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SVS SUB BETTER WITH LOW PASS FILTER OFF

After endless tweaking and experimentation, I have concluded beyond a shadow of a doubt, my system sounds profoundly better by turning OFF the SVS "low pass filter"! My amp has a sub out with a filter option set at 80 db's. Like all good audiophiles I carefully followed instructions, searched google to tweak all settings. I tried all variables in frequency. Until one fateful day, for no special reason, I turned it OFF. "WAIT", I said to myself. This sounds better. "Can't be!" "It must be boomy, or bloated, or congested .....or something bad. NO, it wasn't. It not only sounded more cohesive but the "hole" in the sound stage was gone. (I had a sense there was a perceptible hole in the musical picture which kept vaguely appearing which destroyed the whole overall enjoyment. I'm interested if anyone else has tried this heretical approach?

allears4u
james633
1,047 posts
 

If you play just your subs you will probably hear male vocals in your subs this way. If it sounds fine… no big deal. The slope at your amps 80hz might not blend well with your mains. Maybe try a different slope if possible. If the slope is 12db for example it is out of phase and you would need to make the sub 180 degrees or change the leads on the speakers. Could just be nulls and room nodes 

allears4u OP
147 posts
 

Super good tip! My mains are Klipsch Lascala (II) so the bass is weak. The amazing thing is that the music sounds so much more "organic" (if you can imagine what I mean by that). Cohesive may be an even more unhelpful word but whatever...I like it better. My room too is unique in that I live in a yurt which fails to provide any reflective hard surfaces. (All fabric) So the normal rules don't apply.. I'm afraid I'm on my own on this one. But...it sounds amazing...just sayin'

moonwatcher
482 posts
 

I’m not 100% sure but it sounds like you might have been double ganging the filtering. You say your subwoofer output from your preamp or amp is 80 dbs, I think you might have meant 80Hz. If so, in most cases you would NOT need the low pass filter set at all on the SVS subwoofer itself then. The correct thing to do in this case is to either bypass it entirely (which you have found sounds better) or to turn the setting on the subwoofer as high as it would go, say 250 Hz or whatever, such that the slope of the crossover in the sub doesn’t interact with whatever slope is used by your preamp when it does its low pass at 80Hz. Anyway, that is what my old Klipsch subwoofer manual says to do. In other words, you’d only engage the sub’s crossover and low pass filtering if you were sending it a FULL range signal from your preamp. So, I’m just guessing here, but what you were hearing before might have been the crossover slopes of the preamp or amp subwoofer output interacting with the slope of the crossover in the sub. Removing the one from the sub filled in that "hole" you were describing, so it now blends better with your main left and right speakers.

allears4u OP
147 posts
 

Yes, of course 80 hz was my intention, and as usual for me its the most obvious stuff I miss. Glad I randomly discovered my mistake. Sure is much better. Now to put more Nano goop on my contacts! Any obvious advice on this sub I might have missed as well?

james633
1,047 posts
 

One things for sure… I need to see pictures of the yurt hifi room!

 

I would think your room would be almost 100% null free other than ground bounce. the La scala having very poor bass extension I am sure aids in the higher “crossover” point. 
 

I find my personal subs always lack a bit of detail compared to my mains above 100hz. I also find the sound stage with deep voices can get a little strange when using high crossovers. With that being said I will say a lot of subs play very clean all the way up to 200hz.  

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