Oops, I lost my first attempt at my second post through not being logged in! Here I go again Having read through threads pertaining to members comparing their subwoofer frequency responses (especially the SVS owners), I have a question. The quest for powerful low frequency fun is a fine journey (exempting issues with neighbours, relations, small terrified animals and human hearing of course). Why do decent subwoofers seem to play so low when the very deep bass frequency (whether at a high volume or not) doesn't seem to be encoded on the music CD's or film DVDs fed into them? I might be wrong; my understanding is that most music isnt all that low really,(unless you like organ music that is). It doesnt reach down to the 20-25Hz levels that I regard as low. I had an MJA Pro 50 + 100 btw, so probably never even got that in my bedroom! Blockbuster action movies may feature large explosions and moving vehicles, which are low in frequency. However, do subwoofers generally tend to play a little lower then the information they are fed with in order to sound more realistic? Do they just play to their limit when the bass is very low and become quiter/'drop-off'? I saw somewhere on this forum reference to subs using filters for preventing very deep frequencies and distortion problems, to an extent. The opposite of a high-level filter. Does the nature of the subwoofer with ample power (speaking generally here) and large driver lead them into these low depths a little waywardly when they lose control at low depths? Please feel free to set me straight. I am quite curious since reading SVS owners tuning tweaks (with bung ports and placement) to achieve very low frequency responses in-room. In summary, perhaps I should ask: Do subwoofers at any frequency level actually play accurately the frequncy of the orignal material played through them? Additionally, is more accuracy lost with either high SPL levels or the demand for very low level detail (beyond the subs ability). Have I just partly answered my own questions?