Headphones in live mixing.

[rant]

I’ve probably posted about this before – it’s certainly one of my pet-hates. 

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I often find myself wanting (or having) to remind noise-boys happily mixing in their own head that they’re ripping the heads off the front 20 rows because they’re not dealing with an EQ, balance or feedback issue that they’re not hearing!

In summary, headphones are a great way to check individual inputs or outputs for:

  • problems with mic positioning,
  • distortion,
  • crackling,
  • presence of signal,
  • balance of a mix YOU CAN’T HEAR IN THE ROOM, such as those for foldback, recording, or other rooms.

When NOT to use headphones…
In live sound reinforcement, headphones are simply terrible for listening to the mix that you’re producing in the room, whether for judging mix levels or tonal quality.  You’re hearing small speakers, close to your eardrums, mixing for a space that exists only in your own head.

So don’t use headphones to check or perfect your main mix – it’s truly an accident waiting to happen.

If you’re changing something and you can’t hear a difference in the room then going to headphones isn’t going to help anyone hear that change except you. Worse still, while you’re dealing with a problem that only you know/care about, you’ll likely miss something crucial that everyone will notice!

[/rant]

Another reason to not mix on headphones…

I got curious earlier today and had a listen to some test-tones on some Sennheiser HD25-1 headphones.  Like you do.

These are the headphones that we supply with all our PA systems for troubleshooting and quickly checking recordings are happening, and their signals clean as can be.  They sound quite flattering when listening in “hifi” or “walkman” situations and I’ve always liked them for this, especially where significant isolation is required from external sound sources.  Trouble is, it seems they don’t do so well in the very high frequencies, which I noted this morning while listening to the 30th Anniversary remaster/re-recording of Oxygene. I thought it was just my ears or setup, but the sparkle I remembered from the same recording played on my home “hifi” was all but gone.  That’s what got me doing a sweep with some test-tones, and that’s what had me doing a quick Google search, which turned up this plot, which very much explains what I thought I was hearing.

Frequency response for Sennheiser HD25-1 - shown in green. Frequency is shown in log scale.Note the peak between 8 and 10KHz, and the falloff thereafter.

In live mixing, much of the “air” of a vocal or instrument will be up past 10KHz, and if the headphones are audibly struggling at 13KHz, it’s likely they’ll not be doing what they should be even as low as 10KHz.  If these are used for monitoring, one would likely be thinking everything sounds a bit dull and cranking up HF from 10KHz up on pretty much every channel.  And I regularly see our guys mixing with our headphones as a reference doing exactly that, taking the paint off the walls in the room in the process.  My HD25SP’s have a similar response, and it explains why anything I mix on headphones tends to end up sound far too bright when played on other systems.

One answer might be “get better headphones” – all well and good, but these are absolutely no substitute for listening to, and mixing for, the room you’re actually standing/sitting in, rather mixing for the silent space between your own ears.  Everybody hears the room, only you hear your cans.