From some of the response charts it would seem there's no serious lack of bass.
It wouldn't, silly. But I doubt the width of the room is responsible for the 40 Hz dip.
--Bill
Speaker/Room calibration
- Thread starter Bruce B
- Start date
--Bill
Hi
Room responses are not the end of it all and a system has more to it than simple frequency response but as can be seen here .. Room response in most rooms is far from perfect; Smooth response provides better sound..
The sneers about the addition of subwoofers come from a lack of understanding of some acoustics realities. INa full range system the addition of subs is not for jsut for more bass as much as having better bass... a smoother more even response with fewer dips and peaks. Just one sub placed strategically can alleviate many rooms problems, especially with truly full range mains...
Regardless of the capabilities of the main speakers the best, smoother response in bass will be better with the addition of multiple subs... That your mains reach 0 Hz flat will not change that fact... Out for now
Room responses are not the end of it all and a system has more to it than simple frequency response but as can be seen here .. Room response in most rooms is far from perfect; Smooth response provides better sound..
The sneers about the addition of subwoofers come from a lack of understanding of some acoustics realities. INa full range system the addition of subs is not for jsut for more bass as much as having better bass... a smoother more even response with fewer dips and peaks. Just one sub placed strategically can alleviate many rooms problems, especially with truly full range mains...
Regardless of the capabilities of the main speakers the best, smoother response in bass will be better with the addition of multiple subs... That your mains reach 0 Hz flat will not change that fact... Out for now
Err, that's because there are 4x 15" subwoofers in there.
Have you checked a room mode calculator? The room is 13' 4" wide. Plug it in.
From the dimensions Bruce gave and my little Mathcad program the room modes up to 200 Hz are (in Hz):
25.682
41.852
51.364
53.81
77.045
83.704
102.727
107.619
125.556
128.409
154.091
161.429
167.407
179.773
25.682
41.852
51.364
53.81
77.045
83.704
102.727
107.619
125.556
128.409
154.091
161.429
167.407
179.773
Hi Bruce,
The position changes you formed really helped. I know we can do much better.
Please post 3 graphs for us.
One thing you have to do is make sure whenever you do this, keep the mic in the same spot ever time. I have it marked on my floor. Keeping the setting the same run the first graph with the bass filter at 50 100 and 150hz. Graph 2 - put the bass filter back to where it was then run thru bass level off to +6 (be careful) the bass should be 6 db up. Graph 3 return the controls to the ref. and run thru the bass extension 0 to 2 octives.
Place the graphs in the overlays so we can see the effect each control has. We will look at bass Q later.
John
The position changes you formed really helped. I know we can do much better.
Please post 3 graphs for us.
One thing you have to do is make sure whenever you do this, keep the mic in the same spot ever time. I have it marked on my floor. Keeping the setting the same run the first graph with the bass filter at 50 100 and 150hz. Graph 2 - put the bass filter back to where it was then run thru bass level off to +6 (be careful) the bass should be 6 db up. Graph 3 return the controls to the ref. and run thru the bass extension 0 to 2 octives.
Place the graphs in the overlays so we can see the effect each control has. We will look at bass Q later.
John
Don,
We get many more if we include tangential and obliques
Full simulation of room (6.71m) :
( Courtesy of http://www.bobgolds.com/Mode/RoomModes.htm To see the tables correctly formatted please cut and paste them in Excel. )
Frequency hz Spacing % Wavelength 1/2 Wavelength 1/4 Wavelength p q r Mode
25.7 13.4 6.7 3.35 1 0 0 Axial
41.9 38.6 8.22 4.11 2.06 0 1 0 Axial
49.1 14.6 7.01 3.51 1.75 1 1 0 Tangential
51.3 4.2 6.71 3.36 1.68 2 0 0 Axial
53.8 4.6 6.4 3.2 1.6 0 0 1 Axial
59.6 9.7 5.78 2.89 1.44 1 0 1 Tangential
66.3 10.1 5.19 2.6 1.3 2 1 0 Tangential
68.2 2.7 5.05 2.53 1.26 0 1 1 Tangential
72.9 6.4 4.72 2.36 1.18 1 1 1 Oblique
74.4 2 4.63 2.31 1.16 2 0 1 Tangential
77.0 3.3 4.47 2.24 1.12 3 0 0 Axial
83.8 8.1 4.11 2.06 1.03 0 2 0 Axial
85.4 1.8 4.03 2.02 1.01 2 1 1 Oblique
