Focal Clear Open-back Headphones - Official Thread

[Resolve]

@Saat

Incorrect in two ways - see the original post above, for the guesstimate that was involved in the testing process, in the absence of proper measurement gear, so the conclusion regarding the loudness level cannot be as decisive as the 100dB claimed in the reply (and if it is correct and this unit is not defective - my hearing would have been impaired by now… This is not the volume that I am listening to all these years and with the Clear which clip extensively at my regular listening volume); it clips at much lower loudness levels when the iFi Hip Dac’s XBass is engaged and that was acknowledged to be the case when it was tested.

I’m not going to weigh in on the rest of this, because it probably belongs in a private discussion, but this part benefits from some technical information.

I recently did some measurements on the Clear Mg that indicates the clipping threshold is somewhere between 105dB and 110dB (normalized at 1khz), with calibrated industry standard measurement equipment. The regular Clear behaves in much the same way, as the driver structure is essentially the same (just different material). This probably merits an additional video, but the regular Clear also shows normal behavior under 100dB.

‘Clipping’ is essentially just the driver excursion limit. You can see the effects of that as high order harmonic distortion (purple = 7th for example). Here’s a visualization of that:

To put it bluntly, these are highly dangerous listening levels. Prolonged exposure will cause serious hearing damage over a relatively short period of listening time (a few hours). Anyone listening at 110dB will also likely find that to be quite painful, although if the volume is gradually increased over time, this might not be felt as strongly. So be very careful with how long you listen and by how much you increase the volume.

Here’s the same headphone at much more normal listening levels (even slightly on the loud side). This level would only cause hearing damage if the listener were exposed to it over a long period of time, and should be considered still within the safe range. Notice, no high order harmonics showing up, and no clipping.

Now, the problem you’ve uncovered is that when you’re using the xBass function on certain iFi devices (at a certain volume level), that bass boost means you’re also reaching the driver excursion limit. It’s as if it’s being played at the 105 to 110dB (at 1khz) level, just only in the bass, which is where the excursion limit is going to show up. It’s bound to not be as painful, because it’s just the bass, so it might not be as noticeable for an overall volume increase as it would be if that same level was being played back over the rest of the frequency range.

This is also one of the key reasons why you have to be careful when EQing headphones, and there’s more information on that in this video here:

The Limits of EQ - A case against using EQ profiles for headphones

TL;DR - objective data verifies that these headphones clip at a particular threshold that’s far louder than humans should listen for prolonged periods of time (over 100dB at 1khz). However, when using any kind of adjustment to increase the bass, like using EQ, an analog function like xBass, or a high output impedance source, the volume threshold for clipping is bound to be much lower (at 1khz).

EDIT:
I found an old Focal Clear measurement at 95dB that I took before moving to the new studio, and sure enough it shows no clipping, but I’ll get another one in shortly and update this to find the exact threshold for it.