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Square room horror

ZolaIII

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Alternately, put two subs (fed the same content) on front wall at 1/4" width positions, and sit ~2/3-3/4 of the room length from the front wall, centered between the left and right walls. The front wall sub placement attenuates or eliminates the worst width modes (as Floyd Toole noted generally, not specifically for a square room) , while your seat position puts you between the worst length nulls and peaks. Theoretically at least. Real world in-room performance can differ.



Like many contrarians, you seem angry. Perhaps type more slowly?
Find me a single picture of Harman reference listening room with sub's pushed in corners. And find a single one without acoustic treatment which by the way other firms do for them. I didn't say putting them in corners won't give +6 dB room gain but in a bad way.
 

abdo123

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Who told you that? Any scientific publications to back that up!

I remember watching a video on YouTube that simulated a square room and showed that placing subwoofers along the diagonal lines of symmetry yielded the best results. I spent a good five minutes looking for it but didn't find it.
 

HarmonicTHD

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Take a look at any of their "reference room's" than print that book and burn it and when you are done do what ever you want.
The OP (@Descartes ) asked for research why it would be advisable (as @abdo123 said) to move a sub to the middle of a wall of a square room.

I pointed the OP to such research eg Toole Chapter 8 and for your highness’ convenience now also the relevant excerpt (for one sub in a square room).

1674373132873.png


The chapter goes on and shows the advantages and disadvantages of the other placement options if you have two or more subs (including the diagonal corner approach when having two). I leave it up to you if you are even interested to look it up.

If you disagree with the research address the research and provide some evidence so we can all learn and not some angry slur about book burning.
 
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ZolaIII

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@HarmonicTHD now take a look at their newer research (post no#22). You might want to read story about disasters NY Madison Avenue listening room. I leve that to you. I don't want dominant third and fourth harmonic but to keep second one under control so I will go with accustic treatment, closed enclosure sub's and place them either centered at front and back wall or front wall 2/3 phase of each other centered.
 

abdo123

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I mean acoustic treatment is always superior if you’re willing to fill 25% of the room’s physical volume with absorption. But anything else is a compromise and I never seen anyone actually do that in a domestic setting.
 

ZolaIII

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I mean acoustic treatment is always superior if you’re willing to fill 25% of the room’s physical volume with absorption. But anything else is a compromise and I never seen anyone actually do that in a domestic setting.
Cuple absorber panels and corners on the front wall are achievable by most and even if they aren't you definitely don't want to boost future bad room harmonics.
 

abdo123

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Cuple absorber panels and corners on the front wall are achievable by most and even if they aren't you definitely don't want to boost future bad room harmonics.
This is completely useless below 120Hz.

Edit: sorry I misunderstood. I thought you don’t want to use subs.
 
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D

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All this talk about square rooms and sub placements. Why don't you just use REW to simulate the room response? -It surely also depends on where your main listening position is in the room so the discussion seems kind of futile when the variables hasn't been established, no?
 

ZolaIII

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In my humble onion, it's much better to treat the room, than to use eq. Lilke 1000% better.
You use all you can if you can. First placement and enclosure then accustic treatment to lower actual problems as much as you can and then DSP. In the process you use measurements (original signal and response you are getting) and your hearing (as a confirmation). Wouldn't be smart to discard anything that will help you.
 

theREALdotnet

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All this talk about square rooms and sub placements. Why don't you just use REW to simulate the room response? -It surely also depends on where your main listening position is in the room so the discussion seems kind of futile when the variables hasn't been established, no?

I think post #1 shows the REW simulation. My question would have been: what is the actual room response? In my experience, the REW simulation can be way off, partly because rooms are never as simple as the model and partly because the wall absorption is rarely known well enough.

From the simulated room response I’m guessing that the speakers are about 1.4m apart? That would explain the dip at 120Hz. If that peak at 121-122Hz exists in the actual room response you could try moving the speakers a little bit closer to each other (a couple of centimeters), to make the peak coincide with the dip.
 

