[Danny Richie]

I just read:

https://www.diyaudio.com/forums/subwoofers/346543-gr-research-dipole-subwoofer-post6005797.html

by esl 63

Danny, is it true? I wonder if the fact of being dominant H2 is really important in a subwoofer. I think not but I am not the expert.

* http://gr-research.com/sw-12-16fr.aspx

* [PDF] http://www.gr-research.com/pdf/obsub.pdf

Honestly, distortion numbers for a product like this are marketing jargon.

Lets say that actual distortion numbers are 2% or 3% or whatever. That means means if the woofers are playing at 90db then that distortion number is in the 45 to 50db range. And at what frequency? A 45 to 50db level distortion at what 40Hz? 50Hz? And that is at or below normal room ambiance levels. 

But then what is the distortion of the loading and un-loading of the room and everything buzzing in the room from playing the bass levels that loud?

The real measuring stick is how fast the driver recovers and returns to rest.

These guys are worried about distortion and they have high moving mass drivers taking 50 or 100ms to setting from the movement they just got pushed to. Now that is a big deal and easy to hear.

And this is where the servo control system really shines. They stop on a dime.

[maty]

I was already missed a lot because it is well known that the human ear is very tolerant of distortion at low frequencies. Hence, many specify the max power at 10% THD in class D amplifiers. The neophytes only look at the power data and strapole the entire band, without taking into account that at higher frequencies the maximum distortion must be 0.1% in SS and 1% in tube amps (from habit).

Thank you!