How is the response at 30° and 60° off axis? Also aren't the HT2-TLs rated at 88db? The graph shows a slightly lower sensitivity - unless I am missing something.
Hi. You can't read a sensitivity figure off of a Praxis plot unless you program Praxis to do that. A standard measurement like this will vary widely among Praxis setups in terms of the absolute dB level shown. It depends on how Praxis is calibrated and on the input signal. For example, here's my simulation of the HT2RAAL, based on my measurements of the individual drivers run through the final crossover design. The reference distance is one meter. The absolute dB readout is only about 78 dB on my Praxis.
As for the response below 200 Hz, on your standard anechoic measurement, you won't get anything because the measuring window is too brief to capture the longer wave lengths with any precision. The pressure wave from a lower frequency will arrive after the measurement is over. However, Praxis has a feature that starts lengthening the measurement window below about 250 Hz. This gives you sime idea of the bass response, but it's the response as shaped by room nodes, and also by floor bounce from the woofers. At a frequency of around 120 Hz, the output from a woofer will bounce off of the floor and return out of phase, causing a big cancellation dip. This happens on virtually every loudspeaker, unless the woofer is mounted practically next to the floor (which can cause other problems). The result is a generally alarming series of peaks and dips, generally culminating in a big bass room peak in the 60-70 Hz area. I'm not going to show you that response for ther HT2RAAL because it's likely to be misinterpreted. But here's the relevant plot for one of my own designs that I did as a one-off for a friend. It looks a little funky down there, but that's just how real speakers measure in a room.
Sorry-I didn't save any off-axis measurements of the HT2RAAL, but nothing weird happens off axis. The output around 2 kHz does do down a little, as you would expect from a 7" woofer at the top of its passband, but the response is still quite smooth on out to 60 degrees off axis.
