Monday, 31 December 2012

Happy new year, and glueing!

Right now I'm glueing braces in both speakers. Both speakers are almost done with the damping material, the left one has a bit left by the port and the baffle. I will do the tomorrow when the braces have dried.

Then I will carry #2 outside for drilling and sanding. Then I will screw in the filters and hope that the back panel fits without problems. If it does I will glue both sides tomorrow and have them up and running in the evening or on wednesday.

The smell of burnt rubber...

I've been working about as much today as I did yesterday, maybe even more time-wise.

First thing I did in the morning was to glue the baffle.

Then I went outdoors to the garage and started with the damping materials. I didn't take any pictures since my father and brother were out there sanding some stuff so it was a bit dusty. But I cut all the pieces for speaker number one and fastened most of it. For speaker number two I still have to cut the pieces that shall be on top of the port pieces.

When I was done with the damping material the baffle had gotten a few hours to dry so I started glueing the bottom.

Then it was time to solder the filters, which proved to be a bit harder than I thought.

Using my own equipment this time and not Daniel's

I started with stripping and tinning the cables, thinking it was a great idea. It was great, until it was time to solder them to the filter. I managed to get two of the - cables on before I realised that it wasn't possible. The big 4mm cables were too thick to be soldered easily. So then dad came up with the idea that I could use cable shoe rings and a bolt instead and just solder the bolt to the filter, and so I did. But now the cables were all tinned to getting the cables shoes on the cables was a bit hard and I had to solder them as well. I guess I spent probably two hours or so soldering the filters.

When I was done with the filters the bottom panel had gotten a few hours to dry so it was time to glue the port.

I used less glue this time so aligning it right was much easier than before.

And some time during the day, can't remember when exactly, I tried mounting all the drivers in speaker number one to assure that all t-nuts were straight enough and most of them were. The ones that needed to be fixed got fixed. It was then I realised I had forgotten to drill the holes in the tweeters. Me and dad went out to the workshop, dried some different drills and found that 4.5mm would be fine. Drilled all six holes and I was really nervous but dad showed no signs even though he was drilling.

Holes are now ~4.5mm instead of ~3.5mm so now the M4 bolts fit through
And for those of you wondering about the title of this post, my mom complained several times that it smelled of burnt rubber in the house. It's because I had used lots of head when soldering so the insulation on the cables had melted a bit at some places. "Luckily" I have anosmia and can't feel the smell at all so I wasn't bothered by it.

Sunday, 30 December 2012

Last update for this very productive day

I have done a lot of stuff since this morning. The first thing I did was to use a very sharp carpet knife to carefully cut loose the birchply piece from the oak spacer bit.

I will try to glue it back and then fill with some bondo or something, sand it down and see how it looks like. If it's not good I might try an inlay. If that isn't good either I might just paint the boxes.

While I was in the little workshop I pre-drilled holes in the port pieces and glued and screwed them together like this.

I also drilled holes in the filters to prepare for screwing them to the back panel. I want the filters removable so I wont glue them.

I noticed that the big condensators were a bit loose and could rattle so I used some superglue and glued them to the boards like this.

Then before going to the gym I glued the bottom panel for speaker number one.

When I came home from the gym I started again with glueing the back panel of speaker number two.

And while I was waiting for dinner I made cables from the terminal to filter and then from filter to upper woofer, to both speakers.

I have not stripped the inner insulation from the other ends yet. I will do that when I am soldering them to the filter (maybe tomorrow or on wednesday).

Then I carried speaker number one outdoors into the garage. Found a nice workbench of suitable height there to place the speaker on. There I sanded the edges on the side where glue had come up, so the side panel fits nicely when it is time to glue it. I also drilled holes for the terminal plate screws and for the filter screws.

And a couple of hours ago I started glueing the top panel for speaker number two. I will let this be for the night and then glue baffle and bottom panel early in the day. In the evening I will glue ports for both speakers and start with the damping material.

I wasn't done for today it seemed. Dad thought I should glue the port for speaker number one and so I did.

It was a bit tricky to make it stay in place but after a while I got it to 50mm +- 1mm which shouldn't matter very much I think since I will stuff the port anyways.

Tomorrow the main goal is to glue baffle and bottom to speaker number two. Then add damping material to all panels that shall have it. Cut out for braces and filter and glue the braces. Then drill holes for terminal plate screws for speaker number two, sand joints and drill holes for filter screws.

After that, all that remains is solder all the cables to the filter, mount the filter and then glue the remaining side panel (hoping that it fits because I know not all angles are 90 degrees).

A minor disaster!

So this morning, I was still in bed, my dad started to remove the clamps from the speakers. Some of the spacer bits we've used to avoid damaging the panels had gotten stuck. Apparently some glue had found its way between spacer and baffle and so the spacer had been effectively glued to the baffle. Glue is very strong so he used a hammer to knock it off. This particular bit was of oak and as you all know oak is very hard, harder than birchply, so the birchply gave way and it ended up like this.

