The Sonarworks Reference plug-in makes a difference that is out of all proportion to its modest price, and is capable of turning an unremarkable pair of headphones into a serious mix tool.
Without wishing to sound too hyperbolic, I’d say that this plug-in goes a long way towards making a cheap pair of headphones like the 7506s as useful for mixing as many pricey open-backed ‘phones.
Most importantly, the mid-range issues were significantly improved, but the lower frequencies also came up in the mix. Switching to the averaged calibration profile for the same headphones resulted in a similarly big sonic change, with subtle, but audible, differences from the custom profile.
In the past I have found mixing on headphones a struggle especially when working with monitors as this often mislead some important mix decisions. I've always found it difficult to trust one set of monitors over a set of headphones.
You all know what it's like to finish a mix that sounds amazing on your headphones and then try to show it to your grandma on her hi-fi system, only to discover that it sounds terrible. The mix is completely different: It lacks lows on the chorus but has too much on the verse, the vocals can't be heard. In short, it's awful. Granny is about to disown you...Until Sonarworks comes along to save the day.
The GUI is super intuitive so it took minimal effort to dial in exactly what I needed. There’s a slider that allowed me to determine how much EQ I needed, and I found that backing it down a hair gave me what sounded most “even” to my ears. Setting the EQ to “linear phase” also sounded best to me, but the difference between linear and minimal is pretty subtle.
We tested the average curve on our set of KRK KNS8400s, and a specific curve on a set of Sony MDR-7506s and were pretty amazed – we always felt the KRK cans were lacking in sub, but never knew there was such a low-mid bump and high-frequency peaks. Even just using the average file, the sound felt much smoother and less fatiguing. The Sony headphones also felt much less brash with the plug-in engaged, and the sound when switching between the two was surprisingly similar.