as a pet, but with a little effort, he can be one of the most rewarding and faithful companions you could ever ask for. The GSD is the working dog of choice for all of the UK police forces. Intelligent, loyal, brave, and fiercely protective of his handler.

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I have done my research and fortunately have a good foundation to start. He is well socialized with both people and other dogs.

I have some professional training lined up as well as everything I will do, just to be sure.

And sorry to derail your build thread. I am looking forward to the coming days work.

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No apology needed. It’s my build thread and I’m a dog lover. So are many of the others hereabouts. Gratuitous photos of my canine ā€œapprenticeā€ pepper my posts A little digression here and there around our four-legged companions is fine by me :slightly_smiling_face:

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It’s been a few days of what seems interminably hard graft yet little apparent progress…

More sanding for the last cabinet end piece. Each piece gets through 2 x 40 grit Mirka Abranet HD sanding pads just to rough out the profile:

The sander is pretty much dustless on flat surfaces, but on curves, it does throw out a bit of debris, especially with aggressive grits, so I don my trusty powered respirator. Bought this a couple of years ago and it gets used extensively. Rechargeable battery on the back, has replaceable carrtridge filters and disposable visor films.

Using plywood for the end pieces has the added bonus of the layers providing a nice contour map to ensure an even curve along the length.

Achieving a seamless blend between the main cabinet, the aluminium fillet and the end cap is a laborious and time-consuming process. 40, 80 and 120 grit, filing of the aluminium and hand sanding the plywood at the ends where the sander can’t reach. Even with a belt sander to rip the excess aluminium back to speed up the process, it was still nearly four hours per edge, ~16 hours for both cabinets.

Starting to resemble a speaker cabinet now:

3.2 mm locating pins (short lengths of spare welding Tungsten) glued into the baffle ready for my Jasper circle jig to cut out the holes for the drive units.

I’m taking a slightly different approach to the cabinets than I did for the xover enclosures. There were a few imperfections due to base layer bleed through and inadequate coverage with the black base coat resin.

This time, I’m going all out. Black water-based dye coat first:

Next, I’m applying the black base coat, but allowing it to fully cure, followed by keying with 120 grit abrasive:

Cleaned up, ready for a clear ā€œbasecoatā€ to adhere the carbon fibre skin:

This way if there’s any bleed through, it’ll be clear resin and invisible once the wetting out and build coats are applied.

There was a little movement at the edges of the base panels, despite being glued on with polyurethane adhesive, so I’ve added additional stainless screws to tighten everything up:

Drilling stainless and countersinking the holes is easy with a drill press or a suitably anchored mag drill. Drilling it by hand is a whole different ballgame - exerting enough downward pressure on the bit to get it to bite into the stainless is nigh on impossible. Took me 2 hours to drill and countersink 4 holes. :hot_face:

For the second one, I’m breaking out the magdrill! I have a couple of long ratchet straps in the car for the roof bars which should be long enough to tie it down.

First piece of carbon fibre for the rear of the first cabinet cut, edges bonded ready for final trimming and cutout to fit around the router pin for the midrange port:

I’ll finally be sticking on some carbon fibre tomorrow! :smiley:

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great choice of beer mate!! All dogs are brewed equally good!!

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When they’re finally finished and ready to listen to, I’ll be cracking open a super nice beer with maybe a fine dram on the side.

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that choice needs a separate thread here: ā€œbreaking in beer choice for DIY speakersā€

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And once I’ve tidied it up, I’ll post up a few pics of my man-cave.

If we ever move house again, I’d like a place with a much bigger garden which is close enough to the road for crane access. I’d love to splice together a couple of used 8’ X 40’ corten shipping containers to make a proper workshop and tuck it out of sight behind a row of conifers or a hedge to satisfy SWMBO’s aesthetic requirements!

I’m only a couple of years from retirement and my colleagues insist that I can’t retire on the grounds that I’ll be bored. Little do they know…:rofl:

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HAHA, we’re all more or less the same here; retirement is 1 year away for me, everybody is telling me that’s a no go, but the wife and I have it all planned! The attic room is ready for modeling and all rooms in the house are equipped with Roon endpoints, amps and speakers! Let the good times commence!!

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Aaaaaand finally…

The first pieces of carbon fibre are in place. That was half an hour of intense pressure. Have a very dry mouth from the anxiety of worrying about it all going pear shaped… Need a :beer: now!

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I’m enjoying following this very much. I’ve done some woodworking projects, nothing fancy though. In my experience (sounds like you may agree) it seems that regardless of how much thinking and planning you apply prior to battle, there is always a certain amount of improvisation required!

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