QB3 or not QB3

U130421

Disabled Account
2015-12-16 2:00 pm
I found the most serious DIY QB3 design/built. the Monitor 2
The curves bellow show what was simulated and what the real result is .
(Let me laugh a little bit)






Can someone estimate from both curves ,what would be if the duct is closed.
 

Attachments

  • seas.JPG
    seas.JPG
    107.7 KB · Views: 102
  • seas2.JPG
    seas2.JPG
    102.3 KB · Views: 103

Sangram

Moderator
Paid Member
2002-09-25 11:01 am
India
The measured response is near-field for the midrange unit, not the woofer. It will definitely not match the box sim of the woofer.

Woofer measurements are a mix of farfield and close-mic, spliced at about 200Hz. That measurement is not presented on that page.

I assume a CA26 in a 70L sealed box will have F3 around 55Hz. This is without a simulator at hand, just a rough estimation.
 

Sangram

Moderator
Paid Member
2002-09-25 11:01 am
India
The picture description clearly states that it "Follows the near field frequency band of the Audiotechnology C-Quence15h without filter."

Am I wrong in understanding this somehow?

And yes, depending on where and how steep you cross, you can get output down to 80Hz, even lower, from a midrange unit. I'm crossing a Satori MW13P at 220 Hz with a 12dB slope and there is output down to 60Hz.