Try to learn REW and room treatment physics or just enjoy the music?

[Raymond_61]

This plot represents my listening room response with acoustic treatments and without treatments.

My 2 channel listening space is 15’x15’ with a 7’ ceiling. It’s the lower level of my home so concrete floor with padded plush carpet. Front and right side walls are concrete then studs with sheetrock. There’s are corner fireplace at the front and left wall corner.
9’ of the 15’ back wall is open to an additional 15’ of depth and finished space.
Music system is:
Lumin U1 mini > Yggy GS dac > Herron VTSP-3A > Odyssey Khartago Extreme > Kef r11 speakers & SVS SB1000 subs (sub crossover set at 40Hz)
Room treatments:
2 ea 6.5”x24”x72” bass traps
3 ea 6.5”x24”x48” bass traps
3 ea 4”x24”x48” broadband absorption panels
1 ea 3”x30”x60” diy fiberglass insulation panel

I have days when I think the music sounds great and I have days when it sounds sort of ok. So I took some measurements. I’ve never been able to move the needle much on the bass issue at 35-90 Hz. The issue at 3K Hz is new since I rotated the layout 90* to it’s present layout.
So one day I decide to see if I could learn what the treatments are doing and perhaps I should experiment with relocating them. So I started removing them one at a time, take a measurement and repeat until I had removed all of them. I was dumbfounded that the measurements barely changed.
It seems the only thing the treatments did was deaden the room. Clapping was definitely far more lively without the treatments.
Sometimes I think the r11s are too much for the room and low ceiling.
Sometimes I think having subs is unnecessary.
To be clear, I almost have no clue what I’m doing.
But my question is why do these treatments appear have no affect with room frequency response?

Hans Beekhuyzen always come to my mind and his YouTube sign off of;
“whatever you do, enjoy the music!”

I’d greatly appreciate any thoughts, observations or suggestions.

Kind regards

Jeff

 

[GXAlan]

If the clapping sounds different you should look at the different tabs (clarity and RT60 for example).

 

[phoenixdogfan]

Both!

 

[middlemarch]

You should be able to at least smooth your bass with those two subs. What do your subs look like by themselves running full range? I'm guessing if you set the crossovers at 90HZ you'd reduce that dip a bunch. Maybe need to move the subs around a bit. Bizarre that 90 to 300 is fairly flat but 10dB higher than 300 and up, which looks great until falling off a cliff at 3K.

I'm totally unfamiliar with your electronics, any DSP ability? If you had a Denon or Marantz receiver I'd suggest OCAs Acoustica. With a tailored target curve you could make significant improvements. No idea if you have the ability to implement something like that.

Could you share some sweeps of just your subs, individually, then your mains, also by themselves?

 

[Old_School_Brad]

You should be able to at least smooth your bass with those two subs.

That was exactly my initial thought when I read the original post and saw the trace.

 

[Raymond_61]

Thanks for the replies! I’ll look into all that has been suggested and requested.
I have no means of utilizing DSP. Last year I did look into it. The folks at Deer Creek suggested the miniDSP Flex Digital for my 2 channel stereo system with separate components.
I placed each subwoofer in the listening position then used a spl meter to find the spots in the room with the highest reading.
Both subs are in the front corners. One other strong reading for the right channel sub was back at the end of the space 15 ft behind me and in a corner.
I’ve tried to fill the 40-90 hz dip with the subs but to no avail.
I follow up asap.

Jeff

 

[sam_adams]

Hans Beekhuyzen . . .

Drink!

 

[boxerfan88]

Bizarre that 90 to 300 is fairly flat but 10dB higher than 300 and up,

Could it possibly be due to LFE+10dB gain?

 

[Keith_W]

But my question is why do these treatments appear have no affect with room frequency response?

That's because room treatment has no effect on the frequency response. The direct sound of the loudspeaker, which is what you are measuring with the frequency response, remains unchanged. What changes are the reflections. So if you compare the unsmoothed frequency response, you might notice there is more "grass". Also look at the spectrogram, waterfall, ETC, and RT60 measurements.

You might think you hear that the frequency response is different when you have room treatment in place. This is because of the Haas fusion zone. Reflections that arrive very early are fused with the direct sound by your brain. Later arriving reflections are perceived as "spaciousness" and later still are perceived as echoes. Your microphone can tell the difference between a reflection that arrives 1ms after the direct sound. Your brain can't. So if you have a lot of high frequency early reflections, it will sound bright, but the frequency response remains the same with or without treatment.

Learning REW is a hobby in itself. The learning is endless. If you're the type of guy who loves to learn, then I say go for it! Audio is vast, some guys just want to listen to music, others are in it to learn.

 

[Lion♡]

If you share the REW mdat file you measured, other contributors will be able to provide more detailed comments. Your listening environment looks cozy and pleasant. Are you currently sitting close to the back wall?

 

[Mike123]

In my experience, nothing helps except digital room correction. Room correction can be done at least for testing with a PC, REW and equalizer APO. The result is fantastic. Now I don't listen to anything without room correction. The hum is gone, there is a variety of bass, punch, bass guitar melody. It is possible to listen louder without discomfort. For example, my equalizer file. It is very difficult to remove resonances of 15-20 dB without digital filtering.

