Active subwoofer for TAS5706

Hi, Hans,

I am not sure I follow what you are trying to do. 

Do you want to use the TAS5602 for a sub-woofer with the TAS5706?

OR, do you want to use some powered sub-woofer with an analog input?

-d2

Sorry for being unclear - I want to connect the subwoofer PWM output of the TAS5706 to a convential (consumer product) active subwoofer, i.e. an ordinary sub with a built in amp of its own. That is, yes I want to use a powered sub with line level analog input.

My question is what component(s) I need to have between the PWM output and the line input of the sub.

Regards,

Hanns

Hanns,

No worries!

I have never tried this, but you should be able to simply LPF (low-pass filter) the PWM outputs with an RC filter and feed it to your amp. I'd set the corner freq around 30 kHz or so.

We often do this with HP (headphone) amps, so I don't expect any issues. For an example, check out the TAS5717 schematic R13/C13 and R9/C20 are these LPF.

-d2

That's great, I'll try this. Thank you.

Hanns,

Yes, sorry, I forgot that part. The EVM schematic almost at the end of the EVM Users Guide. It's a little bit complicated b/c there is a jumper that decides the source of the HP - either PWM from the TAS5717, or analog-input from another chip. But, it's got the LPF that I was suggesting.

-d2

Hanns,

Remember, you need an LPF in there, and I doubt your sub has fully differential inputs, so you will need to go thru a differential to single-ended conversion, too. But, as a bonus, you can use an active LPF in that case!

-d2