Kewl, kewl...
Actually just checked out my meanwell drivers and they don't have the minimum voltage listed on there, just the maximum which is 48v or rougly 12 - 3watt leds.. So you may have to get that info from your drivers data sheet, or perhaps the supplier where you purchased it from has it listed.
Example: we'll look at one of my drivers...
Meanwell LPF 60-48. It has an output voltage of 28.8v - 48v in the constant current region. Remember, these are constant current drivers, different from a constant voltage power supply like your wall-wart. Constant current drivers do as they sound, they always put out an even and constant rate of current but the voltage automatically adjusts to the load (led count). A wall-wart works just the opposite.
Depending on how much current (amps/mA) is being pushed through the led's determines whether or not a Red led for instance operates at 2.2 volts or 2.6 volts. If you're only pushing 350mA (milliamps) through them then they will operate right around 2.2 volts. If you drive them at their maximum rating then they will be operating at around 2.6 volts.
By my math...your string of 8 leds even if they were running at their maximum would fall just short of the minimum requirement load of my meanwell LPF 60-48 driver. But your driver is probably a little different. So I can't say for sure unless I know everything about what you're using. If I used your string of 8 leds (same type) I would end up with a total forward voltage requirement for that string of 25.2 volts when what I need is at least 28.8v for my drivers to operate the leds correctly.
So it's important to remember, especially if you want to have dimming capabilities, that you're going to need to meet your minimum requirement for when you're leds are dimmed way low and that you don't exceed the maximum (48v in my case) when the leds are being driven at 100%.
I've ready probably at least a dozen cases of hearing guys run into the same issue. Using the Red leds throws a lot folks off because they require so much less voltage than the others.
In my case, when I was testing my equipment I experienced led flash but it was because of a weak/loose contact in one of the pins in a temporary connection that I had hooked up while I was taking the electrical readings. Drivers do weird things like that when there is a call for power but something is not quite right with the circuit.
HTH
