I have been watching this thread unfold. We seem to have a lot of slow learners here.
This knee jerk reaction, that all bass loss can be solved by more and or bigger subs needs to stop. This is simply not true, and I'm pretty sue in this case it is not true.
As I have said so often that sub range is only a small percentage of the FR perceived as bass. What is perceived as bass is 20 Hz to 400 Hz and actually you can make an argument that it is 500 Hz. However I usually cut it off at the bottom end of the speech discrimination band.
In fact that band between 80 Hz and 400 Hz is absolutely crucial to perception of bass quality. Even small changes in this range have an outside influence on whether a speakers sound thin or bloated in the bass.
Now in this region there is a lot of power in all types of music. Not only that but this is just the range where baffle step compensation is operative. It is also a range where speaker interaction with the room has an out sized influence on how any speaker performs in a given room.
So the other compounding issue, is that it is also the range where impedance needs to drop the most to get optimal baffle step compensation. So basically power output needs to double in this range. Which has to mean halving the overall impedance in this range.
This is a major reason why ALL receivers need to be 4 ohm stable and have honest specs for performance at 4 ohms.
So lets see what we have here.
Ground pane FR of his main speakers.
You can see that baffle step compensation is not quite adequate.
Impedance.
The impedance has been dropped, but not quite enough.
Now as I have stated this is a crucial area and room gain and position have a strong influence. This is why I have designed my speakers to have infinitely variable baffle step compensation. The set of the BSC is very different in my new room from the last. This room requires significantly greater BSC.
The answer to this problem is active speakers. James Larson (shady) has been taking a close look at active speakers, and they are showing better measurements and giving improved sound.
Active speakers will solve the receiver impedance nightmare, they will allow for optimal speaker performance in a wide variety of rooms. That will go a long way to solving the speech intelligibility problem, by solving serious crossover timing issues with the use of DSP. It is now known that timing problems do downgrade speech intelligibility. Personally, I have known that for a long time.
So we could make a quantum leap and I think be cost effective, by putting power amps in speakers and NOT receivers. It is now time for the industry to transition.
What we really need though is an optical standard for transmission from pre/pro to speakers. This will prevent ground loops, so speakers could be plugged in to any circuit. Also optical cables are small and easily concealed. All this absolutely needs to happen.