Author: Karsten Hein
What should a loudspeaker sound like? — Well, if there is a short answer to this question, it is probably this: Ideally, a loudspeaker should sound like the original audio material that is being played back on it. Meaning, the recording of a rocket-launch should sound like the rocket being launched. And the recording of a saxophonist inhaling before playing the next tune should sound exactly like a human being taking a deep breath. A loud sound requires sturdy build quality and lots of air to be moved quickly, whereas a human being inhaling deeply requires the speaker’s ability to present the tiniest nuance.
Acoustic instruments should be tonally correct with wood sounding like real wood, metal sounding like metal, glass like glass, etc. Voices should be as sweet, captivating, or even as raw as the singer’s own voice demands. Tonal correctness requires the speaker’s material resonance frequencies to be minimal and the moving mass of its drivers to be low. Natural instruments and vocals usually have at least two components: the sound that is deliberately produced and the ambient sound caused by the dimensions of the venue on the day of the recording. Both components should be presented equally well.
The speaker’s frequency band should ideally be extensive, ranging from 20 Hz to 25kHz and beyond without significantly dropping in dB volume per watt. The ability to do so assures that sounds occurring along the fringes of the spectrum are fully presented. Even if some of these frequencies fall outside of human hearing, they do affect the audible frequency band through layering and overlapping. Maximum realism can only be achieved, if no aspect of the original signal is omitted.
Much has been written on the linearity of loudspeakers. This refers to the ability to play all frequencies at equal volume. When performing in a home or studio environment, however, the linearity measured and certified in a laboratory has very little to do with the acoustic reality of a private listening room. This is why loudspeaker manufacturers take an educated guess regarding your household or studio furnishings and will accentuate frequencies that they estimate will be absorbed by your furniture and dampen those that will be enforced by your walls and ceiling.
The result of all this is that ‘speaker sound’ exists, even if loudspeakers are usually sold on the premises of being linear. But can this be shown, recorded, and archived for posterity? Well, at this point I am neither sure it is possible nor that the data produced in a recording of a loudspeaker has any value for the decision making process of which speaker to buy. But, since our project is called ‘Explorations in Audio’, I am willing to ‘explore’ the possibility. You see, explorers are naturally attracted to the unknown, especially, if they are greeted with lots of scepticism.
In this new series of explorations I am sharing with you how a given loudspeaker performed on the day of the recording in one of our listening rooms, using the recording equipment available to me at the time. The material is then uploaded to a streaming platform to be played back on any random equipment that you might have at hand: anything ranging from the built-in speaker of your mobile phone to your own High-End stereo system. The listening result is then up to you to interpret. I would be interested in reading about your findings during playback in the comments section below or under the YouTube file. — Enjoy :-)
Standard Audio Source (Type 1):
Standard Recording Equipment:
Standard Measuring distances: