[corndog71]

So I finally got REW and a proper mic for taking system measurements.  I took a shot of my Super 7s, main left, sub left, main right, sub right.

And here’s what I get.  I think I need some help.



I have ATS absorbers at first reflection points and diffusers on the front wall.  I thought I wouldn’t need bass traps but now I think I do.  Not sure how to attack that hole between 100-200Hz.  I have the sub settings as follows:
Phase 0°
Crossover all the way up
Volume at 1:00
Low pass 50Hz 24dB
Rumble filter on
Damping low

Main baffles are roughly 5’10” from front wall.

[neekomax]

Very interesting. I don't know enough about that speaker system, but are the 'tops' designed to roll off at around 200 Hz like that?

[Hobbsmeerkat]

Yes, that is the natural roll off point of the BG Neo 10

[WGH]

I think I need some help.

Low pass 50Hz 24dB

Looks pretty good to me. Nice and even after 300 Hz.

Adjust the low pass to 60 Hz then 70 Hz then 80 Hz, etc. measuring at each point and see what happens. You may have to decrease the bass loudness if things get boomy.

Stereophile's John Atkinson is offering 1/3-octave warble tones (bass, midrange, treble) as a free download. The tones are on the Stereophile Editor's Choice Test CD. I use these tones with a sound meter where my ears usually are.
tinyurl.com/yfkvayat


Based on the Fletcher Munson Curve, an increase in measured bass is not a bad thing
https://www.basilmjose.com/post/fletcher-munson-curve

[Tyson]

Not sure how to attack that hole between 100-200Hz.  I have the sub settings as follows:
Phase 0°
Crossover all the way up
Volume at 1:00
Low pass 50Hz 24dB
Rumble filter on
Damping low

You have the Low Pass set wrong.  You should change it to AVR12. 

[nlitworld]

What does the response graph look like when you add the Subs with Mains? As Tyson stated, the 50/24 rolloff looks to be dropping spl level too early and too quickly for your subs to integrate smoothly. That AVR12 setting should help, then double check phase when adding sub&main together or testing as full range. It could also be a room response issue where the ceiling height is causing issues since you can see the sub response steepen up to 120hz then flatten a little up to 200hz. Otherwise those response graphs are looking pretty good.

[corndog71]

This is in my basement.  My ceiling is only 7'8".  I've been told by an expert on acoustics that I shouldn't even bother having a stereo in this room based on the height alone. 

So flipping just the switch to AVR12 here's what I get. I also added both channels together.

[Tyson]

Run the sweeps with only the mid panels (subs off).  See what the response looks like for them alone.  Then turn off the mid panels and run the subs alone. 

Post the results here.

[corndog71]

Run the sweeps with only the mid panels (subs off).  See what the response looks like for them alone.  Then turn off the mid panels and run the subs alone. 

Post the results here.

[Tyson]

Do you have the PEQ turned on?  If so, what are the settings?

[corndog71]

I don’t.  Suggestions?

[Tyson]

Yes, you have a room mode at 30hz we can use it to deal with.  Try this:

PEQ: On
Gain:  -12
Bandwidth: set to straight up (12 o'clock) position
Frequency - set to 30hz, somewhere between the 9 and 10 o'clock position.

Do it for both subs.

Re-run the sweeps and let's see what we get!

[corndog71]

I really appreciate the help!

The bottom looks better but still have that dip.

[nlitworld]

Yeah the height issue is actually the little dip at 160hz. My room suffers the same. Now that you took care of that big boost at 30hz, try clicking the sub volume up a click and it'll give you a little boosted response down low and fill in the 80-200 area a bit more. Again double check there is no phase cancelation at your crossover and you should be a-ok.

If the bass boost is a little too much, widen the bandwidth on the PEQ and raise the frequency it's cutting to overlap the 45hz area a bit as well.

[WGH]

I really appreciate the help!

The bottom looks better but still have that dip.

Silly question. How does it sound with music?

[corndog71]

Yeah the height issue is actually the little dip at 160hz. My room suffers the same. Now that you took care of that big boost at 30hz, try clicking the sub volume up a click and it'll give you a little boosted response down low and fill in the 80-200 area a bit more. Again double check there is no phase cancelation at your crossover and you should be a-ok.

If the bass boost is a little too much, widen the bandwidth on the PEQ and raise the frequency it's cutting to overlap the 45hz area a bit as well.

How do I determine / adjust for phase cancellation?  I’ve tried adjusting the phase to 90° and 180° but don’t see any change.

What if I pulled the speakers towards the listening position?  And maybe move my seat back?

[corndog71]

After some experimenting I was able to get this.



Still have that hole. 

[Tyson]

It's a room mode, like nlit mentioned.  Actually that's a pretty good response you have there.  Only thing you could do extra would be trying out some bass traps in the corners.  Otherwise, it looks pretty good and it should sound a lot better than when you started out making adjustments.

[nlitworld]

You would only notice phase when measuring both sub and speaker  combined as a full range sweep. Try a measurement running sub and speaker together now.

The other way to get a theoretical full range is using the alignment tool to combine the sub and speaker measurements together. To do that, click "ACTIONS" button on the right side, then click "ALIGNMENT TOOL". Set the two selections to Left Speaker and Left Sub and see how the stack up. If you have phase cancellation issues, it'll be a massive dip near the crossover point. You could also click the cursor at your crossover point and click the button "Align Phase at cursor" and it'll tell you if you're off a bit so you can adjust and re-test. Remember, phase knob on subs ADDS delay to the sub timing so if it's saying your subs need negative delay, that means turn down the phase knob.

Hope that isn't too confusing, but that fiddling has really helped my system.

-Lloyd

[corndog71]

Thanks again, guys.  It does sound better! 

Now to build those bass traps.