I just bought a ddc. I want to use standard engine with 2x lxb and also keep the lrm 20 then maybe throw in a er llas. I know it's a brawl mech but to many time have a need for long range and missile locks are not available anyone think that's a good build or just crap? Sorry there are no pics I just made an account and don't know how to add all that.
As Skribs said, this is in the wrong area, and should be in the general Atlas section. As for LRM Atlaii, I don't really have an issue with them as long as they're not the main weapon platform. Due to the low-slung hardpoints, I have had some very frustrating matches where I can see and target enemies, but can't hit them because of terrain (especially Canyon Network), and I would have killed for an LRM15 to at least keep up some suppressive fire, while my 3xSRM4 just sat there useless for the entire match. I can't access Smurfy right now, but something like 1xLRM15+2xLBX10+2xMLas+ECM, or 1xLRM15+1xAC20+2xLLas+ECM would probably work pretty well.
Welcome to Mechspeccs! No one will blame you, but please refer to the FAQ section on how to properly name a build and posting images from the Smurfy mech lab. Regarding your idea: Atlai are generally considered bad for missile boating for obvious reasons, but having a single launcher can be quite handy at times because fighting enemies above or below your position can be quite difficult. 1x LRM10 + 1x LRM5 would be the same weight as a single 15 sized launcher and are coming with the advantahe of firing all 15 missiles at once. It seems as if you've got no other use for the launchers atm, so this combination seems to be the most reasonable to me. The combination 1x LRM10 + 2x LRM5 would be superior to a single 20 sized launcher in regard to volley size, fire rate and weight.
don't worry, I fixed it yesterday. Your good to build your Atlas anyway you want, and look good doing it.
/not that of a good build. Sorry dude. Atlas DDC is 10 tube, so your LRM20 would fire in two waves. With 2x ERLL and 2x LBX10, you are pretty much stuffed already. You can probably downgrade that to a LRM10, or some LRM5s Still, if you choose to use LBX10 they work better with SRM. If you really want LRM then use AC20, they fit in better together along with LL/ERLL.