Never Put Subwoofers In Corners... Even with DSP and Multi-Sub Setups?

[jlo]

I am not quite sure how he equalized them, but I would always combine multisubs with something like MSO rather than general equalization.

In Igor'system, here is the topic, we use 4 SVS PC2000 subwoofers more or less in middle of walls. We did many comparisons with various positions, DBA, global or unitary EQ, etc... With the QSC processor and the GUI screen, it is very easy to switch each on/of subwoofer, compare EQs or time/phase alignements,....
And we ended with time alignement and global EQ : about +2-4dB from 20 to 100Hz, smoothed at 1/20th octave

 

[Willem]

But isn't that a more or less rectangular room?

 

[jlo]

But isn't that a more or less rectangular room?

More or less..... why ?

 

[Willem]

It allows you to more or less predict what happens, and use a symmetric layout. Not so with an irregular space, where mathematically it makes more sense to go for uncorrelated positions.

 

[Deleted member 48726]

It allows you to more or less predict what happens, and use a symmetric layout. Not so with an irregular space, where mathematically it makes more sense to go for uncorrelated positions.

So the advice of stacking subs in the corner is not bad advice but good may be good depending on the room.
Who would have thought..

 

[Chromatischism]

It always depends on the room.

But, over a bunch of samples, corners will lose for smoothness.

 

[DRNNOO]

Cleaning up the midd and upper bass requires acoustical treatment. There's simply no way around this if one wants a stellar time domain behaviour, and which is crucial for a great result.

I didn't mean to take what you said out of context.

Quality of the low frequency is more than just a good deep bass response. The mid and upper bass and low midrange is actually more important as we more sensitive to this range. Something that the multiple subwoofer approach doesn't adress and is one if its major weaknesse

I think I pulled my position from the information in this post. You said that SBA has advantages in the mid/upper bass..... or rather that multiple subwoofers approach has weakness in that area.... I am trying to brainstorm that thought; Multisubs will have more constructive modes? So even though FR through accumulated responses, is better, it will have more areas of exaggerated decay? Thus muddying up midrange bass?

I think thats when I was like ok then...if Active cardioid is good in most situations then I can definitely use it to lower The amount of modes in the response, since, for one, there are less sources independently located in this situation, simplifying the signal that reaches the ear. Recombining 2 sources instead of 4.....less sources, equal less reflections, in so many words, thus cleaning up an aspect of midbass.

 

[Deleted member 48726]

It always depends on the room.

But, over a bunch of samples, corners will lose for smoothness.

EQ.

 

[Bjorn]

Stacking has the disadvantage of exciting existing modes stronger. But it depends and needs to be tested.

 

[Willem]

Stacking turns two smaller subs into one larger sub, but buying one large sub will be cheaper than two small ones, so why would you stack two? Corner location gives the biggest output with fewer dips but often more peaks. However the latter can be equalized. So stacking subs in a corner gives a lot more power, but at the expense of the smoothness from multiple subwoofer locations. Unless listening to massive explosions in one listening position are the use case, stacking is a bad idea.

 

[Bjorn]

I didn't mean to take what you said out of context.



I think I pulled my position from the information in this post. You said that SBA has advantages in the mid/upper bass..... or rather that multiple subwoofers approach has weakness in that area.... I am trying to brainstorm that thought; Multisubs will have more constructive modes? So even though FR through accumulated responses, is better, it will have more areas of exaggerated decay? Thus muddying up midrange bass?

I think thats when I was like ok then...if Active cardioid is good in most situations then I can definitely use it to lower The amount of modes in the response, since, for one, there are less sources independently located in this situation, simplifying the signal that reaches the ear. Recombining 2 sources instead of 4.....less sources, equal less reflections, in so many words, thus cleaning up an aspect of midbass.

SBA works higher in frequency besides generally better in the time domain because it involves physical treatment. If you can do SBA effectively in the room, there's no good reason to choose cardioid subs instead. Two different worlds in performance.

