Why is my air pump making loud buzzing noises?
Even under the best conditions, the working noises will be audible in quiet rooms. Every air pump produces vibration and buzzing noises that are more or less clearly audible. The JBL PROSILENT diaphragm pumps have rubber feet to reduce the transmission of vibrations to the floor. The air pump can "wander" on smooth surfaces and should be secured with a soft, non-slip underlay. Hanging it on the wall results in a complete decoupling.
Please note that the volume can be very loud when the hoses are not connected, similar to a modified exhaust on a car. The "silencer" is missing. It is only when back pressure is present that it is substantially minimised. A flow reduction at one of the air volume regulators reduces the noise level considerably.
Therefore, never operate the JBL PROSILENT model(s) with two air connections with only one air connection in "idle mode", i.e. without a connected hose with an air outlet stone or similar! This would lead to premature diaphragm wear and increased noise level.