No problem amigo.
The 8 would be amount of strips, 700ma would be drive current. Basically, the lower drive current that you give to your led’s the more efficient your led’s will be. Max current on the 44" inch strips is 1400ma (1.4 amps) that suggests that per manufacturer data, each strip could be run at 62 watts. At this point you would have the most available output from the strip. But you would also have the least amount of light per watt, the most heat, and shortest lifespan.
Stepping down from there in the meanwell driver constant current line, will put you at a drive current of 1050ma (1.05 amps). From here, you will lower the actual wattage per strip to around 47 watts. But increase the amount of light per watt and lifespan, and lower the amount of heat. You can find some people running builds at this current, and they seem fairly happy.
The next step down in the driver line is 700ma (.7amps). This will run each strip at about 31 watts. Again, another jump in lights per watt and lifespan, even less heat. This also happens to be the current that bridgelux bins them at. Their data sheets tell us that this is the test current for binning. The sheets aren’t always exactly the easiest to decipher. But it looks like they binned at 159 lumens per watt here with a tc temp of 50 degrees C. I’m guessing that they were trying to support their claim of not needing a heatsink. The tc temps I measured were about 38 C when mounted on 1.5"x.125 aluminum bar with the double sided thermal transfer tape. Less heat would mean the actual light produced would be more. Probably not much, but any increase is better than a decrease. They also rate the lifespan at greater than 50,000 hours at this point. You can expect some drop in performance over time, but again the lower current will equate to higher performance.
You could continue to drop the drive current and see efficiency numbers get better, but they’re also not exactly linear. So we’ll assume that since the test info bridgelux provided was at 700ma, that’s the “happy medium” for cost vs efficiency. It wouldn’t be unrealistic to sew a number close to 180 lumens per watt when driven at 350ma, but you’d also only be producing about 16 watts a strip, and would require a whole lot more strips to get par levels up. So for our purposes the 700ma and 1050ma are probably the best options.
So the comment about 10 strips over that area but 8 would do, referred to how many strips over that area to hit the target par levels that @Carnako was looking for, and probably a good target. Last night I dug through the meanwell driver catalog and looked at a few different configurations, there’s not a perfect match for 10 strips. The connectors on the strips are only rated for 300 volts, so that really takes all of the bigger drivers out of the conversation. There are options that run 1 strip, 2 strips, 4 strips, or 6 strips.
If you’re shooting for 10 strips, 2 of the 200 watt drivers that push 5 each, but they’ll be more efficient running 6. It can be done with a 200 watt driver running 6, and a 150 watt driver running 4. The price difference between buying 2 200 watt drivers and 1 200 watt and 1 150 watt is literally $3.
The math works out like this
31 watts per strip at 10 strips is 310 watts over your 2x4 fixture.
By adding the $3 and 2 additional strips the build cost goes up about $30, but your 12 strips will run about 372 watts over the same area. Provided more par, better canopy coverage, and because the driver would be nearly full an increase in driver efficiency.
The two 200 watt drivers running 12 strips at 700ma is what makes sense for getting the most out of your money, coverage, and efficiency.
If that’s within your budget, then the way to go with the strips. You will probably see an increase in price over the vero 29 build we were looking at. But you’re also going to get more watts and better coverage with about the same efficacy and probably a more electrically efficient package. That’s pretty much life in building for efficiency and coverage vs cost per watt.
Off the top of my head, you can still get the drivers from rapid led and take advantage of the discount. Should put them in mid $40’s each. The strips are $14.60 each so about $175 for 12 of them. Then whatever deals you can find on aluminum to mount them and build some sort of frame, thermal transfer tape, hardware, and wiring.