Originally Posted by LTD02
rear mounted woofers for a little cleaner look.
That was one of my points in yesterday's post, I think that would be nice. Even a routed fascia piece trimming out the entire loudspeaker front elevation, incorporating a driver round-over and maybe even an eye toward cabinet edge round-overs.
In the other post, I included many shoot for the moon type suggestions. But to boil it down; maintaining the current SEOS high output/low distortion approach, what are the worthy gains to be pursued within the LF driver's coverage? I mean where are the areas that can be improved, .. given the current SEOS platform?
Given an entirely inert cabinet, address the basics; lower Doppler related modulation, lower Le(x) and Le(i) distortions, lessen any negative impact of backspace back-wave.
Aside from whatever is the optimal compression driver mated to the appropriate SEOS waveguide. It would appear utilizing the splendid AE/TD everything mid-bass downward is essentially state of the art. However, the octaves from that point up to the compression driver is the potential weak point area of interest. That said;
1.) mid-band improvement by off-loading the big excursions?
(a three way design maintaining the coverage matching of the full size 12's or 15's, yet implementing another (identical?) LF driver for the range below approx. 180hz? Just looking at every aspect of lowering the motor current, and lessening excursion)
2.) back-wave energy of the drive unit contaminating main front output, Latent Release Stored Energy, etc.
(the high passed LF section possessing it's own back-space, with an eye on addressing the back-wave energy, dissipating it and/or preventing it from interacting with the cone/front-wave. As I mention before, achieve this via serpentine/labyrinth cab path, or by full foam filled cabinet w/open back)
3.) The lowest range section employing appropriate vented or sealed alignment.
There are those that would support a dome/cone based reference line tower, and I think that's very cool. However, all the incredible work and quality inherent to the existing SEOS design is worthy of exploring extracting the last bit of inner detail and design execution remaining that may be in there.
As we know, many of the finest mastering rooms, many of the finest studio mains follow the 15" two-way, horn loaded platform. So clearly the platform has state of the art merit.
As an IB DIY'er and owner, I would suggest that until one experiences a true IB (full and essentially infinite backspace), it's tough to explain and quantify the relative difference in clarity and resolution over other approaches. Theoretically sure, it's valid. I'd have to say there certainly appears to be something significant to keeping the VC currents as low as possible, and assure the back-wave does not impact the cone's operation in any negative manner. There's many quasi IB subs, but loaded in an attic, or other similarly infinite backspaces really helps. I mention this because this was the genesis for my comments above wrt the Reference SEOS.
I'm not the most experienced DIY'er, and I've got nothing but subjective opinion on the theoretical. But it would seem to me that examining the back-wave of the mid-band of the SEOS platform, and determining if there's any merit to pursuing the basic and well understood elements I mentioned above (Doppler related modulation, addressing Le(x) and Le(i) distortions), whatever performance is left on the table could be fleshed out.