I asked Dave Hamilton to come on the show to help us understand the impact of Apple removing the analog headphone jack. I didn’t want to do a big hand wringing about how annoying it might be to replace all of our headphones, rather I asked Dave to come on the show to explain in geeky detail what it means to have analog vs. digital headphones. We start at the beginning talking about how sound is produced in a computer and work our way through sample rates, bit rates and into some of the mechanics of a digital to analog converter (DAC). We also talked about the impact on audio when you use Bluetooth headphones.
Dave and I mentioned a couple of things in our conversation:
Understand the math: Nyquist Frequency
Annoy Children: Frequency Only Kids Can Hear
Add Bluetooth to any headphones: Antec Smartbean Bluetooth Receiver ($11 on Amazon)
Can you hear the difference? ABX Tester for iOS, ABX Tester for OSX
Find Dave on Twitter at @davehamilton. He’s the host of the Mac Geek Gab Podcast and the Gib Gab Podcast with Paul Kent.
I believe the problem with 44.1KHz sampling in the early days of CDs was that the CD players wanted to send out up to 20Khz, so they needed a pretty sharp filter that was nearly flat up to 20Khz and 60 db down at 22.05Khz. Back in the day these were generally recursive filters that had sharp non-linear phase responses, especially around the transition band. You could learn to hear that, and then talk about how much better vinyl was. It’s similar to people liking one EQ over another — the phase response makes them audibly different. Anyway, these days I think the DACs are almost all oversampling DACs that don’t have or need the sharp phasey filter.