I think the problem here, is your trying to lump everything Bill said together into one statement about spl, when there are in fact multiple statements.
If we divide everything up in 4 separate statements, we can then better understand what he was saying:
Originally Posted by Bill Fitzmaurice
Earbuds, and all phones, give low bass response due to cabin gain. Proximity does not enter the equation.
My take on this statement is the sealed environment that is created between the headphones and your ear drums is boosting frequencies up to a very high midrange frequency, due to gain from the very small sealed environment that is created.
There is no difference in the response based on distance. There is a difference based on the size of the room, also attributable to cabin gain.
This is indeed true as well, you might perceive a difference due to the equal loudness curve but the distance required for that to occur in a sealed environment would be quite large. And with subwoofers there is also tactile feel to consider which likely follows its own curve.
If you have a large room it takes a large sub to pressurize it, no matter how close you have it placed to the listening position.
I personally would like to know a little more about this, does room gain have more of an effect when the room is pressurized vs when it isn't?
All that is stated here is that you won't get the benefits of a pressurized room just because you move closer to the sub, no misinformation there.
The only difference that results from the distance to the listener is the level, which drops by 6dB per doubling of distance in an open space, ie., outdoors. Indoors the drop off is far less, and because of room interactions there can be little to no difference throughout much of the room.
This is also true, and you have already agreed with it. However to fully agree with this, you also have to agree that punching holes in your walls will remove the sealed room's effect on the difference in spl throughout the room.
Hopefully that clears it up a little more, and shows that what you think he is saying isn't actually what he is saying.
I think if you manage to pressurize the room completely it might also contribute to the change of the level with distance being less.
There are no absolutes, but the question of whether near-field is particularly important/noticeable in a properly pressurized sealed room is certainly debatable, and will be different depending on the bass frequencies involved.
The bigger issue that sparked the argument however was the lack of respect in your reply to what you thought was an incorrect statement.
Even if you believe someone's post is incorrect, there's really no reason to insult them with terms like "logically opposite" and "horse pucky".
All that will get you is others not being so respectful towards you in their posts.Edited by Mik James - 6/27/13 at 12:50pm