room gain

[johnhay20hz 0]

i have a question for all you experts out there

i have always heard that room gain starts at the frequency which 1/2 its wavelength is the distance from the subwoofer to the farthest distance of the room

of course materials that the room is made of, etc take place but for the example i am going to use lets say there is 0 leaks and really lower resonance of materials used (ex concrete)

is room gain greater if the room is 10 feet high by 10 feet wide by 30 feet long and subwoofer placed in a corner (room gain starts at 19 hz i think) 3000

or if the room is 7 feet high by 5 feet wide by 35 feet long and subwoofer is placed in corner (room gain starts at 16hz i think) total volume of room is 1225

Now subwoofers are more efficient firing into a more dense air space (ex horns i believe relate here) and as the room size shrinks the ratio of subwoofer displacement to room increases, so i would think that there would be more spl increase in the smaller room even thou its longer

but cabin gain says the larger room is louder

am i comparing two different things here?

sorry for long post but thank you for any who try and help

[///M5 2,833]

Not sure I follow your question. Are you implying that the air is more dense in a small room?

[johnhay20hz 0]

Not sure I follow your question. Are you implying that the air is more dense in a small room?

well the air in the room is more compressed from the subwoofer because the volume of air is smaller, i would assume that would help spl

isnt that what spl is at low frequency, a pressurized room by the sound wave?

[///M5 2,833]

Not sure I follow your question. Are you implying that the air is more dense in a small room?

well the air in the room is more compressed from the subwoofer because the volume of air is smaller, i would assume that would help spl

isnt that what spl is at low frequency, a pressurized room by the sound wave?

Not really. It is the amplitude of the sound wave. Room gain comes from constructive interference of waves which isn't directly related to volume at all, but indirectly through the reflections that create interference with itself.

I understand the word is confusing so just think of it as sound level.

Another comment. Pressure in the room is related to height above sea level, not size. Big room, small room in the same house will be at the same pressure.

[johnhay20hz 0]

so a larger but not as long room will be louder than a smaller but longer room

with the subwoofer in the corner all other things being equal?

n by density i actually meant the subwoofer displacement is larger compared to the volume of the room

[ibanender 2]

so a larger but not as long room will be louder than a smaller but longer room

with the subwoofer in the corner all other things being equal?

n by density i actually meant the subwoofer displacement is larger compared to the volume of the room

I'm not sure 100% what you're trying to accomplish here, but maybe this will help. http://www.mcsquared.com/modecalc.htm

[///M5 2,833]

so a larger but not as long room will be louder than a smaller but longer room

with the subwoofer in the corner all other things being equal?

No rule of thumb like that exists and if it did it would be wrong. A simple answer is not one you can come to.

n by density i actually meant the subwoofer displacement is larger compared to the volume of the room

Not sure what you are referring to by subwoofer displacement...or density, volume of the room is straightforward though.