Originally Posted by BeeMan458 Polk Monitor 5
Sadly, in my opinion, part of the setting problem lies in the Polk, Monitor 5's themselves as they're -3dB at 43Hz.
A suggestion, set your sub's high pass filter (limit potentiometer) to 120Hz and for the mains, set your internal AVR's low pass filter (LPF) to 80Hz as a way of dealing with the limitations of both the mains and the subwoofer. As to your surrounds, I'd set those to 80Hz also and yes, this will create a 20Hz hole but if you set the surround LPF to 100Hz, you'll introduce localization issues. If you're ready to jump into this hobby whole hog, consider upgrading all the speakers as 100Hz @ -3dB for the surrounds, is going be a challenging obstacle to overcome due to aforementioned localization issues.
Is your listening venue a room that's closed off (sealed) or a room that's open to kitchen, hallway, dining room or all three? My understanding, it's a sealed body subwoofer for a sealed room and ported body for an open room; both will rock the joint. Personally, I'd go with a pair of RW-12d's over a single PB-1000 or SB-1000 but in the same vein, even in a room of your size, if a budding bass-head, you'd be better served by a pair of 1000's. The choice depending on if your room is open or sealed as both will give you excellent playback characteristics.
Allow me to encourage you to obtain room analyzing capability because without this tool, everything you do will be guessing. Just saying.
Just a couple clarifications because some of the terms are used incorrectly. First, I would suggest not using the term limit potentiometer. I have never seen anyone else but you use this term and it can be confusing. Second, just to be clear a low pass filter allows the frequencies below the cutoff frequency to pass through and filters out the frequencies above, and a high pass filter does the opposite. A crossover is a combination of a low pass filter for the low frequency driver and a high pass filter for the high frequency driver.
Now back to your advice. The sub does not have a high pass filter in the way you are describing and some subs don't have a high pass filter at all. Some are slightly different, but in general, subs have a low pass filter or crossover setting that sets the low pass filter frequency for the input (RCA, XLR, etc) and sets the high pass filter frequency for the speaker level outputs. If the sub does not have speaker level outputs or you are not using them, the HPF is not relevant. For your advice for the AVR, there is no specific LPF setting for the mains or surrounds. The majority of AVRs either have a global crossover setting, which sets the same crossover frequency for all speakers, or advanced / individual crossover frequencies which allows you to set separate frequencies for each speaker (front, center, surround, etc.) Some newer AVRs also have a LPF of LFE which has nothing to do with any specific speaker. It sets a LPF on the LFE channel itself in multi channel mixes. So he would want to set the crossover for the fronts and surrounds not the LPF. As I already posted, I know a crossover contains an LPF, but I would not use this term because someone may look for the LPF setting in their AVR and not find it or incorrectly use the LPF of LFE.
For the OPs specific case, if Audyssey sets the surround crossover to 120hz, I would first leave it there. It is normally recommended to not lower a crossover below Audyssey's setting. By setting a crossover lower then the audyssey setting, you may be sending bass to the speaker it can't handle and you will have little or no Audyssey correction below that point. If you do not get any localization issues with the sub, leave it there. If you start having localization issues with the sub, lower it to 80hz and see if they go away. Then listen to see if the surrounds are being over driven. For the mains, I would agree with setting the crossover to 80hz. For the sub itself, there shouldn't be a difference in localization between the SB1000 and PB1000, but there is a difference in FR and max output so you should choose based on your room and listening habits. The best suggestion is to give SVS a call and discuss your situation. SVS or any other ID company should be able to help you pick the best sub for your personal situation.