Headphones – DJ roundabout

Wireless headphones have been really popular in the last few years. Nowadays many people use good Bluetooth headphones with their mobile. But can they use it with their mixer or DJ controller? And is it suitable? DJ mixers and DJ controllers do not have Bluetooth transmitters. Therefore you cannot DJ with wireless headphones. There is a good reason behind, Bluetooth adds a latency (~150 ms) that makes beatmatching impossible. The only way to remove latency is to mix with a cable. Sure it is still possible to buy a Bluetooth transmitter to make any DJ equipment wireless. But that does not change the fact that latency will be here. Even though 150 ms may not seem much, it is. I will explain why in this article. I will also explain the reason we do find DJ brands making wireless headphones. Why you shouldn't DJ with wireless headphones First, it is good to remind that wireless headphones have batteries. Therefore, it may happen that you run out of battery while mixing. From my point of view, that's a first non-negligible point. You won't like passing for a fool in front of a crowd, do you? But that's not the main issue with wireless headphones. The main problem is latency and its consequence on beatmatching. Let's say you are mixing two songs at 120 BPM, a common BPM in dance music. You have one song playing through the speakers and a second through your headphones. 120 BPM means 120 beats per minute. Therefore, in 60 seconds or 60,000 ms, you have 120 beats. That means you have a beat every 500 ms (=60000/120). When you beatmatch two songs thanks to the headphones, it should be something like this: Here the two songs are perfectly in sync. The beats come as one, the transition is smooth and good to the hears. With regular wired headphones, this is what you hear in both the headphones and the speakers. Now let's say you monitor the song B into wireless headphones while song A plays through the speakers. You beatmatch the songs and it feels perfectly in sync like the above. At least it seems with the headphones. Then you push the fader of song B up, and what you hear in the speakers is a total mess. It's totally out of sync! Indeed it is, because the Bluetooth added a 150 ms delay to the song B in your headphones. But this delay does not exist in the mixer, only in your headphones! What you hear in the speakers is like this: Indeed, in your wireless headphones, song B was in sync with the song A played by the speakers. But your headphones added a 150 ms delay. That means that on the mixer, song B was in fact in advance by 150 ms! My diagram above is at scale. You can see how 150 ms is huge! The crowd will clearly hear the double kicks and will complain. Eventually, that will ruin the mood and probably your future booking. To put things in perspective, let's say you play a song at 119 BPM with a song at 120 BPM. You know how a difference of only 1 BPM can be horrible if not beatmatched, right? Well, after 1 bar playing, the offset between the two songs is only of 16 ms. The Bluetooth latency of 150 ms is 9.4 times more than that! This is very big in comparison and you understand what a disaster it can be. Even without beatmatching, this latency will be very annoying to you in your headphones. Indeed, by monitoring the speakers (the master), you will hear the song twice, like an annoying echo. This is a big discomfort that will get on your nerves, believe me! Why wireless DJ headphones exist then? You have probably noticed that some wireless headphones tagged "DJ" exists. Even among acclaimed DJ brands. Thus, you can find the Pioneer HDJ-X5BT (DJ Brand) or the V-MODA Crossfade Wireless (famous among DJs though not a DJ Brand). V-MODA has been made popular by DJs thanks to its customizable plate. But at first, the aim of V-MODA was never focused on DJ. It was to offer audiophiles great headphones in terms of sound quality and in terms of style. Something many audiophile headphones lack. If you look at the V-MODA page, you can see that the product was never branded for DJs, but targeted to sound engineers. In that case, a delay is not an issue because sound engineers are not dealing with live music. Regarding the Pioneer HDJ-X5BT, that's different. The product is clearly branded for DJs as the product page shows. However, the HDJ-X5BT uses the aptX low latency codec, which is quite rare nowadays. The AptX low latency codec has a latency of 40 ms, which is quite lower compared to regular wireless headphones. But 40 ms can still be heard by musicians and DJs. In fact, Pioneer says itself on their page: If you use your headphones for DJ monitoring or you simply forget to charge them (we’ve all been there) you can also listen via the included 1.2 m coiled cable. Pioneer says itself you cannot DJ with the wireless function on. At least that's not recommended. You can still use the wireless function at home or in public transports, but not really to DJ. Here you have to understand that this is a marketing gimmick. Yes, it is wireless, yes it is a DJ headphone, but it is not really a wireless DJ headphone. It just proposes to do both, but not necessarily at the same time! Don't get me wrong, putting the aptX low latency codec in here is great and a nice innovation. Just remember that you need a transmitter that supports this codec, otherwise the headphones will work with much more latency. But again, 40 ms is still too much when handling live instruments (ask your musician friends!). Here is a nice video showing the difference in latency between several Bluetooth devices. That will help you visualize how bad it can be for DJing and what the aptX low latency codec improves: https://www.youtube.com/watch?v=4_bypcPW5O4 Conclusion It is not possible to DJ with wireless headphones due to the Bluetooth latency. In fact, that's the reason why DJ manufacturers do not bother to add Bluetooth transmitters into their mixers. While they do brand some DJ headphones as "wireless", that's mainly a marketing gimmick. If you really insist on going wireless, then make sure to select an aptX low latency device. In that case, the latency should be around 40 ms which some may find acceptable. Just do not forget to also buy a Bluetooth transmitter. The Pioneer HDJ-X5BT is the only DJ headphones I know that meet this criterion. But in my opinion, 40 ms is still too big to beatmatch. You have been warned!