Lack of shielding could be a problem, assuming the speaker cables are unshielded. The inductance of the wire used as the signal return conductor could result in high frequency noise problems due to ground loop issues, depending on the particular components that are being connected. If the capacitance per unit length of the cable is on the high side, and the cable length is long, and the output impedance of the component driving the cable is high, upper treble rolloff and sluggish transients could result.
On the other hand, depending on the specific parameters of the cable, the specific components that are being connected, and the surrounding emi/rfi environment, it might work ok, assuming you are able to physically mate the cable and connectors with each other.
Regards,
-- Al
