[JohanW]

I have a BMW E91 2006 with HiFi option. I am looking for a DSP and checked out the P-DSP from Helix. I like the user interface but the problem is that P-DSP doesn’t support differential balanced inputs (only high level inputs with fixed 10v sensitivity).

Now Helix has released the next model which has differential high and low level inputs.
The input sensitivity could be changed on the high level input.
The input sensitivity for the low level input is 4V and the impedance is 5kOhm.
4V is a little bit too low for the HiFi HU which outputs 5V.
The high level input impedance is only 30Ohm which would require the HU to deliver 170mA/channel.
Would my HU manage to deliver this?

Any help is very appreciated.

[kaigoss69]

That should not be a problem. As with any source unit, you have to find the point where distortion is produced. The distortion can be from the HU itself, or from the inputs of the processor, it doesn't really matter. Then make sure you never exceed that particular volume level.

[JohanW]

Originally Posted by kaigoss69

That should not be a problem. As with any source unit, you have to find the point where distortion is produced. The distortion can be from the HU itself, or from the inputs of the processor, it doesn't really matter. Then make sure you never exceed that particular volume level.

Do you mean I should use the low level input on the DSP?
I could try to use the high level input but I am a little bit afraid the HU could be damaged (to high current).

[cdgatti]

You would want to use the low level input (0-4V). The hi-fi head unit only puts out the 5V when cranked all the way up to where it is already clipping.