Hit an inductor with a voltage, no current wants to flow, develops a high BEMF that reduces the response, and its current that develops the magnetic field that interacts with the permanent magnet to cause voice coil movement.
DC resistance of the voice coil is an indirect means to limit the power requirements of the speaker, but the key factor is the ampere-turns product. Greater resistance requires more turns because this lowers the current, but also has the nasty effect of increasing the inductance drastically increasing the AC impedance of the speaker. This impedance increases proportionately with frequency.
Actually gained better frequency response in a home system by using low resistant auto type speakers and adding a passive fixed power resistor. TC=L/R, and the higher the R, the lower the time constant and the better the response. But that resistor is necessary to reduce the DC current as to not overload the amplifier, but does this without increasing the inductance that drastically increases the impedance of the speaker. With an average amplifier output of 100 watts per channel, hardly go above five watts per channel anyway, or will blow out your windows in your home.
That resistance does nothing more than dissipate heat, wasted energy, ignition coils were designed this way using the resistance of the primary coil to limit current that also increased the power dissipation. Ideal resistance is zero ohms, got around this by hitting it with a controlled current pulse from the electronics. The lower turns count, and increasing the current gives the same AT product but at much lower impedance. Therefore the pulse can be made much shorter, and with far less heat generated in the coil, can be made much smaller.
Ha, thought about this for an amplifier, tricky to design a controlled current source to eliminate that high impedance of a speaker voice coil. So have to live with a lot of wasted heat and reduced frequency response. Have both an AC and a DC component in these designs.
A standard bridged output audio amplifier chip operating at 14V will output 7 volts at each speaker terminal with a zero input signal. One key reason why both outputs have to be floating, ground a terminal will short out the amplifier. But most are power protected and will shut down.
With a full signal applied, either side will go up to 13.5V, other side down to 0.5 V for a peak signal of 13 V, or an RMS voltage of 9.2 V, this is how positive and negative alternations are generated.
With a standard 4 ohm speaker, 21 watts maximum power output is possible. 8 ohm speaker will only be 10.5 watts, where a 2 ohm speaker jumps up 42 watts, if the radio is rated for this. For greater power outputs, a DC to DC converter must be used to step up that 14V line voltage, if doubled, power output will increase by the square of this voltage with the same resistance voice coil.
Speakers are erroneous rated on the maximum power they can handle before they turn into toast. But doesn't have anything to do with distortion. Is very difficult to find a speaker that can even handle 12 watts of power before they go into distortion. With a woofer, the cone can only move so far even with a drastic increase with current. And when it quits moving,this is when you get distortion.