Questions from the net
?: Is acoustic room treatment important if I listen at low volume?
Room is more critical with louder volume, so depends how the room is now. No treatment, highly reflective room will always benefit.
So why is it less critical at low volume? Because late reflections and resonances falls below threshold of hearing faster.
This also means it is easier to treat a room for low volume listening only.
?: Can a measured in-room frequency response be modified so that it represents the frequency response we hear, so we can easily predict the tonality of the sound?
Unfortunately, there is no simple way to do this, due to the nature of how sound in a reflective environment works.
All the information is already in the measurement (acoustic measurement in-room at listening position), but it is not possible to map all the information into one graph that is easy to read.
This is because the perceived frequency response will be affected differently for different signals, so that a stationary waveform will be like the frequency response graph (no gating), while transient signals (everything where level changes over time) will be colored by the reflections and decaying energy in the room, and this coloration will be different depending on the duration and spectral distribution of the signal.
So tonality for a stationary, non-percussive instrument will be affected different from a transient instrument, like drums. This is also why a live room with lots of reverb can never sound the same as a dry room, and why speakers with different radiation patterns sound different in the same room.
?: I see less woofer movement using a more powerful amplifier, why is that, is it even possible?
Yes, it is possible that a more powerful amplifier gives less movement on woofer cones because it retains control of the speaker cone when you turn up the volume.
This is because when the less powerful amplifier clips it can no longer deliver the current required to control the speaker cone. The cone accelerates, and is then stopped primarily by the current delivered from the amplifier. If there is no current, the cone just continues, and is only controlled by the spider, and stops once its mechanical limit is reached. The cone no longer follows the intended movement dictated by the music signal.
That was the simple answer, which, as usual, is not an accurate or technically correct description of what happens.
Because a less powerful amplifier can still have good control, even if it clips and distort the signal, provided it can deliver the current required. Old style power amplifiers with huge current capacity can do this.
So it is the current capacity of the amplifier that does the control of the woofer cone movement, while the output power specification is determined by the voltage that can be delivered into a specific load, typically 8 or 4 ohms.
Back in the days, we saw a race for very high current capacity, where amplifier could deliver much more current than required for a resistive load of say 8 ohms. This made sense, due to how a real speaker load behaves, where current and voltage appear out of phase, which greatly reduces the available current to drive the speaker, when the output stage is a traditional call-AB or class-A. New class-D technology is different, because actual voltage at a given time does not affect available current, so they are generally much better for bass performance.