Do you think you need a subwoofer?

Rauliruegas...At first I took the same approach as you, (and everyone else it seems) and I tried to find the a frequency for "best quality sound reproduction". I never seemed to get it right. It took me many years to realize why: there is no one best X/O frequency, at least for my system. It depends on the kind of music being played. I do not use the X/O frequency as a tone control. I have my system tweeked up so that there is no audible or measurable (RTA) change when I sweep the frequency. But with music that has heavy LF the six 12" and 15" subwoofer cones have the "punch" that folks say is missing in Maggies.

Dear Eldartford: +++++" there is no one best X/O frequency, at least for my system. " +++++

This is the name of the game. In my system it is an audible change when I sweep the frequency.

Regards and enjoy the music.
Raul.

Rauliruegas...I forgot to mention that when I sweep the X/O frequency I am listening to and observing a white noise signal. Music is another story, which, of course, is the reason that I vary the frequency. My ability to sweep the X/O frequency without audible effect may not be usual, but my claim is that it indicates that my custom designed SW systems are well matched to the MG1.6 speakers.

Dear Eldartford: +++++ " My ability to sweep the X/O frequency without audible effect may not be usual " +++++

Certainly it is not .

In your Organ example ( crossover 200-300 Hz )and in your very well designed system I'm still worried about Intermodulation Distortions that with that high crossover frequency and with organ music it will be really high IMD: the organ music could go down to 16Hz or lower and normally in that kind of music your sub's are trying to reproduce frequencies in the very low bass: 16Hz to 40Hz and at the same time you are asking to reproduce in clean manner frequencies ( very critical audio range ) between 100Hz and 300Hz+, well this is what I'm concern of IMD.

Anyway at the " end of the day " you are crossing over 80Hz that makes more sense to me.

Regards and enjoy the music.
Raul.

Dear Sirspeedy: +++++ " if the main speakers can support a certain low frequency,before rolling off,it will be best to bring in the sub at just under this point. " +++++

Well this is one approach that mainly goes to have a lower bass response: it is the REL approach and other subwoofer manufacturers but not all of them.

My approach is different from yours, mine goes to obtain ( first place ) a better quality performance in my main speakers and in second place to achieve a better quality bass performance that could goes lower too.
I use two subwoofers in true stereo way to achieve those targets, the first one ( that you can't achieve with your approach. ) is obtained lowering the Intermodulation Distortion ( main speakers ), this means to stop to ask to the woofers ( main speakers ) the simultaneous reproduction of frequencies between 20Hz and 200HZ or higher( if yours goes flat to 30Hz then you still have some distorted response at 20Hz that makes higher the IMD subject/problem ), this means ( again ) that we have to choose a crossover frequency higher than what the main woofers are handled : in my case 60 Hz and in Eldartford 80Hz.
In this manner the main woofers will be free/less stressed of the low bass reproduction working from 60Hz-80Hz up and lowering ( cleaning in deep ) the IMD: this fact makes a huge improvement ( in any speaker including yours ) in the quality sound reproduction of the main speakers ( it is not matters what you think about or what I think about, lowering the IMD always improves the quality performance of " that " driver, physics laws. ).
The second advantage on this approach is that now the low bass frequency response not only goes down through the subwoofers but with a better quality bass performance due that those bass frequencies will be reproduced for " drivers /amplifiers " that were designed specific for those kind of bass frequencies.

I respect your approach but I don't like it because it can't give me a whole better quality performance in help to the music reproduction, instead my approach give us all. Through this thread are explained almost all you have to know about, please re-read it.

As I told you it does not matters what you and me think about, IMHO you must try that approach to make the " discovery " of your whole audio life.

Regards and enjoy the music.
Raul.