Abstract: A Speaker Side Air Supply Cabinet that has three things that are working together the Speaker Side Air Supply ducts, the Front Air Chamber, and the Bass Horn. The Front Air Chamber takes in air then compress it so that we get a very high sound pressure {sound wave} output, and the Speaker Side Air Supply ducts supply all the air the Front Air Chamber needs. At the same time the Speaker Side Air Supply ducts also supplying air to the Bass Horn working together to eliminate the pull back on the out going sound wave so there is no reduction of the very high sound wave volume output.

Abstract: A DMT (Discrete Multi-Tone) test method is provided. The test method is employed by two test devices to estimate the theoretical and practical data rates of a cable under test for a pair of target ADSL (Asymmetric Digital Subscriber Line) DMT modems. The present DMT test can also be used to analyze the cause of, or to predict a problem, whereby a pair of ADSL DMT modems could fail to synchronize. The method includes (a) synchronizing two devices at lower frequencies; (b) measuring the frequency characteristics of the cable with test signals; (c) measuring the cable noise and interference for every sub-channel of the ADSL bandwidth; (d) determining the theoretical and practical data rates for every sub-channel, based on the measured frequency characteristics and noise characteristics, as well as modem parameters selected by the user; (e) estimating the theoretical and practical data rates for the ADSL bandwidth based on the ADSL DMT standard selected by the user.