Archived from groups: rec.audio.high-end (
More info?)
A third octave EQ is a rather crude way to do any equalization. Parametric
EQ's can be so much better, since you can shape the filter to what is
actually required. If you need a boost with the third octave EQ at 31, 40
and 50 it probably means that all frequencies below 50 need to be boosted.
If you pull up these frequencies with the 1/3 octave EQ, the frequency
response usually is not smooth, there can be dips between the center
frequencies.
Trying to make up for a cancellation due to standing waves is usually not
successful. If the direct sound from the sub is cancelled out by a
reflection from a wall, and the frequency at which this happens is boosted,
then both the direct sound and the reflection will be proportionally louder
and still cancel each other out.
I have had a DSP based EQ in my system before (Shure DP11), it was certainly
fun to play with. In my room, it actually helped the sub's frequency
response quite a bit. The compressor/limiter function can also be useful,
especially if you boost the lower frequencies a lot. I did not find that the
sound was degraded in any way, no hum, no hiss (hard to get a subwoofer
hissing anyway), no distortion. The EQ only was connected between the sub
out of the preamp and the subwoofer, so it couldn't have any effect on the
main speakers. Another advantage to this approach is that the crossover
function can be tailored exactly to suit the main speakers, so there is no
peak or dip. A problem with the device was that it's frequency response only
extends to 20 Hz and my sub isn't quite finished at 20 Hz.
Have fun.
"---MIKE---" <twinmountain@webtv.net> wrote in message
news:cqamoq0jqf@news3.newsguy.com...
>I am using a 1/3 octave equalizer (Rane) to manually compensate for room
> effects on my sub woofers. I would think that a single band parametric
> would not do a complete job. I found it necessary to make boosts at 31,
> 40 and 50 and substantial cuts at 63, 80, and 100 to get good balance
> (in my rather large room).
>
>
> ---MIKE---