answer:Aah hi Andrew; just finished talking about a very similar topic (see the previous disc on Ohms); in your particular case the situation may be somewhat related although your system is slightly more complicated. The short answer is that your Marantz may not have adequate Wattag to handle the load for that system. The issue becomes one of adding up the resistance of speakers that are wired in series for each channel of the system. In all likelihood, if the speakers are ceiling mounted then it could be a mono signal path (summed stereo into mono), it would be advisable to find out how many of them are in the circuit, and the specifications of the speaker-specifically the wattage and Ohms rating (resistance basically), then you’ll be able to add up the collective resistance (impedance) of the circuit. For example, if you had 4 speakers wired end-to-end in series, and each speaker carried a wattage rating of 20 watts [at] 8 Ohms, then the total wattage necessary for that circuit would be 80 watts at 32 Ohms; however, the trick comes in the conversion. If your amp is delivering 80 watts at 16 Ohms, then at 32 Ohms (increased impedance), the actual output wattage is cut in half. That is, your amp would only deliver 40 watts at 32 Ohms. Conversely, if you only had a single speaker to drive at 8 Ohms, then your amp would be able to deliver double its 16 Ohm wattage, which would be 160 Watts at 8 Ohms. The result is that if you don’t have enough watts for your load (and taking into account the additive Impedance in a circuit with speakers (resistors) wired in series, chances are you’re underpowering your speakers. Underpowering is usually to blame for the symptom you’re describing, and I the case of most audio systems is the cause for speaker failure (you’d think it was from overpowering, when in reality it’s the opposite). Lastly, the knob on the wall is just a variable resistor-it controls the current but has little to no I pact on the impedance of the speakers themselves.