The Xen to One Ratio Build it, buy it, break it, fix it


Speaker Build: Zaph Audio ZDT3.5 Derivatives

One of the reasons I built my CNC router is that I wanted to make speaker enclosures. It took a few years, but I recently completed a very nice set of speakers, based on Zaph’s ZDT3.5s, and thought I’d share the results. The design was fun to build, and they have turned out fantastic! All respects to the designer, Zaph, for the good documentation, and impeccable crossover design.

My one addition to the project was to build a set of chip amps directly into the lower enclosure, making the speakers a bit taller to accomodate the equipment. My modest HT receiver has poor amps, but good pre-outs, which I wanted to take full advantage of.

The amps are built with the 68W dual mono boards from by BrianGT. The idea is that each speaker will have a single channel amplifier with power supply built into the base. The amps were very easy to put together, using the provided parts, and a simple potentiometer, IEC power plug (with fuse) and heatsink from the surplus shop. I went with two 200VA 120/20V toroidal transformers which are recommended for handling a 4 ohm load. The amplifier power was determined by looking at the power handling graphs on Zaph’s project site, comparing them against my desired listening volumes, and the maximum excursion of the drivers. From that simple analysis it seemed like anything in the 50W-100W RMS range would work.

A pair of LM3886s

The cabinets are a modification of the standard cabinet – the baffle is unchanged, but the cabinet pushes out beneath the baffle, giving it a recessed look. I also changed the size of the lower enclosure (not an acoustic enclosure), and made some small internal tweaks. Cabinets were cut on my CNC router (a fantastic tool).

CNC cutting baffles

CNC cutting baffles

The cabinets were assembled and glued (no screws), then after rounding the edges over, I primed and sanded endlessly. The order of events was to sand the enclosure as smooth as possible while still bare MDF (to 220 grit). Then I filled a few areas with Bondo, and sprayed 4 coats of high build urethane primer. After blocking the primer down with 220 (using guide coats to ensure flatness), I filled a few low spots with glazing putty, and shot 3 more coats of primer. After that was sanded flat again, then sanded progressively up to 800 grit, I sprayed the final paint, using 4 coats w/ 5 minute flash time between coats to achieve the color and thickness I wanted.

A discussion about paint, since it comes up a lot in questions… This was my first project using an automotive paint system. Getting into it can be quite the daunting task, but I’m glad I took the time.

I have a 208V 3hp compressor, and an Astro Euro HTE HVLP gun (with 1.3 and 1.9mm nozzles). The biggest issue with HVLP spray guns is the quantity of air they need – not pressure, but volume. 13-15CFM is a minimum for many guns, beyond what most 120V compressors can do. The Astro Euro HTE uses slightly less, and they make a LVLP gun that uses as little as 7CFM called the EVO. Both guns are less than $150 and are well regarded as “cheap but reasonable quality” – a good place to start.

The paint I chose was a high build two-part urethane primer, Finish Line FP411, with standard hardener. The paint was Sherwin Williams 3rd Dimension single stage urethane (as opposed to two stage, meaning base coat and then clear coat), Rouge Sevillian color (originally a Peugeot color, I learned). Single stage urethane paints are still mixed with multiple parts (paint, hardener and reducer), but are less expensive since only one layer is being sprayed. The look is not any worse than base/clear, just different – older cars tend to have single stage paints, newer have base/clear. In my case I wanted the slightly richer color of single stage. If you like a more modern look, or want to use pearls or metallics, look to base/clear. It isn’t any harder to spray, it just takes a little longer. Base/Clear is also more forgiving with runs and sags in the paint, since those can be easily sanded out of the clear, without affecting the color.

