Bec

my site ... you should know that.
BUT first you need to work out how and what you will drive this distribution box with.
If you only have a standard Headphone out from say ... an M-Box then you probably can't get much more than two H/P's out of it with something like a standard
Y cord.
If you have a small HiFi amp at about 25 to 50 watts then a 4 to 8 way distribution box or two 4 way units will be fine ...
Basically all H/Ps are driven in parallel with some resistors in series with each line (left and right). 15 to 30 ohms say. I may have used 18 ?
If this will mean you have to buy or make an amp and spend money then an alternative option might be one of the budget Headphone amps from
A or
B.
They are quite good value and do give some cool options.
These will give enough volume except when working with loud drum kits and screaming guitar solos at MAX level.