Nano (n) - A prefix meaning 1/billionth

Near Field Sound. - Any point in relation to a speaker where the direct sound emission is measurably louder than the reflections of that sound.

Negative Feedback - (Also called Global Negative Feedback) Frequently used in designing op-amp circuits and audio power amplifiers. By comparing the output signal to the input signal, any signal noise added by the amp is exposed. By duplicating the signal, inverting the noise 180 degrees and combining it with the original signal, the noise will be cancelled out (due to phasing).

The is how some low cost amplifier manufacturers can achieve ridiculously low THD numbers. Unfortunately, excessive use of negative feedback degrades the sound quality of the amplifier. So they end up with a amp that looks good on paper, but doesn't sound so great.

Negative LCD - A liquid crystal display employing a dark backfield with lit elements.

Neodymium Magnet - A magnet material providing 7.5 times the magnetic strength of standard magnetic materials. Commonly used in tweeters where physically small magnet size is a plus.

Net Volume - The amount of airspace within a speaker's enclosure. This does not include the airspace taken up by bracing, vents or the speaker itself.

Noise - Perceived sounds not in the original soundtrack or signal. Such things as hiss, crackle, pops, hum, and buzz are typical of the types of extraneous signals described as noise. Noise of more than 90 dB below the level of a typical audio signal is noise free as far as average human perception is concerned.

Noise floor - The lowest threshold of useful signal level.

Nominal Impedance - The minimum impedance a loudspeaker presents to an amplifier.

Non-Lossy Compression - A form of data compression which seeks out chunks of data which are identical, replacing them with markers called keys. The file is reduced in size and when it is decompressed by the recipient, the keys are replaced with the large chunks of data that were originally there (Run Length Encoding). The result is a uncompressed file that is identical to the original file.

Normally Closed - Refers to the electrical state in which a switch may rest. Its contacts are held together or closed so that current is allowed to flow through its contacts.

Normally Closed - Refers to the electrical state in which a switch may rest. Its contacts are held together or closed so that current is allowed to flow through its contacts.

Notch filter - A type of cut-only equalizer used to attenuate (not boost) a narrow band of frequencies. Frequency, bandwidth and depth are the elements that determine the notch.

NTSC - National Television System Committee. This committee sets the standards used for video broadcast and playback signal parameters.