Center Channel Speakers
- Written by John E. Johnson Jr. and Cynthia B. Johnson
- Published on 26 August 2013
On the Bench
I tested the Stage X with a calibrated microphone placed 1 meter on-axis, except where specified, from the center of the speaker, which was 24" off the floor on a stand.
At 60 Hz (output from the woofers), THD+N was 1% at 90 dB. At 50 Hz, distortion rose significantly, so the speaker is tuned for best use at 60 Hz and above.
At 1 kHz (output from the ESL midrange panel), distortion dropped to well below 1%. This is excellent.
And at 10 kHz (output from the tweeter), distortion was less than 0.5%. Again, quite good.
Here is the room frequency response, at 1 meter, on-axis. You can see the dip in the midrange that I heard. Again, this can be managed, if you wish, with your processor's room correction feature. Response falls off rapidly below 60 Hz.
At 450 off-axis, the high frequencies are down only a very small amount compared to most other speakers.
The impedance appears to average about 6 Ohms, with a high of 16 Ohms at 10 Hz and a low of 2.7 Ohms at 3.8 kHz. This is an improvement over older ESLs, which dipped below 1 Ohm at 20 kHz. So, it would appear that a good quality receiver would be able to drive this speaker.
The phase deviation from 00 is mostly capacitive, which is not surprising since an ESL is like a big capacitor.