- Written by John E. Johnson, Jr.
- Published on 12 May 2008
On the Bench
Distortion tests used an 80 kHz bandwidth.
At 1 kHz, 100 dB, and 1 foot, THD+N was less than 0.3%, primarily third order. The signal was coming from the midrange drivers, but since the mids and woofers were in pairs, I kept the calibrated microphone in the same position for all the distortion measurements, i.e., directly on-axis with the tweeter.
At 10 kHz, distortion was less than 0.8%. In this case, the signal was coming from the tweeter.
For THD+N vs. Frequency, the EPS2's performed admirably. Notice that the distortion in the lower frequencies competes well with a dedicated subwoofer. Distortion stays generally well below 1% from 100 Hz up through 20 kHz. Overall, quite excellent.
Room response was all over the place depending on distance from the microphone. This is because there are multiple drivers emitting the same signal, and is one of the drawbacks of multiple tweeters, midrange drivers and woofer drivers. However, the benefits are a much larger soundstage and the ability to play intense music at higher SPL without too much distortion.
The quasi-anechoic response showed this same tendency. Note the dip at 4-5 kHz which is reflected in the room response as well. It is not a big deal. Just something a purchaser of big speakers needs to be aware of. The impulse response measurement used a window of 0.75 ms, so it is accurate only above about 2 kHz, which is the region I was interested in for this comparison.
The impedance/phase curves show that the EPS2's are truly a 4 ohm load. The phase stays within ± 400 between the usable range of 20 Hz to 20 kHz, so this should not be a problem with most amplifiers.
Well, I have to say, "WOW!" I certainly was not disappointed with my first in-lab experience with Montana loudspeakers. They are beautifully constructed with the highest quality parts, and the sound is definitely "dynamite". As the ESP2's are just the mid-level model in their line, I can only imagine what something like the WAS would sound like.