Do You Believe in the Crazy Train?

Greetings friends,

I tried my hand at a music mash-up between Crazy Train by Ozzy Ozbourne and Do You Believe in Love? by Huey Lewis and the News. I've had this in my mind for a while and always thought the two songs would make a decent mash-up. I'm happy with how it all came together, though my least favorite part is the bridge section from DYBiL, but it's fine enough I think. I hope you enjoy it, and I'd love to hear feedback if anyone has comments!

Thanks,

Juju

Leather Music Folder

Greetings friends,

Ever struggling with finding a music folder that will accommodate large sheet music, I decided to take matters into my own hands. Having dabbled a bit in leathercrafting previously, I decided this would be a fun project to practice dyeing leather, and to construct a durable folder that will last for years!

I started with a large piece of heavyweight veg-tanned leather, and cut the pieces from it that I needed. I opted for a folder with dimensions of 12" x 15", small enough to not be cumbersome but big enough to protect large sheet music. I wanted 2 simple flaps inside the folder to tuck the music into, as well as a small pocket to hold a pencil.

For the dyeing process, I used Eco-Flo Waterstain in Bordeaux color. This stain was easy to use and wiped on with a sponge. I moistened the leather beforehand which helped the dye dry more slowly, so it was easier to achieve a consistent color. The hardest part of dyeing such large pieces of leather is achieving a consistent color, and I'm pleased with the job I did.

Punching the holes and stitching the pieces together was uneventful and very straightforward. I scored the interior of the folder down the middle, to assist in making the main fold. A little bit of water along the crease helped a bit. After all the stitching was done, I followed the usual progression of sanding the edges, dyeing them dark, sealing them with gum tragacanth, and burnishing them.

I fashioned a pencil holder out of a leftover scrap of leather, and stitched it to the inside of the folder. The pencil fits in a little bit tight, but it's better than falling out too easily.

After an amount of use, I decided that I wanted some way to keep the folder closed when carrying it, so I opted to add a snap to the open corner. This holds everything together really well and opens very easily. The folder has been really awesome to use, and I have yet to run into any large sheet music that won't fit in it!

Thanks for reading,

Juju

1930s Electronic Metronome Restoration

Greetings friends,

Recently, I lucked out and received a very cool vintage metronome from someone in my local "Buy-Nothing" group. As some of you know, music is a big part of my life and I was very excited about this find and at the prospect of restoring it to fully-functioning condition.

Let's start with a little bit of history on this device, since it has some cool design features and is one of the first electronic metronomes to hit the market. The Franz electromechanic metronome was invented in 1938, and saw production through 1994. The mechanism by which the metronome operates is very interesting in that it uses a synchronous motor to spin a wheel which drives a shaft containing a ledged cam lobe (not sure what else to call it?), which on each rotation strikes a spring-loaded hammer onto the interior wall of the metronome box. Changing the angle of the wheel with respect to the motor spindle by way of the external dial ("selecting the tempo") changes the frequency of the hammer strikes.

The metronome I received was in fairly good condition, but with a fair amount of dirt on the exterior. The mechanism worked well at higher tempi (80+ bpm) but was very irregular at slower tempi. The bottom plate, seen above, is in good enough condition that I won't be altering anything about it during this restoration. I'm happy that the label is legible, so I won't try risking any damage to it by trying to clean it. I'll just have to live with the small amount of rust.

To start the restoration, I disassembled the entire mechanism and right away cut the old power cord which was very brittle and starting to crack in some places. I bought a cheap 8-foot extension cord to re-purpose as the power cord for the metronome. The socket is interestingly designed, and it's plenty obvious how the cord connects. The other end gets soldered to the switch and motor, which we'll see later. 

To clean the exterior, I started off with simple dishsoap and warm water, and used an old toothbrush to get into the dirty crevices. Since the white lettering was oxidized and already chipping out a bit, I decided to just scrub until all the letters were cleaned out. With all the dirt removed the appearance of the case was already hugely improved, but I decided to polish a little bit using rubbing compound just to give it a little bit of shine.

The mechanism itself was quite clean and didn't require a whole lot of manipulation, though I did need to make some adjustments to make the slow tempi more consistent. I noticed that at the lower settings the wheel that operates the hammer was not making full contact with the motor spindle. To fix this I simply cut some pieces of thin leather to act as shims, which lowered the height of the motor and allowed the hammer wheel to make full contact across the full tempo range.

I used a lacquer-stik to fill in the numbers on the face on the metronome as well as the "ELECTRONOME" lettering underneath the dial (although these didn't seem to be filled when I received it). The metal indicator on the dial was polished using Brasso, and the reassembly went without a hitch.

Fully functional again, the metronome has a permanent place on my piano. I use it occasionally, especially when showing off to guests. After 80 years of use, it's great to see some new life in this metronome!

Thanks for reading,

Juju

References:

1. http://www.franzmfg.com/history.htm

Home Theatre Subwoofer Build

Greetings friends,

Another little bit of a learning project here. I've been thinking about improving the sound quality for my home "theatre", and a logical step was to get a subwoofer. Unfortunately, any sub of decent quality or with the frequency response I want will cost at least a few kilobucks, so I decided "why not just make one myself?" Well here we go!

