Wireless subwoofers ... by gutting an old wireless headphone?

[TheBatsEar]

What are the downsides to using old FM wireless headphones to connect a subwoofer to my system? I never had such headphones, so i really can't say anything about them.

Clearly analog is to be preferred, as it has almost no latency. Wireless digital solutions have at least 17ms (the lowest i have found).

I expect distortion, but does say 1% even matter below 80Hz? Noise isn't a problem either, i guess.

I would gut the headphones, use them as line in and use left for one subwoofer and right for another.

Makes sense, stupid, doesn't work? What do you think?

 

[Philbo King]

A lot depends on the output impedance and voltage of the headphone amp circuitry. Generally speaking, a headphone output and a line output can be interchanged (assuming there is a level adjustment to do gain staging). But the game can change drastically if, for example, the headphones use electrostatic transducers.

 

[TheBatsEar]

A lot depends on the output impedance and voltage of the headphone amp circuitry. Generally speaking, a headphone output and a line output can be interchanged (assuming there is a level adjustment to do gain staging).

Right, i would look for headphones that have a classic potentiometer. Digital attenuation would work, as i likely to have to reset it after any powerloss.
Maybe i can find a proper gain, measure the resistance of the potentiometer and just replace it with a resistor, to make sure i don't change it by accident. Or maybe a bit of scotch tape will do the same trick.

But the game can change drastically if, for example, the headphones use electrostatic transducers.

I don't think these cheap ones do.

The question i have is why isn't anyone using these like that? Why do people buy digital versions instead?
Clearly i must have missed something!

 

[DVDdoug]

I wouldn't expect any "impedance" or level problems. Analog headphone levels in the same ballpark as line-level signals. A headphone output is capable of driving a lower impedance load, but connecting to a higher impedance line-input is fine. Another difference is that headphone outputs always have a volume control.

Why do people buy digital versions instead?

There are advantages to digital (particularly low noise) and overall it's usually better for audio wherever you can use it.

Digital doesn't always have latency but Wi-Fi is shared so it has buffers which add delay. I don't know that much about Bluetooth but there will buffers whenever a computer is involved (because of the multitasking operating system).