Can I Have Two Headphones Connected to the HT4106 at the Same Time?
The HT4106 normally supports Dual Link, meaning you can have up to two headphones connected to the transmitter at the same time. You can connect either Avantree headphones as well as Bluetooth headphones from other brands. Both will work. However, there are a few caveats to this:
The HT4106 set, which consists of the Audikast Plus transmitter and the TWS106 earbuds, DOES NOT support dual link with other aptX codec headphones. This means you can not connect an additional aptX headphone to the transmitter.
As a result, we don't recommend to use the HT4106 with two aptX headphones at the same time. TWS earbuds and other small, compact devices often have miniaturized internal antennae which can impact the overall range.
The HT4106 set supports Dual Link with non-aptX headphones such as Airpods, Bose headphones, and other headphones that don't support the aptX codec. However, they don't support most of our headphones, such as the Ace 130 or AS90T, because most of our headphones support the aptX codec.
We are working on a DFU to downgrade the aptX codec to SBC, which will let you freely Dual Link with the HT4106. This FAQ will be updated when it's ready!
Here are some suggestions for Bluetooth Sets that support Dual Link:
Earbuds
Audikast Plus Transmitter + 2x TWS116
Headphones
In addition, due to the bandwidth constraints of the Bluetooth 5 specification, the 2nd pair of headphones must connect to the HT4106 using the standard Bluetooth SBC (Sub-band codec) only. That's why you may notice that your 2nd pair of headphones has more audio delay than the 4106.
Any other codecs such as aptX, aptX-HD, AAC, LDAC etc. will take up too much bandwidth and may lead to an unstable connection. Please check your headphones' user manual to verify that they only use the SBC codec. If it lists other codecs in addition to SBC, then the headphones are not suitable, leading to the aptX issue listed above.
For more information: