I thought it would be interesting to share a small tweak.
My LCR speakers are very big and can go below 40 hz. Nevertheless, on my Denon AVR, I set them as "Small." For Onkyo, that would mean not "Full Band." There are many reasons for doing this, among them:
1. Subwoofers can normally go much lower than even big floorstanders. In my case, I have 2 subs which can go below 20 hz.
2. The bass frequencies put a lot of stress on the amps for your LCR speakers. Transferring this load to the sub(s) will give more headroom to the LCR amps and minimize clipping.
In addition to these, it turns out that in the case of AVR's which have Audyssey room correction, there is another important reason. Audyssey applies 8x more filters for the sub, as compared to the other speakers! Applying this even further, I raised the crossover of my LCR and surround speakers from 60 hz to 80 hz. This means that the subs and Audyssey would now be handling the 60 to 80 hz region. I watched a familiar concert with the new setting and the bass was more accurate and distinct. To my ears, it is a big difference.
There is a limit to this. If you raise the crossover to 100 hz and above, those are frequencies which are "localizable." You will detect them as coming from the sub. Therefore, the practical limit seems to be 80 hz, which will cover roughly the lower half of bass guitars and the lowest octaves of the tuba, trombone and bass vocals. Even the frequencies of kettle drums are barely touched at 80 hz. When you think of it, there doesn't seem to be a lot of information at 80 hz and below but in fact, that information is vital for both music and movies.
