The answer to the question is definitely YES.
Why DAMPING
Sorry a lot of those posting on here just don't understand.
Performing a subjective test won't answer the question posed. If the question had been "is it worth spending the money on thicker cable", then a subjective test may reveal the answer wanted. The only way to answer the question posed is a theoretical one.
The first problem you and I have is with our ears, the sound we hear is measured in dB (decibels). the minimum change we can hear is defined as 1 dB. So is that your hearing or that of someone else’s? The next problem is our frequency response, when we were young some of us heard down to 25 to 30 Hz and up to 16 to 22Khz. In older age this drops of may be 50Hz to 12Khz. The bandwidth of an amplifier is measured to where the outputs to lower and higher frequencies has fallen by 3dB. Today most amplifiers are DC so they don't have the lower -3 dB point but your speaker system will. Hold on what about phase shift> the -3dB point has 45 degrees phase shift.
What? Ok lets think about a trumpet, it produces a note and like a bell rings with harmonics, we call it tone. So your ears alone may change the timing the higher frequencies by 45 degrees or more from the original and then your Hi sorry Lo Fi system has the same effect or greater, the harmonic now is at the wrong time, so it should sound different. Hence my reasons for saying subjective / comparative tests are useless unless it is you who perform the test.
I designed transducers, (changes energy in one form to another), vibrators, inertial platforms, vibration transducers and servo systems. At times I tested structures to destruction and at another designed industrial harsh environment tape recorders (one of the best sensors for movement).
Moving on to the theory a little more.
The amplifier you have can be described as a x100 RC (resistor capacitor) network. That is a low pass filter with a gain of 100. The wire to the speaker is an LRC (Inductor, Resistance Capacitance) network. The speaker is also an LRC network. The characteristics of an LRC circuit are a notch (narrow band) pass filter with gain determined by the R element. Back in the days of steam radio the station tuner circuit was a high Q LRC circuit (low R) if you remember we turned a dial turning an interleaved set of aluminium half discs, that was a variable C (capacitor).
Now you come to design your speaker, 3 Ohms is quite common but back in my day 8 ohms was the norm. So that means you will have a high Q network, very spiky and not flat at all. What one has to do is set this point way, way out of the audio range and one ends up with a compromise as the L should be large for power (how many watts) your speaker can handle which means lots of turns in the coil which means a higher R and a higher C value, diminishing returns come to mind.
Ok we now have an imperfect amplifier driving a loud speaker and some silly sod connects them up using a piece of high C high R high L cable. The result could be the cone is so badly controlled by the amplifier the sound is unrecognisable. The damping has been lost.
So at this point one can start and specify what a speaker wire should be like.
Low R so big CSA (Cross Sectional Area) so 6mm is better than 0.1mm and the shorter the better.
Low C, that means great spacing between the conductors and as small a CSA between the conductors as possible. So again short thin, put a steam roller over the conductors flat and wide is fantastic, I am currently looking for some under carpet wire even if it is not used under the carpet.
Low L, that means as short as possible.
So what about this zero oxygen copper cable? Noise from corrosion is what I hear from the posts. I can't see that is such a problem, tin the wires and for me that is job done. All the amplification is done at the early stages of the amplifier to make the signal big, not at the out put where the amplifier makes the signal power full. The input can be a Millie volt while the out put 30 Volts, the input current negligible but the out put current 50 Amps. The important thing is tight connections. Prior to someone saying soldering makes a thermocouple connection I agree but a few micro or pico volts is lost in the scheme of things but if money is no object and you want to be a 100% purist I would not argue and willing sell you expensive cable you don't need.