My AAM (moded BS-22) vs Amir's. Why the difference

[ck42]

Not sure where to start with this. I'm fairly green with REW but think I know enough to be dangerous.
Reason for this post is that I seem to be measuring something QUITE different than what Amir measured for a speaker that I also have.

In Amir's measurement here, we can see how flat things are from about 70-200Hz, and then a clean sharp roll off.

In my own measurements though, this is what I'm seeing: (1/6 smoothing)
It's all over the place.
mic is about 5ft away and aimed directly between the two drivers.
Speaker is about 1ft away from back wall and about 5ft away from a corner (room is 13x15)

Additionally beyond the crazy curve, it seems to completely roll off at about 115Hz
Is this just a measurement technique problem on my part?

If I go to 1:1 smoothing, I get this which certainly looks better, except the bottom end still rolls off WAY too soon.

 

[dougi]

It's likely the room. Move the speaker to another location and see if the suckout at 90 Hz changes.

 

[ck42]

It's likely the room. Move the speaker to another location and see if the suckout at 90 Hz changes.

Okay, so I moved the speaker to near the middle of the room. Mic again about 5ft away.
This is what I get now. Red graph is the new one.

 

[flipflop]

Could still be the room. Try a few different mic positions at varying distances while still pointing it between the speakers.

 

[ck42]

Could still be the room. Try a few different mic positions at varying distances while still pointing it between the speakers.

New one in green. Moved the speaker several feet. Aimed in a different direction.

 

[flipflop]

Is the room sealed?

 

[Vini darko]

Your measuring two speakers in a room from 5 feet away and Amir is measuring one speaker anacoic very close. It's perfectly normal to see significant room interaction below 500hz. Your response isn't too bad for in room uncorrected in a untreated? room. As you've seen for moving the speakers respones varies massively. However your inital measurment has the desired downward trend.
Things to try are room correction software , playing with placment of speakers and listening position , rudimentry room treatment at reflection points.
Having the ability to measure response is great but response of speakers in a room is always going to be a bit choppy.

 

[Eetu]

I recommend reading this guide, very helpful: https://www.minidsp.com/applications/acoustic-measurements/loudspeaker-measurements

 

[pjug]

What are you using to drive the speaker? Any chance there is a high-pass filter?

 

[muad]

Also, try doing a moving mic measurement to get a more representative picture of the sound over an area. It will average out the rooms effects and will more true to reality.

 

[ck42]

Is the room sealed?

It's my home office, and at the time of measurement the door WAS closed, so yes.

 

[ck42]

Your measuring two speakers in a room from 5 feet away and Amir is measuring one speaker anechoic very close. It's perfectly normal to see significant room interaction below 500hz. Your response isn't too bad for in room uncorrected in a untreated? room. As you've seen for moving the speakers responses varies massively. However your initial measurement has the desired downward trend.
Things to try are room correction software , playing with placement of speakers and listening position , rudimentary room treatment at reflection points.
Having the ability to measure response is great but response of speakers in a room is always going to be a bit choppy.

Probably doesn't make a ton of difference, but my measurements here have been for 1 speaker only.
The room is untreated.
This is all running through a DDRC-24 but I've bypassed the HP filters and any PEQ that I was playing around with....and DL is -OFF-.
If this is 'normal' I can live with that. Just needed to see if there's something wrong with the way I'm measuring things since the plot looks SO different than Amir's.

 

[ck42]

Okay...had some fun with the PEQ's on the DDRC. Set Xovers too.
This is about as good as I can get it. Problem with this office space is that unless I **completely** redesign the layout ENTIRELY, the speakers can only go in one place. The sub has a little leeway though.
But, after doing this, it just confirmed how pathetic this 20 year old sub is (and it's an 8" sub). Looks like I'll be having a new SB-1000 Pro coming my way.
(and yes, I've apparently got a nasty room mode right around 66Hz. Couldn't correct that with the PEQs to save my life)
Next thing though that I discovered after I extended the frequency range is that the top end also completely falls off at around 11.5KHz! seriously....WTH? Can't blame the room on this one either.

 

[ck42]

So couple updates:
Got the sub. Had a problem with sub measurements in REW that I ended up fixing with a checkbox in windows for the mic. It appears that this fix for the low end dealing with the sub measurements also fixed the top end problem.

Latest plot here.
Still have a big room null though. Deal with that next.