Localisation of very low frequencies sounds

[Greebster]

But if the graph is offset by 20 dB to fit the scale this should be subtracted from the curve

 

[Pano]

I see the distortion as highest at 70Hz, being approximately -9dB. But that graph looks like a plain baffle measurement of the driver, not the driver in a box. Or maybe a small, sealed box.

 

[markus76]

Ergo gaetan8888 would need to measure distortion of his box at the SPL he is doing the test.

 

[Greebster]

Too true, requires reality check

 

[Pano]

Yes, it would be best to see measurements of the driver in a box.
But don't forget that there are two separate issues here:

1. Can you hear the direction of a pure tone below a certain frequency? (no distortion)
2. Can you hear the location of the typical subwoofer low passed below a certain frequency with its attendant normal distortion?

I think item number 2 is the more important, as that's what we will encounter in real usage.

 

[dumptruck]

The dark black line is phase, guys. It says it's a 10L box.

 

[Greebster]

Wasn't the line I was comparing to.

 

[Pano]

It says it's a 10L box.

So it does! Thanks for that.

...maybe a small, sealed box.

Yep. 10L is small.

 

[jimbones]

0.5% distortion at 10hz? I want that speaker!!! (BTW I wouldn't be able to hear it anyway)