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early reflection of sidewalls: absorption or not?
early reflection of sidewalls: absorption or not?
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Old 20th January 2019, 11:35 AM   #21
Bill Coltrane is offline Bill Coltrane  Netherlands
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If your speakers are good, you don't need acoustic treatment. Multiple subs and eq work just fine.

If your speakers are bad, no amount of acoustic treatment can make them sound great. It can improve it though.
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Old 20th January 2019, 11:42 AM   #22
scottjoplin is offline scottjoplin  Wales
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I hope you aren't suggesting EQ can be used to deal with reflections?
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Old 20th January 2019, 12:34 PM   #23
Pano is offline Pano  United States
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early reflection of sidewalls: absorption or not?
Quote:
Originally Posted by AllenB View Post
Building speakers to properly fit the room corners without modifying the room gives a large delay for the early reflections, but building this way is challenging.
Do you mean like this?

Click the image to open in full size.
I just let Pele do the building.

I have no studies to back it up, but in my experience good diffusion at the first reflection points works well. Instead of eliminating the reflections it scatters them around and doesn't sound bad. There is acoustic energy remaining, but it doesn't bother the sound bad like direct, hard reflections do.
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Old 20th January 2019, 01:06 PM   #24
Bill Coltrane is offline Bill Coltrane  Netherlands
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Quote:
Originally Posted by scottjoplin View Post
I hope you aren't suggesting EQ can be used to deal with reflections?
No.
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Old 20th January 2019, 02:20 PM   #25
scottjoplin is offline scottjoplin  Wales
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That's alright then
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Old 20th January 2019, 05:21 PM   #26
Monteverdi is offline Monteverdi  United States
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Quote:
Originally Posted by AllenB View Post
Building speakers to properly fit the room corners without modifying the room gives a large delay for the early reflections, but building this way is challenging. Consider treating what you have if it falls into the early category.
That room (an addition) is still in architectural review but I am thinking about design and construction detail.
My present plans are 30-35 corner wedges and I am quite o.k. with these construction challenges. It also places the drivers (wide range + woofer) closer to the side walls and therefore side wall reflections should have a smaller time delay than a placement further in the room.
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Old 20th January 2019, 06:37 PM   #27
Monteverdi is offline Monteverdi  United States
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Quote:
Originally Posted by scottjoplin View Post
I suspect it helps with the monitoring and mixing process, whether you want that kind of sound in your room is another issue
One reason I am considering this is that when I am sitting closer to my speakers (near field) I hear better detail and timbre but it yields an artificially wide sound field and is a suboptimal position for bass. So having less early reflections might be close to near field but with a more reasonable soundstage width.
As my speakers have a single crossover point at around 200Hz it would be likely very easy to compensate for bass gain via DSP.
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Old 21st January 2019, 03:04 AM   #28
AllenB is offline AllenB  Australia
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Quote:
Originally Posted by Pano View Post
Do you mean like this?
Your way may be the epitome of a diffuse environment.. No, I was talking of a clean entry with the intention of reducing reflections. Attachment is a rear view of a sub 700Hz radial that sits flush into a room corner. (The pic has been rotated 90deg, sorry)
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Old 21st January 2019, 03:16 AM   #29
AllenB is offline AllenB  Australia
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Quote:
Originally Posted by Monteverdi View Post
side wall reflections should have a smaller time delay than a placement further in the room.
Are you seeing this as the problem or something you want?

One benefit of the flush mount will be the smooth directivity index into the baffle step region by eliminating it as an issue. (Normally you'd try for pseudo-random distribution of modes through speaker placement.) The reflections can cause comb filtering at frequencies where it's hard to prevent, thus a large acoustic mirror is a plus.
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Old 21st January 2019, 11:05 AM   #30
Bicicletta is offline Bicicletta  Europe
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Quote:
Originally Posted by Bill Coltrane View Post
If your speakers are good, you don't need acoustic treatment. Multiple subs and eq work just fine.

If your speakers are bad, no amount of acoustic treatment can make them sound great. It can improve it though.
I'm looking at digital processing these days, and I have a lot of doubts and ignorance. PE:
If at a given frequency the signal has shape as in A, in the time domain;
If it produces in the room the shape in B ;
After equalization will it take shape like in C?
Is it the area of the triangle that matters?
Does the time window of the measurement have to correspond in some way to the integrative features of the auditory system?
Or is it simply a distortion in the time domain that we can not equalize correctly by controlling the signal level?
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