Negative signal-to-noise ratios

I'm reading an awesome technical book at the moment: Bob Katz, Mastering Audio. This guy is a audio master - read it! One thing thats really tripping me at the moment is this part.



We can hear signals below the noise floor? It seems like the LSB (least significant bit) represents the smallest variation in amplitude available digitally, so where is that signal actually coded and stored? My understanding of the explanation (not shown) is that it exists in the time domain as a modulation on the LSB.

Thats some tricksy stuff right there!

iCompass

The compass isn't perfect, but its ok.



I wonder what the Android sensor is like in comparison. Come on internet, send me a video of your android doing this.

Invisible Guard for iPhone 3GS

So now I have a shiny new iPhone, I have a few important things to do to it.

Extend its functionality..

and install a cover. I got an invisible guard, a kiwi-made transparent cover.

It is installed with some soapy water and lots of patience. I applied and smooshed for about an hour, but it ended up fitting very well. The corners took a while, but eventually I got them all in place.

2G on the left, 3GS + invisible guard on the right. The plastic has a slight orange-peel look to it, but it doesn't affect the picture quality.

It does feel quite different to the glass, slightly stickier. But it is still great to use. The extra grip on the back is a welcome addition. Even the home button has a guard, which fit perfectly.

Here you can see how the shield covers most of the corner, and how tight and accurate the cover is. Check around the headphone socket and the volume keys.

Another shot of the corner. Also note the one blemish that I decided I didn't care about: the chrome bezel has a flake of missing chrome. It looks like a manufacturing defect, but is too small for me to care.

This is how the rounded back is handled: a slit up each corner.

The back looks nice, like its been duraseal-ed. The guard can be peeled off without damaging the phone. So far, I'm really happy with how it come out, its hardly visible at all, and no bubbles!

Is that an Iceberg?

From http://www.stuff.co.nz/national/2739551/Is-that-an-iceberg-in-Wellington-Harbour/:

A fake 'iceberg' in Wellington's Oriental Bay this morning was made by special effects wizards Weta for a climate change stunt.

iPicky

So I got a brand new iPhone 3GS and it isn't up to Apples' quality control. Its' silver bevel surrounding the screen sits proud of the glass in the top left corner and runs half the left edge, and a third of the top.

The chrome is slightly proud on the bevel on the outer edge of the same corner, but not very much.

update: Apple happily replaced the unit, and my new one is flush and nice...

How I lowered my speakers noise floor by 6db

As many of you know, I use Behringer B2031A amplified speakers plugged directly to my soundcards' line level output, with software based volume control and a custom cable with a 3.5mm headphone to 2 x 1/4" jack cable.



They sound completely awesome I love this set up so much. The only little thing that bugged me was that I can hear the noise floor of my soundcard at louder slider settings. If I turned them up for quiet material or for stuff with large dynamic headroom the white noise was just perceptible.

The SB Live wiki page has an uncited note that "the original SB Live! had a very low noise floor for its time". Doh! I considered getting a better soundcard with balanced outputs to lower the floor, but meh - money, linux support etc. just for something that is so minor and uncommon.

In practice, I usually stay within something like 2-10% of max signal level from my soundcard on the speakers, and the noise floor is far below hearing level.

I recently realised that I had the input trim on each speaker central at 0db, but they could go to -6db. By setting both speakers to this, I am forced to have a higher output signal from the soundcard to compensate. This makes the soundcards' signal to noise ratio much better (by 6db!) for any given actual listening level. Of course, my 100% setting is also 6db quieter, but I dare anyone to site in front of these at 100%!

So now I probably use something like the 20-40% signal level, with plenty in reserve should I wish to wind something up loud. This is a much more sensible use of the range, as I was right at the bottom 1/4 of the mixer sliders most of the time. I can't hear the sound floor, even with everything at 100%/max/11 !

Google Reader keys:

I have been using a few of them, but OMG in list view, the spacebar is awesome. its a page down, and at the bottom of the post, space also auto jumps to the next post. Can skim view high volume sites the best way.

http://www.google.com/help/reader/faq.html#shortcuts

Keys are so much quicker.