87.6 2.5 3.93 1.97 0.98 1 2 0 Tangential
87.7 0.1 3.93 1.96 0.98 3 1 0 Tangential
93.9 6.6 3.67 1.83 0.92 3 0 1 Tangential
98.3 4.4 3.5 1.75 0.88 2 2 0 Tangential
99.6 1.3 3.46 1.73 0.86 0 2 1 Tangential
102.7 3 3.35 1.68 0.84 4 0 0 Axial
102.8 0 3.35 1.68 0.84 1 2 1 Oblique
102.9 0 3.35 1.67 0.84 3 1 1 Oblique
107.6 4.3 3.2 1.6 0.8 0 0 2 Axial
110.7 2.8 3.11 1.56 0.78 1 0 2 Tangential
110.9 0.1 3.11 1.55 0.78 4 1 0 Tangential
112.0 0.9 3.08 1.54 0.77 2 2 1 Oblique
113.8 1.5 3.03 1.51 0.76 3 2 0 Tangential
115.5 1.4 2.98 1.49 0.75 0 1 2 Tangential
115.9 0.3 2.97 1.49 0.74 4 0 1 Tangential
118.3 2 2.91 1.46 0.73 1 1 2 Oblique
119.2 0.7 2.89 1.44 0.72 2 0 2 Tangential
123.3 3.3 2.79 1.4 0.7 4 1 1 Oblique
125.7 1.9 2.74 1.37 0.69 0 3 0 Axial
125.9 0.1 2.74 1.37 0.68 3 2 1 Oblique
126.4 0.3 2.72 1.36 0.68 2 1 2 Oblique
128.3 1.4 2.68 1.34 0.67 1 3 0 Tangential
128.3 0 2.68 1.34 0.67 5 0 0 Axial
132.3 3 2.6 1.3 0.65 3 0 2 Tangential
132.5 0.1 2.6 1.3 0.65 4 2 0 Tangential
135.0 1.8 2.55 1.28 0.64 5 1 0 Tangential
135.8 0.5 2.54 1.27 0.63 2 3 0 Tangential
136.4 0.4 2.53 1.26 0.63 0 2 2 Tangential
136.7 0.2 2.52 1.26 0.63 0 3 1 Tangential
138.8 1.5 2.48 1.24 0.62 1 2 2 Oblique
138.8 0 2.48 1.24 0.62 3 1 2 Oblique
139.1 0.2 2.48 1.24 0.62 1 3 1 Oblique
139.2 0 2.47 1.24 0.62 5 0 1 Tangential
143.0 2.6 2.41 1.2 0.6 4 2 1 Oblique
145.3 1.5 2.37 1.19 0.59 5 1 1 Oblique
145.7 0.2 2.36 1.18 0.59 2 2 2 Oblique
146.1 0.2 2.36 1.18 0.59 2 3 1 Oblique
147.4 0.8 2.34 1.17 0.58 3 3 0 Tangential
148.7 0.8 2.32 1.16 0.58 4 0 2 Tangential
153.3 3 2.25 1.12 0.56 5 2 0 Tangential
154.0 0.4 2.24 1.12 0.56 6 0 0 Axial
154.5 0.3 2.23 1.11 0.56 4 1 2 Oblique
156.6 1.3 2.2 1.1 0.55 3 2 2 Oblique
156.9 0.1 2.2 1.1 0.55 3 3 1 Oblique
159.6 1.6 2.16 1.08 0.54 6 1 0 Tangential
161.4 1.1 2.13 1.07 0.53 0 0 3 Axial
162.3 0.5 2.12 1.06 0.53 4 3 0 Tangential
162.4 0 2.12 1.06 0.53 5 2 1 Oblique
163.1 0.4 2.11 1.06 0.53 6 0 1 Tangential
163.5 0.2 2.11 1.05 0.53 1 0 3 Tangential
165.5 1.2 2.08 1.04 0.52 0 3 2 Tangential
166.8 0.7 2.06 1.03 0.52 0 1 3 Tangential
167.5 0.4 2.06 1.03 0.51 1 3 2 Oblique
167.5 0 2.06 1.03 0.51 5 0 2 Tangential
167.6 0 2.06 1.03 0.51 0 4 0 Axial
168.4 0.4 2.05 1.02 0.51 6 1 1 Oblique
168.8 0.2 2.04 1.02 0.51 1 1 3 Oblique
169.4 0.3 2.03 1.02 0.51 2 0 3 Tangential
169.6 0.1 2.03 1.02 0.51 1 4 0 Tangential
170.7 0.6 2.02 1.01 0.5 4 2 2 Oblique
171.0 0.1 2.01 1.01 0.5 4 3 1 Oblique
172.6 0.9 2 1 0.5 5 1 2 Oblique
173.3 0.4 1.99 0.99 0.5 2 3 2 Oblique
174.5 0.6 1.97 0.99 0.49 2 1 3 Oblique
Last edited:
Plug the dimensions into http://www.hunecke.de/en/calculators/room-eigenmodes.html and you can see the peak locations. 4.1m x 6.7m x 3.2m
The modes can be nodes (nulls) or anti-nodes (peaks) in the center of the room.
Aside: My program actually gives primary, tangential, and oblique modes, but I only printed the primary since we were talking about the 40 Hz'ish primary and I didn't want to list everything.
RUR: The program runs on my desktop (last you provided that link the program didn't run; I need to update my notebook). Yay!
Aside: My program actually gives primary, tangential, and oblique modes, but I only printed the primary since we were talking about the 40 Hz'ish primary and I didn't want to list everything.
RUR: The program runs on my desktop (last you provided that link the program didn't run; I need to update my notebook). Yay!
Bruce,
This is great, atleast we now know what each control does. I have got to tell you this will not be a 1,2,3 i'm done thing. Like I said earlier, I have been doing this for years. We just need to find the correct combination of position vs controls.
One question - what FR do you want? Then it's how do we get there. In REW you need to enter what you want as a "House curve". That is what we will shoot for.
Bass Q is diff from what I thought is was, good thing you did it.
John
This is great, atleast we now know what each control does. I have got to tell you this will not be a 1,2,3 i'm done thing. Like I said earlier, I have been doing this for years. We just need to find the correct combination of position vs controls.
One question - what FR do you want? Then it's how do we get there. In REW you need to enter what you want as a "House curve". That is what we will shoot for.
Bass Q is diff from what I thought is was, good thing you did it.
John
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