What decibel rating should a noise-canceling headset have, to work well in my plane?
This is an opinion, based on some reported problems. It is not the result of instrumented testing, so opinions may differ. One of the problem scenarios has been described, to illustrate the issues. The owner’s XC2 headset proved inadequate when he moved from his training aircraft into a Sundowner. Note that there is a passive rating as well as an active (ANR) rating. This text addresses the active rating.
The Tomahawk has a lower-displacement, lower-horsepower engine (Lycoming O235, usually with 112 HP ) that is turning a smaller prop. The B23 has the Lycoming O360 producing 180 HP, with a much larger prop. A very large percentage of the noise signature of an aircraft comes from the propeller. It is a certainty that the B23 generates a significantly stronger noise signature than the PA38; it would be like the difference between the PA38 Tomahawk and a PA24 Archer (which also has a variant of the O360).
With the above providing a factual background, look at how the low cost XC-2 ANR compares to something like the 25XL on active noise reduction.
The XC2 is a 10-12 db active, 24 db passive noise reduction headset that retails for $295. It is targeted at the low-cost market, typically the novice flyer in a low-horsepower trainer.
The 25XL is a 25-28 db active, 22 db passive headset that retailed for $595. It was targeted as Lightspeed’s second (actually, third) generation ANR headset, replacing the 20K/20XL. It was intended as a low-cost alternative to $1,000 Bose ANR, and was intended to be a highly competitive, full-function ANR headset for all GA cabin environments.
You probably noticed that the 25XL has two and a half times the active noise reduction of the XC2. For any piston GA aircraft with an engine larger than the O235, you probably need at least 20 db active noise reduction. This is a classic case of getting what you pay for, without realizing that it would not be enough when you step up to a more powerful plane. Lightspeed told this owner that the “headset is being overwhelmed”, without outright saying that perhaps they should be warning buyers that their low-end, low-cost headset may not prove satisfactory in larger piston GA planes. Having said this, it is hard to fault them too much. I can’t think of any manufacturer that takes pains to point out the limitations of their products. That’s why we as consumers have to do our research and make informed purchases.
Personally, I like the Lightspeed products very much, and the company has treated me very well over the past ten years. For what it’s worth, I just paid the upgrade fee to trade two of my 20XLs for two new Thirty 3Gs. I was frankly amazed at the difference. It sounded like the same improvement I experienced when I first purchased the 15Ks, and again when I bought two 20XLs. One of the notable improvements in the Thirty 3G is the near elimination of “motorboating”, which I used to hear during the takeoff roll. I could stop it on the 20XLs by pressing in on the earcups, but it wasn’t worth doing; I just waited it out. The new headset is also markedly more quiet overall than the 20XL.
And one last comment; try to spend the money to get auto-shutoff. It will save you a boatload of batteries!