Rep Power: 347

I have a lil bit of a cancellation issue at 90 hrtz. What should I try to fix this?

Here are the facts:

-Midbass to bass crossover is at 80hrtz
-the subs play flat from about 35-65 hrtz, but they start to drop after that going up.
-If I turn off the subs, the midbass will play about 5-6 dbs louder.
-I also tried a crossover frequency of 70hrtz, and the problem was pretty much the same.
-Midbass is in the doors, and bass in the trunk, right next to the back latch.
-I am using a radioshack meter to make measurements.

any ideas?

 
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You could try putting the subs out of phase with the mids.

 
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you could try that... and it may work, but itll probably also change the transparency (if youre even well enough adapted yet to search for such small things)

 
Rep Power: 347

Probably not, but I can just switch the button on my radio and see what happens.

 
Rep Power: 347

I tired switching the polarity, and this is what happened (testing with test tones twice)...

-I gained back my 10 dbs at 90 hrtz
-I lost 3 dbs at 70, and also at 130 hrtz
-The bass sounded different and weird to me. My bass seemed like it was coming from my feet (where my midbasses are). When the polarity is normal the bass was harder to localize. Also, the bass seemed a lil more punchy, and not flat in the lower frequencies...but this all could be phsyco acoustics.

 
Rep Power: 339

try underlapping between your midbasses and subbass.

 
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I had tried underlapping by as much as 20hrtz (90hrtz/70hrtz), but that didn't work. A funny thing happened today though...I have been doing all of my tests with my windows down (because it gets damn hot after awhile)...when I rolled my window up most of my cancellation seemed to go away...go figure.

Regardless, I changed my bass to midbass x-over point from 80 to 70hrtz...maybe this will help a lil with localization. My bass seemed to start naturally roll of at around 65hrtz going up anyway.

I have a question though...Why do people choose the round numbers of 80 and 120 as x-over points...it seems in a lot of articles I read, people use these numbers...what is so special about these numbers? ...and what is wrong with 70 and 90hrtz?

 
Rep Power: 339

try underlapping more. at that show we ran agasint each other, my cut off frequencies were 40 Hz and ~110 Hz, respectively.......

 
Rep Power: 347

No way, really!! Yeah, I'll experiment a lil and see what happens