Show your mom this article: http://www.intellexual.net/bose.html
"...To reiterate the above, the Acoustimass's bass module responds to 46 Hz to 202 Hz at ±2.3 dB, while the satellites respond to 280 Hz to 13.3 KHz at ±10.5 dB. This is, by the way, the only speaker that I have ever seen tested...