tuga
Major Contributor
Linkwitz' thoughts on loudspeakers and domestic reproduction
http://www.linkwitzlab.com/conclusions.htm
A few clippings with which I concur:
• Loudspeakers
• The best one can hope for with 2-channel sound reproduction is the illusion of listening into the recording venue. Physics does not allow the accurate reproduction of the original sound field with only two speakers.
• Since sound reproduction is about creating an illusion it becomes very important to avoid or minimize any clues that would detract from the illusion. Such clues come from linear-distortions, such as frequency and polar response, and from non-linear distortions with their generation of tones and sounds that were not in the original.
• Linear distortion - frequency response, polar response, resonance - affects primarily the timbre and clarity of a loudspeaker.
• Non-linear distortion - intermodulation, harmonic, clipping - affects primarily the maximum tolerable sound pressure level.
• When designing a loudspeaker it is essential to perform free-space measurements to see the effects of driver directivity and baffle shape on the important polar response.
• Box loudspeakers
• Typical box speakers have a generic sound due to their polar response, panel resonances, re-radiation through the cone and vented bass.
• Bass from box speakers has more "punch" than from open baffle speakers, but is less "airy".
• Vented bass speakers are resonant structures and store energy which is released over time. For accuracy, bass must be reproduced from sealed or open baffle speakers that are non-resonant.
• Closed box speakers are best listened to from very close distance to minimize masking from an uneven room response.
• Listening rooms
• The room is rarely at fault. If it is comfortable for conversation and living in it, then it is also suited for sound reproduction. The problem is usually the inadequate polar response of the loudspeakers and their placement in the room.
• Rooms should have lots of diffusive elements and not sound like a stuffed pillow if open baffle or omni speakers are used.
• Placing absorbers at reflection points is the wrong approach. It only absorbs high frequencies and increases the difference between the direct sound and the delayed room response. It works against perceptually masking the room response as merely a copy of the direct sound.
• Equalization for a certain response at the listening position is fraught with serious problems. DSP can do many things, but which acoustic inputs to take, and how to process them, is still very much at a research stage. It will change the sound you hear.
• When I hear an unfamiliar loudspeaker in an unfamiliar room and it does not sound right, then I look for faults in the loudspeaker's design and placement long before I blame the room.
• Listeners
• People listen differently. Performing musicians and members of the audience are used to different perspectives and focus on different aspects of the sound. Both are valuable for analyzing a loudspeaker. People who only listen to loudspeakers and thus always compare loudspeakers are poor judges of accuracy.
• Very few sales people of "high end audio" ever listen to unamplified life sounds. They are highly susceptible to marketing department suggestions.
• Unbiased listeners have no difficulty recognizing accurate sound reproduction, even with hearing damage or with hearing aids.
• Unfortunately, marketing departments and dealers think that bass and high frequencies need to be emphasized for products to sell.
• Some listeners prefer euphonic loudspeakers. Accurate, and thus neutral, loudspeakers are not that exciting unless the source material is.
• I find it disappointing when loudspeaker manufacturers run extensive double-blind listening tests with trained and untrained listeners where they only compare loudspeakers to each other, but not to any live source. These are strictly preference tests within a given paradigm.
• Source material
• A loudspeaker can never do better than to accurately convert electrical signals into acoustic signals. Thus the source material determines ultimately how well an illusion can be created.
• Recording is still an art, not a science. Two loudspeakers in a room cannot reproduce the original sound field. Surround sound could be science based, but today is far from it and mostly pan-potted mono.
http://www.linkwitzlab.com/conclusions.htm
A few clippings with which I concur:
• Loudspeakers
• The best one can hope for with 2-channel sound reproduction is the illusion of listening into the recording venue. Physics does not allow the accurate reproduction of the original sound field with only two speakers.
• Since sound reproduction is about creating an illusion it becomes very important to avoid or minimize any clues that would detract from the illusion. Such clues come from linear-distortions, such as frequency and polar response, and from non-linear distortions with their generation of tones and sounds that were not in the original.
• Linear distortion - frequency response, polar response, resonance - affects primarily the timbre and clarity of a loudspeaker.
• Non-linear distortion - intermodulation, harmonic, clipping - affects primarily the maximum tolerable sound pressure level.
• When designing a loudspeaker it is essential to perform free-space measurements to see the effects of driver directivity and baffle shape on the important polar response.
• Box loudspeakers
• Typical box speakers have a generic sound due to their polar response, panel resonances, re-radiation through the cone and vented bass.
• Bass from box speakers has more "punch" than from open baffle speakers, but is less "airy".
• Vented bass speakers are resonant structures and store energy which is released over time. For accuracy, bass must be reproduced from sealed or open baffle speakers that are non-resonant.
• Closed box speakers are best listened to from very close distance to minimize masking from an uneven room response.
• Listening rooms
• The room is rarely at fault. If it is comfortable for conversation and living in it, then it is also suited for sound reproduction. The problem is usually the inadequate polar response of the loudspeakers and their placement in the room.
• Rooms should have lots of diffusive elements and not sound like a stuffed pillow if open baffle or omni speakers are used.
• Placing absorbers at reflection points is the wrong approach. It only absorbs high frequencies and increases the difference between the direct sound and the delayed room response. It works against perceptually masking the room response as merely a copy of the direct sound.
• Equalization for a certain response at the listening position is fraught with serious problems. DSP can do many things, but which acoustic inputs to take, and how to process them, is still very much at a research stage. It will change the sound you hear.
• When I hear an unfamiliar loudspeaker in an unfamiliar room and it does not sound right, then I look for faults in the loudspeaker's design and placement long before I blame the room.
• Listeners
• People listen differently. Performing musicians and members of the audience are used to different perspectives and focus on different aspects of the sound. Both are valuable for analyzing a loudspeaker. People who only listen to loudspeakers and thus always compare loudspeakers are poor judges of accuracy.
• Very few sales people of "high end audio" ever listen to unamplified life sounds. They are highly susceptible to marketing department suggestions.
• Unbiased listeners have no difficulty recognizing accurate sound reproduction, even with hearing damage or with hearing aids.
• Unfortunately, marketing departments and dealers think that bass and high frequencies need to be emphasized for products to sell.
• Some listeners prefer euphonic loudspeakers. Accurate, and thus neutral, loudspeakers are not that exciting unless the source material is.
• I find it disappointing when loudspeaker manufacturers run extensive double-blind listening tests with trained and untrained listeners where they only compare loudspeakers to each other, but not to any live source. These are strictly preference tests within a given paradigm.
• Source material
• A loudspeaker can never do better than to accurately convert electrical signals into acoustic signals. Thus the source material determines ultimately how well an illusion can be created.
• Recording is still an art, not a science. Two loudspeakers in a room cannot reproduce the original sound field. Surround sound could be science based, but today is far from it and mostly pan-potted mono.
