Brooks Hi Fi speakers Echo

1) One distinct repeat of a sound because of the sound reflecting off a surface.
2) Loosely, used to mean reverberation (the continuing of a sound after the source stops emitting it, caused by many discrete echoes closely spaced in time).

High Impedance Mic
A microphone designed to be fed into an amplifier with input impedance greater than 20 k ohms.

Brooks RM 909 Channel
1) In multitrack tape machines, this term means the same thing as the term Track (one audio recording made on a portion of the width of a multitrack tape).
2) A single path that an audio signal travels or can travel through a device from an input to an output.

Ground Loop
A double grounding of a line or electronic device at two different "ground" points of differing voltage.

Brooks RM 909 reviews Cable, 1/4 inch
An unbalanced cable most often used for instruments and patch cords. Commonly referred to as "guitar cords".

Amplitude
The extreme range of a signal. Usually measured from the average to the extreme.

Impedance
1) A term for the electrical resistance found in a/c circuits. Affects the ability of a cable to transmit low level (e.g. sound) signals over a long distance. Measured in Ohms. Speakers are rated according to power handling capabilities (Watts, W) and impedance (Ohms).
2) The total opposition offered by an electric circuit to the flow of an alternating current of a single frequency. It is a combination of resistance and reactance and is measured in ohms. Remember that a speaker's impedance changes with frequency, it is not a constant value.
3) The opposition to alternating current.

Horn
1) The part of the speaker that emits midrange and higher range frequencies.
2) A speaker or speaker enclosure where sound waves are put into a narrow opening (by a speaker cone or driver) and the narrow opening flairs out to a larger opening.