A note about headphone impedance

As a basic rule the lower a headphones impedance value, the ‘louder’ they will sound for a particular output. So a pair of 16 ohm headphones will sound louder than a 600 ohm pair when plugged into the same headphone socket. (There are other factors that affect the volume of headphones, such as the strength of the magnets used.)
Lower impedance headphones, usually 150 ohms or less, are usually better suited to devices that have lower output levels like portable recording units or cd / mp3 players that run from batteries. (There is no reason why you could not use headphones with higher impedance; they just would not be that loud!)
Impedance values from 150 – 600 ohms are usually better suited to general studio use. The higher a headphones impedance value, the more power needed to drive them, which makes them less susceptible to damage from over powering. Higher impedance headphones are also better suited when using multiple pairs connected in parallel.
Impedance values of 1.5 – 2K (ohms) are used mainly in broadcast environments. The relatively high impedance value allows headphones to be connected to devices directly and monitor signals without causing noticeable drops in signal level.

A more in depth article covering impedance can be found here;



Intel Pentium G840 HTPC

This build was to be installed into a living room and connected to a 1080 HD TV and a NAS. It was mainly going to be used for playing media content such as TV, films and music. The case needed to be small enough to integrate into a living space but did not need to be particularly discreet. The Antec MINUET 350 Case has a reasonably small footprint and is good value for money with the PSU included in the price.

Most of the media content would be stored on the NAS, so drive space was not a major concern but the customer was intending to upload photos and videos from cameras and smartphones so we decided to install a 1TB Seagate Barracuda to ensure that there was enough space for the future. We also installed a card reader into the 3.5″ bay so transferring media from cameras would be easier.

The Intel Pentium G840 was more than capable of handling all the media tasks and is very reasonably priced.

The unit was running Windows 8 64 with VLC and Winamp handling a lot of the media playback. The customer had quite a few films they had ripped from DVD on the NAS and the nice thing about VLC is that it will play DVD image files as well as media files.

We also installed a Hauppauge WinTV-HVR900 DVB-T USB tuner which also has an analog input. I really like the Hauppage products. The software is easy to use, stable and fully supports Windows 8. This allowed the customer to schedule record TV programs and also connect an old VHS video recorder so they could watch and also record old videos on the computer.

The full spec…

  • Antec Minuet Piano Black Slimline PC Case inc 350w 80+ PSU
  • Asus P8H61-M LE Rev 3.0 Motherboard
  • Intel Pentium G840 (2.8GHz,65W,32nm,3MB)
  • 4GB kit (2GBx2) 240-pin DIMM DDR3 PC3-12800 CL=11 Unbuffered NON-ECC
  • Seagate Barracuda ST1000DM003 1 TB 3.5″ Internal Hard Drive
  • CIT IO-001B USB2 3.5″ Internal Card Reader with SIM slot
  • Hauppauge WinTV-HVR900 DVB-T USB Tuner.

Antec HTPC

Antec case inc PSU

Antec case without cover