A big disappointment of course. It's on the baffle, close to the edge (which could be both good or bad) and far down (which is also good and bad).

But I decided to try to remove the bit that had stuck to the oak. I used a very sharp carpet knife and carefully cut it off. Starting in one end going towards the middle and then turning it around and starting at the other end and going towards the middle.

So I guess I will make an attempt to glue it back into the hole and then use some bondo or something and see how it ends up like.

10000+ pageviews!

This blog has now been visited over 10000 times, since I started it back in april. A very nice milestone and I hope to achieve 20000 pageviews in not too long.

A little cabin I photographed last thursday when I was snowmobiling up on the mountains in Vemdalen

Day two of glueing the Oy

Today I continued glueing the speakers. I started with glueing the top panel.

Lots of speaker cabinets in one picture!

Somehow the top panel is ~1mm too thick at some places. No biggie since I am thinking of chamfering  all edges like Ingvar has done.
For this it was easier to have the speaker standing, so I could add weights on top. I still have the whole box "assembled" except for the side panel to make it easier getting all the angles correct. This has one drawback though, because the glue also has contact with the panels that are not being glued at the moment. So when I was going to glue the baffle today some glue from the top panel had gone to the baffle so I had to use a hammer to get the baffle loose. This lead to some wood splintering on the inside of the baffles, no big deal though since it wont be visible anyways.

And in the evening when the glue has gotten some hours to dry it was time to glue the baffles.

Using all available clamps but I could still use a few more. Might be I'll raid my neighbour's garage and see if he has any. The glueing of the baffle went smoother than the back panel because I can put clamps in the driver cutouts as well.

Tomorrow I will not spend the whole day in front of the computer playing Dota 2 as I have done today. Tomorrow I will glue the bottom panel early in the morning. Then I will screw and glue the two port pieces together, for both speakers. I will mark and maybe drill holes for the terminal backplate. I will pre-drill holes in the filter boards and backside of the speaker so I can screw the filter boards instead of glueing. I want to be able to remove them if needed so glueing is not an option. Then I will make a new pair of cables for the top woofer and then a pair of cables from terminals to filter and put a ring connector on the terminal end. If I have time I will also solder all cables to the filters. A lot of work, and it will take many many hours but hopefully I shall have time to go to the gym at some time during the day.

Saturday, 29 December 2012

Glueing the very first piece of the Oy speakers

Today it was time to start on the Oy speakers, for real. I started with clearing my working table and then getting all the needed parts for one speaker and quickly taping it up to see how everything would fit. After a couple of minutes of discussing with dad what would be the best way to glue them we start working. Get clamps, all the clamps we have, and place the speaker on three of them. Add glue, a little of pressure from the sides and then adjust the back panel sidewise  before adding the weights on top. I used the old baffles for the Mar-Kel70 speakers to put the weights on. In the end it looked like this.

I pretty much used all the heavy objects I could possibly find. At first I put the weights on the sides but there was a little gap in the middle so I decided to move it all to there instead.

As you can see in the first and last pictures the gap is by the middle clamp, and it's quite small, about a millimeter or less. On the sides it's all fine, as you can see in the middle picture. I guess I will just add some more glue later and then sand it down, just to fill the hole. It is 100% sealed though, because the glue filled up nicely all the way on the inside. And if I want I could seal the entire cabinet from the inside later if I want to, but I guess there will be no need for that.

Friday, 21 December 2012

Google+ diyaudio group

For the few of you who have Google+ there is a diyaudio group here ->

Thursday, 20 December 2012

The end of the journey

I have now come to the end of the journey. I came home from school just after lunch today so I decided to start immediately with finishing the speakers. I grabbed my new Koss Porta Pro headphones and connected them to my phone so I could have some music in my ears when working, because I knew it would take some time.

Two hours later both cabinets were sanded nicely. I started with a 40's paper to get all surfaces level with eachother. Then I used a 180's paper to do the fine sanding of all joints and panels. It was a very dusty enviroment so I didn't bring my camera and I used a mask over my mouth and nose. I used compressed air to blow away most of the dust.

Old vs new cabinet

Time for a food and toilet break before continuing. Now it was time to solder cables to the terminals.

It was a bit tricky and I had to use gloves quite often because it was too hot to hold. But in the end it turned out nice.

I decided to put some solder between the flat thing and the nut, becase they were a bit loose and it felt wrong leaving them loose. A bit of solder worked well for holding it in place.

Mounting time. I could have drilled the holes a bit larger, I hade to use a fair amount of force for the screws.

