The Little IBP That Could

December 24, 2008 11:16:11 AM PST by Dave Crane

In 2001, Jonathan Little of Little Labs released the IBP, or (In-Between-Phase) alignment tool, and the process of mic’ing has never been the same (in a good way). As a well respected studio tech in the LA studio scene, Jonathan Little had been dealing with phase issues the way everyone else did: you listen, and flip the phase switch. Ninety percent of the time, that did not fix it, so you had to go move the mics around. Then what would happen was that you'd end up compromising the sound of each mic. The best placement for each mic on a drum kit might sound great for each mic, but as a group, there can be a lot of phase issues.

UAD Little Labs IBP
UAD Little Labs IBP

If you’re not familiar with phase issues, this is the problem: Two signals from the same source arrive at two different mics out of phase. Audio signals swing between positive and negative values. When the signal in one mic is going positive, and the same signal in the other mic is going negative, some of the frequencies cancel each other out. This makes the audio source sound thin, or hollow, and the low mid frequencies tend to be attenuated. If two signals are exactly 180º out of phase, you won’t hear anything at all!

The Little Labs IBP Phase Alignment Tool easily eliminates these undesirable, hollow, comb-filtered sounds when out-of-phase and partially out-of-phase audio signals are combined. It has established itself with audio engineers as not only a "fix-it" tool, but as a tool for manipulating audio phase as a creative, tonal, color tool. Sometimes an audio source sounds just right when a little out of phase, and you can get a sound that no amount of EQ and compression can create. Whether combining direct and miked signals, acoustic guitar and vocal mics, drum kit mics, or multiple split-guitar amps, the recorded audio signal phase can be quickly and easily controlled with the Little Labs IBP.

The best placement for each mic on a drum kit might sound great for each mic, but as a group, there can be a lot of phase issues.

Universal Audio’s Workstation version of this tool is optimized for the DAW environment and expands on the original design with a continuous Delay Adjust control, which provides a perfect digital phase alignment option. The Delay Adjust moves one signal in relation to the other in 0.01ms (millisecond) steps, up to 4 ms. This is basically changing the phase relationship between the two signals, but in a different manner than the IBP’s phase adjust.

Each method does produce a different result, and UA did an exacting digital model of the IBP’s unique analog phase adjust circuit, which delays different frequencies by different amounts. The Delay Adjust is a time-based phase adjust and delays all frequencies by the same amount. We urge you to experiment with both to get the results you like best, and you can use both controls for even more options. Watch the video for some creative uses of both these controls.

More features include a 90º phase adjust option for finer control. Also included is the “Phase Center” high and low position filter switch, which adds additional frequency-dependent control over the phase-adjusted source. A standard 0º/180º Phase Invert switch is included, as well as individual bypass switches for the Phase Adjust and Delay Adjust sections of the circuit. Finally, a Power switch bypasses the whole plug-in.

In the video, you can hear the IBP as it adjusts two out of phase recordings of a guitar and a snare drum.