Help with crossover settings..

The crossover isn't a wall where the number you set it at will stop at exactly that....the crossover is like a slope downwards from where you set it at....I'll let another person chime in who knows the Infinity speakers to help out even more.

According to the product sheet:
- the 163s extend to 49Hz @ -3dB; and
- the 153s extend to 58Hz @ -3dB.

Those numbers strike me as optimistic for bookshelf speakers...but I digress. I'd go with 80Hz for all channels, try 100Hz with the 153s (and also 100Hz for all channels) for good measure, and go with whichever setting(s) provides the best overall blend of sound between speakers & sub.
The speakers won't play content below that point (actually a narrow range during which the output of the speakers rolls off). It will be directed to the sub.

(Conversely, the sub won't play content above that point (that range during which the output of the sub rolls off). It will be direct to the speakers.)
Edited by eljaycanuck - 2/25/13 at 6:29pm

You should be able to set crossovers for all of them to 80 Hz, which is a major industry standard. This simultaneously helps ensure that the speakers aren't asked to reproduce too much of the bass, and that the sub doesn't reproduce too much of the higher frequencies that you may be able to detect as coming from the direction of the sub (and most subs don't sound that great in this range anyway). If your speakers were smaller and had less bass capability, then you would probably have to cross them over at a higher frequency, which would be a compromise.

Just leave the crossover on the sub turned all the way up. The bass management in your receiver uses a low pass filter (for the sub) and a high pass filter (for the speakers) to correctly manage the crossover.

And I agree. 80hz is a good crossover to try. Above 80hz, and the bass from your sub could become localizable.

What receiver do you have? If running Audyssey, be sure not to set the crossover lower than what Audyssey determined initially. It won't provide any EQ filtering to the speakers below that point.

So just don't go lower than what the Audyssey and the receiver set initially. Otherwise, while 80hz is often recommended, go with what sounds best to you.

Don't confuse the speaker crossover point with the LPF of LFE setting. That setting should be 120hz.

You can crossover the speakers between 60-80hz and see what you like. 80hz is a good starting point. Make sure all speakers are set to small.

The crossover control on the sub itself, if that is what you're referring to, should be set to the highest frequency, and if there is a switch to enable/disable this filter, you set it to disable. The point here is to let your AVR handle the crossover filters and in general all of the bass management, with your sub simply playing whatever it is given. The crossover filters on the sub are for those who are not using an AVR that can handle all of the bass management, but yours can. Setting a filter on the sub unnecessarily can actually cause you to lose some of your bass content because the filters are a slope, as others have explained.

Yep, this is yet another filter on the AVR. In theory you should be able to turn it off completely with no ill effects, but with the most modern HD codecs (typically found on Blu-ray discs) the ".1" channel is actually full-range now, and the LPF of LFE filter is there to make sure that only bass frequencies are sent to the sub, just in case somebody mixed the soundtrack in a weird way. This should never happen in practice, but since the filter is up at 120 Hz and typically has an unusually steep slope by design, it shouldn't hurt to leave it on, either.

With speakers of this class, I like 80 Hz because it relieves them and the receiver of a burden that the subwoofer could probably handle better anyway. With larger, more efficient speakers and more powerful amps, I may feel differently, but for the most part just stick with 80 Hz (that's what the pros do when mixing the soundtracks in the first place).