How do the Hsu sub crossovers work?

[Erukian]

I'm posting this just out of curiosity. With my old speakers my sub xover'd at 120hz and didnt play anything above that. I notice that on my STF-2 when I set the xover to 90 it's hitting notes above 100hz. BTW i use the 'Crossover In' switch and the high level inputs.

How does it work? It's not a clean cut from sub to my two bookshelf speakers. If someone can get technical to explain it that'd be really helpful.

[mrtristan]

No analogue electronic crossover circuitry provides a "clean cut" at the selected crossover frequency. What you'll get is a gradual drop in gain at the crossover point (that point is determined when gain is -3db from the rest of the spectrum that's passed through). The rate of drop depends on the crossover slope. Most subwoofer amplifiers have a crossover slope of about 24dB per octave or more meaning that if you have your crossover set at 100Hz, at 200Hz you'll still have output but it will be 24db quiter. That's a very significant drop but still audible.

This property can work well in tandem with your main speakers as they too will have a natural gradual roll-off. If the proper crossover frequency is selected on the sub you can have a nice seamless transition between the sub and main speaker. Many people aim to set the subwoofer crossover frequency at the main speaker's specified bottom limit but that's not really necessary. Spec sheets can be pretty innacurate and so can the crossover knob on a subwoofer so it's best just to listen to different setting to see what works best.

Tristan
HOME DIGITAL (http://www.homedigitalav.com/)

[Dudley]

It is not supposed to be a clean cut. The sub rolls off as frequencies increase and your speakers roll off as they decrease.

The HSU subs tend to have a sharper roll off than most subs though. What was your old sub?

[Erukian]

How does the sub split the signal coming from the amp? Since i'm using the high level inputs. Obviously it's altering the sound set it to xover in, but if i set it to xover out, will it just split the signal between the stereo and the sub driver and the sub driver takes what it gets?

[Dudley]

If you use speaker level inputs and crossover out, then sub and mains will both get full range sound.

[Erukian]

My bookshelves go down to 50hz with power before they start rolling off. I'm after the most "musical" setup here. I got my sub in the position that it's as flat as possible.

With crossover set to out, is overlapping frequency a bad thing?

[Lwang]

With crossover set to out, is overlapping frequency a bad thing?
Yes, you would get a 3-6dB boost in the overlapping region, and maybe even other regions where you might even end up with a suckout, depending on the speaker/sub/seating locations.