I call myself an audiophile even though I don’t fit a lot of the stereotypes. You won’t find me bragging about my pure silver ‘interconnects’. (Heck, the speakers I’m listening to now are hooked up with solid-core ethernet cable.) Another thing that differentiates me from the audiophile stereotype is that my love affair with audio has been largely… digital. I deeply appreciate how digital audio can capture and reproduce any sound, without adding (much of) its own character.

So if not a digital hating cable snob, what makes me an audiophile? I think it comes down to a love of recorded sound. I’ve been mesmerized by headphones since I was a baby. When I was 6 years old, my Dad came home with some Tannoy bookshelf 2-ways. Ever since, I’ve been moving speakers around, adjusting tone controls and signal processors to extract the maximum amount of musical information on playback...

Does it make sense to drive slower, if time has (monetary) value

Ever since driving a car equipped with a fuel economy meter, I have become pretty interested in conserving fuel while driving. (Obviously, the best way to conserve fuel is to not drive at all.) Not surprising, the best way to do this is to minimize the use of the gas pedal.

Turns out there’s a whole community of people called hypermilers doing this for various reasons - reducing emissions, cutting fuel costs, and simple pride at getting a better MPG figure than advertised. Hypermilers advise driving no more than 90 km/h, since fuel efficiency tends to drop pretty quickly above this point due to increased drag, both aerodynamic and mechanical.

Let’s compare the cost savings in fuel to the increased time spent on the road, based on the following assumptions:

• the main reason to conserve fuel is to save money
• time...

The Apple TV was designed for a minimum number of controls, such that the user can feel their way through on-screen interactions without looking at the remote.

For this minimal control scheme to be successful, the buttons must produce consistent, predictable results. Putting aside the mostly useless “play/pause” button, there are two spatial metaphors which provide a (usually) intuitive user experience.

1. The directional buttons move the on-screen cursor (selection rectangle) in the same direction as pressed - a natural mapping.
2. The unlabelled centre “Select” button moves inwards in hierarchical menus, while the Menu button moves outwards.

One would rightly expect the directional buttons to move the cursor a single step for each tap, and holding the button to repeat that move. By the same logic, the Select button should move inwards by a single step, and the Menu button outwards...

In the pro audio / audiophile community, certain traits are consistently identified with the hi-fi (high-fidelity) label.

For me, performing speaker and room measurements has recently clarified what these traits are.

Tonal range

The accepted tonal range of human hearing is 20 Hz - 20 kHz. This can be thought of as four ‘decades’: 20 - 200 Hz, 200 Hz - 2 kHz, 2 kHz - 20 kHz.

In musical terms, doubling the frequency raises an octave. Starting instead at 16 Hz, which is the lowest pipe organ note, shows eleven octaves:

16 32 64 128 256 512 1024 2048 4096 8192 16384 32768 Hz

I can’t hear much over 20 kHz in terms of pure tones, but calibrating for an extended high-frequency response tends to give better results in the audible band. And everybody - not just teenagers or dogs - can hear the extra octave (or 2, or 3) of bass.

Suffice to say, 11 octaves surrounding 20 Hz - 20 kHz is...

Note: I have now thrown these out because they sounded horrible (and I’ll explain why later) but it was a fun experiment!

I was trying to think of a good way to combat cabinet edge diffraction, improve uniformity in the polar frequency response, and reduce cabinet resonance. Suddenly this idea came to me - of slicing up a box and twisting it. I went to sleep that night with a pretty good idea of how it might look.

When I woke up, I went straight into SketchUp. Once I started turning the squares, I was reminded of this cool video that I saw on Khan Academy:

And so, I began referring to the speakers as “pinecones”. (Also porcupines, hedgehogs, and most disturbingly “porcucones”).

Build photos

I am extremely lucky to be the son of a woodworker. I had planned out the basic steps of the build, but certain details are best handled by the experts. And it really helps to have two...

You’ve probably noticed that many speakers have more than one uh, speaker. These speaker systems are called 2-way, 3-way, 4-way, and so on depending on how many individual speakers, or ‘drivers’, they have.

Multi-way speaker systems usually split the incoming signal into several signals tailored to each driver in the cabinet. The woofer gets low frequencies while the tweeter gets high frequencies. This way, the tweeter doesn’t ineffectually try to produce bass notes (this will produce distortion and could actually damage the tweeter) or vice-versa (woofers “beam” high frequencies unpleasantly).

The component that splits the sound up is called a crossover.

Passive vs active crossovers

Passive speakers have a passive crossover. This means that they take away unwanted frequencies post-amplification, using passive analog components like resistors and capacitors. Passive crossovers...

When the headphones I’d been eyeing suddenly dropped in price by 60%, I had to take the plunge. At $120, I’d never spent this much on headphones before, but that didn’t stop me from ripping them apart right away. :P

Acoustic mods: less is more

The following Sennheiser headphones are ordered left-to-right by price low-to-high: HD558 ($180), HD598 ($250), and HD600 ($400).

Sennheiser has added extraneous sound-shaping materials to the cheaper models, opting to leave the higher-end headphones more open. Can you upgrade the HD558 to HD600 performance just by removing stuff? Probably not, but it makes sense to remove it anyway.

Speakers of all kinds are prone to comb filtering …

Instructions

1. Inside grill removal

Remove the earcups. Remove the inside grills. Do not replace the earcups yet.

2. Outside grill foam removal

One at a time, unscrew and carefully remove the...

Many headphones suffer from a limited frequency response, but what’s worse is that the frequency response is basically different from person to person. This makes mixing for headphones a moving target.

The target

Headphones aim to reproduce an acoustic wave accurately at a specific place. This place is the target.

In-ear headphones target the ear canal opening, because that’s where they are placed. But blocking the ear canal changes its resonant frequency, so in-ear headphones have unique difficulty in achieving this goal. When the ear is plugged, the original resonance is muted, while a higher resonance is produced by the now shortened ear canal.

Is the ear canal opening a suitable target for over-the ear headphones? Frequency response would be highly sensitive to placement over the ears, and the shape of the listener’s pinna.

Calibration

The acoustic effects of both the...

I have been tooling around with typewriter “ASCII art” style image reproduction for some time, well, since I acquired my typewriter.

I found several problems with existing image to ASCII generators for my application (reproducing digital images on a typewriter):

• Character set too small (lack of color depth)
• Character set too large (slows typing and adds false textures if asymmetrical characters are used, adds error)
• No custom font (assumes all fonts have same character gradient)
• Character set not weighed at all (character brightnesses should be measured and colors indexed for correct gamma)
• No image adjustments in-converter (monochrome balance, contrast, crop)
• No realtime preview of settings (such as line spacing, font, and line length)
• No dithering option (losing color depth, especially in highlights)

Is a picture worth a 1000 word ASCII image?

I decided to write an ASCII image...