I's a mini listening room: the furniture and the listening point are locked.
There is no place on the floor for speakers or components, so we tried a wall solution.
This sounds boxed. We can press the play button only with three peak filters.
However I don't understand the origin of the powerful 16 ms echo. No secondary source in the room can be at 5.44 m, and secondary reflections can not be so powerful (?).
[two channels]
The peak is evident in the 8KHz octave, and it doesn't change by moving an absorbent panel around the room. Can it be caused by electronics?
Any suggestions?
There is no place on the floor for speakers or components, so we tried a wall solution.
This sounds boxed. We can press the play button only with three peak filters.
However I don't understand the origin of the powerful 16 ms echo. No secondary source in the room can be at 5.44 m, and secondary reflections can not be so powerful (?).
[two channels]
The peak is evident in the 8KHz octave, and it doesn't change by moving an absorbent panel around the room. Can it be caused by electronics?
Any suggestions?
Attachments
Have you tried the string technique to verify? You can google the REW String Technique. The short of it though is you cut a string to the length you're trying to figure out. You then affix one end to speaker, and other end to mic. Move the string around until you find where it touches, that is where your reflection is coming from. It's possible it's coming from behind the listening position as well.
In your last graph, what is the blue line and what is the red line?
How tall is your ceiling? Could you also post what drivers you're using, enclosure size, and your crossover?
To me it looks like you still have an issue at 70Hz, 140Hz (might be same as 70Hz), and 200 to 500 Hz (I'd suspect floor bounce if it isn't the driver/crossover/enclosure).
70 Hz = 4857 mm wavelength, pretty darn close to 4100mm.
140 Hz = 2428 wavelength, pretty darn close to 2500mm.
And of course 140*2=280
See where I'm getting with all this? Room modes, you're fighting them. Also, placing those panels over the amplifier could have done any number of things and I won't hazard a guess what actually changed.
Placing those subs probably did not affect the actual reflections, rather they're fighting your room modes. Still a good thing, but different form of action. Make sense?
How tall is your ceiling? Could you also post what drivers you're using, enclosure size, and your crossover?
To me it looks like you still have an issue at 70Hz, 140Hz (might be same as 70Hz), and 200 to 500 Hz (I'd suspect floor bounce if it isn't the driver/crossover/enclosure).
70 Hz = 4857 mm wavelength, pretty darn close to 4100mm.
140 Hz = 2428 wavelength, pretty darn close to 2500mm.
And of course 140*2=280
See where I'm getting with all this? Room modes, you're fighting them. Also, placing those panels over the amplifier could have done any number of things and I won't hazard a guess what actually changed.
Placing those subs probably did not affect the actual reflections, rather they're fighting your room modes. Still a good thing, but different form of action. Make sense?
Hi mushroommunk!
the blue line refers to the speakers as in picture in post # 1. In my room the 150-200 Hz region was quite regular, in the destination room the irregularities were unacceptable. I have motivated this with reflections from the walls, and I have used two boxes in the corners, up to 150 Hz.
Instead, the irregularities in the 300-800 region have diminished only after the panels covering the amplifiers are mounted. The result of yesterday in FR, is the red line. I thought the panel would bring the speakers closer to the model of emission in half space.
The ceiling is 3 m tall.
I also think that the issue at 70Hz, 140Hz has a modal origin. Not sure I can solve. Boxes and listenig position are locked. In the picture low FR unsmooted 1 channel
The system:
mid: Peerless HDS-P830991 in 5 l sealed
tw : TB SPEAKERS 28-847SD
XO : LP ind 0.8mH
HP res 2.2Ohm cap 6.8 uF ind 1 mH listening not on axis
bass: Monacor SPH200TC vented in ca 30L Fb around 30Hz, non sure, it was five years ago.
Digital active filter (equalizer APO), I have not here the code, but (?)
two LP at 150 and 170 Hz, Q 0.7
a low Q peak filtre for level, around 100 Hz,
an HP 150 Hz Q 0.7
Two Rotel RB971
In the picture low FR unsmooted 1 channel
thanks for your attention, I apologize for my english.
the blue line refers to the speakers as in picture in post # 1. In my room the 150-200 Hz region was quite regular, in the destination room the irregularities were unacceptable. I have motivated this with reflections from the walls, and I have used two boxes in the corners, up to 150 Hz.
Instead, the irregularities in the 300-800 region have diminished only after the panels covering the amplifiers are mounted. The result of yesterday in FR, is the red line. I thought the panel would bring the speakers closer to the model of emission in half space.
The ceiling is 3 m tall.
I also think that the issue at 70Hz, 140Hz has a modal origin. Not sure I can solve. Boxes and listenig position are locked. In the picture low FR unsmooted 1 channel
The system:
mid: Peerless HDS-P830991 in 5 l sealed
tw : TB SPEAKERS 28-847SD
XO : LP ind 0.8mH
HP res 2.2Ohm cap 6.8 uF ind 1 mH listening not on axis
bass: Monacor SPH200TC vented in ca 30L Fb around 30Hz, non sure, it was five years ago.
Digital active filter (equalizer APO), I have not here the code, but (?)
two LP at 150 and 170 Hz, Q 0.7
a low Q peak filtre for level, around 100 Hz,
an HP 150 Hz Q 0.7
Two Rotel RB971
In the picture low FR unsmooted 1 channel
thanks for your attention, I apologize for my english.
Attachments
Posso eseguire il mio inglese tramite Google Traduttore se preferisci.
Joking aside, I'm trying to figure out what you could do. I'm seeing two things. One is you could build soffit/corner absorbers and put them along the ceiling where the wall and ceiling meet. Kind of like where you have the subs now but extending around the entire room (leaving the subs in place).
Building two more of those subs and adding them in the rear and then really dialing in the integration using something like This Tool would help a little.
Finally, gobo style moveable acoustic panels that can slide in front of the window would help. It looks like a tight fit though so I understand this might not be possible.
It looks like you're running from a pc and have some experience active filters so have you considered using rePhase? It's a fir filter tool you can use to create room eq.
Look Here for a guide on how to use it with jriver to add room EQ, and Look Here for the diyAudio thread on the tool.
Joking aside, I'm trying to figure out what you could do. I'm seeing two things. One is you could build soffit/corner absorbers and put them along the ceiling where the wall and ceiling meet. Kind of like where you have the subs now but extending around the entire room (leaving the subs in place).
Building two more of those subs and adding them in the rear and then really dialing in the integration using something like This Tool would help a little.
Finally, gobo style moveable acoustic panels that can slide in front of the window would help. It looks like a tight fit though so I understand this might not be possible.
It looks like you're running from a pc and have some experience active filters so have you considered using rePhase? It's a fir filter tool you can use to create room eq.
Look Here for a guide on how to use it with jriver to add room EQ, and Look Here for the diyAudio thread on the tool.
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