Connecting a subwoofer to a single DJ controller RCA output

[spaghetti]

I want to add a subwoofer to my Numark FX Prod DJ Controller which spots a single RCA output. This output is currently used to drive 4" active monitor speakers so I don't have an amp or separate DAC in my setup (the DJ controller is connected to a computer and has its own internal DAC).

Do I need to buy a dedicated crossover to split the frequency below 100Hz and send it to the subwoofer through a separate RCA cable?
This article claims subwoofers can have an RCA output to chain into speakers, but the models I looked at don't show any.

 

[staticV3]

You can connect your active monitors and the sub to the RCA output in parallel, just with a simple splitter.
Downside is that both the monitor and sub will have to work with the same signal amplitude. Depending on the gain of the integrated Amps, matching the output levels may be tricky.

 

[spaghetti]

I think it's better to split the frequency below 60Hz to offload the monitor speakers, especially for small 4" woofers?

 

[DVDdoug]

A basic Y-Splitter will "work". You can try that first and if you don't like the way the speakers "blend" you can upgrade to something else. If the subwoofer only has one input, just connect the left OR right. The bass is normally the same in both channels... Don't "short" the left & right signals together.

Some active subwoofers have a built-in crossover. Most have a low-pass filter but that doesn't block the bass from your main speakers.

Another option is an active crossover. Most "pro" DJ setups or PA systems used for live music use an active crossover, or sometimes a DSP crossover/filter is built into the power amps.

For home setups, AVRs have a crossover built-in (part of the "bass management"). But most AVRs don't have preamp outputs (except for the subwoofer) so they don't work with active speakers/monitors.

 

[spaghetti]

I checked my subwoofer and indeed it has a builtin crossover (screenshot attached). I will have to adjust the low filter on the monitor speakers though.
I am confused about the cable. Right now I have a male-to-male RCA cable going to the speakers. How is a stereo female to mono male RCA going to help? I need to feed a stereo RCA male to both the speakers and the subwoofer. Don't I need a male-to-2 female full stereo RCA splitter like this?