The graph pic alone should dissuade the normal person from reading, but if you are game, allow me to share a little secret: This post is more of a reminder to myself than anything entertaining. It might even be totally nerdy. But you are here, and I appreciate you taking the time to peruse this. Let's get into it.
After a few years in this apartment, frustrated with my small studio where my speakers could not be turned on for mixing, I was faced with several dilemmas about mixing. The room is not ideal for mixdowns at all. It's too small, and at the moment I don't have much choice but to mix on headphones. I hunted down a plethora of headphones to mix on and my search culminated in owning three headphones that I use to record, mix, master, and stream on. The problem is they sound as different as can be. Enter Headphone plugin compensations, EQ, and whatnot.
Of my three most used headphones are the AGK K701s (also the most expensive of the lot). Without correction, the 701s severely lack low bass response. So I would find myself bumping them more than I should. I do love them, but they need to be amped, and cannot travel with me. The way things get thrown around, taking a $300.00 pair of bulky headphones on the road is a non-starter. Because they are open-backed, and I love to use Omnidirectional mics for recording, these cannot be used to track vocals or do the stream. So their studio duty is for mixing and mastering only. More recently, I have paired them with the correct amp, and using this FREE app https://autoeq.app/ I have been able to tune them to get really great results. So there's a light at the end of the tunnel.
The pair I do travel with is going to sound really odd. They are Sony XB550AP. I got them because of the frequency response. At first, the 5 - 22,000 Hz Dynamic Frequency Response spec seemed almost too good to be true. But as it turns out, this is a headphone that truly reveals things in the lower spectrum that gets by almost every headphone I own! As an example, when I'm listening to podcasts on YouTube, I can routinely hear the low-frequency rumbles of bumping off the desks, rumble from the mic stands, and more 'noise' that cannot be heard when I switch cans. But can I mix on them? Nope.
But damn they sounded good when I heard the Beatle's latest single on them. The bass is perfect down to the lowest possible notes. As a side note... I loved the song, and through these cans it literally made me burst into tears. I am a sentimentalist. Here's the song...
https://www.youtube.com/watch?v=AW55J2zE3N4
Now then, the XB550APs are not accurate, although quite pleasant. They are great for writing, though, and I could probably get away with tracking vocals on them (not needed to yet). I take these with me on the road for making music while in hotel rooms and whatnot. But I do like to put them on AFTER I've mixed a song to listen for strange bass artifacts missed by the K701s and CB1s (more on these later). I liken the Sonys to turning on my powered subwoofer in my old studio. I test for odd bass things, make quick corrections (while avoiding anything else in the tonal soundstages of the mix), and get back to work.
Now then, my other headphones are a funny pair. These are the Status Audio CB1s. Relatively inexpensive, and to my surprise quite balanced. I had no idea. I like mixing on them, but because I had to frequency response chart (from when I bought them), I tended to shy away from them. I did find one and it shows what I suspected... The frequency response is not terrible. If you compare the target line (blue dashed line), the CB1 exhibits a few resonant frequencies.
To my surprise though, using the correction app gave me this curve:
Because it uses a convolution EQ to correct (linear phase), it is amazing to see how close the convolution gets. I did a similar correction to the 701s and I got the exact curve. So now, I can mix on either, swap for differences, and make better decisions. But I want to show you the curve of the cans themselves. As you can see, it is not that far from the target (the blue line). In fact, the roll-off from 50Hz is what I like about them for vocal recording. That bump (although exaggerated a bit) may be why I like tracking vocals with them (I hear myself better). But now 'corrected'? I have no idea. I only found their curve setting today while researching cable replacements for another headphone I needed to repair.
But I am thrilled. The correction curve on the AKGs was a game-changer, but I knew from their original curve that they were farther from the target. But when I heard back my mixes on the CB1s (uncorrected) to that of the corrected 701s I found that my decisions on the K701s were solid. That does not mean I became a world-class mixer overnight. Far from it. But at the very least, I am closer to getting better results. Now if only there was a Frequency curve for the Sony XB550AP... I would be over the moon. The AutoEQ app does not have it. But that does not mean I cannot make my own. I could, but I need to find the raw curve first. As it turns out, I may have gotten close...
I found the curve for the Sony MDR-XB50AP, which is an earbud version of the same model. While this is not a perfect match, the Frequency response is so similar that perhaps the curve could make it worth trying. In studying the curve, I noticed that the raw output is not terribly off-target.
When the correction is applied, the bass is flatter (relative to the Harmon Curve). Because these can go down to 5Hz, it may be possible to really mix on them when corrected. I will have to do a comparison and see. but I am excited because if this all works out, my travel headphones may get me closer to studio mixing than I thought possible.
I downloaded the convolution curves and will be trying these out...