Subwoofer for classical music listener

Rvpiano 6-9-2017
The SVS guy told me to set the phase to zero. How do I determine phasing differences?  What do I listen for? I really couldn't hear differences when I first set up the sub.

From the manual for the sub:

Phase Control:
This control delays the signal being processed through the amplifier. For connection to an A/V receiver, it should be set to 0 degrees. For 2-channel applications, it should be adjusted to obtain the most coherent and stable soundstage and transition between the loudspeakers and the subwoofer.

Although it isn't stated clearly, I assume "the amplifier" in that statement refers to the amplifier in the sub, not to the external amplifier which drives the main speakers. 

Keep in mind, also, that the optimal phase control setting is likely to vary somewhat depending on where the sub is located.  Also, I'm not sure how the SVS person could make a blanket recommendation of zero degrees without knowing the phase shifts (or possibly even 180 degree polarity inversions) that might be introduced by your amplifier and/or your main speakers.

Regarding the high pass filter in the sub, note that it has a fixed corner frequency of 80 Hz, and rolls off at 12 db/octave below that frequency.  The sub's low pass filter also rolls off at 12 db/octave, above whatever corner frequency its control is set to (between 50 and 160 Hz).  Therefore if the high pass filter function is used (and it is certainly worth trying, although depending on many variables its use may or may not prove to be optimal), the low pass corner frequency should probably be set in the vicinity of 80 Hz, with fine tuning by ear.

Regards,
-- Al
  

sevs said: "If you cannot bring pipe organ into your living room, then all the heat of some previous posts is moot, at least for me. I tried and failed!"

rvpiano wrote: "I just want to be able to hear the fundamental tones of, for example, an organ."

A good subwoofer well placed may let you hear the fundamental tones of an organ or large bass drum; however, unless you live in a cathedral, you will never successfully "bring a pipe organ into your living room," in my experience. The goal is for your system to sound more convincingly realistic and musical in your room than played through the best of headphones. If it does, you have succeeded and can relax and enjoy the music. 

I want to acknowledge almarg for all of his informative and practical posts in this thread. I learned a great deal and appreciate your very generous investment of time. You are not only extremely well informed but also exceptionally kind and patient. You represent the best of what the Audiogon forums should be. Thank you, sir.

Amen to mark's statement!!!

I've  been fiddling (pun intended) with the three sub controls and I think I've come to a very satisfactory solution. I WAS trying to bring a concert hall (or cathedral) into my living room. Unrealistic.  I now have extremely satisfying bass that goes very deep without sounding muddy.
  Interestingly, when I set the low pass filter from 80 to 100, everything started sounding more realistic. I also adjusted the phase control to get better results.
The variable of the bass control was a little more tricky.  I think I've got it where it sounds good on the majority of the records and CDs that I've been testing.
So, so far, I'm a happy camper.  I'll keep experimenting, because that's the way we are, but I'm very happy to have gotten the SVS sub.

Thank all of of you (of course, especially Al) for all your comments and suggestions. 

Just be happy you can hear the overtones of say, a Bach fugue , all you need to glory in the music .

"I was trying to bring a concert hall (or cathedral) into my living room. Unrealistic."

rvpiano- good to see you were able to make an informed purchase, and outcome is positive. 

You're hearing what a sub can bring to the party. 

As mentioned in my page 1 post, I advanced a couple of steps into the "real" room, when I added a second sub. Playing with your location a little more and bumping the gain a notch may get you closer to hearing the pedal tones/feel of a 
17th century Cathedral organ. 

I play a number of LP's titled "Historic organs of..." They are a real acid test for my mid fi system. While I thought the single sub was fine, adding the 2nd was a game changer. You canget a closer approximation of the crescendo in the opening of Bach's "Toccata "with a sub(single or..) 

2 subs is like sitting in the upper level, and the usher has just escorted you to prime seats, stage level.

Happy listening with your new sub , and continue to fiddle.