Preamp & Subwoofer impedance mismatch?

I have Primaluna Dialogue Three preamp which according to Stereophiles has around 4000 ohms output impedance at around 20Hz and 2400 ohms output impedance at 1KHz and 20KHz

Right now I am hooking it to a Parasound A21 with input impedance of 33K ohms

However, I want to add a JL Audio E112 to my setup and was on planning using the build in high pass filter feature of it

The problem is, I just find out E112 has input impedance of only 10K and concern the mismatched impedance between my preamp and E112 will cause bass roll off

Do you guys think if I can eliminate the issue by add an active crossover between the preamp and subwoofer?
(I am looking at either JL Audio CR-1 with unbalanced input impedance of 50K or Marchand XM66 which either has 50K or 100K input impedance?)


Showing 1 response by ieales

I use a passive level control of my own design, -10db is about 6.7kΩ in series with the CD player driving a Force sub with 10kΩ nominal impedance in parallel with main amp.

I used it with a Parasound A23 which also has 33kΩ input impedance. Currently driving a NuPrime ST-10 with 23.5kΩ impedance. Measured output is flat in both cases.


However, I would not recommend using the HiPass feature of any subwoofer. IMO 4th order Linkwitz-Riley filter in the very region where the mains are beginning to fade is not the best solution and creates difficult to integrate slope and phase issues, particularly with 3rd party subs. See No mention is made of the main speaker capability, but unless they already have substantial low end capability, the lowish 130Hz E112 corner frequencies would give me pause. My experience has found that a simple passive XO for the mains and integrating a sub with higher corner, lower order filters on its own may be a better solution as there is a wider region for ’melding.’ Steep filters can be problematic with a sub and mains cut from divers sonic cloths.

See for more.