Here are a few little things to remember when buying automotive urethanes:
  • Stay in one family of paints for maximum compatibility – most major brands are good quality.
  • Work with a local supply shop that knows their stuff – they can recommend a lot and answer your questions – seriously do not bother with online ordering, at least for your first few rounds.
  • Do not bother with acrylic enamels – they are a bit cheaper, but it is NOT worth it for a project you’ve spent a lot of time on.
  • Single stage urethanes are great for solid colors, but very tricky with metallics – if you want a metallic color, use base/clear.
  • The paint is very toxic – build a spray booth to ventilate to the outdoors, and wear a good 3M respirator with organic vapor cartridges (your paint supplier can sell you one for less than $20). Safety is not black magic – just read up on proper mixing and ventilation, and ask your paint supplier if you have questions.
  • When you pay a lot for paint, make sure your prep work is impeccable. Sand primer to 800 before spraying on top. Any blemishes won’t be hidden by paint, they will be magnified. Read about “guide coats” to help with primer sanding. Use Bondo (or equiv.) for larger blemishes (deeper than a penny), and “glazing putty” for smaller low spots, or pinholes.
  • It is worth it! This was my first urethane paint job, but I’ve painted a lot of things before – this was by far the best finish I’ve ever gotten, and with a little practice, I know I can do even better next time.
Cabinets, bondo'd and primed

Cabinets, bondo'd and primed

Cabinets with final primer coat - back

Cabinets with final primer coat - back

Completed cabinets

Completed cabinets

Completed speakers - rear

Completed speakers - rear

The paint on the baffles was Rustoleum Fine Texture, available at Lowes. It has a finish that is very similar to the finish on the speaker frames, and looks great contrasting with the shiny depth of the paint.

The amplifiers are in the lower case, and work great – the 68W/ch output is well matched to these speakers – they sound good all the way up to full output (which is far louder than I can listen to in the living room).

The speakers themselves are a great design – certainly the best I’ve ever owned, and among the best I’ve ever listened too. A true pleasure!

More photos can be seen in the Flickr Set.


Mexican-style Pickled Veggies

In Austin all the Mexican joints have an addition to their salsa bar that I rarely see elsewhere – pickled sliced vegetables. The blend always includes carrots and jalapenos, and sometimes onion, cauliflower or other firm veggies. They are sour, spicy, and delicious. I’ve pickled many things, but never hit the distinctive flavor of these Mexican pickles.

After reading a number of recipes, I think I’ve got it just about nailed. This will be a standard “fresh pack” pickling recipe – you will need a water bath canner, which is easy to improvise if necessary. If you haven’t done this type of pickling, do a few google searches – there is a LOT written about it. It is very easy, but food safety requires that you understand the basics.


  • Carrots and other veggies, sliced into regular sizes and shapes (carrots on the bias, cauliflower into pieces, jalapenos halved and seeded, etc.)
  • Brine (this is enough for 2-3 quart jars full of veggies, make as much as you need)
    • 1.75 cups White Vinegar
    • 0.25 cups Cider Vinegar
    • 1.5 tsp Salt (pickling salt preferred)
  • Spices for each jar (again, get as much as you need for your batch size)
    • 2 cloves Garlic
    • 1 tsp Paprika
    • 10 Black Peppercorns
    • 3 Bay Leaves (this is the key ingredient for that authentic flavor)
    • 1 tsp Ground Mustard
    • Optional – more spicy in the form of cayenne or similar


Slice and dice your veggies into desired shapes. Traditional seems to be carrots sliced on the bias, jalapenos halved and seeded, cauliflower and onions into “chunks”, but really, it is up to you.

Load the fresh veggies into canning jars – I prefer wide-mouth quart jars. Make sure you have fresh lids (rings can be reused, lids should not).

Get your water bath canner fired up – I like to have it at a low boil before starting my brine so that I can load the jars into the canner as soon as possible after filling with brine.

Bring your brine to a boil. I find I needed one “batch” for each 2-3 jars, but it depends on your veggie density. Add the spices and bay leaves directly to each jar, and then pour the brine over the veggies, filling the jar to 1/2″ from the top. Tap to shake out the bubbles, add a bit more brine if necessary, and then put on a lid and a ring (ring should be finger tight only, just enough to hold it together).

Load the jars into your water bath canner, and return to a boil. Measured from when the canner is boiling again, you should process for 15-20 minutes (USDA has charts based on altitude for fresh-pack pickling process times). After processing, pull the jars out and let them sit on the counter until cool. Once they are cool, remove the rings and let the jars hang out for at least a week in a cool dark place. Then crack them open and enjoy! I like them by themselves, or on tacos, or in burritos. Remember not to eat the bay leaves. Once open they do need to be refrigerated.


