Elephant Candy’s entry into the iPhone audio processing apps market, eQu, is the most polished of those we’ve tested to date, with helpful presets, full AirPlay support for playing audio throughout the house, and a nice-looking, user-customizable interface.
The attractiveness of EQu ($3) is anything but skin deep. Its fully-parametric equalizer gives you complete control over the parts of the sound you want to tweak — and by how much — while the app overlays equalizer controls on top of a graphical depiction of the output signal, so you can see what effect your EQing is having, as well as hearing it.
When any frequency’s signal grows too loud, which can lead to distortion, a red bar flashes to warn listeners. A limiter option promises to stop such peaks from damaging your headphones (or your ears), although we heard distortion when boosting signals greatly, even with the limiter switched on. Meanwhile, equalization presets such as Vocal Booster and Small Speaker can make music sound dramatically better in specific scenarios.
One shortcoming of the EQu app is the time is takes to process changes. As you move EQ levels up and down, there’s a one-second delay before you hear the difference. This may not seem significant, but if you are trying to switch between two possible settings to decide which you prefer, the lag can become annoying.
Still, EQu is a fine option for tweaking the sound on your iPhone, iPod Touch, or iPad, despite its high-end (for such apps) $3 price tag.