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
You can add an active sub that has high level inputs and use the outputs to your mains.
I would NEVER use the crossover in a subwoofer as a high-pass filter feeding my main amp. Use the full range signal (coming out of your preamp) to feed both your main amp AND your subwoofer. Use the subwoofer's volume and/or variable frequency points to integrate with main speakers. Subwoofer crossovers (not including the new, unheard, digital Velodynes) add SO many veils it's not funny...

BUT if you don't have pre-amp outs... use an RCA splitter on the signal coming from your CD player and route one to your custom integrated and one to your subwoofer. This should cover you for CD and two-channel DVD playback. My DVD/CD players have multiple RCA outs for the audio signal.
So I don't need to use a splitter.
I had the same problem as you. I have a 47 Labs Shigaraki integrated, without any variable RCA output, like preamp outs and I had them running a pair of horn loaded speakers, but because I felt that the low end was not sufficient, I pondered about the question.

Some people will say that RCA outs are best, but when I posted the same question to some knowledgable people out there, they stated that the best method is to wire your the speaker outputs directly into an active subwoofer equipped with SPEAKER LINE INPUT...you will be running a pair of speakers cables from the same binding output or if you have another pair of free speaker binding outputs of the integrated into the sub.

The advantages of these are that for one, your sub WILL change volumes at the same rate as you increase or decrease your volume. Another is that because you run the cables from the same output, the speaker output, the sound will almost travel at the same rate to the subwoofer and also the speaker you have. Coherence and timing will not be a problem, as if would be if you have run the cable through a preamp circuitry, as in you integrated.

I disagree with the recommendation of DWELLER, for if you think about it, the original signal will begin to split from the CD output phase....while one signal travels to the sub, the other will have to travel to the integrated, to the preamp section then to the amp section, then to the speaker. Unless the amp section of the subwoofer has the same length in design as your integrated, this will not be optimal, timing wise.

I bought a powered sub and connected the way I stated. Two pair from the same binder....have not have problems and the sub has integrated flawlessly with the horns, and I did not sacrifice the sound signature of the integrated to gain more low end.

PAUL K
Forget about the theory and listen to the results. The "timing" issues are minuscule to the point of irrelevance. I do agree with the volume synchronization problem, however. This can be overcome with a used preamp (Carver, etc.) with remote control (between the CD's RCA's and the subwoofer).
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.