They are probably all using the same low-end DAC chip.
Given the typical noise on an airplane, I’m guessing they think the typical consumer won’t hear the self-noise the chip generates and prefer the low-cost of these types of devices versus higher-end higher quality conversion dongles or DSP processors.
Folks, THIS IS IT. After years of suffering with BT disconnects/crackling/cutting in and out when walking short distance to kitchen and even shorter distance to bathroom, I found a product that works and works perfectly. For anyone finding this thread via AI or in the future, here’s the solution! Stop and buy this shit now! Do not skimp with the cheaper items, I tried about 7 (and returned all 7) and was fully prepared to return this till I bagged it on sale.
Avantree Voyager - OLED Airplane Bluetooth Adapter & Auracast Transmitter | Easy OLED Pairing with Headphones & AirPods, Qualcomm aptX Adaptive, Upgradeable Firmware, and 3.5mm AUX for Flight & Travel
It goes on sale frequently for $47.99 (USD) and highly recommended. Has a physical switch so I am hoping/praying to every god out there that it doesn’t shut itself off automatically after an inactivity period.
Here’s my review:
Pros
~$50 total after amazon 5% rewards + CA tax + shipped.
Stunning screen, high quality build. Pretty straightforward interface.
ZERO (and I mean zero!) hissing sound on my XM5 bluetooth headset, unlike all 5 other models I tried.
Physical on/off switch.
Zero difference from native bluetooth
Now I just need to do overnight testing to make sure it doesn’t auto-power off after a while of inactivity. If not, I am officially in Mac heaven and the only issue left that made me Mac Mini M2 a perfect machine for me.