$600 MTM Horizontally Oriented Measurements

This is one beautiful speaker. Naturally, we wanted to look at higher-end designs and see to what degree higher quality drivers improve the overall response versus what if any limitations these more expensive speakers have with wave interference. This traditional MTM design has the crossover point at 4 kHz, which is rather high. This unfortunately increases the frequency areas where the two midrange drivers are interfering with each other, but at this point we can just assume. Let’s turn to the charts to see what we get for our hard earned 600 dollars.

In the 1/24 octave chart below you can see some significant wave interference, ranging from +8 dB additive to -10 dB of cancellation. The frequency range where the two midrange drivers would be interfering with each other is highlighted by the yellow bracket. The variation in this range is where we will also be scoring the speaker and comparing against other configurations.

In the 1/6 octave chart below, you can see that the interference between the two midrange drivers is audible. In the upper midrange we can see over -6 dB of cancellation and almost 4 dB of wave reinforcement. You can also see the tweeter has audible off-axis attenuation, but it’s important to emphasize that these tests only reflect variation from the on-axis response and how well we can avoid wave interference. This speaker series has a wonderfully musical sound quality, and I’d take rolled-off beautiful over well-dispersed junk any day.

When the variation of the frequency is calculated at various angles, the average standard deviation of this MTM speaker, from 80 Hz to 4 kHz is 1.62. It’s a beautiful and musical speaker, but the off-axis response of the midrange drivers is mediocre. In this design, the midrange drivers reproduce over five octaves compared to the tweeter’s two, so let’s see if we can improve things by rotating it.