Wireless headphones - do they have a hidden secret that spoils your sound?
Question from an Audio Masterclass visitor...
Do you have any advice to give on headphones, other than that they should be closed-back? Specifically, I would like to know what you think of wireless sets, as compared to traditional wired ones.
Thanks in advance
Pieter van de Paverd Luxembourg
P.S. Congratulations on the good work - I always find one and sometimes several articles of interest to me, in every newsletter!
David Mellor responds...
My personal favorite headphone at a reasonable price is the Sennheiser HD 480. Headphones though are very personal and I am reluctant to make a recommendation.
The HD 480 is open back. I wouldn't recommend any closed back headphones for pleasure listening or assessment of audio quality. The sound is always too 'boxy'. However there are many sound engineering applications where the freedom from leakage is very important.
Now, regarding wireless headphones. I haven't gone so far as to survey every option on the market (I have many more interesting things to do!). However, I would strongly suggest that you check specifications to see whether there is any form of compander system in use.
The problem with anything wireless is noise and interference. So the signal-to-noise ratio of such a device is likely to be degraded. Consider the noise on an FM radio for example - it rarely reaches a standard that would be useful for professional sound engineering purposes, even in ideal conditions.
To combat noise therefore in many of these systems, the audio is compressed in the transmitter. The ratio would probably be around 2:1 as higher ratios have in the past been found to be too harsh. But this would be the entire dynamic range, so this is a hell of a lot of compression.
The purpose of this is to make the audio signal much stronger than the noise and interference. A reverse 1:2 expansion takes place in the receiver.
This is useful, but the problem is noise modulation. The noise level will now change according to the level of the signal. It can be quite unpleasant.
So when you choose a system, listen carefully. Can you hear the noise floor changing in level? Take the headset far away from the transmitter so you can hear the effect clearly. Then approach to a more practical distance and see if it is still audible.
I would not recommend wireless headphones for critical monitoring. But for foldback to musicians in the studio, they could cut down on a lot of cabling. I would say that for that application, their drawbacks could easily go unnoticed.