When my Co-Captain, Rich Pickett, was offered a pre-release Bose A30 headset for review, I contacted Lightspeed’s marketing department to see if they would provide their newest active noise reduction (ANR) headset: The Delta Zulu.
Lightspeed released the Delta Zulu in late 2022, creating a new niche in aviation headsets: the safety wearable. Still boasting the ear protection of passive and active noise reduction, Lightspeed added two safety features: carbon monoxide monitoring and alerting and customizable hearing profiles via their HearingEQity™ feature in their iOS app.
Carbon Monoxide Monitoring & Custom Hearing Profiles
Of these two new safety features, I found the most important was CO monitoring. When I’m not flying CitationJets, I am usually in our family’s Cessna Turbo 206 or one of the many club Cessna 172s at Plus One Flyers. Older single-engine pistons are notorious for leaky exhaust pipes sending poisonous CO into the cabin. Odorless CO gas can quickly impair pilots with headaches, drowsiness, and possible death.
I tested the headset in a few piston aircraft and, fortunately, did not discover any hidden CO leaks like other Delta Zulu owners have found. And I didn’t have the opportunity to test this safety feature in an actual CO environment, so I can’t comment on its efficacy. But with its iOS app, pilots can program the controller’s smart button to take CO readings to help monitor levels and provide peace of mind.
The other safety feature, custom noise level profiles, didn’t make much of a difference in my experience with the product. Lightspeed says that the hearing test and setup helped users identify hearing issues, and they’ve found the feature to help, but I didn’t see any marked difference with it on or off. I also found it frustrating that I had to retake the hearing test after I went back to adjust a high-frequency level. However, I can see how, in the future, after a few thousand hours of flight time and idle jet engines and APUs blasting on tarmacs, I could benefit more from this feature.
Best New Feature: Rechargeable Battery Pack
The new feature that I appreciate the most is the lithium-ion rechargeable battery pack. No longer will you need spare AA batteries when your battery dwindles; connect the Universal Accessory Connector (UAC) plug and recharge from your plane’s power via a USB-A port. Note that you must purchase an additional cable if you want to go UAC-to-USB-C.
Lightspeed proudly boasts that Delta Zulu “is the first headset to adopt the UAC plug.” They will likely be the last. Why so gruff? Because in an age of attempting to consolidate plug types, Lightspeed requires us to use a non-ubiquitous plug to recharge our headset battery. So, now that means three cables in the flight deck to handle my iPhone (Lightning), iPad (USB-C), and now one for the Delta Zulus (UAC).
Other pilots have griped about this issue, and I agree with them. Switching from a UAC plug to USB-C is wise for future versions (and yes, certification costs may prevent that from happening soon).
If you wish to forgo the rechargeable battery pack, Lightspeed includes a battery pack cartridge for those who would rather rely on two AAs to power their headset’s ANR, safety features and Bluetooth functionality.
An App — But for Only Half of Us
Another new feature is the Lightspeed App, but currently only for iOS users. The ANR, CO monitoring and Bluetooth work independently of the app, but you won’t be able to use the HearingEQity™ hearing test and profiles, nor will features like safety metrics or audio recordings and playback be available.
If you don’t own an Apple iOS device, and you do wish to customize the hearing test for your unique inner ear architecture, you’ll need to ask an iPhone buddy to download the app for you and borrow it for about 10 minutes as you pair, setup, and run the audio test.
As an iPhone user, I could use all the available features of the Lightspeed App as of this test. The audio recording function was a big draw for me since we record lots of videos; capturing quality audio is important and sometimes frustrating. The quality of the audio recordings was very impressive and true-to-source and seemed better than what we captured with our inline headphone jacks.
Controls for recording, waveform monitoring, and the app’s propensity to continue recording even when the headset is powered off were frustrating. Thankfully, the app doesn’t require FAA oversight, so their bug fixes and update timing should be faster than a UAC plug conversion. And I have heard of an upcoming drawing pad feature I’m itching to use.
But How Do They Feel?
Ah, the fit! I feel for any product manufacturer attempting to make a one-size-suits-all headset. Pilots’ heads, jowls, mustachioed parts, and ear bits are all shaped differently. The Delta Zulu felt good on me and my slightly smaller head and narrower skull. The clamping force was similar to Bose A20s but more than the new A30s. I’m not a fan of the headband spring providing the clamping force. We own an old Lightspeed Zulu 2, and that headband has given up the ghost and won’t clamp securely. Compare that with the spring-controlled clamp of the A20/A30s. The Bose products don’t change in clamping force over many years.
The boom mic is fixed to one side (the left) and isn’t swappable like Bose’s headsets. The boom is also shorter. The mic picks up audio well, given that it’s not centered in front of my mouth, but I prefer the Bose boom length.
The ear cups feel fine, but the drum-like design was a big issue for me. Both Rich and I noticed that any tap or strong cord tug produced an irritating vibration on
our eardrums.
It’s hard to describe in words, but imagine putting a cup over your ear and tapping the bottom of it. Your eardrum will receive those vibrations. Maybe we’re super sensitive with our hearing (don’t confirm that with our wives), but I did the same taps and cord taps/tugs with my A20, and the effect was not as irritating or painful as in the Delta Zulu.
ANR and Sidetone
The critical component justifying the high cost of any aviation headset these days is ANR/ANC and Bluetooth functionality. The latter was excellent. Bluetooth powers on immediately when you turn on the unit, pairing was smooth, and the audio quality was excellent.
However, the ANR was not an enjoyable experience. What I found for myself (note: my head and experience may differ from yours) was a varied noise reduction experience. As I moved my head to look for traffic, talk to others, or adjusted my aching body from sitting for so long — depending on my head position — I would experience a noticeable decrease in the ANR functionality and different sound intrusions.
This ANR experience became very distracting during my last flight with the Delta Zulu in our Turbo 206. Somehow the flight deck noise and how the ANR reacted to it produced loud wah-wah-wahs in my ears. Combined with my already sensitive eardrums due to the drum effect, I removed the headset for the remainder of the flight and put on my trusted A20s.
Lightspeed’s customer support replied that it may have been an ear cup fit issue, but I tried the same movements with the A20 headset, and while variations were present, they were not as distracting or irritating as they were with the Delta Zulu.
Lastly, the sidetone (the way you hear yourself while talking into the mic) had a slight yet perceptible delay and a distorted sound to it that both of us found unpleasant. The Bose products do not have this delay or distortion in our flight tests.
Are Delta Zulus for You?
All my issues aside, the Delta Zulu headsets are likely excellent — for the right head and ears. I am a bit biased, too, I have used the A20 for many years, and its active noise-cancellation tech is remarkable.
I was genuinely excited to try out all the new features and see if Lightspeed had improved on prior Zulus. Unfortunately, I didn’t have that experience, and I will stick with Bose until a future Lightspeed revamp comes along. And I’ll be excited again to give them another shot.
Should my findings rule this headset out for you? No way! All headsets react differently to each of us and the aircraft we fly. I may have a head that loves Bose’s form factor, or my ears may be too sensitive. Please refrain from any verdicts until you try the Delta Zulu at your local pilot shop, or borrow them from a friend and see how they work for you.
