Originally Posted by ALEXAROY
Hi! I've read lots of thread about that, so I won't ask explanation on that matter, but I just want to know if my settings are right. I got 5 small speakers min. 100Hz and a subwoofer of 24Hz-160Hz, the auto calibration has set the x-over at 80Hz... which I think is wrong since I'll lose frequencies from 80Hz to 100Hz. I set it manually to 100Hz to get all range of frequencies, but I just read on another thread that it is preferable to have a little overlap of frequency between the sub and the speakers. So should I set it to 120Hz instead ? Having only small speakers and no columns, I kind of think it is better to have it on 100Hz... give me your thoughts please. Thanks !
What do you mean by over lap? With an AVR, you can't set the sub to go to 120hz and the speaker to go to 80hz. A crossover is not a brick wall filter. For example if your AVR crossover slope is 12DB per octave for the speakers and the sub, then when set at 100hz, the speaker and the sub will be down 12db at 100hz. The speaker still plays content below 100hz, but at a much lowe volume. Same goes for the sub. It plays above 100hz, but at lower volume. The goal is to get the frequency flat at the crossover point, because the SPL at the crossover is the combined speaker and sub.
Yes you will have a gap, if you cross the speaker at a lower point than it can play flat to. This point is commonly called the -3db point (f3) of the speaker. If the f3 of your speakers is 100hz, then that is where you should cross. Keep in mind, we have been talking design spec of the speaker and sub. The actual acoustic f3 of the speaker in room will be different. Often times lower.
If you do not have measurement capabilities, I would try 80hz and play music that you are very familiar with (make sure it has lots of content well below 80hz) and then try 100hz and see which you like better. Another thing to consider, once you get above 80hz, bass can start to be localized. In other words the bass will not sound like it is coming from the speakers. A way around that is to have the sub located between your two speakers or use two subs, one under each main speaker. That will help the left and right main, but will not help the surround speakers.