question re: poor bass response


Apologize in advance if this is a naive question. Unless they are played very loud, I have been a bit disappointed in the bass response from my Sonus Faber Concertos driven by NAD C370 integrated; source: Arcam cd92. However, at reasonable sound levels, the volume control on the amp is positioned only about 8:30 - 9:00. Is it possible that I'm underpowering the speakers when they're played at lower volume (sensitivity of speakers is 87dB, 1W, 1m). Would bass response improve if I switched the jumpers to the variable pre-outs and reduced the gain to the power amp, such that more power would be required to achieve a given sound level?
pordoi
Yes you may be underamping. But your main problem is likely speaker and seating placement/positioning, and their relation! If your speakers or seats are not coupling well in parts of frequency spectrum, you WILL get a weak bass response! Also, from a "height perspective", if your ceiling is 8', the standard Sonus stands at 30+ inches are too high in my experience! The speakers do better aimed up slightly on 24-26" stands at best!
Still, you need to put the speakers where you sit,play music, and move around near the room, with your head down where the speakers go!. Then you move around till the bass sounds right!...repeat for each speaker.This is the easy quick way to "earball" the response for each speaker. If you don't get your seats and speakers set up where they couple best for "flat frequencey response", you'll get poor overall response in the bass. You can also measure when you're done with test tones and a sound level meter to make sure. IF it measures reasonably flat from the bottom of the bass to the upper bass, you'll have dynamic, full, fast, accurate sounding bass!
Learn to set up speakers in a room, and you'll be rewarded. Also, if a large large room, don't expect deep room filling bass, as the woofers can't fill the room. Good luck
I would reposition the spkrs, of course. The amp may be a tad light for the job -- but should do for now (unless you're bent on investing).