Room Acoustics, minimal treatment and measurements

If this was my system, I'd bi-amp, using a miniDSP as an active crossover in front of the amps.  It sounds really good.  This is going to give you the ability to properly high pass the mid-woofers, low pass the woofers, which will improve off-axis imaging and overall smoothness, give you a lot of extra headroom AND let you equalize the 12" drivers to function as subs.  Also, I'd plug the ports, which will raise the -3 dB a little, but also slow down the rolloff below 100 Hz significantly.

Fortunately, plugging the ports just takes a pair of clean socks.  I suggest organic cotton ... :D  Really anything that closes the ports and doesn't get lost. 

You may seriously want to try plugging the ports and re-measuring anyway.  You may find this extends the bass in just the right way.

OP:

To confirm what I thought I read in the polish site, can you measure the frequency response for 1 speaker 45 degrees off axis? 1 to 2 meters away (3 to 6’) is fine. I want to see if there’s a major dip there.

If you see a big dip, unplug the woofers and see if it vanishes.

Thanks!

Erik

@erik_squires   Yea I'll do a sweep to see that potential dip.  Are you thinking there's some frequency cancelling happening or a cross-over issue? 
I've read up on MINIDSP and watched a bunch of videos on their use.  I think things like DSP is a MAJOR step forward in music reproduction (which yes can also be over done).  I  agree with you though I would still do all the heavy lifting with proper room treatment (regardless of speakers or equipment), then concentrate on "better" speaker placement for a better balance of frequency response and sound staging.  Then, the DSP "should" only need to do really minor adjustments and moves which will keep all the best qualities of all aforementioned aspects.  I would 100% bi-amp:  that would be another HUGE increase in audio quality and presence..

Morning @mapman .  The speakers are (now) 4 year old Legacy Focus SE, (link below).  From all I have seen so far, the woofers are working properly---but I want to try running pink or white noise thru them and measuring what the voltage is at/on the speaker terminals (inside the speaker).  I am 100% certain there is no way dad would change them for anything else.  Again, to him, things sound perfectly fine but he isn't aware of how much the basement is swallowing the sound.  What is that saying about how humans bias their hearing....?  😆  With that much bass fall off, honestly the only thing to fill that void would be subs.  Bi-amping and obviously making those best practices of balancing proper speaker placement for frequency response AND sound staging combined with proper room treatment all needs to be exercised FIRST.  He's locked himself into one aspect: most accurate "best soundstaging" based on room dimensions.  (I think I'm assessing that right?).

 

@erik_squires Yea I’ll do a sweep to see that potential dip. Are you thinking there’s some frequency cancelling happening or a cross-over issue?

If there is no bass to mid-bass crossover, then I expect destructive interference (frequency dips) somewhere, either horizontally or vertically. I also expect the 7" drivers would sound much better if not trying to reproduce 20 Hz.

It may be worthwhile talking to Legacy and asking if the woofers actually have a low pass filter. Your measurements, and the impedance charts from Poland suggest the answer is no.

The way to tell without opening your speakers is with an impedance sweep. REW has a way to do this if you make a custom jig, or you can purchase Dayton DATS. Measure the combined impedance, and separately. Take a look at this blog post to understand "High pass impedance" and "Low Pass Impedance"

Hey @erik_squires   Attached is a screen shot of the 45degree reading with and without the woofers.  Distance was about 5 feet.

I'll take a look at the impedance sweep.