When the terminals were mounted it was time to make sure the driver had contact with the brace. It did, and I didn't have to use any of the round things that Ingvar supplied.
I have no idea what it is, Ingvar just said "don't eat them".

When I had made sure that the drivers fit nice to the brace it was time to solder cables to the drivers. It was a bit tricky and gloves were needed but after a while I made it.

Time to mount the drivers. Again, the holes could have been bigger because I had to use A LOT of force for the screws. But I let it take its time, I didn't want to mess up now and destroy the drivers. Each screw took about a minute and my hands were sore afterwards. As I finished one speaker I hooked it up playing with the old Zachry speakers I've been using lately. Woah, what a difference in sound quality! But there was no time for listening to that, it was time to finish the other speaker and get both up and running.

Right channel speaker. The bright spot in the upper right corner is just a reflection from the window or something.
Left channel speaker, photo taken with flash.
I haven't heard the Mar-Kel70 for a while so I have kind of forgotten how the sounded like, and I haven't run them full-range for almost a year I think, maybe even more. But I tried running these full-range and I think there's less bass, as Dave said it would be. But the cabinets vibrate much less and the drivers move a lot less than before as well. It seems like the cabinet dampens the cone movements a bit better.

And last but not least, I'd like to thank some people who made this possible.

  • David Dlugos at Planet10-hifi, for providing drivers, plans, inspiration and lots of help throughout the years.
  • Ingvar Ahlberg at Halland Audio Design and Manovi, for selling me cheap CNC-cut plywood, providing damping material and other cool stuff.
  • "Loj" at Olskogen Trävittra, for doing the 45-degree cuts for me. I would never have been able to do it myself.
  • My dad, for help with glueing, thinking, transport and of course providing me with all the tools I have used.
  • Daniel Nyström who lives further down the street, for letting me borrow his soldering equipment.
  • Several other members of the diyaudio community, you know who you are ;)

Wednesday, 19 December 2012

The end is nigh...

As the title says, the end is nigh. In two ways. We're closing in on december 21st when the world is supposed to end and the Mar-Kel70T journey is coming to an end.

Today me and my dad went to Olskogen Trävittra, far out in the forest. The woodshop is old, very old. On the way they my dad told me that the big wooden glass cabinet we have downstairs has been made there by the father, who is now retired since long ago and the son has taken over. I think they started the business by make furniture, but nowadays everybody buys their furniture at IKEA so now they have specialized in making skis for hunting and such. He's also doing custom jobs every now and then, like making guitars for local bands, cutting speakers for me and so on. This is their facebook page

Now, back to my speakers. When we got there "Loj", as he is called, was a bit busy glueing some skis so me and dad waited for him to finish. It was very interesting seeing such a skilled craftsman doing his work. When he was done I told him how the cut was supposed to be. He said it would be difficult, since he would have to do it a bit free-hand since the sawblade of the BIG table saw machine could only be tilted one way. But he said he could always give it a try. He did a test cut to see if the wood would splinter or not, and it didn't. The cut was as clean as it could possibly be, probably  because of the very high rpm of the saw and I guess he has a really expensive blade as well. He finished the cuts in a few minutes and they all came out very clean. I will have to do some sanding though, because the guide he used was old and a bit loose so the cut wasn't 100% straight (but almost).

"Loj" himself at the tablesaw
When we were done he continued to glue another pair of skis while we were talking about audio stuff. It turned out he was an old audio-geek as well, having built some exponential horns and such in his youth. He said it was very nice to see young people like me being interested in good sound and that most kids nowadays don't even know what good sound is. Very true, and sad indeed. When he had finished glueing another pair of skis and put them in the pressure mould he went on to show us a pair of guitars he was building. I don't know who he was building them for, but I know he's been building guitars for local bands recently. Very interesting indeed! There is something special watching and hearing an expert doing his job, to see the refined skills and art.
The guitars, in an early stage. The wood is from trees grown in the area.

Tomorrow is the last day at school for this year, and it's only a half day so I will try to sand both speakers tomorrow and get them up and running.

One speaker finished, see how clean the cuts are. There's no way I could've done it as good myself.

Saturday, 15 December 2012

Just a quick update

Got clear from the woodshop that I can go there on wednesday to do the 45-degree cuts. Might be I'll be able to use some sanding equipment as well to sand edges, corners and joints.

Friday, 14 December 2012

Glueing the very last piece!

Today I decided to glue the top panel of the second speaker, which means I'm done with all the glueing. Same procedure as before.

The first setup

After a couple of minutes I realised I needed some more pressure in the corners in the front because the blue clamp sucks. Added the two big metal ones and re-arranged the weights on top.

If I find enough time I might add drivers, terminals and cables and get them up and running. I have contacted Olskogen about cutting the 45-degree cuts, hopefully I'll be able to go there on wednesday.