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[Nathan Riddle]

My understanding was that you gain 6dB when either the listener or the source is in half space vs full space.

Because the listener is already in half space there is no 6dB gain from moving the subs. Yes they are usually physically closer thus gaining SPL from their position being closer, but not because of loading.

[Jean-Pierre Coetzee]

My understanding was that you gain 6dB when either the listener or the source is in half space vs full space.

Because the listener is already in half space there is no 6dB gain from moving the subs. Yes they are usually physically closer thus gaining SPL from their position being closer, but not because of loading.

The listener has nothing to do with it.

If the subs are on the floor their polar pattern is hemispheric, if the are flow they are omni so literally half the power goes up into the air, thus 3dB reduction.

[Nathan Riddle]

The listener has nothing to do with it.

If the subs are on the floor their polar pattern is hemispheric, if the are flow they are omni so literally half the power goes up into the air, thus 3dB reduction.

I'm not trying to detract from your previous help as I really DO appreciate help with the acoustic treatment and discussion about the situation.

But Ivan would disagree.
http://forums.prosoundweb.com/index.php/topic,158814.msg1457868.html#msg1457868

So this PROVES (at least to me) that the whole idea of "getting more bass" when the subs are on the ground OR simply that you can "add a magical 6dB" to a whole space measurement is simply false.

Since the mic (or person listening) is already in half space, you get the loading.  But no additional loading when both are in half space.

Yes the curves are not exactly on top of each other, but remember that the distance to the mic is further when the cabinet was in the air.

I think going to reach out to Perdue Acoustics for some help and some modeling. Another member PM'd me and suggested that.

[Ivan Beaver]

My understanding was that you gain 6dB when either the listener or the source is in half space vs full space.

Because the listener is already in half space there is no 6dB gain from moving the subs. Yes they are usually physically closer thus gaining SPL from their position being closer, but not because of loading.

The listeners POSITION has everything to do with it.

If either the listener or the speaker is in half space (ie close to the ground relative to the size of the freq wave) then you will get a 6dB increase-relative to both being in whole space.

Putting the other (listener or speaker) in half space will not change the outcome.

Most people listen when they are near the ground.  Not very many listen while up on a tall ladder.

Often times flown subs are blamed for not being as loud.

But you MUST take the distance into account when saying this.
If you are 2m away from a sub, and then move it up in the air 5m, of course it is not going to be as loud-you are further away from it.

But stand back 30m and then lower and raise the sub and see what happens.

Distance away from a loudspeaker, and the relative freq make a lot of difference when talking about if something is "louder" or not.

[Jean-Pierre Coetzee]

The listeners POSITION has everything to do with it.

If either the listener or the speaker is in half space (ie close to the ground relative to the size of the freq wave) then you will get a 6dB increase-relative to both being in whole space.

Putting the other (listener or speaker) in half space will not change the outcome.

Most people listen when they are near the ground.  Not very many listen while up on a tall ladder.

Often times flown subs are blamed for not being as loud.

But you MUST take the distance into account when saying this.
If you are 2m away from a sub, and then move it up in the air 5m, of course it is not going to be as loud-you are further away from it.

But stand back 30m and then lower and raise the sub and see what happens.

Distance away from a loudspeaker, and the relative freq make a lot of difference when talking about if something is "louder" or not.

I would love to be proven wrong, I can't access the link in the post above so cannot read that topic and would love to. What your saying doesn't make sense to me but will research it since I trust your experience.

[Nathan Riddle]

I would love to be proven wrong, I can't access the link in the post above so cannot read that topic and would love to. What your saying doesn't make sense to me but will research it since I trust your experience.

The topic name is:
Topic: PROOF-Whole vs half space sub loading
Strange the link doesn't work. Works for me. *shrug*

[Craig Hauber]

The topic name is:
Topic: PROOF-Whole vs half space sub loading

Strange the link doesn't work. Works for me. *shrug*

Either something is wrong with my browser or you did something deliberately strange as this is what it looks like on my screen:

[Ivan Beaver]

I would love to be proven wrong, I can't access the link in the post above so cannot read that topic and would love to. What your saying doesn't make sense to me but will research it since I trust your experience.

Well that is what I have actually measured.

Dave Gunness (Fulcrum Acoustics and EAW) has also talked about the same thing.

This is just another misunderstood aspect of our industry

[Jean-Pierre Coetzee]

The topic name is:
Topic: PROOF-Whole vs half space sub loading

Strange the link doesn't work. Works for me. *shrug*

Will post a bug report, I get a no permission screen when I try to click on the link.

To Ivan thanks for the additional resources to look into, glad I can learn something new regarding this topic.

[Nathan Riddle]

Either something is wrong with my browser or you did something deliberately strange as this is what it looks like on my screen:

This is very weird. I've noticed it as well on many of Scott Holtzman's posts. Now it is happening to me 

I was on Chrome on my desktop when I wrote that post and it was "fine". Now when viewing the post at work on IE the post was definitely messed up. I deleted the text sizing code, so it should be fine. But those are some strange issues