Speaker Anatomy: Broadband Disputes
It so happened that sometimes in our blog we touch questions that cause quite a lively, lively discussion on this and other resources. I believe that this will happen this time too, since it will be a question of an almost philosophical (for some people) question: the advantages and disadvantages of broadband speakers in comparison with multiband ones.
Discussions on the topic:whether size does matter , which is better - one broad or many narrow ones, has been shaking the forums of philophonists and music lovers for more than one year. As before, I do not intend to put an end to the disputes and will only set the stage for discussion, detailing some facts, and outline my own subjective opinion about the problem.
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I note that I am a supporter of multiband speakers, and for several reasons I believe that the more bands (within reasonable limits, of course), the better. By virtue of the above, I may be somewhat biased in assessing the polar point of view (but I will try to maintain a neutral approach).
The practice of using wideband dynamic emitters and speakers created on their basis has formed a stable stereotype that the wider the frequency range of an electrodynamic emitter, the lower its linearity. Accordingly, in the overwhelming majority of broadband emitters, as a rule, not very flat frequency response, also for many emitters of this type is characterized by a high level of harmonics and intermodulation distortion.
This opinion is confirmed by a number of pure, in terms of sound physics and psychoacoustics, experiments conducted in the last 40 years. In the experiments, broadband and multiband speakers were compared. Due to the presence of serious flaws (low linearity of components equipped with wideband emitters), the vast majority of manufacturers abandoned broadband and began to produce multiband acoustics.
Opponents of multiband acoustics claim that the low linearity of the speakers of such systems is more than compensated for by the absence of “terrible phase distortions” and “monstrous problems” with the linearity of the crossovers dividing the sound into strips.
In other words: at multi-loop filters “shamelessly twist the phase” filters, which “horribly” reflect on the sound. In addition, it is not rare to say that passive crossovers can significantly impair the dynamic characteristics of the system, reduce the detail of the sound and make it "flat." These disadvantages relate mainly to passive crossovers, and the disadvantage of active ones is their cost.
Among other things, supporters of broadband speakers often appeal to certain magical-metaphysical features of the influence, the sound reproduced by them. As a demonstration of the “magical” effects of sound emitted by such a speaker, I will quote one (it fully reflects the opinion of those who appeal to “shamanism” in this matter):
(spelling and punctuation preserved)
Objectively, the vast majority of multiband speakers have several advantages. For most multiband systems with passive crossovers, the following are typical:
Loudspeakers with active crossovers have the same advantages, while having a significantly smaller number of problems with phase response and a large slope (about 10-25 dB). The main disadvantage of systems with an active crossover is the cost, they are usually 2-3 times more expensive than their passive counterparts.
AFC quality three-way speakers
As I have already noted, in addition to the complexity of the design and price, multi-band systems are characterized by the presence of phase-frequency distortion. It should be borne in mind that this type of distortion can only be noticeable if the thresholds of hearing of the group stop (which are about 1 ms in the 2 kHz region) are exceeded. The vast majority of manufacturers of acoustic systems are guided by this criterion from the mid-90s to the present.
Despite the "dominance" of multiband acoustics in the modern market, not all companies have abandoned developments in the "wide band" area. For example, B & C, BHL, P.audio, Edge and Beyma consider research in this area to be justified and continue to produce high-sensitivity wideband dynamic loudspeakers. In particular, these companies have proposed technical solutions to increase the range of high-frequency such speakers. This was done through the use of coaxial design of emitters and other original solutions (placement of special diffuser "superstructures", joining the central core dynamics, etc.). Such systems are especially popular in car audio and built-in acoustics.
Comparison of the frequency response of 2 wideband speakers
Speakers based on such speakers are close to multi-band frequency response. However, by virtue of the principle used, they are still prone to the formation of a hump in the medium range and the “cutting back” of other frequencies, especially in the low-frequency range. It should also be noted that the expansion of the range of broadband speakers towards the woofer is inevitably associated with an increase in the area of ​​the radiator, which, as a rule, leads engineers to a dead end.
In addition, it is necessary to take into account that among adherents of such acoustics, the use of a closed acoustic arrangement is considered a “true-variant”. This, in turn, does not allow manufacturers to use the phase inverter type of “boxes”, which could strengthen the low ones in the overall “picture”. For the same reason, speakers with high sensitivity are used in such speakers, which by no means adds linearity to such systems.
It is known that the most serious problems with the linearity of broadband emitters are noted within the boundaries of the frequency section, which explains the high prevalence of multiband.
No matter how hard I tried to be neutral, it didn't work out. In conclusion, I can say that my personal impressions of listening to broadband acoustics quite coincide with what I have read about the problems of these systems. The sound is replete with medium frequencies and does not create the expected volume of the scene, the bottom - no. In other words, despite the absence of phase problems inherent in multiband systems, broadbands cannot be considered satisfactory. Nonlinearity, especially expressed in the spectra of the frequency section, kills all the advantages of the “wide band”.
While writing the post, a familiar weather organizer came to visit, summarized: “All the statements that linear sound is extracted from one radiator are complete nonsense”.
I sincerely hope that among the readers there will be people who know for some reason that broadband acoustics are popular among audiophiles. As I wrote, I could not be objective. Waiting for comments, refuting my point of view.
Discussions on the topic:
')
I note that I am a supporter of multiband speakers, and for several reasons I believe that the more bands (within reasonable limits, of course), the better. By virtue of the above, I may be somewhat biased in assessing the polar point of view (but I will try to maintain a neutral approach).
