Sub/Speaker Crossover?

I cross over my mains into my sub at 80Hz. I tried everything from 50Hz to 100Hz, and found that 80Hz resulted in the smoothest integration. However, I cannot say that 80Hz would necessarily work best for you, since, after setting up several mains/sub systems in several rooms, I came to the conclusion that the choice of crossover frequency is very system/room dependent.

Another thing to keep in mind is that the perception of of the "best" crossover frequency will be influenced by other parameters of subwoofer setup, such as placement, phase, level, and time alignment. All of those parameters interact psychoacoustically, so it is often challenging to identify which parameter needs to be adjusted. In my case, it was a frustrating process that took several full days of experimentation distributed over a couple months.

Having offered those words of discouragement, I will say that it is totally worth it, so hang in there!

Wow. See what I mean? :)

Thanks for all the input, folks. I used to have the REL and know they are designed for just the low stuff below what any monitor can reach -- hence the setting in the 20s.

I've always just fiddled with my subs until the bass sounds just right in Jimmy Smith's excellent "Dot Come Blues." I trust my ears. But it does seem like reasoned audiophiles have very different "rules of thumb" when it comes to this topic!

Keep in mind that a good low setting won't draw attention to your sub.Done right,nobody should know its on.

The rule of thumb is to set the crossover one octave above the F3 of the main speakers. This much overlap is needed to get a smooth transition. If your speakers are -3 dB at 45Hz, then you should set the crossover to the sub at 90Hz. No matter where the crossover, integration is not easy. You can try to do it by ear, but test signals and an SPL meter will get you there faster and easier.