Vanilla Bourbon Peach Jam

I received about 6 pounds of peaches from a friend’s trees, and decided to look for something to do with them. You can only gorge on fresh peaches so long!

I tried this recipe, adapted from Blondie’s Cakes and Things, which was in turn adapted from Bean Town Baker. Wacky!

Here are the values I used:

Vanilla Bourbon Peach Jam
  • 6 pounds of peaches, or 5 pounds after peeling and pitting
  • 1 package Pectin for low-sugar recipes
  • 2 cups sugar
  • 1/2 cup honey
  • 4 Tbsp lemon juice
  • 2 vanilla beans – split with the tasty gunk scraped out of the inside – reserve the shells
  • 6 Tbsp Kentucky Bourbon
  • 1 Tbsp Frangelico Liqueur (hazelnut)
Equipment Needed
  • 8-10 twelve ounce canning jars with unused canning lids
  • water bath canner (or just a very large pot)
  • large pot
  • immersion blender (or potato masher and strong arms)
  • jar lifter

Begin by peeling and pitting all the fruits. Some recipes call for blanching the fruits in boiling water to aid peeling, but these peaches peeled by hand very easily. You can scale the rest of the recipe based on your final fruit weight. Don’t worry about brown spots or bruises, but do remove anything that looks moldy or truly “gone bad”. While peeling I toss the fruits into a bowl with the lemon juice, tossing occasionally, to limit browning.

5 pounds of peaches, broken down!

Add the fruits, lemon juice, sugar and honey to a large pot and put over medium-low heat. Mash everything up with the masher or immersion blender to your desired consistency, and stir well to combine. Taste the sweetness level – my peaches were very ripe so I used less sugar, you may need more.

A southern treat - booze in everything!

When the mixture has come to a boil, add the package of dry pectin, mix well to prevent clumping, and return to a boil for 1 minute. At the end of the minute, remove from heat, add your vanilla bean gunk, bourbon and liqueur and mix thoroughly.

I put a short chunk of the vanilla bean itself into each jar, then ladled the mixture into the jars to 1/4″ from the top of the jar. Put the canning lids on the jars, and tighten the rings to finger-tight only. Place the jars into a large pot or water-bath canner with at least 1″ of water covering the jars, and boil for 10 minutes. Carefully remove the jars, and allow to cool at room temperature. Any that do not seal their lids (they shouldn’t “pop” when you press on them) after cooling should be put in the fridge and used first.

The completed jam! I got about 8.5 12oz jars worth.

Note: When water bath canning, you should read up on the recommended times for your region. Different altitudes call for different canning times. Your local university extension office probably has a whole page on canning, and the USDA publishes lots of useful information as well! Familiarize yourself with the basics of water bath canning before diving into it. It is very easy to do, but you want to make sure you are doing it right to prevent the spread of disease.

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Pickled Asparagus Experiment

I tried a pickled asparagus experiment. I purchased 3 pounds of asparagus on sale, and decided to pickle the hell out of it. I used a recipe from the blog Food in Jars. It’s a great blog, but unfortunately in this case, the recipe was not a success. I have a theory why, which may be as simple as a transcription error in the recipe, though I may have made a mistake elsewhere in the process.

For my own records, here is the recipe I used:

Pickled Asparagus, adapted from Putting Up by Stephen Palmer Dowdney
  • 4 pounds asparagus, trimmed to fit your pint jars and blanched in boiling water for approximately 10 seconds
  • 3 cups vinegar (half apple cider vinegar, half white vinegar)
  • 3 cups water
  • 1/2 cup kosher salt
  • 4 tablespoons Penzeys pickling spice
  • 3 small jalapeno peppers
  • 3 garlic cloves, peeled

I blanched the asparagus for 15 seconds before jarring. I added the spices, and poured in the brine mixture. I processed in a water bath canner for 15 minutes. After processing, the asparagus were shriveled, as though the moisture had been sucked out of them. In retrospect, the recipe seemed to have a lot more salt than the other pickling recipes, about 50% more. Perhaps the recipe should have been 1/4 cup of salt or something similar.

I’ll still try them when they have finished pickling, but my hopes for good texture are not high. A future experiment with a modified saline level should prove useful.


