Grant, thanks to you and all that responded, I don't have sealed 15" woofers that roll off @ 60Hz, so I will not attempt to run full range with sub, I have run full range in the direct or pure mode and was quite satisfied with results. Again thanks for the replies.
Jeff
There is nothing wrong with using your mains full range and supplementing with the sub.
Actually for most music and most speakers it is the best approach.
Set your mains to large and set the sub to between 1.5 and 2 X the F3 of your speakers. Experiment to find the best frequency to bring in the sub.
Avoid over driving the sub. Keep it at a volume where the music has a natural balance. If your attention is drawn to the sub, it is too loud.
This is the method preferred by B & W.
I use this on my downstairs system. The speakers have a good bass response, but slightly filling in the last half octave makes a worthwhile difference. You hear virtually nothing from the subs up close, but switch them off and you notice it as soon as there is deep bass on the program.
In most parts of the program the sub makes no difference which is the way it should be.
HT is a little different, as Hollywood blast the LFE channel at unrealistic levels. This bass content might damage some speakers.
As I have said often, there is little program below 80 Hz, and seldom much going on below 40 Hz. Most of the power is between 80 Hz and 2.5 kHz. The power divide is 400 Hz, so as much amp power is used above 400 Hz as below it.
I was watching the spectrum meter on a performance of Elijah from the Royal Albert Hall to day. This used 500 performers, including the "Voice of Jupiter". Most of the time the big power demand was between 200 Hz and 1.5 kHz and quite often out to 3 khz. Only when the organist let the "Voice of Jupiter " rip, was there content down to and below 20 Hz. Even then the power demands between 400 and 700 Hz, were much greater than those below 80 Hz.
This nonsense that there are huge demands on bass power outside Hollywood's realms of fantasy are just plain wrong.
Part of the problem arises because of the ubiquity of narrow front speakers with small drivers.
All of the budget speakers have grossly inadequate BSE, and so sound puny and thin. Full BSE compensation puts huge demand on drivers, especially small ones, and you end up with thermal compression and or damage, unless they are very costly drivers. Also with passive crossovers full BSE makes for big amp demands, because of the db/spl curve. So it is a good blower of receivers.
So the result I find is that people tend to over compensate for adequate BSE by over driving their subs. This is far from natural reproduction.
