Bass management with stand alone preamps

I can do better Atmasphere. It is not far off the distributed array idea but is a more powerful. I have mentioned it before on this site. I have linear arrays which project power differently than point source speakers. Their power drops off at the square of the distance. Point sources drop off at the cube of the distance, much faster. The distributed array idea is using 4 rather small point sources. I use 4 woofers set up as a linear array using the walls as boundaries. The two end woofers must be in the corners and none of the woofers can be further apart than 1/2 the wavelength of the highest frequency they are expected to reproduce. All woofers are right up against the front wall. The two inner woofers are facing each other so that their drivers are right up against the front wall. What you get is 4 woofers acting as a single driver. Since they are using three walls as boundaries the only primary reflection is the rear wall which is delayed and down in volume. I built this house and purposely designed it so that there is essentially no rear wall. The end result is very powerful base that matches the output of my ESLs without any standing waves. You can walk through the room and the base response does not change until you get right up against a lateral wall. This is with room control disabled. The ESLs have their signals delayed by less than a millisecond so that the woofers are exactly in phase with the ESLs. I cross over at 125 Hz 48 and 24 db/oct. You can not hear the cross over. It is entirely seamless. Is is much harder to match sub woofers with speakers at lower cross over points because of the longer wavelengths. 100 Hz is around 10 feet. 20 Hz is 32 feet. You try and cross over at 60 or 80 hz and you have to move your speakers 1/2 way across the room unless you have room control that measures the delays and accounts for them. Most don't yet people are trying to cross at 80 Hz and do not understand why things don't sound quite right. Properly set up you should not be able to tell at all  that there are sub woofers in the system. You should be presented with one powerful whole. I have yet to see an analog system do this. They can come close but not quite there. Digital bass management and phase or time management seem to be crucial to make this work correctly. I am sure you have heard SoundLabs speakers. They project a large as life sound stage. With woofers set up like this the bass sounds just as big and powerful as the SoundLabs except the SoundLabs become cleaner and are capable of another 10 db or so if you care to crack all your windows.

They project a large as life sound stage. With woofers set up like this the bass sounds just as big and powerful as the SoundLabs except the SoundLabs become cleaner and are capable of another 10 db or so if you care to crack all your windows.

:)

Dr. West has long been an advocate of such as you probably know. Have you ever tried his ESL subwoofer system?

They are not listed on the site. At least I have not seen them. What does he do?

^^ I don't see the B1 listed there either... Dr West is the designer of the Sound Lab loudspeakers.

No, I meant with the sub woofer. I know Dr West. One of my heroes. He has kept the faith and the flame alive.
Making an ESL sub woofer that you could use in an average room is a tough one. My own feeling is that ESLs having to be dipoles have never been good at deep bass and forcing them to do it just ruins the beauty of what they do everywhere else. Any dipole in an enclosed space is going to have the same problems but ESLs do not cross over to other drivers
making it worse for them. I would not ever use a full range ESL without a  sub woofer system unless you just listen to string quartets.