The essence of disputes
The practice of using wideband dynamic emitters and speakers created on their basis has formed a stable stereotype that the wider the frequency range of an electrodynamic emitter, the lower its linearity. Accordingly, in the overwhelming majority of broadband emitters, as a rule, not very flat frequency response, also for many emitters of this type is characterized by a high level of harmonics and intermodulation distortion.
This opinion is confirmed by a number of pure, in terms of sound physics and psychoacoustics, experiments conducted in the last 40 years. In the experiments, broadband and multiband speakers were compared. Due to the presence of serious flaws (low linearity of components equipped with wideband emitters), the vast majority of manufacturers abandoned broadband and began to produce multiband acoustics.
Opponents of multiband acoustics claim that the low linearity of the speakers of such systems is more than compensated for by the absence of “terrible phase distortions” and “monstrous problems” with the linearity of the crossovers dividing the sound into strips.
In other words: at multi-loop filters “shamelessly twist the phase” filters, which “horribly” reflect on the sound. In addition, it is not rare to say that passive crossovers can significantly impair the dynamic characteristics of the system, reduce the detail of the sound and make it "flat." These disadvantages relate mainly to passive crossovers, and the disadvantage of active ones is their cost.
Among other things, supporters of broadband speakers often appeal to certain magical-metaphysical features of the influence, the sound reproduced by them. As a demonstration of the “magical” effects of sound emitted by such a speaker, I will quote one (it fully reflects the opinion of those who appeal to “shamanism” in this matter):
“But on the other hand, without noticing it myself, after a while I switched from analyzing the sound to listening to music. He put the composition for the composition, listened to the hour instead of the planned 10-15 minutes. Then there was a very interesting feeling - I wanted to sing along with the performer, try to play a chord for the instrument - although both of them, after my usual homemade ear on SkanSpika, were hardly understood =). Turning off the equipment, I left in a very positive mood - I had the feeling that I had heard something that I had never heard before - what it is difficult to say. But - it turns out that those who speak about some magical side of broadband are right ... "
(spelling and punctuation preserved)
Multiband speakers
Objectively, the vast majority of multiband speakers have several advantages. For most multiband systems with passive crossovers, the following are typical:
- More uniform frequency response, in comparison with broadband systems;
- A frequency spectrum sufficient to reproduce all audible frequencies (20 Hz - 20 kHz versus 60 - 18 000 Hz for most broadband);
- Lower sensitivity, but due to this greater linearity of the component;
- High-class systems, as a rule, have solved the problem of the phase polarity of filters (phase delays are beyond the threshold of human perception).
Loudspeakers with active crossovers have the same advantages, while having a significantly smaller number of problems with phase response and a large slope (about 10-25 dB). The main disadvantage of systems with an active crossover is the cost, they are usually 2-3 times more expensive than their passive counterparts.
AFC quality three-way speakers
As I have already noted, in addition to the complexity of the design and price, multi-band systems are characterized by the presence of phase-frequency distortion. It should be borne in mind that this type of distortion can only be noticeable if the thresholds of hearing of the group stop (which are about 1 ms in the 2 kHz region) are exceeded. The vast majority of manufacturers of acoustic systems are guided by this criterion from the mid-90s to the present.
Pros and cons of broadband
Despite the "dominance" of multiband acoustics in the modern market, not all companies have abandoned developments in the "wide band" area. For example, B & C, BHL, P.audio, Edge and Beyma consider research in this area to be justified and continue to produce high-sensitivity wideband dynamic loudspeakers. In particular, these companies have proposed technical solutions to increase the range of high-frequency such speakers. This was done through the use of coaxial design of emitters and other original solutions (placement of special diffuser "superstructures", joining the central core dynamics, etc.). Such systems are especially popular in car audio and built-in acoustics.
Comparison of the frequency response of 2 wideband speakers
Speakers based on such speakers are close to multi-band frequency response. However, by virtue of the principle used, they are still prone to the formation of a hump in the medium range and the “cutting back” of other frequencies, especially in the low-frequency range. It should also be noted that the expansion of the range of broadband speakers towards the woofer is inevitably associated with an increase in the area of ​​the radiator, which, as a rule, leads engineers to a dead end.
In addition, it is necessary to take into account that among adherents of such acoustics, the use of a closed acoustic arrangement is considered a “true-variant”. This, in turn, does not allow manufacturers to use the phase inverter type of “boxes”, which could strengthen the low ones in the overall “picture”. For the same reason, speakers with high sensitivity are used in such speakers, which by no means adds linearity to such systems.
It is known that the most serious problems with the linearity of broadband emitters are noted within the boundaries of the frequency section, which explains the high prevalence of multiband.
Total
No matter how hard I tried to be neutral, it didn't work out. In conclusion, I can say that my personal impressions of listening to broadband acoustics quite coincide with what I have read about the problems of these systems. The sound is replete with medium frequencies and does not create the expected volume of the scene, the bottom - no. In other words, despite the absence of phase problems inherent in multiband systems, broadbands cannot be considered satisfactory. Nonlinearity, especially expressed in the spectra of the frequency section, kills all the advantages of the “wide band”.
While writing the post, a familiar weather organizer came to visit, summarized: “All the statements that linear sound is extracted from one radiator are complete nonsense”.
I sincerely hope that among the readers there will be people who know for some reason that broadband acoustics are popular among audiophiles. As I wrote, I could not be objective. Waiting for comments, refuting my point of view.
Source: https://habr.com/ru/post/373507/
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