COMPARISON OF S4 S4R DT770 DT990 M50X HD650 AKG712 @600hz
Let's start with what is a deviation in this chart. We use a Z weighting calibration based on IEC 61672:2013 / BS EN 61672-1:2013 standard as the zero point. When we measure headphones frequency response we make a sweep signal from 20Hz to 20kHz and capture the response with a measuring tool. The deviation from the zero at every frequency is charted. The only compensation on the measuring device is a calibration file for the microphone capsules. That means the curves represent an SPL at every frequency without considering human ear sensitivity or any of the transfer functions.
What this chart shows is how much is the total deviation from zero in negative and positive dB readings. For example, if headphones would read -10dB at 400Hz and then + 10 dB at 8kHz and these two would be the peaks, then the total deviation would be set at 20dB.
We choose to show this as a way of supporting our promise of a balanced headphones response in full spectrum. You will find many measurements online to go through specific frequency ranges and decide what is important for you. Just keep in mind that comparing measurements from different labs or even reviewers can be very misleading. Make sure you have them normalized and you know for a fact what you're comparing actually goes together. For example, at what volume the measurement was made, what was the compensation used, if any and of course what measuring device was used. Every manufacturer will have different results. Yes, very frustrating, but that's how it is. Oh and also tolerances are important. They are from 1-3db +/- on good measuring devices. If you touch compensation standards then it's up to 10dB easily. And that's A-Lot! Now you know why we recommend trying headphones out and judge for yourself if they fit you or not. Don't make decisions based on measurements alone.
Looking at the frequency response curves
These measurements are RAW measurements, so they don't have any compensation curve applied for the ear canal resonance or for equal loudness such as ISO 226. Just calibrated microphone capsules. Readings are in dB(z).
Read more about that topic in this wonderful InnerFidelity bloghere.
Measured using miniDSP HEARS, REW software, calibrated card. Matched SPL at 600Hz.
Individual measurement of your headphones
Each OLLO headphone comes with an individual frequency response measurement you can download and open in REW software to see all the details.
How to use it in a way that works for you, you've got to take some steps from logging into/creating your OLLO account, getting your measurements by your serial number, downloading REW software, to exploring it and translating/applying it to the master channel's EQ. More in the video below.
... your ears are the best judge.
We know it's difficult to make an educated decision based on tech specs and reviews. The only true way to know if it's for you is to try it out. That's why we offer a 30 days trial period. If the headphones don't suit you, just send them back and we will refund your purchase, no questions asked.