|   Subwoofer Help needed | ozonetourist
May 18, 2001 7:20 AM | | I have a Subwoofer with it's own seperate amp, not on board. My queston is that it does not have any adjustable freq controlls, Can I add one myself? Any advice would be appreciated. |
| re: Subwoofer Help needed | manny
May 18, 2001 9:42 AM | | Check Parts Expres or MCM Electronics for crossover. Mine have 150hz cutoffs. Really dedicated them. Works well. |
| Paradigm X-30 | bigwally
May 18, 2001 10:00 AM | | The Paradigm X-30 is a very popular and relatively inexpensive unit for what you propose. Should run about $170 or less from a Paradigm dealer.
http://www.paradigm.ca/Website/SiteParadigmProduct/PModels/HighPassSWControlUnits/controlunits.html |
| Paradigm X-30 had serious problem in Audio Magazine review | Richard Greene
May 18, 2001 10:46 AM | | Audio magazine tested the Servo 15 sub and X-30 combination.
They reported the X-30 low-pass filter was 12dB/octave rather
than the advertised 18dB/octave.
In my opinion even 18dB/octave filtering is often not a steep enough slope if you want to use a room corner for your subwoofer (often the best location for rectagular rooms) and have the bass frequencies sound like they are coming only from the satellite speakers ("invisible subwoofer").
If Audio magazine was correct (I have doubts -- Paradigm has a good reputation -- Audio magazine is out of business), then the
X-30 does not meet its very important low-pass filtering specification. Does anyone else have an X-30 test report where the crossover slopes were measured? It's difficult to believe Paradigm would advertise an 18dB/octave low-pass filter slope but give you only a 12dB/octave low-pass filter slope. |
| Paradigm X-30 had serious problem in Audio Magazine review | bigwally
May 18, 2001 12:19 PM | | Thanks Rich, didn't hear about that. I don't know how much of a problem that x-over slope would be if crossing over at below 80Hz, but I see your point if a point at or above 80Hz were the point selected. |
| Much easier to locate sub with 12dB/octave low-pass filter | Richard Greene
May 18, 2001 1:07 PM | | My Rule-of-Thumb is to select a crossover frequency and slope that
results in subwoofer bass down 24dB or more at 150Hz. relative to output at about 50Hz. because for my ears, in my listening room,
that makes my subwoofer sonically invisible almost all the time.
My Rule-of-Thumb is based on a lot of trial and error and is almost the same as the THX spec (80Hz. 24dB/octave crossover) that would be down 24dB at 160Hz.
I believe most audiophiles would be able to hear the location of a corner subwoofer with an 80Hz. 12dB/octave low-pass filter.
I find that even a 50Hz. 12dB/octave low-pass filter is not as good as an 80Hz. 24dB/octave crossover in making a corner subwoofer invisible.
If you placed your sub between or near your satellite speakers,
an 80Hz. 12dB/octave low-pass filter would allow too much of the lower frequencies of male voices to come through the subwoofer, something I don't like to hear from my subwoofers. |
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