Filter Settings file

Room EQ V5.31.3
Dated: 17.05.2025 21:02:13

Notes:Better-19-1

Equaliser: Generic
17-19-No
Filter 1: ON PK Fc 41.15 Hz Gain -21.10 dB Q 7.093
Filter 2: ON PK Fc 50.90 Hz Gain 9.20 dB Q 5.054
Filter 3: ON PK Fc 64.20 Hz Gain 10.00 dB Q 7.500
Filter 4: ON PK Fc 75.90 Hz Gain -18.00 dB Q 5.909
Filter 5: ON PK Fc 137.0 Hz Gain 8.20 dB Q 4.782
Filter 6: ON PK Fc 161.5 Hz Gain -14.80 dB Q 7.664
Filter 7: ON PK Fc 206.0 Hz Gain -8.00 dB Q 4.909

 

[ppataki]

View attachment 453393
This plot represents my listening room response with acoustic treatments and without treatments.

My 2 channel listening space is 15’x15’ with a 7’ ceiling. It’s the lower level of my home so concrete floor with padded plush carpet. Front and right side walls are concrete then studs with sheetrock. There’s are corner fireplace at the front and left wall corner.
9’ of the 15’ back wall is open to an additional 15’ of depth and finished space.
Music system is:
Lumin U1 mini > Yggy GS dac > Herron VTSP-3A > Odyssey Khartago Extreme > Kef r11 speakers & SVS SB1000 subs (sub crossover set at 40Hz)
Room treatments:
2 ea 6.5”x24”x72” bass traps
3 ea 6.5”x24”x48” bass traps
3 ea 4”x24”x48” broadband absorption panels
1 ea 3”x30”x60” diy fiberglass insulation panel

I have days when I think the music sounds great and I have days when it sounds sort of ok. So I took some measurements. I’ve never been able to move the needle much on the bass issue at 35-90 Hz. The issue at 3K Hz is new since I rotated the layout 90* to it’s present layout.
So one day I decide to see if I could learn what the treatments are doing and perhaps I should experiment with relocating them. So I started removing them one at a time, take a measurement and repeat until I had removed all of them. I was dumbfounded that the measurements barely changed.
It seems the only thing the treatments did was deaden the room. Clapping was definitely far more lively without the treatments.
Sometimes I think the r11s are too much for the room and low ceiling.
Sometimes I think having subs is unnecessary.
To be clear, I almost have no clue what I’m doing.
But my question is why do these treatments appear have no affect with room frequency response?

Hans Beekhuyzen always come to my mind and his YouTube sign off of;
“whatever you do, enjoy the music!”

I’d greatly appreciate any thoughts, observations or suggestions.

Kind regards

Jeff

Looking at your graph I would be a bit worried about that huge 15dB dip starting from 4kHz
Have you tried fixing that to hear what difference it will make?
In my opinion it shall bring back life to your system

 

[respice finem]

I've once had a similar dip, the "dried up" ferrofluid in my 20 years old B&W tweeters was the cause.

 

[Tio]

what microphone that you use for measurement, and how do you perform your measurement?

 

[Purité Audio]

Yes what’s happening to the h/f?
Keith

 

[Sokel]

It's both channels there if I can see well, the dip up there can happen this way if distances from speakers are identical at MLP measured with laser,etc.

What's strange is the above 300Hz response, something is off there.

 

[Old_School_Brad]

I placed each subwoofer in the listening position then used a spl meter to find the spots in the room with the highest reading.

What test signal did you use?

 

[zakman]

I would not worry at this point about the room. It looks like there is an issue with your tweeters.

Measure your speakers at 1 meter at tweeter level first.

 

[Raymond_61]

That's because room treatment has no effect on the frequency response. The direct sound of the loudspeaker, which is what you are measuring with the frequency response, remains unchanged. What changes are the reflections. So if you compare the unsmoothed frequency response, you might notice there is more "grass". Also look at the spectrogram, waterfall, ETC, and RT60 measurements.

You might think you hear that the frequency response is different when you have room treatment in place. This is because of the Haas fusion zone. Reflections that arrive very early are fused with the direct sound by your brain. Later arriving reflections are perceived as "spaciousness" and later still are perceived as echoes. Your microphone can tell the difference between a reflection that arrives 1ms after the direct sound. Your brain can't. So if you have a lot of high frequency early reflections, it will sound bright, but the frequency response remains the same with or without treatment.

Learning REW is a hobby in itself. The learning is endless. If you're the type of guy who loves to learn, then I say go for it! Audio is vast, some guys just want to listen to music, others are in it to learn.

Thank you Keith, this helps me. I do have much to learn... especially with REW. I'm retired so I can & will find the time Although other things that also require my time seem to be endless. All good though! Gotta keep the brain & body working!!!

 

[Raymond_61]

what microphone that you use for measurement, and how do you perform your measurement?

I'm using the UMIK-1 in a vertical position. I watched some YouTubes on how to set up REW to take measurements mostly geared to HT setups. I just followed the steps they described and got it to create a measurement. I really didn't go much further than that. I wish I could articulate more detail but I just haven't invested the time to learn more about REW. But that's why I'm here.