SPL's

vmaharaj

I have RTi A3's as my fronts, CSi A4 and FXi3 with a single PSW505 subwoofer connected the Polk way. I have now used an SPL meter with test tones and running my AVR at 75db reference level and all the speakers on and croosover set to 80Hz on the subwoofer I find the following measurements:
50Hz - 75, 60Hz - 76, 70Hz - 70, 80Hz - 69, 90Hz - 78, 100Hz - 78

When I set the crossover to 120Hz I get all the frequencies going higher. Why am I getting a dip between 70Hz and 80Hz? Will two subs make a difference? If so, do they have to be the same make and model or can they differ?

Ricardo

Hi and welcome; that dip is probably coming from the interaction of room boundaries and your speakers/sub. It is impossible to have a perfectly flat response over the whole frequency range. You can try moving the sub to a different spot and measure again to see if it improves, but I wouldn't be too worried. You won't notice much of a difference when enjoying a movie.

vmaharaj

Thanks, Ricardo. That is exactly what I did and now enjoy excellent surround sound

jakelm

My friend, thats actually not a bad responce. I have seen alot worse. The sub crossover seems to be working very well. The dip between 70-80hz is the crossover. The A3's are rolling off before 80hz thus the dip. If the A3's were flatter down to say, 60hz, the problem would not be as bad.

Being your working with A3's I would set my xover to 100hz on the sub. The A3's should have a flatter responce down to 100hz, then the sub would take over.

ShinAce

+1 . Either set the crossover higher or move the sub around.

That's not a horrible dip honestly. It will make the bass response 'boomy'.