nulls in frequency response

[Beatin' 10+ year member]

What causes this loss of output at certain frequencies?

I know for sure in my trunk car, there is a bad null around 70-80hz, I'm guessing. It is the most audible null in my car, but why does it happen and how do I fix it?

Click to read more...

 

[trumpet 5,000+ posts]

Phase problems. If you sit somewhere else in the vehicle that null should disappear, but you may hear a different null. Move the box.

 

[Full Tilt 10+ year member]

Are you sure you're just not rolling off at that point? By then your mids would usually be taking over..

 

[T3mpest 10+ year member]

Nulls between 60-80hz in cars are pretty common. Upfiring a woofer in most vehicles cause one at 60hz in most vehicles and many trunks have them closer to 70 or 80hz regardless of driver orientation. Box orientation can sometimes move it around some. If your rear firing perhaps forward firing sealed off might help, or visa-versa. A more advanced option for some users is to use a alignment that actually has an increasing frequency response through that region. My next box will be a 6th order bandpass based on that premise. By giving myself a 3db hump at 60hz and a rising response to the xover point at 80hz, when you apply the xover and put it into a car, the response should be very flat.