Bass management with stand alone preamps


In researching an upgrade to separate preamp from an av pre pro (marantz 8802a) I’ve noticed that 1) most include no bass management 2) some include dual preouts but no bass management 3) some have a basic sub preout but no bass management.    Are subs not popular in the two channel arena?  I know in years past they were considered anathema but like every other issue in society views seem to have changed.  Interested in how people typically integrate and if NOT running the mains with a high pass filter is common.  Seems part of the point is to take that out of the amp and speaker and direct all that effort to the sub. If this has been beaten to death in another thread feel free to redirect. I have JL F212V2 subs which don’t have high level connections like REL appears to have.  
esthlos13
Atmasphere, I think you are confusing room correction with bass management. Bass management supplies cross over points, slopes and outputs for sub woofers. Room control without careful woofer set up and acoustic management in the room just shifts the comb filtering around at the cost of a lot of power. I do not like the term room control. I like speaker control better. It is to fix response abnormalities of the speakers or woofers in the position they occupy in the room. If you move a speaker from one point in a room to another its frequency response will change. The most important function of room control is not to make everything Flat. Flat actually sounds awful at volume. Way too bright. It is to make the response of the speakers exactly equal at all frequencies. The result of this is razor imaging. If frequencies vary in volume one side to another you smear the image. Then if you have a good unit that allows you can create target curves and tailor the frequency response to your liking. You can also create target curves for specific purposes. I have a curve with a 3 db notch filter at 3 kHz which I use for violins and female voices that are too harsh. Once you are in the digital domain you can do anything you want. Those that think "room control" is only for bass are sadly mistaken. Audiophiles that hear this in action on a good set of ESLs are dumbfounded. The improvement is such that I do the unspeakable of digitizing the output of my phono preamp and input it to the TACT. 
@mijostyn You are correct in what you say, but if you use a distributed bass array you don't have such profound problems with the bass changing as you move the speakers; much of that is due to standing waves. So this makes getting the bass right a **lot** easier!
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?