Martin Logan / Jonathan Foulkes - SL3XC
This design arose out of my desire to have a center channel that
could keep up with the Monoliths. While bass is well handled by the
IB sub, the mid-bass region as well as midrange and highs, all
suffered from power compression issues with prior factory designs.
Basically, I needed a center that could play cleanly across the full
spectrum at and beyond 105dB SPL.
Since creating that level of output cleanly requires significant
size, I am fortunate to be able to accommodate a large center behind
my perforated, acoustically transparent screen.
I go into detailed design goals and parameters as well as full
detailed description of the build process (with tons of pictures and
measurements) on this thread over at the
Martin Logan Club.
The result is an astoundingly coherent front soundstage. The
blend of L/R with the new center is perfect. And its ability to play
loud and clean is downright amazing.
If anything, it has better mid-bass performance than the
Monoliths.
The specifications are:
- System Frequency Response
77 - 24,000 Hz +/-3dB
- Electrostatic Frequency Response
125-24,000 Hz +/- 2dB
- Line Array Frequency Response
77-2,000Hz +/- 3dB
- Crossover Frequency - Using
DBX DriveRack 4800
ESL to Line array: 420 Hz at 24 dB per octave
Line Array to Sub: 80 Hz at 24 dB per octave
- Dispersion
Horizontal: 30 degrees
Vertical: 4' Line Source
- Sensitivity
88dB/1 watt/meter
- Power handling
High
- Supplied Amplifier Power
ESL
- 800 watts
Line Array - 200 watts
- Jonathan's recommended amplifier
Sunfire Amplifier
- Impedance
ESL -
nominal 4 ohms; minimum 2 ohms - Direct drive
Line Array - 11 ohms
- Weight
154 lbs
This is an older pic of when I just set the speaker up. The entire
wall behind them is now covered with RealTraps MiniTrap HF
treatments to mitigate the rear wave.
