Subwoofer question

[ThA tRiXtA]

<font color='#000000'>can someone please explain what the term 20 hZ at 18 dB/octave means when dealing with a subwoofer?</font>

[av_phile]

<font color='#000000'>In most likelihood, this refers to the steepness of the frequency roll-off at that frequency. &nbsp;It means that you'd hear a 20Hz signal from your subwoofer 18 decibels quieter than an octave of frequency above it, say 40Hz. &nbsp; In short, relative to the frequencies above it, you probabaly won't hear much in the area of 20Hz at normal listening levels. &nbsp;An 18 db/octave rolloff is very steep.</font>

[ThA tRiXtA]

<font color='#000000'>Thanks AV Phile!

So I assume it is better to have a steep roll off then to have one roll off very drawn out?</font>

[annunaki]

<font color='#000000'>Could you please explain the spec a little more. Is it( the response) -18db at 20 hz? +18db at 20 hz? Or is the sub crossed over high pass or low pass at 20 hz/18db per octave?</font>