HUG - here for all audio enthusiasts

The Harbeth User Group is the primary channel for public communication with Harbeth's HQ. If you have a 'scientific mind' and are curious about how the ear works, how it can lead us to make the right - and wrong - audio equipment decisions, and about the technical ins and outs of audio equipment, how it's designed and what choices the designer makes, then the factual Science of Audio sub-forum area of HUG is your place. The objective methods of comparing audio equipment under controlled conditions has been thoroughly examined here on HUG and elsewhere and should be accessible to non-experts and able to be tried-out at home without deep technical knowledge. From a design perspective, today's award winning Harbeths could not have been designed any other way.

Alternatively, if you just like chatting about audio and subjectivity rules for you, then the Subjective Soundings area is you. If you are quite set in your subjectivity, then HUG is likely to be a bit too fact based for you, as many of the contributors have maximised their pleasure in home music reproduction by allowing their head to rule their heart. If upon examination we think that Posts are better suited to one sub-forum than than the other, they will be redirected during Moderation, which is applied throughout the site.

Questions and Posts about, for example, 'does amplifier A sounds better than amplifier B' or 'which speaker stands or cables are best' are suitable for the Subjective Soundings area only, although HUG is really not the best place to have these sort of purely subjective airings.

The Moderators' decision is final in all matters and Harbeth does not necessarily agree with the contents of any member contributions, especially in the Subjective Soundings area, and has no control over external content.

That's it! Enjoy!

{Updated Oct. 2017}
See more
See less

Read this first! Sound waves - what are they?

  • Filter
  • Time
  • Show
Clear All
new posts

  • Read this first! Sound waves - what are they?

    Sound waves fall onto the microphone, and are pumped out by the speaker. What are they exactly?
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

  • #2
    "Sound waves are nothing more or less than a localised variation in the prevailing atmospheric pressure in the vicinity of the sound generating source."

    Let's break that down:
    • localised variation = sound waves are not a fixed quantity, they can go up and down (in loudness, pitch), and they are relatively local to the source (loudspeaker etc.)

    Observation: Your hifi speaker's sound cannot be heard 100km from your home, but it could be heard in the adjacent apartment.
    • prevailing atmospheric pressure

    Explanation: If atmospheric pressure can be measured right here beside me now in this room with a domestic barometer (rain prediction instrument), then if sound waves radiate in the ordinary room's atmosphere, there must be a localised change in the atmospheric pressure right around me in this room, and that change must be moving the local barometric pressure up and down very fast (according to the loudness/pitch of the sound), but too fast for my sluggish mechanical barometer to detect ...
    • in the vicinity of the sound generating source

    A bomb might be heard 100km away, but as my speaker cannot be, so the perceived sound energy (loudness) has a correlation between the amount of sound power generated by the source (speaker or bomb) and the distance away the observer is.

    The purpose of an audio system, and especially a quality audio system, is to capture the local variations in ambient barometric pressure around the microphone and pass it precisely along the audio chain as an electrical signal, ultimately to the loudspeakers. The speakers then take that electrical instruction and pump up and down the ambient pressure in the listener's room. If the loudspeakers are perfect, the listener's ears experiences a pressure variation experience very similar to that experienced standing at the microphone in the recording studio.

    So, sound waves around the microphone > cause localised ambient pressure variation > detected by movement of the microphone's sensitive diaphragm > turned into electricity > passed along the audio chain > into the loudspeaker > sound wave out of the speakers cause localised ambient pressure variation > human ear/brain detects localised pressure change and interprets that as "sound".

    Can we collaborate to improve or simplify this core concept? We need to get this just right. The audio business is built on this concept.
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK