simple questions. Don't Laugh, I'm an SQ guy.

Reply Subscribe

Thread Tools

Search this Thread

Jun 16, 2004 | 09:27 PM

#11

Brandon

Thread Starter

4000 Watt CAFz'r

iTrader: (1)

Joined: Jan 2001

Posts: 4,603

Quote:

Originally posted by DWVW:
<blockquote>quote:<hr />Originally posted by Brandon:
<blockquote>quote:<hr />Originally posted by DWVW:
What Moe said about finding resonant frequency is very good, but he missed one important step. You must also measure the response of the sub and enclosure in a free field environment and subtract it's response from the in car response. This will make sure you are focusing on the cars resonant frequency and not the subwoofer systems resonant frequency.

How is this done Derreck? Again with the RTA mic? [/QUOTE]Yup, your are just elimanating the sub systems resonance from the equation. [/QUOTE]Ok, now, where's the BEST place to do this test and where do I need to place the mic?

Jun 16, 2004 | 10:20 PM

#12

Juggernaut Sportage

50 Watt CAFz'r

Joined: May 2004

Posts: 88

Do not tune your box to the vehicles res frequency tune it anywhere from roughly 5-8hz below the res frequency for best results

Jun 16, 2004 | 11:09 PM

#13

Brandon

Thread Starter

4000 Watt CAFz'r

iTrader: (1)

Joined: Jan 2001

Posts: 4,603

Yea, I figured that, because there's always a peak, but I still need to figure out the rez freq of the van so I can tune the box accordingly.

Jun 16, 2004 | 11:18 PM

#14

mister steve

50 Watt CAFz'r

Joined: Feb 2004

Posts: 295

there are never any stupid questions, every one has to lear some time

Jun 17, 2004 | 07:59 AM

#15

Dereck Waller

Guest

Posts: n/a

The best way to do it would be out in an open field with no buildings etc. for the free field measurement. For the near field measurement (in the car) I would make sure that anything that will be in the car (sub box, wall, consoles etc.) is in the car when you do the measurement. Makes sure to plug off any sub openings, and ports with something so it's not just open. I would put the mic about the same distance from the test box in both tests. Ideally in the car it should be located approximately where the measurement would be taken in competition.