School project exhibition tomorrow

Tomorrow is the day when all third year high school students will show off their projects at an exhibition in the city centre. I will bring most of my stuff with me there. Speakers, amplifier, cables, computer, two monitors, camera and some other stuff, like a subwoofer driver, 41Hz amplifier board and so on. I have already started packing some of the small stuff, but I'll do the rest tomorrow morning. Since I don't have my driver's license yet and my parents are not home I will have a friend help me drive all the the stuff downtown. I'm really excited, I hope it will be a good day. I have made a playlist with lots of different songs and I have made picture slideshows of my DIY work (kind of all pictures that are here on the blog).

I was planning to start writing part #1 of the step-by-step construction guide today but unfortunately I ran out of time. But here's a sneak peek ;)

As a little side note. I will be building two more amplifiers in the coming weeks. One is already sold and I'm hoping to sell the other as soon as possible too. If you're in Sweden and you want a O2+Odac combo, don't hesitate to send me a message!

Mud, water and bolts.

I was in the city today. I brought my bike with me on the train to be able to travel faster when searching for M6 insex bolts and M6 t-nuts. I started with biking 4km to a shop I thought had what I needed. They didn't have any. The told me to go to another place. So I did, I biked another 1.5km to the next place. They didn't have any either and told me to go to a third place about 500m away. They had the insex bolts so I bought 16 of them for 17SEK, good price!

They didn't have any t-nuts though, so I asked them if they knew any place that had. They told me to go to place #4 about 2km away. I went to that place and they only had four left. But they told me about a fifth place about 5km away that definitely had M6 t-nuts. Problem was I had to go to the dentist so I didn't have time to go there. I had to head home with only the bolts, no t-nuts. My bike was dirty like never before, so was my shoes, my jeans, my jacket and backpack. This is a bad time of the year for biking in the city!

But to brighten up my day I just ordered some stuff from Thomann.

Speakon connectors for the speaker cables. 2x4mm speaker cables, damping material, connector cable between the amplifiers, the sub amplifier itself and finally some t-nuts. I'm hoping it will arrive before the weekend. It is shipped from Germany but if I remember correctly it's pretty fast anyways.

Delayed step-by-step construction guide

Unfortunately the step-by-step construction guide for the O2 amplifier will be delayed  a bit. I have been very busy this weekend and I doubt I'll have enough time during the coming week. We'll see, I might divide it up into several smaller pieces maybe...

Making progress!

I'm making steady progress. Today was a perfect day for working outside. -5c and sunny, so I only had to put on a jacket and some slippers and head outside.

I started by removing the old drivers and the glassfiberwool insulation I had used as damping material. Blow it all clean with compressed air to avoid getting in contact with glassfiberwool dust.

New vs old driver

Big difference in size and quality, and of course in weight!

Next step was to measure the old driver holes. They seemed to be 23cm diameter and I needed 28cm diameter for the LAB12. Funny enough the internal width of the cabinet is exactly 28cm too. It took me a while to get both holes done. I didn't want to make the holes too big but I didn't want it to go too slow either.  After about an hour both holes was done and I went indoors to warm my hands and feet. I mean, I had been outdoors for more than an hour wearing no gloves and only slippers on my feet.

While I was warming myself I decided to seal the rest of the inside. I couldn't find the silicone I had used before so I just used normal wood glue and smeared it on the insides like this.

White glue and grey/black silicone

When that was done I headed out again to cut pieces for bracing. I can't do any fancy bracing since I can't remove any of the sides. So I decided to do like this...

The bottom picture only shows one side done. I'll do the other side when the glue has dried for an hour or two. I'm also wondering if I should try to add a brace going from one side panel to the other, which in this picture would mean from top to bottom. I think it would be able to do that since the driver hole is so big. I'm also thinking of adding a triangular brace between bottom panel and baffle below the driver cutout, which is this picture would mean on the left wall to the baffle. Maybe I'll do the same in the opposite corner (back panel and top panel).

The subwoofers arrived today

So today the drivers arrived. I got a text message while at school that said that I could pick them up as soon as I wanted to. My parents aren't home so I needed somebody to give me a ride. Thankfully a friend offered some help.

When opening the package I realised they were a bit bigger than I had expected them to be, that's good. And they were also a lot heavier and sturdier than I had thought. The basket feels rock solid and like very high quality.

Size comparison vs my LG Nexus 4 with bumper case on

I will start on the cabinets tomorrow. The plan is to use the old hole, just make it a bit bigger. I did some measuring yesterday and the LAB12 should fit on the baffle. We'll see though.

The subs might be ready earlier than expected

My dad came with the brilliant idea today. He said why not use my old subwoofer boxes to put the LAB12 in? My old boxes are ~40-45l internal volume and the LAB12 should fit on the side. The original baffle is too small though so I'll have to cut a new piece of particle to board and glue it on the old baffle to cover up the old driver hole. I'll also add some bracing when I have two big holes to work through.
This should mean that I can have them ready to be played in only a few days after I have picked up the subs.

Sent from Gothenburg 10:12 AM today.

Such a shame I don't have a second powerful amplifier to run them on next Wednesday when it's the school project work exhibition. Might bring them anyways and use my dad's old Yamaha amplifier and just run them a little easy. We'll see.

#3 finished

I have finished the combo and I'm actually listening to it right now. No guide and no pictures yet, I don't have the time to finish that tonight. I guess I'll do it on Friday evening or during the weekend. I'll send the amp to the customer on Friday but I'll make sure to take enough pictures before that.

Old picture of my amp (on the top) and #2 underneath.

Another O2+Odac combo coming, with step-by-step construction guide

Short post, should go to bed ASAP.

Picked up a package today containing an O2+Odac combo which I am building for a guy. I will take the opportunity to make a step-by-step construction guide to show you how simple it is to build. More about that tomorrow evening when I have started building.

Old picture of my O2+Odac combo

The subs have been shipped

For those of you who don't know Swedish, this means that the package has been sent and is on its way north to where I live. Ragnar (the guy who sold the subs) also upgraded the shipping to priority shipping. What that means I don't know but I guess it's good to have.

Eminence LAB12 subwoofers coming!

Today I just bought a pair of subwoofers from a guy at a Swedish forum www.minhembio.com
The price was 1820SEK for a pair including shipping and insurance. He will post them tomorrow so I should have them on Wednesday or Thursday I guess.

The plan is to put them in small sealed boxes, about 30 litres net volume. Power them with a Behringer iNuke NU6000DSP and use EQ to boost the bottom. I have contacted Ingvar about the boxes and hopefully he can cut all the panels for me, it depends on how much it would cost though.

I will use Neutrik speakon contacts. Between my HK amp and the Behringer I will use RCA in one end and XLR in the other (I think that works).

This is the planned order from Thomann, so far. NC3 MMX-B is the XLR connector. NYS 373-0 is the RCA connector. NL2 FC is speakon. XXR is just color coding rings for the XLR connectors. NL2 MP D-TYP is the speakon connector panel. I also chose to order a B-Stock amplifier, it's €33 cheaper so why not? Cordial CDS122 is the RCA/XLR cable, 0.5m per cable should be enough. CLS240 is the speaker cable, 2x4mm, but I'm not sure if I need it since I have some spare cables from my HAD Oy build. And finally some damping material. The specs said it was enough for 20 litres so four packets should be fine.