23-Feb-2020, 00:03
@no32
No echo from the archway openings to my ears and no visitor has mentioned it. I'm in a local audio club which has its meetings in members homes. There have been many meetings here and I've had lots of comments about the room and the layout but no visitor has mentioned that issue. I've been here for 18 years and I've had lots of thoughts about the various issues with the room and I've tried lots of tweaks to the acoustic treatment in the room over those years.
The one problem I have had with reflections from the hallway ended up being due to high frequency reflections from the ceramic tiled floors outside the archways but putting woollen rugs on the floor in both locations fixed that. Over the 18 years I've been here I've tried a number of things with that opening, a screen across it, acoustic panels there, acoustic panels against the wall opposite the archway, a DIY diffusor, and a wooden panel. In other words I've tried absorbing sound reflecting back into the room, I've tried to create a false wall to keep sound in the room and reflecting back as if there was a wall there, and I've tried balancing the loss to the hallway with absorption in the same position on the opposite wall. There were plusses and minuses with each approach but in the end I felt that the minuses outweighed the plusses in each case. The one thing which has worked really well is covering the tiles in the hallway there with a woollen rug, and doing the same just outside the rear archway as well.
I suspect a lot depends on geometry since sound reflects from a surface at an angle equal to the angle at which it strikes the surface. The angle of toe in of my speakers, pointed directly at the listening position, results in the archway being considerably off axis for both speakers. That ensures that the mid and high frequencies which would be most noticeable if reflected back into the room are somewhat down in level, the increased length of the reflection path relative to the direct sound path also weakens the reflections significantly, and the angles at which the sound is exiting the room ensures that much of the first reflections from the wall in the hallway opposite the archway are not reflected back into the room anyway. There is certainly some audible effect at times from the opening on the sense I get of the acoustic space captured by a recording but that is relatively minor.
Given what I've tried, especially the acoustic panels, I seriously doubt whether curtains would be beneficial in my case. What I found with placing absorption there is that while it reduced the amount of sound reaching the hallway area through the archway and also reduced the amount of sound reflecting back into the room, what it didn't do was to provide the reflection into the room that the wall on the left side of the room provides. Absorption there actually increased the reduction in sound pressure within the room and that loss ended up having a worse effect than just leaving the archway open. The rug on the tiled floor of the archway deals with the worst problem from sound reflecting back into the room without increasing the sound pressure loss from the opening.
Thanks for the thought. What you're suggesting could well be an issue in some situations but it's not an audible problem here after installing rugs on the tiled floors outside the room.
No echo from the archway openings to my ears and no visitor has mentioned it. I'm in a local audio club which has its meetings in members homes. There have been many meetings here and I've had lots of comments about the room and the layout but no visitor has mentioned that issue. I've been here for 18 years and I've had lots of thoughts about the various issues with the room and I've tried lots of tweaks to the acoustic treatment in the room over those years.
The one problem I have had with reflections from the hallway ended up being due to high frequency reflections from the ceramic tiled floors outside the archways but putting woollen rugs on the floor in both locations fixed that. Over the 18 years I've been here I've tried a number of things with that opening, a screen across it, acoustic panels there, acoustic panels against the wall opposite the archway, a DIY diffusor, and a wooden panel. In other words I've tried absorbing sound reflecting back into the room, I've tried to create a false wall to keep sound in the room and reflecting back as if there was a wall there, and I've tried balancing the loss to the hallway with absorption in the same position on the opposite wall. There were plusses and minuses with each approach but in the end I felt that the minuses outweighed the plusses in each case. The one thing which has worked really well is covering the tiles in the hallway there with a woollen rug, and doing the same just outside the rear archway as well.
I suspect a lot depends on geometry since sound reflects from a surface at an angle equal to the angle at which it strikes the surface. The angle of toe in of my speakers, pointed directly at the listening position, results in the archway being considerably off axis for both speakers. That ensures that the mid and high frequencies which would be most noticeable if reflected back into the room are somewhat down in level, the increased length of the reflection path relative to the direct sound path also weakens the reflections significantly, and the angles at which the sound is exiting the room ensures that much of the first reflections from the wall in the hallway opposite the archway are not reflected back into the room anyway. There is certainly some audible effect at times from the opening on the sense I get of the acoustic space captured by a recording but that is relatively minor.
Given what I've tried, especially the acoustic panels, I seriously doubt whether curtains would be beneficial in my case. What I found with placing absorption there is that while it reduced the amount of sound reaching the hallway area through the archway and also reduced the amount of sound reflecting back into the room, what it didn't do was to provide the reflection into the room that the wall on the left side of the room provides. Absorption there actually increased the reduction in sound pressure within the room and that loss ended up having a worse effect than just leaving the archway open. The rug on the tiled floor of the archway deals with the worst problem from sound reflecting back into the room without increasing the sound pressure loss from the opening.
Thanks for the thought. What you're suggesting could well be an issue in some situations but it's not an audible problem here after installing rugs on the tiled floors outside the room.
Roon Nucleus+, Devilalet Expert 140 Pro CI, Focal Sopra 2, PS Audio P12, Keces P8 LPS, Uptone Audio EtherREGEN with optical fibre link to my router, Shunyata Alpha NR and Sigma NR power cables, Shunyata Sigma ethernet cables, Shunyata Alpha V2 speaker cables, Grand Prix Audio Monaco rack, RealTRAPS acoustic treatment.
Brisbane, Qld, Australia
