Matching levels between headphones

I think we all know how important it is to match volume levels before comparing headphones or other audio equipment. I’d like to start a discussion on what procedure you like to use to level match your headphones.

But also I worked out my own procedure over the weekend and I’d appreciate your thoughts:

I use REW software with a miniDSP EARS rig. I’m not sure it’s necessary but I start by calibrating the REW SPL meter to 84 db as per EARS documentation for measuring frequency response. Then I use REW to play pink noise over the headphones and REW’s SPL meter to measure the level. I use the SPL meter in C weighted mode and the pink noise type I use is what REW suggests for speakers. I’m not sure these are the correct choices for headphones, though. Maybe I should use full spectrum pink noise and Z weighted mode or some combination of the above.

I start with whichever headphone is less sensitive than the other so that I’m always reducing the gain on the second pair to match it. The measured SPL does tend to fluctuate but I turn the volume knob on my amplifier up until it hovers around 84.0 db.Then I put the second pair of headphones on and use my equalizer to lower the gain until it also hovers around 84.0 db. I don’t think it matters that I use 84.0 db here as long as it is the same.

At this point my understanding is that I can change the volume on my amp in either direction and as long as I continue to switch the equalizer gain to match the headphone being played, the headphones will have the same perceived volume.

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As long as you’re hearing the same perceived volume, I guess it’s all that matters, right? Did you take the sound difference blind test? I can’t detect any difference below 1dB, for instance. At least for that test tone. So that should establish your own (ear/human) tolerance.

Procedure-wise, I just play this noise track while pointing the decibel meter as close to the source as possible – i.e., at maximum level within the ear cups.

Volume-wise, it works great for me when comparing several cans in the same listening session. See this post for an example in action:

Cheers.

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This is tough in practice, as one can match measurements but not the anatomical fit between products. Each headphone cup and headband interacts differently with each head. Even if the volume coming from the drivers is identical, the ear pad foam, ear pad coverings, and cheek tissues may absorb sound differently based on the direction and placement of each specific driver.

I’ve used a dB meter to get close, but then end up relying on perceived similarity (if I’m honest).

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I started out doing it just by using my own ears as the SPL meter, but quickly discovered that some perceived differences in punch and sibilance were actually just a slight mismatch in the volume levels. So now I’m more comfortable using an objective measurement.

I’m definitely going to check out that sound difference blind test when I have the time, though.

The problem with using a measurement at a specific frequency is that each headphone performs differently at different frequencies, so if it is matched at 1kHz for example, it doesn’t mean that it is matched at other frequencies.

As @generic mentioned, different fits with different anatomies can also play a big part.

Although I understand the importance of volume matching to give a perfect result (if there is even such a thing), I only AB things for personal listening preferences (totally subjective) therefore I set volumes at a comfortable level, whatever they may be in each headphone/IEM.

I do check with an SPL meter now and again, just out of curiosity, but I am not really set on volume matching (at least not to minute detail) as I listen for pleasure and if something seems to sound better to me, that is the impression I come away with, even if it is not an objective conclusion.

I do listen at low levels though, it is rare that I turn something up loud, I learned that from experience :wink:

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Agreed, which is why I think pink noise is better. But which pink noise and which meter weighting? :thinking:

To be honest, I have no idea which pink noise. I have a CD with pink noise that was given to me by one of our room tuning guys, I have no idea what the source was.