[FeiJai]

Hi, I will be purchasing a dac/amp, bookshelf or studio speakers, and a subwoofer over the holiday. However, I do not know how to connect them at all. I want to connect all with RCA but don't now how to connect and if I need additional cables (Y cable?). Sub - Line In RCA, Dac - Dac Out RCA, Speaker - Line Out RCA. Thanks.
Subwoofer: Polk Audio PSW111                                 
 

 
Dac/Amp: Audio-GD NFB-12
 

 
Speaker: Have not chosen one but will use KRK rockit as example
 

 

[majestic12]

It looks like an interesting situation if you're planning on using powered speakers with your setup instead of going the more traditional route of using an external amp to drive the speakers.  It almost feels like blasphemy recommending the use of RCA splitters out of the DAC so a signal can be sent to both the speakers and the sub, but if this is the gear, it looks to be the only way. 
 
USB/Coaxial/SPDIF > DAC > 2 sets of RCA splitters out (one per channel) > RCA cables to speaker inputs and two to the sub (one per channel)... 

 

[FeiJai]

USB > DAC >
 
Would these options work? If they do, do I go with:
Option 1 - connect Dac and speakers to Subwoofer
Option 2 - connect speakers and subwoofer to dac
Option 3 - connect dac and subwoofer to speakers
 

 

[majestic12]

I'd use a splitter or a piggyback style RCA cable out of the DAC.  Each of the stereo speakers could receive their respective cables (left and right) and the sub could get one of each.