I will attempt to condense this one down to the Coles notes (Cliff notes to some I believe) for the purpose of this post. But we should think about doing a mini series in our newsletters about it some time. There are many different types of distortion and they are all audible at different levels down from the fundamental depending on frequency and type of distortion. For instance harmonically related distortion is very hard to detect if it is the second harmonic but gets progressively easier as you head towards the fifth harmonic at which time it is as audible as straight noise. Low frequency noise distortion is very hard to hear where as high frequency is easy. Getting to the original question here; speakers, if properly designed and this is a big if out there, can have very low audible distortion at high power. They will exhibit compression which is comparable to just running out of volume or perhaps soft clipping. Inevitably this compression does not happen equally at all frequencies so you have a level below which there is no compression and then a level at which the compression would start to become worth noting which should be considered the max level the speaker can play to. A single M80 in an anechoic chamber starts to exhibit compression at about 118 dB. You can keep pumping more power in but you won’t be getting all frequencies back out in a linear fashion. The other very important fact to keep in mind is that even though 118 dB sounds well above any sort sane listening level; music and movies are dynamic. So if you want really clean reproduction at moderately high listening levels, or normal levels in a large room, you have to consider those peaks. This where lots of power and lots of speaker output without compression becomes heavenly.
