Hi I am actually confused on the relation of standing waves and resonance. I know that standing waves are fromed when two waves of equal amplitude and frequency (one travelling and the other reflected or both travelling waves ) are superimposed in each other. This is the case when we also say that we have resonance. From here it seems that resonance is actually the formation of standing waves Then again resonance is the situation when driving frequency mathes the system frequency. So can I have resonance even if there are no standing waves. Whats the exact relation. Moreover , I have always seen this figure of stanging waves where two sine waves (one reflected and on travelling ) superimpose on each other and crates nodes and antinodes. How does this thing takes place in case of a speaker. A speaker generates spherical waves and when such waves meets with a reflected wave of equal amplitude , do they form nodal and antinodal planes. Since the waves are sphere , I wonder how can it forms plane of uniform pressure .Is it the spherical that we call nodal plane or its s plane perpendicular to horizontal axis?