Ingo Noka

Blessed silence – Lightspeed Zulu

In Gear on April 16, 2011 at 6:40 pm

Lightspeed Zulu in hard case

The Zulu Headset has been my first “aviation” purchase and I am pleased to say that it delivers everything I hoped for.  I spent considerable time on the computer to research active noise canceling headsets.  I looked at the Bose A20, the David Clark H10-13, the Sennheiser HMEC 460/350 and the Lightspeed Zulu.  The Internet is great for this sort of research, but there are so many contradicting reviews and opinions that it is hard to decide which one to believe.  The Lightspeed, however, had consistently better reviews than the others and it is not even the most expensive device.  I also liked the look of the “magnesium alloy” ear cups, so I went for the Zulu and do not regret it.

How to buy

I bought the Lightspeed Zulu from the Sporty’s shop in the US and had it shipped by vPost.  Both Sporty’s and vPost handled the whole transaction with professionalism.  I have no complaints and plan to continue patronizing this shop in the future .  The headset itself was USD 850.  I also bought five microphone muffs for a total of USD 27.50, replacement ear seals for USD 25 and a replacement head-pad for USD 13.95.  The total purchase was USD 916.45.  Shipment to the vPost facility in the States was free.  For every shipment over SGD 400 you have to pay a 7% customs fee of the total cost plus shipment, which in this case came to SGD 84.54.  The shipment cost was SGD 31.94 (which includes a discount of SGD 20 for paying with my UOB card).

What is in the box

What is in the box

What is in the box

The box contains a protective hard case for the headset, the headset itself, batteries, a microphone muff, two cables to connect the headset to auxiliary audio inputs, a user manual and an extra cable clip.  The manual is good enough, though not a beacon of clear English or design.


Headband adjustment

The Zulu has no controls at the ear cups.  All buttons, sliders, etc are located on the controller, which also houses the batteries.  The basic aircraft audio function and the active noise canceling are plug-and-play and do not require any explanation or a handbook.  Needless to say that the headset would continue functioning as a normal passive noise canceling headset of the batteries go flat or the electronics of the active noise canceling stop working.  The configuration can be changed with little dip switches, which is not the most intuitive way, but as far as I can tell there is no reason to change the default settings for a standard GA aircraft, unless you have a very new audio panel with stereo output.  The Bluetooth interface is controlled by just one button and it requires some discipline to make it work in a consistent manner.  Trial and error will likely not work, especially not in-flight.  There is one more small button, which switches on and off the fading away of the auxiliary input when the ATC activity.  I have not been able to try this one out.
The Zulu has fairly robust sliders on both sides that allow adjustment of the head band to different head sizes.  It has a nice solid feeling to it.  I think it will last and won’t slide unless you want it to.

Volume Controls


Depending on the audio source, the Zulu provides different options to control the volume.  The first and most obvious one is the two sliders, which control left and right volume for the aircraft radio input.  This control only affects the input from the audio panel and has no effect on the auxiliary or BlueTooth input.  If the hearing on your left and right ears is different, having separate volume controls helps you compensate for that.  My ears seem to be equally good or bad, so I move both sliders to the same position, which is easily done, due to the side-by-side design of the sliders.  The aircraft audio is really loud when the radio is cranked up to maximum output and I had to reduce the volume down to 30%-40%.
The second control affects only the BlueTooth audio.  There is plus and a minus button to reduce or increase volume.  On my headset only the plus button generates a beep when I press it.  I also noticed that after pressing the button it takes a while before the volume is increased or decreased.  So pressing either buttons in fast succession will only register every second or third time.
There is no control for the auxiliary input.  The volume can only be controlled at the output device, i.e. the computer, mobile phone or MP3 player.  Of course, changing the volume at the Bluetooth device, the radio or the aircraft audio panel will also change the volume.

The Battery Compartment

The battery compartment

The batter compartment with dip switches

The Zulu needs two AA alkaline or lithium batteries.  The user handbook says that Lightspeed does not recommend rechargeable batteries.  I think this has more to do with the faster discharge rate of rechargeable batteries, than with actual compatibility. I guess, if you want to be sure the headset will work when you take it out of your back after a month or so, it would be better to use the recommended batteries.  The battery compartment cover is solid and firmly attached to the controller.  However, I would say it can only be opened with two hands, which may be an issue if batteries have to be replaced in mid-flight.  A little band ties the cover to the controller, so that it cannot fall to the floor when it is open.  Since half of one battery is covered by the controller and the other battery is held by two clips, the batteries won’t fall out when the battery compartment is open.  Again, changing the two batteries with one hand is probably not possible.

Cord Clips

Cable clip

Lightspeed includes two cord clips with the Zulu.  The clips grip the cable tightly, so that the clip would neither slide up or down the cable nor rotate around it.  A strong metal spring keeps the clip firmly attached to your clothing.  The clips are big enough to grab anything up to a thickness of about half a centimeter.  While the clips are surely not the most important feature of the Zulu, they add to the professional feel of the Zulu and are a welcome departure from the flimsy clips that often come with mobile phone headset and the like.


