DIY End Grain Cutting Board

When our counter-top wears out I want to make a full butcher block and wanted to experiment with a cutting board first. So to practice I made a birthday gift for my wife who says she can never have enough cutting boards.

It is rouhgly 10x12 and is 1.5 inches thick. It is much thicker than any of our other cutting boards. It is an end grain design made from oak. The advantage of end grain is that it prevents the knife from dulling as quickly, and makes the board last longer. I started by gluing scrap strips of oak together, letting them dry, and then ripping them on my table saw to the same height. Then I glued them together again. It is finished in two coats of wipe-on food-grade polyurethane. Which is no different than regular polyurethane, but costs more :)

It has circular pieces of inner-tube glued to the bottom to prevent sliding.  One thing I did learn from this is you basically need a belt sander to level things; and orbital type ain't gonna cut it, that taks way too long, even of something this small.  Here I am cutting some carrots into sticks.

It is now my wife's favorite cutting board by far.

My Home Theater Setup - 5.2 Dolby/DTS

I figured I show off my home theater setup a little and give some thoughts on what makes a good one on a budget. My setup is by no means the largest or most advanced, but there are some key elements which really matter, and don't have to cost the earth.

I am very happy with my setup and prefer it to the real theater. My objective for a home theater is as a direct a replacement of the real one in terms of its positive benefits.

The Display

The heart of any home theater is the display. The most important thing here is to get a technology that looks good to you, specifically. Not to your friends, not to the sales guy at the store. When I set mine up, the LCD/plasma war was still in full swing. I went with plasma, for two reasons:

1.) Motion on plasma looks fantastic to me. On LCD, I can see the refresh flicker on high-motion scenes (even on the 120 and 240 Hz at the time) and its very distracting.

2.) True darks. Plasma has them. LCD does not. I primarily watch movies, and in a darkened room. I can practically read a book by the dark screen presented by an LCD. It lessens the experience for me.

Here is my 720P display. It is mounted to a real brick chimney using 4 expanding masonry anchors that can take 500 lbs each. The anchors holes were made using a masonry bit and in the mortar between bricks. It uses an aftermarket swiveling mount. Above it I have mounted my center channel.

My display is angled down since it must sit over the fireplace. The most important thing is to put it at a comfortable height you can watch for several hours without neck strain. Plasmas are very heavy so mounting this was a two person job. LCDs are much lighter, and OLED screens are even lighter still.

The next step in a home theater setup is sound. This is the foundation upon which the entire experience is built. It is also why most home theaters leave much to be desired. Splurging on a great screen and skimping on the sound will have you craving the real theater with its high price, lackluster food, and distracting movie-goers. Most of my sound equipment has been custom designed and built to save money.

The Front Channel (L+R)

The most important speakers in a home theater are the left and right front channels, hands down. A great pair of front channels for a stereo configuration only can easily beat a full 7.1 lineup of mid-grade speakers in terms of performance and sound reinforcement. Why? Well, its simple - even in a 7.1 configuration, the vast bulk of program material is still carried by the front and left channels. If they aren't up to snuff, the whole experience suffers, and cannot be salvaged no matter how great your center channel or subwoofer is.

Here is one of my front channel speakers. These have more cost in terms of labor and design work than all my other speakers combined. I designed and built hem almost 6 years ago. For a long time they were the only speakers I had, and they performed quite well.

My right channel speaker. Notice that it presents a fairly confined beam of sound where it sits - this is only ideal for the center couch listening position.

My left channel with / without the speaker cover.  The speakers are built from 3/4" solid MDF, and are quite heavy.

Each contains two 6.5" woofers, and a single silk dome tweeter. It uses a second order custom crossover I built myself. These are not simply ported boxes, either - each has two separate sound chambers, with their own external ports, and connected by an internal port. This spreads resonance over a much wider range. Between just my front channel speakers, I have more woofer cone area than a single 10" or 12" subwoofer.

The Center Channel

The next speaker to look into is the center channel. Center channels are important for one thing in particular: dialogue. All dialogue should be anchored on the screen. The center channel can go above or below the screen, I had to mount mine above since there was not enough space between the mantle and the screen. Center channels should provide good, flat response in the range of the human voice. Fidelity is far more important here than power capability.

My center channel uses the same speakers as my front channels, but has a simple ported alignment. It also has an adjustable volume control for the tweeter to get the tone just right, on the back of the speaker.

