ABH4

The nice thing about the ABH4 is the simplicity. There’s nothing to configure, no volume adjustments, anything. You just plug it  in and it works. It has a set of RCA inputs on the top. These are connected to my Airport Express for playing music wirelessly from iTunes. On the bottom are 4 RJ-45 jacks to go to remote locations.

I need to set up the IR repeating feature next. This works by receiving IR commands from remote volume controls (if they have an IR window). On the bottom of the ABH4 are four mini-plugs. These can each connect to an “IR Blaster,” which you then stick to your audio source’s IR window.

When you aim a remote control at one of your remote volume controls it will repeat through the ABH4 and send the command to your audio source. In my case I’ll be using the Keyspan Airtunes Express Remote. This plugs into the Airport Express and lets you control any computer with iTunes installed.

At first I plugged my Airport Expres (with Airtunes!) into an FM modulator and used FM radios. This is nice, except for the sound quality isn’t great. Also you need to leave the volume in iTunes set right in the middle. Too low and the radio will be full of static. Too high and the signal distorts. This means you can’t adjust the volume throughout the house from iTunes, but instead must adjust it on each radio.

Enter ABUS. ABUS is a standard for sending audio, power, and IR over CAT5 cable. I have plenty of that. It’s cheap. It’s designed to pull through walls (not all speaker cable is). At first look, ABUS seems expensive. But when you relize what you’re getting in the kit, it’s quite reasonable. Finding second-hand equipment also helps.

ABUS is designed around three components. A hub goes in a central location, just like an Ethernet hub. Your main audio source(s) plug into the hub. At the other end of the CAT5 cable is a small (single-gang) volume control. Finally, speaker cable goes the short distance from the volume control to your (in-wall) speakers. The amplifier is built into each volume control.

I decided on using the single-source Harman/Kardon ABH4 hub. This supports up to 4 locations out of the box. Expansion packs can be added to power additional volume controls.

Stay tuned for more information about the ABUS system as I’ve installed it.