Subwoofer for classical music listener

Thanks to Stfoth for providing the data on the SoundPath RCAs. Their price is indicated at the SVS website as $89.98 for a stereo pair of 8 meter cables, and those are the only interconnects listed, so I assume those are what RV was provided with.

RV, given the lengths that are involved (even if you were to change to 16 feet), and given the somewhat highish output impedance of your preamp, and the unknown but very possibly highish output impedance of the sub’s high passed line-level outputs, it is particularly important for the cable to have low capacitance per unit length. The SoundPaths provide that, at 39 pf/meter. But of course a shorter length, such as 16 feet, would reduce the total capacitance correspondingly, and very possibly be beneficial in other ways.

I could probably get away with 15’ cables. I understand from SVS that’s the next size down, but I’d feel comfortable with a foot or more longer than 15.

The SVS website lists the SoundPath offerings only in metric lengths, including 5 meters, which is 16.4 feet.

Another possibility for a modestly price cable having very low capacitance (12.2 pf/foot), which can be ordered in any desired length, would be Blue Jeans LC-1.

Cable differences are generally system dependent and hard to predict, of course, but I wouldn’t be surprised if changing to a 5 meter length of the SoundPath cable, or a 16 foot length of the Blue Jeans cable, would provide a worthwhile benefit.

Best regards,
-- Al

Al:  Again, thank you for your detailed post!

I'm going to trade in the 8 meter cables for the 5 meter to see if that improves things.  
Also, I suspect an intermittently misbehaving preamplifier tube might be  the culprit since the anomaly varies from time to time.
I just ordered a new set of tubes, just in case.

Ahh, I remember the DQ-10's well. I always wanted to try a pair. 
Yes, I know you have the DQ-20's. but it brought back nice memories.
B

stfoth:  Yes, except for lacking deep bass, I was happy with the system before I added a sub (but, for other reasons, was not happy when I hooked up the sub the normal way.)
With the high-pass I started experimenting, alternately physically removing the sub and putting it back into the system.  During this process I sometimes noticed exaggerated highs even without the sub.  That's why I'm suspecting a bad tube may be developing in the preamp.  Alternately, sometimes the system sounds fine with the sub connected.
 I recently had the amplifiers upgraded, so I don't think there's a malfunction there.
It's not an exact science.
 I'm trying to cover all bases.