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jhharvest t1_isf3ykv wrote

Yes, correct: Bluetooth headphones will have a DAC and an amplifier built into them.

But the second question, if I understood correctly, you're asking if you have a pair of Bluetooth headphones which also have an analog input, if you could plug another pair of headphones into that input and it would act as an output? The answer is most likely not. It would depend on how the circuit is designed but any reasonable headphone manufacturer will disable the Bluetooth if the analog connector is enabled.

If you're asking can you tear open a pair of Bluetooth headphones to get to the DAC and amp inside, then sure. But you can probably just buy the same chip off AliExpress for less money and hassle.

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GabolMarchewka OP t1_isf6uw2 wrote

Shit, if that's what you understood from the second question, then my English is worse then I thought xD. Byt being serious, what I meant was when you have a pair of Bluetooth headphones which also have analogue input (I have m50xbt2 for example), if you connect them to your computer by cable (headphone output), is there a way to use their built in dac. In other words transmit a signal (via this cable) that is digital so that it will be converted by the headphones itself and not the motherboard's dac before, or does the headphone dac work only while Bluetooth is on?

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audioen t1_isf7tux wrote

No, there is probably no protocol, e.g. digital audio protocol, that the headset would receive over the analog cable. Also, it is usually not described if the analog audio will be used and sent to amplifier, or whether it needs to be digitized first. Chances are that the amplifier in the headset is class D and it can only work from digital signal (it is both a DAC and amplifier at the same time).

At least noise cancelling headsets usually have wildly different frequency response when you turn them on vs. when you connect analog to driver and drive it directly. I can't quickly find out the answer to this question: does the sound change if the headset is turned on vs. off? In the headsets I have owned that have had optional wired connection, the sound has always been absolutely terrible when powered off because manufacturer actually fully relies on DSP (or whatever amplifier circuit) to fix the frequency response of the driver.

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jhharvest t1_isfcwfx wrote

Right, gotcha. Analog inputs in general wouldn't be tied to the digital input of the DAC (this will be true regardless if you're talking about a pair of headphones or any other device), and besides your computer's motherboard wouldn't be able to output a digital signal from the headphone socket*.

(Well, with one caveat: in the past some manufacturers had a combo analog + Toslink connector - Toslink is optical digital connector so your receiving device needs an optical input.)

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