[StereoNut]

Hello all!

I own a pair of VR-4 Gen.III speakers with the 2012 mods done by VSA. The "old" (original) cross-over specs for my speakers (before they had the 2012 mods done) were 150 Hz and 2.6 kHz.  Can anyone tell me whether the crossover specs have changed now with the 2012 mods done and if so, what are they!?!

Thanks!
Bill

P.S. - I'm looking into trying to Bi-Amp them. 

[Albert Von Schweikert]

Hello Bill,

When we designed the VR-4 Gen III upgrade a couple of years ago, we changed the upper crossover to the tweeter to 2kHz.  The lower crossover point is still at 150Hz.
By the way, the crossover slopes are non-symmetrical and do not follow text book theory.  We're basing the crossover filter slopes and phase shift on the driver's acoustic responses, and no drivers on the market have symmetrical roll-offs in their pass bands.

To design a good electronic crossover, I would use a 6dB/Octave filter using passive parts, calculated on the amplifier's input impedance.  This type of simple crossover will allow the midrange/tweeter amp to have some protection from over-modulation from bass frequencies.  You won't need anything more than 6dB on the woofer amp, either.

Cheers,

Albert Von Schweikert

[StereoNut]

Thanks, Albert.  I will pass the info. on to my much more tech savvy buddy who is helping me with this adventure.  I will keep everyone on AC posted as things progress. 

Bill