As always, I started by scouring the internet for ideas. What shape should it be? How big does it need to be? What drivers produce the right frequencies for a sub? After reading and weighing to pros and cons of various designs, I settled on the SonoSub design. It essentially consists of a simple cylinder into which a driver and vent tube are installed, and blam-o, you've got a sub (at least in principle). Let's dissect the process!

Lucky for me, I got to stand on the shoulders of those who have done this before. Two pieces of software exist to help in designing the sub, SonoSub and WinISD. WinISD allows me to enter the specifications of the driver I select and will calculate the theoretical frequency response for a subwoofer under certain conditions. SonoSub allows me to enter the parameters from WinISD and calculate the dimensions for the actual subwoofer housing.

I decided to get a 12" driver, which seemed a good size without getting ridiculous. This would also fit nicely into an 18" tube, which became one of the independent variables in the calculations. Information for the driver I decided to purchase can be found here. I entered the specs of the driver into WinISD and started playing with the performance specs I wanted from the sub. As a collector of classical music, I have several recordings that play frequencies below 20 Hz, so at the very least I wanted frequency response a few Hz below that. Given the capabilities of the driver, an 18 Hz tuning frequency with a tube volume of roughly 190 litres have me a frequency response I was happy with.

Assuming an amplifier with a low-pass filter, the size and tuned 

vent gave a really nice frequency response.

I entered the parameters from WinISD into the SonoSub software, and played with the numbers until I had an arrangement that I liked. I wanted to keep the dimensions easy to work with, so I decided that a 48" tube length (excluding caps) would be simple.

I started off by buying the 4-foot section of 18" SonoTube - they're cardboard molds used to pour concrete columns. Since it has a lot of rigidity and comes in large diameters, it's perfectly designed to be the casing for a sub. Luckily, the supplier cut the tube to length for me so I didn't need to fuss with trying to make perpendicular cuts on a ridiculously big tube.

To line the tube to provide some sound dampening, I got some 11 mm thick carpet padding from Home Depot, and used spray adhesive to line the inside of the tube. Because caps will go into the ends of the tube eventually, I cut the padding slightly short so the tube can accommodate the caps. Peeking my head inside and singing some low tones showed that the dampening was quite effective.

Onward to cutting the caps, into one of which the driver will be mounted, and into the other the tuning port. I foolishly first tried to cut circles freehand with my router, but was quite unhappy with the result. Simply put, a lot of extra sanding a shaping would have been required, an amount of effort I was looking to avoid. I then fashioned a very simple circle jig using a yard stick. Bolting one end onto the router and using a centered screw as my pivot point, this surprisingly made ridiculously easy work out of cutting circles. Though I unfortunately wasted 2 MDF boards in my freehand attempt and had to get replacements, in the end the simple jig was very worthwhile.

Both caps consisted of two rounds cut out of MDF, the outer round having a diameter of 19" and the inner 18". I cut appropriately-sized holes to accommodate the driver and the 4" port, and rounded over all edges to give it a pleasant look. I glued the pieces together and applied a few coats of shellac to seal the MDF. Below you'll see the cap for the port and the driver sitting in its cap.

The driver nestled neatly into the (bottom) cap and is held in place with 8 screws. Binding posts needed to be installed on the outside to connect speaker wire to the driver within the subwoofer, so I drilled additional holes for these. I didn't bother to make the holes inside look perfect, as they'd never be seen when all is said and done.

The posts were very easy to install, and are tightened into place with a few nuts. From the outside they're quite innocuous and will accommodate either speaker wire or banana plugs. A short length of speaker wire made the interior connection clean and easy!

I pushed the 4" ABS pipe into the port hole on the top cap, and set both caps onto the tube to give it a try... Currently the caps are just pushed in and not glued into place yet, since the exterior of the tube is not yet in its final state.

Wow, this thing really packs a punch. It's almost unbelievable how much sound this can produce for what it cost to build. The sound completely fills the room, and the low frequencies are incredibly rich! An incredibly successful project to say the least! Unfortunately no recording I could post here would do the sound justice, so you'll just have to come hear it for yourselves!

As far as aesthetics, the caps will ultimately be painted and the tube will be covered either with carpet or some other soft dampening material so that the sub will be more inconspicuous. When weather permits, I'll spray paint the caps outside and I'll update this post with some new pictures showing the final look. For now, I'm going to sit back and enjoy it!

UPDATE - 2020.40.15

I finally decided it's time to dress this sub, and my wife had some time to give me a hand with the sewing! Here's how I did it.

I bought a regular moving blanket/pad, that people usually use to protect furniture when moving. Blue on one side, black on the other. We'll be going with black!

To start, we sewed and cut the blanket to rough dimensions to see what we're working with. Another quick stich makes a tube out of the blanket and we're very close to a perfect fit. It only took a few more tweaks to have a decently tight fit, and the overhanging fabric will be tucked into the tube by the caps.

The caps were pretty difficult to press into place. Ultimately I had to take some clamps and gradually tighten while the caps slid into place. At least it won't be coming apart anytime soon!

It looks great, sounds great, and we'll be enjoying it for a long while! The caps will stay light-colored; I think it looks pretty nice!

Thanks for reading,

Juju