HarmonicTHD

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@HarmonicTHD now take a look at their newer research (post no#22). You might want to read story about disasters NY Madison Avenue listening room. I leve that to you. I don't want dominant third and fourth harmonic but to keep second one under control so I will go with accustic treatment, closed enclosure sub's and place them either centered at front and back wall or front wall 2/3 phase of each other centered.
There is no contradiction between Welti and Toole. Again, the question of @Descartes was about, where to best place a sub (in a square room) if you only have 1 sub (at least that is what I understood). Toole (Chapter 8, Figure 8.17), quotes the Welti (2012) study linked in post 22 and if you look at post 22, page 50 (configurations 1) and page 56 (configuration 2), Welti says exactly the same - if you have only 1 sub, place it in the middle of the wall (to optimize the LF factor).

What am I missing?


Edit: Correction: Ah crap. I just noticed, I somehow got the configs screwed up which Welti used in my paragraph above. So here we go: Config 1 (corner) and 3 (mid wall) have almost identical LF factors. Sorry gents.

1674388520736.png


1674388537265.png
 
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Yameyo

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I think post #1 shows the REW simulation. My question would have been: what is the actual room response? In my experience, the REW simulation can be way off, partly because rooms are never as simple as the model and partly because the wall absorption is rarely known well enough.

From the simulated room response I’m guessing that the speakers are about 1.4m apart? That would explain the dip at 120Hz. If that peak at 121-122Hz exists in the actual room response you could try moving the speakers a little bit closer to each other (a couple of centimeters), to make the peak coincide with the dip.
Hi. I've lent my UMIK-1 to my brother while he tries to decide which of two pairs of speakers to keep. I'll be measuring the room once I have the mic back. Curious also to see if YPAO has any benefit or not.
 

fpitas

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In my humble onion, it's much better to treat the room, than to use eq. Lilke 1000% better.
Or at least a combination. Treat as much as feasible given WAF etc.
 

ZolaIII

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@HarmonicTHD middle of the front wall, not middle of the room. I admit I don't have complaints against that. My complaint whose against putting it in the corner which would give bass boost of around 6 dB and problems you had with it equally. It's insane to recommend that to anyone. What DSP room corrections do is slap down bass output in order to get fundamental peaks down which doesn't work well.
 
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@HarmonicTHD middle of the front wall, not middle of the room. I admit I don't have complaints against that. My complaint whose against putting it in the corner which would give bass boost of around 6 dB and problems you had with it equally. It's insane to recommend that to anyone. What DSP room corrections do is slap down bass output in order to get fundamental peaks down which doesn't work well.
Works fine in my room. Put sub in corner to get maximum efficiency. Cut down with DSP to flatten the response.
 

HarmonicTHD

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@HarmonicTHD middle of the front wall, not middle of the room. I admit I don't have complaints against that. My complaint whose against putting it in the corner which would give bass boost of around 6 dB and problems you had with it equally. It's insane to recommend that to anyone. What DSP room corrections do is slap down bass output in order to get fundamental peaks down which doesn't work well.

See my correction here: https://audiosciencereview.com/forum/index.php?threads/square-room-horror.40664/post-1456767

Sorry if my error in quoting Welti caused confusion.
 

ZolaIII

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Works fine in my room. Put sub in corner to get maximum efficiency. Cut down with DSP to flatten the response.
Well then you are among lucky cuple who don't have a room fundamental peaks. Those are room peaks (usually between 40~60 Hz but not unusual and around 100~120 Hz) not tied to the reproduction chain so you can't really fix them in one but fixing the room response.
 
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Well then you are among lucky cuple who don't have a room fundamental peaks. Those are room peaks (usually between 40~60 Hz but not unusual and around 100~120 Hz) not tied to the reproduction chain so you can't really fix them in one but fixing the room response.
I don't get your point. Are you claiming that my Dirac EQ cut at e.g. 31 Hz modal peak doesn't do anything? :)
 

ZolaIII

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It doesn't do much as the peak is there even when you don't play anything (in environmental noise) and neither will acoustic absorbers when it's that low. I have one at 43~46 Hz. Experimented with absorbers, closed enclosure speakers and subs which did help make it less prominent but it didn't disappear nor it ever will. When you combine all bit by bit you menage to get it better and ideal doesn't exist. At least that's my experience.
 
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