The sub itself will sound the same whether they are wired to a 4 ohm load or a 1 ohm load.
What can make a difference is how the amp performs at a 1 ohm or 4 ohm load. At a 1 ohm load the amp will produce more power then at 4 ohms (if the amp is 1 ohm stable that is). The amp would produce more disotrtion and heat at 1 ohm then at 4 ohms but with a well built amp this is not usually a big deal.
It will be cheaper to find an amp that produces the power you need at 1 ohm then it would at 4 ohms. This would be a good option unless you were going for a strictly SQ setup. Then going to a 4 ohm or higher load may be neccessary.
Good Luck!!!