My wife’s kitchen scale shows 401 g (14.14 oz) for the headset itself and 592 g (20.88 oz) for the headset including controller, cables and batteries.  This is close to the 13.9 oz. mentioned in the user manual.


Microphone without muff

The mic boom can only be used on the left side.  It can be rotated upwards for storage or to get it out of the way if you want to use the headset to listen only, but it cannot be rotated 180º to wear it on the right side.  The boom is long enough to reach my mouth comfortably.  It is rigid and stays in place without the need for adjustments over  time.  The mic also has a “talk” side, which also prevents using it on the right.  The Zulu comes with the usual Mic muffs and you can buy replacements relatively cheaply.

Active Noise Canceling (ANC)

ANC is an impressive bit of electron wizardry.  The drop of noise when the ANC is switched on is very noticeable.  It works best with low-pitched noise.  For example the noise of my aircon at home is cancelled out almost entirely.  For listening to music this is quite handy.  In the aircraft it works well too.  The engine is quieter and static noise is less of an issue with ANC on.  At the same time I could hear the stall warning (during landing !) perfectly fine.  A couple of times my instructor Captain Singh was surprised that I didn’t have a problem while he had to fiddle with the audio panel because of too much noise in his headset.
As soon as the headset is switched on, active noise canceling will be on as well and there is no way to deactivate it while the headset is on.  So it won’t be possible to use the headset with a Bluetooth device without ANC.

Ear Cups and Ear Seals

Earcup in storage position

Ear-cup seals

The ear cups are not very big, but fit over my ears quite comfortably.  (My ear is 7.5 cm by 4.5 cm.)  The seals are very soft and a pleasure to wear.  Somebody at the flying club pointed out that similar looking seals have disintegrated in great heat on other headset types, but after, admittedly very light, use there is no sign of that yet.  The cups also look much smaller on my head than other headsets.

Passive Voice Canceling

It is hard to tell whether the passive noise canceling is better or worse than other headset’s.  My personal impression is that it is better than the passive Sennheiser and DC headsets we use at the club.  I am not really qualified to tell since I usually use Bluetooth and auxiliary audio which do not work with active noise canceling switched off and in the aircraft I haven’t used the headset without active noise canceling for any significant period of time either.


Bluetooth works as advertised, which is to say it has the same issues with cumbersome setup and erratic behavior as any other bluetooth device.  I managed to connect the headset to my Macbook Pro and to my iPhone.  At no time was I asked for the passcode as indicated in the Zulu user guide.  On the MBP I  had some problems with noise and static, which I do not have with the iPhone.  Bluetooth in general is often unreliable.  At one point I had the Zulu connected to my iPhone and could do phone calls, but I could for the life of me not figure out how to send the iTunes audio to the headset too.  The iTunes music insisted on coming out of the phone’s loudspeakers.  I had to completely restart the phone and pair the headset with the iPhone again.  For inflight phone calls the setup is probably not reliable enough and should only be used as a last resort if no other communication is available.  To have some assurance that the headset would be connected to the phone constantly, I would use the following pre-flight checklist for inflight bluetooth connection:

  1. “Forget” the headset in the iPhone’s Bluetooth settings
  2. Switch off the headset
  3. Restart the phone
  4. Pair the headset with the iPhone
  5. Call your most important number to have this number as the last called number
  6. Keep the phone where you can reach it in mid-flight

Step number 5 allows me to call the stored number by simply pressing the Bluetooth button on the headset controller.  To have the number registered as last called number it is ok to hang-up before the other parties answers.

Important: I have not tried this, but according to the user handbook, the audio from the Bluetooth will not fade into the background when there is a transmission from the aircraft radio.  This is a function that apparently only works with auxiliary audio input.

Using the Zulu as a headset for phone calls at home

I have tried this in a longer call today and I cannot recommend it.  The other caller complaint about echos and had a hard time hearing me.  The Zulu also has no side-tone, i.e. you cannot hear yourself when you speak.  Since the noise cancellation is so good, this is very unpleasant.  (This reminds me that if I buy a hand-held transceiver I need to buy one with side-tone.)

Battery life

I cannot tell yet how long a pair of AA batteries is going to last.  My son used the headset for hours (playing online games) with the original set of batteries that came with the Zulu and so far there has been no noticeable degradation in the Zulu’s performance.

Auxiliary audio input

The Zulu controller has a socket to connect a standard headset cable and Lightspeed included a cable to connect the Zulu to a phone, an MP3 player or a computer with an audio in/out (or just out) socket.  The auxiliary cable is low quality and is not designed specifically for the Zulu (it has its own microphone, which tells me it is meant to be used for a phone).  The connection on the headset side looks very solid, but I am not so sure about the dimensions.  It took some wiggling of the connector to get a clear signal on both stereo channels.  Once you get a good connection, just do not touch it anymore and everything will be fine.  For use in in-flight this is questionable, but I haven’t used it in the aircraft, so cannot say for sure.

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