I'm going to play with only the crossover fuction as well as the timing/delay functions.
It will sit between my DAC/PRE and one pair of RCAs going to my mains and the other pair going to my subs.
I'm hoping/expecting better integration between my subs and mains, along with a audible insertion loss of the unit itself.
It sounds like the intended use is to blend subs and probably deal with bass problems at the same time.
One comment that seemed related is this one:
No..... I'd say first, fix the room.
So it appears that the idea of fixing bass problems is part of this, at least as others on this thread seem to be talking about.
The thing is, DSP and room treatment are poor solutions and only should be used as touchup. If you want a sub to integrate well, the simple fact is keep it from going about 80Hz, and it will not attract attention to itself. If we are talking about a powered sub, or a sub driven by a dedicated sub amp, this should be easy to do. This eliminates the need for time-aligning the sub- it can be placed anywhere if that makes the bass work and the main speakers will convince you that the sound is occurring in front of you.
But there is more to it, and that is the
standing waves in the room. Almost everyone deals with this with varying degrees depending on speaker placement, room treatment and the like, but if you want the elegant approach the way to solve this, use a Distributed Bass Array (the best example of this in high end audio is the Swarm). There are two ways to do this:
First, if you're speakers already play deep bass, the wave front is going to create a standing wave at a variety of frequencies. This results in both peaks and valleys in the room response and likely a lack of bass at some frequency at the listening chair. For speakers like this you need 1 or 2 additional subs depending on the room. It/they will only be active below 80Hz. At about 80Hz in most rooms bass becomes omnidirectional because the ear can't tell a sound is there until the entire waveform has passed by it, and in most rooms below 80Hz the waveform is so long that it has bounced off of the wall behind the ear and is interfering with itself before the ear can even acknowledge it.
So this means that the bass can be handled in mono. It also means that you can place the additional subs in an asymmetric fashion in the room (with at least one behind you) to break up the standing waves, resulting in evenly distributed bass everywhere in the room.
The second way is to have 4 subs, also asymmetrically placed, if the main speakers don't go down all that far, maybe to 50-60Hz. Two will probably be in front of you. Otherwise it works the same.
This method is
FAR more effective than DSP or room treatment with bass traps. For bass traps to really work right, they would have to actively move about the room as the bass notes change, to be where the peaks of any standing wave happen to be; obviously impractical. DSP can work for reducing a peak at the listening chair but it can't help you with a dip, because the waveform is
cancelling when there is a dip and you can put as much power as you want into the room at that frequency and it will still cancel. That will really task your amplifiers and not solve the problem. So these 'solutions' aren't.