Measuring subwoofer to determine if I need a BFD

[Adam321]

Ok, I finally finished my sonosub. This is the thread: https://www.htguide.com/forum/showthread.php?t=26418 I will post pics to that thread when I get a chance.

I tuned my sub to ~16hz. I would like to take measurements to determine if I need a BFD. My concern is feeding it a sweep from a program like Room EQ Wizard. If the sweep starts below my tuning frequency isn't there a chance this could damage the driver? I am driving it with EP2500.

Also, my pre/pro is a Lexicon dc-1 v4. I had to crank the sub output level to +7. It was -5 with my old Velo sub. However, the test tone is now a lot lower in frequency response than it seemed with the old sub. So, I may have a calibration problem due to the response of my old RS SPL meter. I was wondering if the BFD would help with level matching, as well. I dont want the art cleanbox because of the frequency response issues that have been discovered.

Thanks.

[ThomasW]

The trick running sweeps is to use a low output (SPL). In addition the sweep occurs so quickly there's little chance the driver would be damaged unless the output level is set to "11"....

No the BFD won't work as a line level shifter.

[---k---]

Also, I don't believe that there any problem with having the prepro at +7, regardless of what you read around the net. It is a very low level signal. So, if +7 works for you, leave it and move on.