Help with Sub Woofer connection


How can I connect a sub woofer in my current system System consists of a custom made 25 watt per ch. integrated amp and JM Labs Electra 906 Monitors. Amp Does not have any pre outs.Is there any way to add a sub woofer to this set up?
oddmorning
I think it is a pain to adjust the volume separatedly....acquiring the preamp might be a pain. Furthermore, you will be able to adjust the gain for just only 1 source, unless you want to add the Y patch for all sources. You need to minimize the time alignment issue, and besides, what does REL advocate? The same connections as what I stated. Seamless integration is what you want, definedly do not want add more incoherence, regardless of how minimal it is to the chain....and another preamp on the path of the signal? Dweller, you need to read the whitepaper that the designer for 47 Labs wrote on the subject, it is in the Konus Audio website...he has an interview. It will give you an insight into this aspect.
For your practical purposes, the set up you advocate might be fine, but for MOST people, in my circumstances, it might not be the best solution.

PS: Check my user name, for I had posted a similar question in speaker and got very interesting responses....from about 7 posters, just one advocated the RCA option.
All I'm saying is I've never found a subwoofer crossover to come anywhere close to transparent (when passing the audio signal forward to the main speakers).
Happy Holidays!
Dweller, I agree with you. I do not believe in extra crossover in.....if you study the set up I advocated, the integrated signal would run directly into the main speakers, without passing through a subcrossover. Furthermore, the sub would get a full range signal and its crossover or drive would reproduce the only thing it could. My wiring system does not send all signals to the sub crossover and then, some back to the main speakers, after it has been crossed over, by what is most likely an inferior design. The main disadvantage of this set up would be that the signals to the main speakers would the fullrange, thus not really cutting any output in the lower frequencies. Still, for what I can hear, it works fine. Cheers all!
Bmopti123: Yes, this sounds good. I didn't read your orig post closely enough. As long as this setup doesn't present some wierd impedance profile to the integrated.