Does room size affect how low the subwoofer can go? (1 Viewer)

[Ariel]

hi to all!
my room is about 17' x 13' x 9' (L,w,H). i am wondering
if i use a sub that is capable of reproducing 20hz and below like the servo15, will i hear or feel these frequencies? if not then i can save some money and buy a smaller sized sub that can just go to about 24hz.
thanks in advance.

 

[Ned]

Headphones can do 20hz. Those are a pretty small "room". Room size doesn't matter (except if it's huge of course, but that's another issue).
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[Ariel]

thank you very much. i just become confused when i read
from another forum that the room size is a major factor
on how low the subwoofer can go.

 

[MarkO]

Small rooms do limit the low end. Im not sure exacaly how. Maybe Tom V will chime in here. My guess is that small rooms hinder the long wave needed to reproduce the really low stuff because of early reflections.

 

[Dirk E]

Hi MarkO,
sorry, but what you wrote is incorrect. One of the SVS-people explained this "small room, low bass"-thing a few month ago.
You can get a lot of deep bass in a small room, a car or even a headphone. Size doesn`t matter. Small rooms tend to boost low frequencies. Believe me, my room is only 10m² and I get a lot of deep bass down to 20 Hz.
I hope Tom or Ron can explain it again in more detail.

 

[Bob McElfresh]

Here is my Understanding (open for discussion/debait) :
If your sub can go 20 hz, you will hear 20 hz.
But in a normal room, you are hearing 2 types of sound:
- Direct
- Reflected
Much of the time, the walls of the room will reflect several frequencies much better than others.
Here is how to calculate the frequency a wall will reflect:
Measure the long, un-broken wall in feet. Let's say 8 feet, 6 inches. This becomes 8 + (6/12) = 8.5 feet.
To get the frequency that this wall will reflect better than others, do this:
frequency (base) = 565/L = 565/8.5 = 66 hz.
But wait, that wall will also reflect 2/3/4 times this base-frequency quite well. So the wall will enhance all of these frequencies:
66, 133, 199, 266 hz
Take a smaller 5 foot wall, the numbers become:
frequency (base) = 565/5 = 113
So this wall will enhance:
113, 226 hz
(Note: We stop calculating at about 300 hz or after 4 frequencies).
So a small room wont ENHANCE the lower-frequencies like a room with longer walls will.
Now lets analyze your room:
17' wall: 33, 66, 100, 133
13' wall: 43, 86, 130, 174
9' wall: 63, 126, 188, 251
So the room will ENHANCE: 33, 43, 63, 66, 100, 126, 130, 133
But if you listen to pipe-organ music, the sub will still produce 20 hz sounds. It just wont get help from the room until about 33 hz.
Hope this helps.

 

[Ariel]

thanks bob. that is a very good explanation and a big help
for me.

 

[Tom Vodhanel]

I see much has been explained.
Generally,the larger the room...the smoothed the bass will be over a variety of seats because of the mode spacing. The smaller the room, the more *room gain* will allow the subwoofer extend lower.
Tom Nousaine acoustically mapped his old(2136 cu-ft) room and compared it to the mapping of his new (7500 cu-ft)room in a SR piece a while back. He found the smaller room increased 20hz bass performance 8.1dB and 25hz bass performance 3.6dB.
I believe 16hz was 11.5dB.
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