What is the norm? How many of you use the subsonic filter with your turntable?

@mulveling 

My Boulder 1108 does have a button. It's described as a 3-pole (18db/octave) low cut filter, with response of -3db at 10 Hz. When I asked a former Boulder tech person about it at my dealer they told me I shouldn't need it under normal listening circumstances. I have yet to find a use case where I feel I even need it. Record warps are inconsequential to me since I use a 750 gr record weight and 1500 gr peripheral ring. That's enough weight to make Dolly Parton flat.

For owners of sealed box speakers it is less an issue, but since the advent of vented speakers it can be a big help in controlling woofer overexcursion. 

Even though I have a vacuum-hold down turntable, there are some records that will cause subsonic rumble. I do use the filter under those conditions and thus will always buy a phono stage that has a filter.

@dman777 

First, if you carefully match your cartridge's mass and compliance to that of your tonearm you should be able to achieve an optimum vertical and horizontal resonance of between 8 and 12Hz. This is precisely what you do to ameliorate the effects of record warp information being amplified and sent to your speakers.

Rumble is a characteristic of a poorly designed main baring or one that has been "modified" and contaminated with foreign matter as opposed to just leaving the original permanently lubricated one alone.

Many phono preamps are designed with a gradual and progressive roll off below 100Hz which leaves the response down by 5 - 10 dB at 10Hz or so and forego an adjustable subsonic filter. Probably most of them. 

Both my pre-amp and power-amp have subsonic filters. Have played around with them. Both are turned off, and never really needed. I understand if you get rumble, the filters are necessary. 

Interesting about the sealed box theory. Both my speakers and subs are sealed, my TT is isolated on a platform with rubber footers. I can jump up and down next to it with no issues. 

Wonder how much rumble is an issue with the level of turntable, meaning, the lower quality tables might be more prone to rumble over the higher quality ones? Or maybe phon-preamps are just better now, or carts are better?