quick question

[Professor smith]

Is it true that even if you have the most powerful 18inch subwoofer and misplace it in your room, you will hear no bass? It has been my experience that the placement can make the difference between very deep loud bass and quiet unextended bass. Is it also true that what may sound like thunderous rattling bass inside the room can barely be heard when you go outside the room or house?

[Dag Johansen]

No and no.
Depending on standing waves you will have more or less deep bass in diferent positions in the room, but i will never be quiet.
The same goes for bass outside the room, some places will have less deep bass.

Dag

[epa]

if you place a sub in a corner,or put it somewere in the middle,that wil make a lot of difference in what you hear.
the sub put out the same ,it just gets amplyfied by the corner(symply said)

[revboden]

Originally Posted by Professor smith

Is it true that even if you have the most powerful 18inch subwoofer and misplace it in your room, you will hear no bass?

There are more variables. If you place a sub in the corner or some other place which maximally excites a room mode, at a particular frequency and specific spot in the room you will have a null, ie. one spot, one frequency phase cancellation. Corner loading creates all of them that can exist.

Originally Posted by Professor smith

Is it also true that what may sound like thunderous rattling bass inside the room can barely be heard when you go outside the room or house?

Unless it's a sealed 1m thick solid concrete bunker of a room... No

[Djim]

Originally Posted by Professor smith

Is it also true that what may sound like thunderous rattling bass inside the room can barely be heard when you go outside the room or house?

It really depends on what you describe as "thunderous rattling bass inside" and the location where you live. Here in North Europe our modern building standards of high insulation and stone houses (insulated dual wall constructions, thermopane glass ect), it is possible to play loud enough to make your relative lightweight furniture tot resonate/rattle. An innocent neighbour outside wouldn't have a clue. If you repeat the same setup in a wooden house, badly insulated, your innocent neighbour may turn out to be less innocent as you thought. My parents probably describe these levels as "thunderous rattling bass inside" while the kids call it "normal"...as long they are not on their cellphone. So I agree with Revboden that there are more variables and definitions to look at and in short, the answer will be long to your "quick question".

[boris81]

You will get peaks and dips in the frequency response depending on the distance to and number of walls.

These are consequences of the constructive and destructive interference between the direct and reflected waves. In the case of parallel walls like in a typical room there's also the phenomena of standing waves.

Placing a sub near a wall will give a +3dB boost(for each wall) at the frequencies < 1/4 wavelength to the wall.

[Professor smith]

Originally Posted by boris81

Placing a sub near a wall will give a +3dB boost(for each wall) at the frequencies < 1/4 wavelength to the wall.

Why then is it that in my room all the corners I've tried don't give me deep low bass? The best position is about half way along one wall. This contradicts the usual advice of corner placement.

What position would give the deepest bass in a cubic shaped room?

[yangbaibing]

Placing your ears near a wall will give you a volume boost,and what's more is the lower bass(the real bass that can impact your body).

[chris661]

Originally Posted by Professor smith

Why then is it that in my room all the corners I've tried don't give me deep low bass? The best position is about half way along one wall. This contradicts the usual advice of corner placement.

What position would give the deepest bass in a cubic shaped room?

Depends. Extrapolation is a dangerous thing.

Can you give details of the subwoofer you're trying this with?

"The deepest bass" is also very non-specific. If you're talking about maximum output at 20Hz (or some other arbitrary figure), then corner loading. But that doesn't automatically make corner loading the best option.

Chris

[Professor smith]

Originally Posted by chris661

Depends. Extrapolation is a dangerous thing.

Can you give details of the subwoofer you're trying this with?

"The deepest bass" is also very non-specific. If you're talking about maximum output at 20Hz (or some other arbitrary figure), then corner loading. But that doesn't automatically make corner loading the best option.

Chris

why would it depend?