If you look at my system page you will see Aerial LR5s as main speakers, plus two Aerial SW12 subs. The LR5s use two 9-inch LF drivers in a sealed box. Acoustic suspension (i.e., sealed box) speakers can provide better controlled bass response with less distortion than bass reflex (i.e., ported) speakers, but they also tend to roll-off more slowly below their -3dB point. The LR5s are supposed to be pretty solid down to about 40 Hz and they actually sound pretty good rolled into the subs that way.
There is usually less distortion (HD) in a ported sub because of less excursion and it is operating in a more linear fashion.
But there is more group delay and phase distortion.
I have been curious about whether relieving the main amplifiers and speakers of trying to reproduce the very lowest bass in the roll-off zone would provide any sonic benefit.
Well 650 wpc is a lot… At say 100 Hz, then amount of power below 100 and above 100 Hz would likely be about the same. So in a more modest system, I would suspect more of an improvement.
I could also accomplish that by using the crossovers built into the SW12 subs, but it would require using two runs of much longer balanced cables.
The length of the XLRs will not likely matter a whole lot,. Unless they have a high amount of capacitance/inductance.
Michael Kelly at Aerial told me simply letting the LR5s roll-off naturally and then rolling in the subs at a relatively low frequency would be a better approach, …
I think that is what I was also recommending with rolling off the mains using a shallow sloped high pass.
Then on the subs one can use something with a steeper slope.
The Vandy system uses shallow slopes and I believe sealed subs? In other speakers they seem to possibly be using folded waveguides, which also are low order. I am not sure of the 2C is using a PR or some folded design… So they are seemingly trying to keep the group delay low and keeping the “order” low… which is needed for phase/time alignment.
So I would be using the Harrison Labs inline RCAS, with sealed boxes.
And with ported or other higher order boxes I would be using digital. It does not take many iterations of hardware to equal the cost of the DSP.
Hence; I would probably just go straight to the DSP as I suspect any magic lost, would be gained with room correction (e.g. Dirac Live). And if the fun did not pan out, then you could likely move it on for not much of a loss.
Their DDRC 88BM (or similar bass management DSP solutions) is something I was looking at a few years ago. And the low freq integration takes a lot work to make it seem like it is almost not even obviously there.