 

[JRS]

A person selling acoustic treatments says to spend your money on acoustic treatment, not more subwoofers. Not surprising. I don't know what he means by room response vs speaker response, or why the former is supposed to be worse than the latter. This guy's business must be getting killed by DSP and room correction software.
My first subwoofer was a HSU, and their first advice was to try putting it in a front corner. SVS also recommends starting with front corners when trying out sub placement. Are so many popular sub makers purposefully sabotaging the sound of their products?
I now have an SVS PC2000 in my front corner and a SVS PB2000 on my side wall of a large room, using Audyssey xt32 with dual sub outputs and SubEQ HT. Low frequencies in this setup are very good in my opinion.

One has to wonder. And possibly the most expensive and large treatment around. As to manufacturers recs, one gets a massive bump in room gain--going from out in the middle of the room to a wall is worth 6dB and going from there to a corner is another 6. 12 dB is subjectively twice as loud. Unfortunately putting pressure sources there leads to the creation of large standing waves at the fundamental (1100/distance between corners) and harmonics at 2x, 3x etc times that frequency. So think loud and lumpy

 

[DRNNOO]

Maybe its just a matter of perspective....Here is the best position in the room hands down, next to flush mounting

Now whos saying that, that, isn't, corning loading!?

 

[benanders]

Stacking turns two smaller subs into one larger sub, but buying one large sub will be cheaper than two small ones, so why would you stack two? Corner location gives the biggest output with fewer dips but often more peaks. However the latter can be equalized. So stacking subs in a corner gives a lot more power, but at the expense of the smoothness from multiple subwoofer locations. Unless listening to massive explosions in one listening position are the use case, stacking is a bad idea.

I’m not sure stacking subs is that limited, as you suggest, depending on use case.

I’ve two of the same sub model (10” sealed, powered), tried it both ways (1 sub per L / R channel in mono vs. 2 stacked subs, each in stereo) due to perceived lack of throw compared to the stereo towers. Throw improved when subs were stacked, but also had issues not present with each sub run as a L or R mono.

If for stereo (subs), there surely must be cases where stacks of smaller subs offer pros over one larger sub, especially when (1) total cone area and (2) cone excursion are considered.

Disclaimer: I do not run my subs in corners stacked or otherwise, nor on the floor for music - fine for movies but makes for too many issues in music (in my use case).

 

[DRNNOO]

 

[ozzy9832001]

One has to wonder. And possibly the most expensive and large treatment around. As to manufacturers recs, one gets a massive bump in room gain--going from out in the middle of the room to a wall is worth 6dB and going from there to a corner is another 6. 12 dB is subjectively twice as loud. Unfortunately putting pressure sources there leads to the creation of large standing waves at the fundamental (1100/distance between corners) and harmonics at 2x, 3x etc times that frequency. So think loud and lumpy

It's for that reason I keep mine away from the wall and the corner. At one point my harmonics 2nd and 3rd were peaking at 70dB - 75dB! They were beyond loud and annoying. I found that not only moving it out from the wall a foot or two made a huge difference, but raising it off the floor by about 18" helped as well. I love bass in music especially rock, but when it's out of control it sounds awful.

 

[DRNNOO]

My version of TLDR

 

[Adi777]

My version of TLDR

So the version with subwoofers in the corners must be as in the picture, i.e. the left subwoofer on the front facing to the right, and the right one must "look" at the left one?

 

[Tom C]

Many other configurations were tried. The ones in the diagram were shown to be the very best.
The paper is kind of a dense read, but I think worth the effort to go through it on your own.

 

[Adi777]

Many other configurations were tried. The ones in the diagram were shown to be the very best.
The paper is kind of a dense read, but I think worth the effort to go through it on your own.

"Positioning in the corners is aimed at maximizing the excitation of standing waves (because 7/8 of all room modes have their maxima there). This is what you do with small, cheap subs that lack the power to "play with the room". Bass in such a setup is non-linear, very long reverberating and generally has nothing to do with what is recorded in the film. That subs placed in the corners generate maximum mods is not an opinion. I fight mods as hard as I can. I don't want to listen to a rambling bun, just what's in the signal.
Subwoofers are omnidirectional and this is due to the wavelengths they radiate. If they were directional, you could hear where they were. They can even stand backwards."

True or not true?