Digital Room Correction vs Room Treatments

BTW - if you are a ROON or JRiver user then Mitch's Convolution Filters are easy to use.

Honestly too hard and too much.  Simple parametric EQs  in Roon will solve the OP's problems.

So it's worth using the AM Acoustics simulator to see where your room modes are, but one possible solution would be to run soffit traps actually in the soffits.  If the modes are vertically in the corners though you'll want to put them to the side of the TV. 

Sorry for contributing only infrequently.

A point that I may not have properly addressed earlier is that the benefit of a sub in a situation like this is not it’s bass output but the ability to move it to an ideal location.  However if you are severely space constrained, then a sub is almost useless. 

TO place the sub you’d put the sub in your listening location, then move the mic around potential locations until you find the best measuring place.  That’s where you put your sub.

My earlier advice to clip the peaks and lift up the entire bass region still stands.

If you can’t do this and your sub is generally where your main speakers are there’s no point.

Overall, if you did this ONLY with EQ, I'd flatten the 35Hz and 95 Hz first, and then raise the entire level bellow 150 Hz to taste. 

Bass traps are a good idea, but may be too expensive.   Adding a subwoofer in the right location, with the low pass filter set high could also help.  May take some experimentation, adds more hardware and of course, is expensive too.

OP:

Turnimg off smoothing and gating, of any, is pnly useful as a learning exercise.  I wanted you to see hpw much filtering was being done for you and why this measurement only answers part of ypur question.

The link I posted to GIK acoustics will send you on your journey

OP:

It occurs to me you are using gating and smoothing.  Turn those off and re-examine your measurements.  I think you can re-use what you've already captured. You'll see a much nastier image of your results.

Also, when comparing speakers, it's very much worth measuring off-axis to see how good of a sweet-spot they would provide.  Speakers that measure similarly on-axis may be crap off. 

OP:

If I wanted to take time based plots, is that doable using reasonably priced tools, or is that a pro assessment job?

Room EQ Wizard (REW) has a variety of tools for that, and their forums are very helpful.   Here’s a starter page.

Let me give you a little more background.  For frequency response REW and similar tools (I use OmniMic) gate the signal above the bass.  That is, they stop listening a few milliseconds after the impulse start to arrive.  This deliberately excludes as much of the room as possible to get the response of the speaker.  The sound waves are still busy traveling back and forth around the room for a much longer time period than this.

Our ear/brain mechanism does not hear like a microphone.  We don’t stop listening, but integrate the experience of the direct sound and the reflections over time and this fully integrated perspective is what gives us an impression of the tonal balance.  Often audiophiles only think this is an imaging problem but there is a very significant effect on the perceived tonal balance.

If you ever hear Fritz speakers at a show, he travels with only a few absorber panels.  He knows what he's doing, and that his speakers will sound more full that way.  We should all take a lesson. 

In a very reflective room where the mid/treble bounces around for too long our hearing tends to exaggerate the mid and treble frequencies, so as a result will sound as if the speakers lack bass.   So, a tip I often give which people resist is that adding mid-treble absorbers and diffusors will improve the apparent bass, and none of this is captured by simple frequency response plots. 

The other thing these plots fail to capture is how having multiple direct reflections, and / or the absence of the right diffuse sound field ruins the illusion of an audio image. 

In the bass things are different.  The wavelengths are so long that it’s nearly impossible not to integrate the room, so as a result your frequency measurements are integrated.  Speaker builders always face a challenge with this and use a variety of techniques to try to get the real speaker measurements like putting the mic 1/4" in front of the drivers, measuring outside, etc.

While room correction software may do a lot for the bass and maybe even correct for perceived extra mid/treble they cannot stop reflections.  That’s why in my mind the two approaches are not equivalent but complementary.

OP:

For the record, room treatments and room correction are not equivalent.

Using a frequency response curve to determine if you need room treatments is only useful in the bass.  Above that the microphones won't integrate frequency response measurements over time the way we do.  You need time based plots for that.

Having said that, REW includes a room mode simulator but I find the AM Acoustics version free and easier to understand.

Now, as for EQ / Room Correction... the best you can usually do without bass traps is to clip peaks.  After that you raise the overall level of the bass to taste.

With bass traps that are effective at your problem frequencies you can mitigate both much better.

Point is, for your bass, use the simulator to make sure your speakers and listening location are away from the room modes you are finding.  Consider placing bass traps near the areas activated by those modes. 

As for the rest of your speakers, leave them alone, but in the mid to treble regions having appropriate mid/treble absorption and diffusion helps greatly with imaging and comfort levels.  Also taming reflections (which won't show up in a frequency graph) will make the room sound like you have much more bass.