Pickled Brussels Sprouts – Experiment 1

For my own reference, and your potential amusement, here is the documentation of pickling Brussels Sprouts from the garden. I used a hot-pack canning method (read up on it for context) with water bath processing.


  • 1 lb of sprouts fills about one quart canning jar.
  • Sprouts were boiled in a light brine for 4 minutes before packing.
  • Brine: 5 cups white vinegar (5%), 5 cups water, 5 oz. salt
  • Flavoring for each quart jar:
    • 1.5 jalapeno peppers, sliced, seeds in
    • 4 cloves garlic, crushed
    • 1/2 teaspoon cumin, ground
    • 1/2 teaspoon yellow mustard, ground
    • 1 teaspoon cumin, whole
    • 1 teaspoon yellow mustard, whole
    • 1.5 teaspoons dried dill
  • Processed for 15 minutes


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    Fettuccine Alfredo Recipe

    To celebrate getting four fresh tomatoes from the garden, we made a traditional alfredo. Here is the recipe.

    Fettuccine Alfredo


    • 1 pound fresh or frozen Fettuccine pasta
    • 6 tablespoons unsalted butter
    • 1 cup heavy cream
    • 1 shallot or small sweet onion
    • 1 cup grated parmesan cheese
    • 1/2 teaspoon salt
    • 1/2 teaspoon freshly ground pepper
    • 1/2 cup chopped fresh parsley
    • Optional: A few small fresh chopped tomatoes


    Boil at least 4 quarts of water, and add a few tablespoons of salt to the water. Boil the pasta according to the directions on the packaging (usually 2-3 minutes for fresh pasta). Drain and rinse.

    While the water is boiling for the pasta, melt the 6 tablespoons of butter in a small sauce pan over medium heat. When it is melted, add the shallot or small onion, and cook for a minute, or until the shallot is soft. Do not allow it to brown! Add the cup of heavy cream, and bring to a boil, reducing heat to low. Simmer, stirring often, for 3-5 minutes, until the sauce reduces slightly. Add the salt to taste, and remove from heat.

    Return the pasta to the pot, and add half the parmesan cheese, the tomato and the parsley. Slowly pour in the sauce, tossing as you go. The residual heat will melt the parmesan. When tossed, add freshly ground pepper to taste (I like a lot). Serve with another quick grind of pepper on top, and a sprinkle of the remaining parmesan cheese.


    Garden is Cooking

    Today we removed the walls of water from the tomato plants, and wrestled them into their cages. We already had some ripe tomatoes hidden beneath the protective walls! I can highly recommend the walls of water, our tomato plants are huge and healthy, where most others are half the size. Plus, getting ripe tomatoes in the first week of July is a first for us here in Colorado.

    We’ve also been making good harvests of Rainbow Chard, Collard Greens and Sweet and Snap Peas. Onions are producing well, and we harvest some tops as scallions here and there. Herbs of course are going strong, and my Cascade and Centennial Hop bines are going nuts. The East Golding Hops may not make it, however. All in all, this is the best start to a new garden I think we’ve ever had.

    Madalene in the Hawthorn Garden

    Collard Greens and Rainbow Chard in the garden

    Basil seedlings


    Gears, gears, gears

    I love machines that do nothing. You turn them, crank them, operate them, all to no practical effect. That satisfies me. To that end, here is a device, about 8″ square, that I cut out of 1/4″ MDF board on the CNC router. You turn the outer gear, and the inner gears all parade around mindlessly. It’s a planetary gear arrangement, commonly used in your car’s transmission, only this one doesn’t do anything.

    Planetary gears cut from 1/4" MDF

    I cut it from some modified designs from the Thingiverse, where people upload designs for things they made. You can then make copies or derivative works, and post them as well. Its very concrete! Most of the participants so far use laser cutters, CNC routers, and 3D rapid prototypers, so the variety of “things” is pretty wide. These gears were originally intended to be laser cut out of cardstock and assembled into a tiny, machinated business card.

    Rapid prototyping and machining is becoming so common for “regular people” that I think we are approaching a manufacturing revolution, wherein instead of buying things, you buy meta-things, things that make other things. Why buy plastic cups when you can print your own?


    Blogging again

    Trying again to journal my thoughts! Let’s get started again.

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