The center is mounted using an LCD mounting bracket using 5 masonry screw-type anchors that actually penetrate the brick in spots.

The Subwoofer

Subwoofers basically fill the low-end gap that your front channels cannot reach unless they are absolutely gigantic. The other thing they do is explosions, which aren't so much heard as they are felt. To do this, a sub must be able to play to 20hz.

If you have very good front channels, your subwoofer can be focused better on a narrow range of frequencies. I have front channels that can play down to 40 Hz. The means my subwoofer must only take care of 20 to 40 hz - this is set at the receiver. However, do not be fooled into thinking this is an easy octave to cover - it is the hardest, by far. A really terrible sub can go down to 40hz. A better sub can play at 30 hz. A very, very good sub can play to 20hz. Generally, you will not spend less than $500 for such a subwoofer. Keep in mind that part of the price will be the amplifier built into the subwoofer. It will also generally need to be ported, which will make it much larger than a sealed box (twice as big).

My subwoofer construction and setup is covered here. I have two 12" diameter subwoofers in sealed enclosures equalized to 20 hz. This is where I get the ".2" in "5.2" :) This gives me more cone area than a single 15" speaker, and less distortion. I use an external 100W stereo amplifier to save on space and give flexibility. I also built the equalizer itself.

The Surround Speakers

The surround speakers are invaluable for providing and immersive experience.  However, they need not be large or capable of  low frequency reproduction.  They do however, need to be positioned correctly.
If they are not, they are basically worthless. In home theater setups, the surround speakers often present the most difficult problems since they must be located in a walkway, or floating in space.

My surrounds are built into my end-table lamps to sit at the exactly correct height without being a separate decor item. Construction information on them can be found here.



The Receiver

The receiver is one area where you can get great equipment for very little cash. I have an Onkyo. It has worked quite well. Be sure to get a receiver that can do 7.1 (most can) for future upgrades. I'd also get one that has optical inputs if possible - they break ground loops and the cables are quite cheap. Beyond $300 you aren't getting much extra. I'd recommend 70 watts minimum per channel as well, with efficient speakers, this will be plenty. By efficient, I mean greater than 85 dB/w.

On top I have an upconverting DVD player. Blueray players are quite cheap nowadays, just be sure outputs you use are HDMI for video. For audio, optical outputs are best to the receiver. My media center PC has optical out and this is what I use.

I hope this has been interesting and may give you some ideas for your own home theater.

Custom Speaker Lamps

I wanted to build surround speakers for our entertainment system. This would bring us up to Dolby/DTS 5.2. Unfortunately our couch end tables already had lamps, and would look to cluttered if speakers were placed there as well. The WAF was low on this idea.

So my wife came up with a compromise: build speakers into the lamps. This sounded crazy to me. After pondering for a while, we decided it might be crazy enough to work. So I got to work. I built boxes from scrap plywood, and smoothed them with bondo, and painted them black. I dismantled the lamps, performed some surgery on the connecting rod inside, and wallah...

The lamps have had there middle sections removed and the connecting rods jb-welded into the boxes.

The lamps function normally and have there original power cord. The speaker cord also feeds into the lamp base.

The speakers are 3" in diameter. Not something you will gut much bass out of for sure, but surround speakers aren't designed for that. They are sitting on 12" diameter subwoofers that give me all the bass I can handle :)

You can see the connections into the wall, one set for the sub, one for the surround. I will get to putting banana plugs on them later.

I set the distance and levels for them on my receiver, and popped in The Fifth Element to test 'em out. Awesome! For anyone tempted to go to 5.1, I highly recommend it, it makes movies far more immersive. The cost/benefit is high as well considering how cheaply  satellite speakers can be compared to say middle or front channel speakers .They work admirably - now I am just salivating to put some in-walls to go for Dolby 7.2!!!

Cyclone Dust Collection System

I've wanted to build a dust collector for my tablesaw that is quiet and doesn't clog. Commercially available dust systems cost a fortune.

The best systems use cyclonic separation. This usually is difficult to fabricate for the DIYer. But I built a cyclone separator and relocated the shop vacuum to the attic of my workshop. It uses common parts that are cheap.

First I had to make an adapter for my tablesaw. It had a 4" port. I made a wooden plate to attach the 2" PVC pipe. This pipe is solvent welded.

The vortex seperator is mounted on the wall and constructed from a 5-gallon plastic pail attached to a metal cone made form HVAC ducting. The input and output pipes are jb-welded into place. A bungee cord holds the bucket it place. When the system is on, there is a tight seal created with the bucket and lid.

