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Message: <blockquote data-quote="audioholic" data-source="post: 6869733" data-attributes="member: 549629">Octave slope.An octave is a doubling or a halving of the frequency. So 100ha is 1 octave above 50hz, and 25hz is 1 octave below 50hz.12.5hz is 2 octaves below 50hz.Slope is how steep the frequency roll off is at the cut off frequency. In other words, if you set your crossover at 100hz (lowpassed), it is not a brick wall that stops everything above 100hz. A crossover with a slope of 12db/octave means for every octave moved away from the crossover point, there will be a loss of 12db's of output. If your crossover is set at 100hz (lowpassed), at 200hz the crossover will filter out 12db worth of material (it will be 12db quieter). At 400hz it will be 24db quieter. A crossover with a 24db/octave slope will, of course, cut off the sound twice as fast.There is no best slope for a crossover. In some instances you want a sharp transition (cutoff) between speakers, while other times you want a gentle transition. Generally speaking, subs like steeper slopes (18 and 24db) while mids and tweets like a shallower slope (6-12db), but this is speaker/install/listener preference dependent. The best crossover is one that allows you to adjust your slope to find out exactly what cutoff point, and slope, works best for your setup.Now that you understand the slope is how steep the crossover filters out the sound, you should understand that slope affects the crossover point. Generally speaking its bass that kills a tweeter. If you run it to too low of a frequency, the diaphragm will bottom out and damage will occur. This is why watching the HP filter on your tweeters is critical. Back to slope affects xover point... say you can safely run your tweeters down to 3.5khz with a highpass (HP) filter with a slope of 12db/octave. If you changed to a 24db/octave slope, you could possibly run down to 3.3 or 3.2khz, because the xover is filtering out the bass quicker once the xover point is met. That is simply an example, as I said many times people run a mere 6db/octave slope to HP filter their tweeters because a sharper slope can sometimes create an audible anomaly in this range due to it being in the middle of the human ear's most sensitive frequency range.The amp has to have x1 or x10. That's a new one on me. No clue what they are talking about.Bandpass. In this context, bandpass simply means the speaker in question will have both a highpass filter, and a lowpass filter. In a 3-way setup (tweeter, mid, sub), the midrange is "bandpassed" because it has a highpass filter cutting off bass between it and the subwoofer, and it has a lowpass filter blocking treble that passes to the tweeters. The term bandpass originated from the phrase 'pass band', which simply means the band of frequencies that the filters allow to pass through them. The midrange in my example might have a pass band of 80hz to 3.5khz.Subsonic. This is referring to the subsonic filter. A subwoofer in a vented enclosure should also ba bandpassed. Most people just think of the lowpass filter on a sub (80hz and below for example) but a vented sub should also have a filter blocking too low of frequencies from passing to it. Vented enclosures are tuned to a spoecifc freq, and when the sub plays notes lower than it, cone excursion increases rapidly. Over excursion to the point of damage can occur quickly. So a subsonic filter will be placed on the system to guarantee nothing below 20hz passes to the sub, again for example. Slope is also a factor on a SSF, but most SSF's have a very steep slope so it can be applied at as low a frequency as possible.Time alignment, ask if you have any questions.Hope I helped.</blockquote>

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