Big Brain Engineering

It was winter of junior year, my two bookshelf speakers needed something to support the low frequencies. Subwoofer time! Again, being an engineer, size, shape and marketing was never a concern. The dayton audio DCS385-4 15" classic subwoofer went down to 19hz. I think I can do better than that. Plugging in values to WinISD gave me a -3db of 17hz! Nice! Time to empty my wallet. 1 week later I got this box: I went and bought a sheet of 4 x 8 1/2" thick MDF, and had home depot cut it for me. Surprisingly, it only took me one sheet. dimensions were 2' x 2' x 3', with an outer volume of 12 cubic feet.  Assembling it was a whole another circus. I used wood wood glue and did the sides. To brace the box without another trip to home depot, i used wooden curtain rods (boy was my mom mad when she found out)   The braces were going to take up lots of vibrations. Chemically, PVA isn't a very strong glue. but when bonded with wood fibers, it is stronger than wood. Thi...

As pretty as JBL's copper domed speakers looked, they all sound sub optimal in my opinion. Either way, I needed a pair of bookshelf speakers. It was junior year of high school and I decided to buy myself a gift, a project. The transducer selection was quite a difficult process, until I saw the prices. I sorted from low to high and filtered by full range speakers on parts express. I settled on the Tymphany TC9FD18-08. Not the optimal for good bass reproduction, but high frequencies were decent, at least in the on axis response. overall nothing a good box can't fix. While I waited for the parts to arrive, I plugged in values into winISD, a speakerbox modeling program. I got a final box size of .494 cf and a rectangular port of 4.7cm by 8.2cm with a length of 42.86 cm. What I realized, was that because I do not have a marketing team, this box will end up being ridiculously huge. after modeling it in Autodesk Inventor, based on the materials I had laying around, I started b...

Man a lot has happened since my last post. Where do I begin? I got admitted into Western Washington University, almost didn’t make the cut for my major, electrical engineering. This year has been going well besides wanting to jump off a 4th floor building for the 10th time. ( survival rate is 50% , not worth) I am dedicating time to revive this blog to not only catalog my projects for myself, but for my future resume portfolio. This is going to take a while, and I am gonna tell it in chronological order, in first person. Happy early thanksgiving!

My home theater setup always lacked a high quality source. Unlike the newer AV receivers from even the cheapest brands, my 15 year old Onkyo tx-ds696 delivers amazing sound and lacks majority of the modern features, such as Spotify, Pandora, or many network connected sources. I tried using the Xbox to stream music from my personal library of FLAC’s. Microsoft’s media player app had a sluggish interface, and required booting up the Android TV every time I wanted to browse for songs. Speaking of browsing, the Xbox seems to be incapable of browsing for music and playing a track at the same time. For this project, I had a couple of requirements: stream music without turning on the TV Be able to browse music Hi-Fi Streaming, supporting FLAC, WAV, etc. Accepting streams from a phone (DLNA, Bluetooth etc.) would be a plus I was browsing the web for a solution, when I came across this lovely platform: https://www.musicpd.org/ The Media Player Daemon (mpd) protocol is cross platform, open sourc...

Ugh I feel old. The original WII is nostalgic, bringing me back to the days with my childhood best friend. Recently just bought a used (in fact my first) WII, and with my addiction with DIY, it is hard not to mess with the software. There are lots of tutorial online, yet most of them have steps missing or are outdated. So, I compiled a tutorial here for my own reference, of start to finish step by step to make the WII run CUSTOM SELF-PROGRAMMED 100% LEGAL ISOs, and this will probably never be patched, as the last update was in 2010. This tutorial will use the Letterbomb method. 1. If you haven’t done so, update your WII to the latest version. I have only tested this with my WII, which is a US model. If you cannot figure out this step, then this tutorial is not for you, and please continue enjoying your WII as it is. 2. Go to https://please.hackmii.com/ , and enter your WII’s WI-FI MAC address. Do the recaptcha and “cut the red wire”. You will get a download. It is important to do the ...

I guess start this blog page with one of my favorite projects right? An easy way to power bookshelf speakers without breaking the bank is with a class D amplifier. The TPA3116D2 is a chip-amp that can pump out 50W+50W, while keeping the distortion at a minimum, 0.1% at half power. On Aliexpress, these boards go for around $5-15, depending on what features you get on them. I got mine for $8.88US with free shipping. Here is what my board looked like: That heatsink does look very small, but with the high efficiency class D amp, a big heatsink is unnecessary. Time to build a box. I found an old usb hard drive enclosure. Drilling the holes for the volume knobs: Fitting on some speaker terminals: Used a bolt sliced partway through for the single channel 100W: To improve on power supply filtering, I will have two of these sticking out of the amp, 54,000uf imported from japan: To mount the capacitors, I had to make a pcb. Using pcb creator, I printed out these traces onto toner transfer paper ...