 Here is the pipe that connects the separator to the shop ceiling. I used a hole saw to drill this and put a coupler in place in case I wanted to remove the pipe. My ceiling is insulated so I had to drill a hole in the top as well.

To keep things quieter the shop vac (which is extremely loud) is located in my attic. The shop vac is plugged into a switched outlet for simple wall control, and connects to the pipe. This is a 5HP unit (yeah right). So far no dust actually has made it to the shop vac, which is the whole point of the separator.

I spent about $20 on my vortex separator. The PVC parts and hoses cost an additional $50, but I have a fancier setup that is needed since I wanted it to be quiet, too.

Ghetto Christmas Smoker

I like both eastern and western styles Carolina BBQ, but I don't like spending too much time futzing around with cooking something. So I made a dedicated smoker from some junk heap parts using my welder. This smoker can not only smoke meat, but it can slow cook a boston butt so it forks apart by just looking at it.

The most irritating thing about doing "low and slow" is controlling temperature over the course of 8 hours. I found this to be important when I previously was doing this on the grill.  You get wide outdoor temperature variations - the wind picks up, a cold front moves is, the sun shines, etc. Thus constant tweaking is required to keep the temperature in the correct range, around 212-250 degrees. Since babysitting a pork shoulder is on the lower end of my list of fun things to do, I wanted to automate this.At the most I'd only like to have to change the wood chips a few times towards the beginning, and come back 6 hours later to some succulent, delicious pork.

Notice the combination of the digital  PID controller and the welded air tank for a pleasing combination of high and low technology.

The PID controller, hot plate coil and a thermocouple give thermostatic control for unattended operation. The PID along with the solid-state relays that switch the current are enclosed in an old computer power supply. The unit as well as the air tank are grounded for mains safety purposes.

Custom Linkwitz Stealth Subs

The only space we have in our living room for a subwoofer is under our end tables. Most commercial subs won't fit under them, and if they were small enough, they'd have terrible response. So I decided to build custom subs with 12" drivers that just fit. But you can't simply stick a 12" speaker in a 1.7 cu foot box and expect it sound good. More on this later.



The best material I have access to is 3/4" MDF. A 4x8' peice is around $30 and is enough to do both subs with some left over. That sheet is heavy. VERY HEAVY.



Glued and screwed together with titebond II and drywall screws. This avoids the need for clamping.



A quick check to make sure it fits. It does! The boxes are very long to give as much internal volume as possible. The dimensions are 13" x 17" x 22".

After making the driver and terminal cup cutouts with a jigsaw, I sealed the screw holes with water putty. I have had success with drywall compound in the past, and I imagine auto body filler would work well too. Then I sanded, painted, stuffed the boxes with fiberglass insulation, and mounted the speaker and terminal cup. I used T-nuts for the speaker, I highly recommend them.




Installed and connected, tested to make sure at least sound is coming out :)





As you can see they are pretty stealthy. Just imagine the other one on the other side of the couch :)

So here comes the interesting part. Those 12" speakers have a Vas of 4.25 cubic feet. So how are they not going to sound terrible in a 1.7 cubic foot enclosure?

Well, the magic of linkwitz transform.



This chart explains it. If I stopped here and simply hooked my subwoofer amplifier up to "subwoofer out" on my home theater receiver, I would get the blue line. That's an F3 of 42 Hz. I am missing an entire octave, and my front channel speakers can play that low, which would make the subs basically worthless.

I would rather get the green line, with an F3 of 20 Hz.  But how? Adding the frequency dependent gain of the red line, I can reassign the system parameters to make the green line a reality. What is this witchcraft?

Signal processing. I need to create a precise equalization curve that counteracts the terrible response of the system as is. The gain, as mentioned above, is frequency dependent, and goes up as the frequency decreases, but in a very accurate manner. With a "brute force" approach of just increasing the gain at some cutoff, there would likely be a lump in the response, which shows up as "boom".



Here is the magic box I just finished. It makes my subs respond to 20 Hz. In that steel and wood enclosure is a power supply, the linkwitz transform, and  +12 dB of gain buffer. I designed and built the transform and gain buffer on PCBs, populated the boards, and installed them. It feeds into the stereo amplifier below it which runs both subs.

I have to be careful as I can probably damage the framing in my house. These subs absolutely thunder when called upon.