XPR-2 Balanced Input Impedance=>line level high pass filter

[harsh]

Hello,

I'd like to use a simple PLLXO (Passive Line Level Cross Over) on my XPR-2 but I'm confused  about it's input impedance.

Spec sheet says
Input Impedance:
100k Ohms (unbalanced).
51k Ohms (balanced).

Over the balanced input, is it 51 k Ohms per leg or something else?

Thanks!

[harsh]

No one has a clue?

[Gary Cook]

From memory for pro gear the input impedance is measured to ground, so for the XPR-2 it's 51K Ohms as quoted.

Cheers
Gary

[harsh]

Thanks Gary!
So 40 nF capacitors in line with each signal leg (hot and cold) to get around 80 Hz first order high pass filter, -6 db slope combined to -12 db slope on speaker output.
I will confirm when done.

[harsh]

Finally took time to do it, it works as expected.
Stacked a few 10 nF polystyrene capacitor (cheap but really good)

Might be subjective but it sounds far better than XSP-1 included high pass filter, with the bonus of staying fully balanced inside the pre amp.
Recommended!

[moko]

did you measure the frequency response ? adding a high pass passive filter to already finished speakers is not easy as adding active filter. here is why. look at the second graph. i think if you want the best way to integrate your speakers with your sub you should only using the crossover setting from xsp-1 or adding active crossover with pre-amp running fullrange.

BUT (it's a big but) if your ears happy with current setup, you can leave it like this.

[harsh]

I agree with you, messing with a speaker crossover by adding a high pass filter here is a bad idea.
But it's not what I am doing.
I'm using a line level high pass filter, between the pre and the amp.
It is working only against the amp input  impedance and doesn't disturb the speakers crossovers.

I made a quick mesure with Rew to confirm it's working as intended.
I only had to adjust the phase on the subwoofer, but that's all.

And yes, it sounds gorgeous!