"This Harbeth User Group (HUG) is the Manufacturer's own managed forum dedicated to natural sound from microphone to ear, achievable by recognising and controlling the numerous confounding variables that exist along the audio chain. The Harbeth designer's objective is to make loudspeakers that contribute little of themselves to the music passing through them.

Identifying system components for their sonic neutrality should logically proceed from the interpretation and analysis of their technical, objective performance, since deviations from a flat frequency response at any point along the signal chain from microphone to ear is likely to create an audible sonic personality in what you hear. That includes the contribution of the listening room itself. To accurately reproduce the recorded sound, as Harbeth speakers are designed to do, you would be advised to select system components (sources, electronics, cables and so on) that do not color the sound before it reaches the speakers.

For example, the design of and interaction between the hifi amplifier and its speaker load can and potentially will alter the sound balance of what you hear. This may or may not be what you wish to achieve, but on the face of it, any deviation from a flat response - and the frequency balance of tube amplifiers are usually influenced by their speaker load - is a step away from a truly neutral system. HUG has extensively discussed amplifiers and the methods for seeking the most objectively neutral amongst a plethora of available product choices.

HUG specialises in making complex technical matters simple to understand, aiding the identification of audio components likely to maintain a faithful relationship between the recorded sound and the sound you hear. With our heritage of natural sound and pragmatism, HUG cannot be expected to be a place to discuss the selection, approval or endorsement of non-Harbeth system elements selected, knowingly or not, to create a significantly personalised sound. For that you should do your own research and above all, make the effort to visit an Authorised Dealer and listen to your music at your loudness on your loudspeakers through the various offerings there. There is really no on-line substitute for time invested in a dealer's showroom because 'tuning' your system to taste is such a highly personal matter.

Please consider carefully how much you should rely upon and be influenced by the subjective opinions of strangers. Their hearing acuity and taste will be different to yours, as will be their motives and budget, their listening distance, loudness and room treatment, not necessarily leading to appropriate equipment selection and listening satisfaction for you.

If faithfully reproducing the sound intended by the composer, score, conductor and musicians in your home and over Harbeth speakers is your audio dream, then understanding something of the issues likely to fulfill that intention is what this forum has been helping to do since 2006. Welcome!"

Feb. 2018
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Microphones - how do they response to the sound waves around them?

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  • Microphones - how do they response to the sound waves around them?

    Clearly, they generate an output. But how does that relate to the sound waves they sensed?
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

  • #2
    We defined sound waves here. What humans call sound is nothing more or less than the consequence of a sound energy source - a loudspeaker, a voice, a bell, a bomb - rapidly raising and lowering the local atmospheric pressure in the vicinity of the source.

    The front end of the audio recording/reproduction chain requires that those local sound pressure variations are sensed. The sensor is called a microphone.

    Clearly, the moving parts of the sensing microphone must be of very low mass. The moving parts must be practically as featherlight as the wings of a butterfly. Only if they are extremely light weight could they be expected to detect the minute changes in air pressure caused by the sound source modulating the air around the microphone.

    If we disassemble a modern condenser (capacitor) microphone, we can identify the working parts, mechanical and electronic. The sound pressure around the microphone is detected by the diaphragm, typically about 25mm diameter, and far thinner than the thinnest paper. That gold-plated plastic diaphragm is clamped rigidly with a ring of tiny screws, and as you can imagine, the diaphragm is very stiff.

    Because the movement of the diaphragm in response to local sound pressure is tiny, millionths of a millimeter of movement, signal-boosting electronics are needed as close to the diaphragm as possible to minimise hiss and hum.

    See here:
    Click image for larger version  Name:	diaphragm.jpg Views:	1 Size:	173.6 KB ID:	74300
    Featherlight diaphragm inside microphone that senses the sound pressure around the microphone

    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK