Погружаясь в тематику все глубже, я обнаружил, что во всем мире есть, как обычно две стороны, имеющих противоположное мнение.
Я хотел бы поделиться с вами той информацией, которую я нашел изучая разные мнения наших коллег и консультируясь с профильными специалистами.
Скажу сразу, что же касается меня, то я разницу после "прогрева" в мониторах APS и не только в них, слышал.
Но так же считаю, что этому придается слишком большое значение, так как, вы все равно начнете пользоваться своими мониторами и этот "прогрев" случится. Если не случился уже, так как некоторые компании при производстве своих АС, тестируют их на протяжении долгого времени после сборки.
Это письмо одному из редакторов SOS Hugh Robjohns, от главного инженера и хозяина компании PMC, с ответом на вопрос о "прогреве".
Так же следом я обнаружил следующую информацию, обьясняющую почему это стоит делать:
Peter Thomas, PMC wrote:The simple answer is that the crossover circuits are designed assuming a specific free air resonance of the drive units. So, the cabinet design will take the bass unit resonant frequency, say at 25Hz. When the drive unit is new its free air resonance will be higher (by up to 10%) and therefore incorrect for the designed cabinet. I don't believe that ATL's are any more sensitive to this than infinite baffle and reflex, but the lower distortion and extended LF allows you to hear the effects more readily in the ATL. Certainly a new bass driver will have an excessively damped bass which sounds dry and lacking in weight until run in.
The tweeter will also have a higher resonant frequency when new and the crossover which is designed to work optimally with a certain load impedance and to minimise the effects of that resonant frequency will not accurately filter the tweeter output to match the woofer crossover. This usually results in a rather harsh and edgy hi frequency response that mellows as the units run in and match the parameters that the crossover expects.
All drive units change their characteristics when they are used initially so it should effect all designs........my experience is that the cleaner and more revealing the speaker design, the longer and more noticeable is the burn in period.
Еще я встречал вот такие измерения, проведенные тоже инженерами компании PMC.
Here are some graphs of pre and post run-in data. The waterfall plots show the inherent resonances in the drive unit pre and post burn-in. The effect is obvious if you overlay the two plots and switch between them -- the resonances clearly reduce after burn-in. For anyone not familiar with waterfall plots, the waterfall shows the output from the drive unit after the input signal is switched off at 0ms. All output thereafter is the speaker resonating...the mountain range effect indicates the primary resonances.
Original Driver:
After 8-hours run-in:
The two plots below indicate the changing free-air resonant frequency for PMC's 5-inch and ten-inch woofers as the compliance of the surround alters. The two lines on each plot are for the original (black) and 8-hour run-in (red) drivers. The free-air resonance shows up on the impedance plot very nicely and reduces in both cases. Pete tells me that these measurements were taken after 8-hours of medium level use, which is the period of greatest change, but that the changes continue to settle down further over about 40 hours and are then fully stable for the life of the driver.
10-inch driver, free-air resonance changes from roughly 45 to 40Hz:
5-inch driver, free air resonance changes from roughly 50 to 45Hz:
Что можете сказать, какие ваши наблюдения на этот счет?
Или возможно у вас есть какие либо измерения и вы могли бы ими поделиться до и после "прогрева" студийных мониторов или АС?
Любой диалог приветствуется, так же прошу заранее быть более сдержанными и не переходить на личности, уважать ваших собеседников и коллег.
Я хотел бы поделиться с вами той информацией, которую я нашел изучая разные мнения наших коллег и консультируясь с профильными специалистами.
Скажу сразу, что же касается меня, то я разницу после "прогрева" в мониторах APS и не только в них, слышал.
Но так же считаю, что этому придается слишком большое значение, так как, вы все равно начнете пользоваться своими мониторами и этот "прогрев" случится. Если не случился уже, так как некоторые компании при производстве своих АС, тестируют их на протяжении долгого времени после сборки.
Это письмо одному из редакторов SOS Hugh Robjohns, от главного инженера и хозяина компании PMC, с ответом на вопрос о "прогреве".
Email response to query from Hugh Robjohns to Peter Thomas, designer and MD of ***** speakers.
Hi Hugh,
The effects of 'running in' is very obvious with high end speakers and is well supported by physics, so we're on a winner here!
The change is greater or lesser depending on the type of surrounds used to support the diaphragm of the drive unit. This applies to all kinds of drive units but effects them in different ways. Most flexible materials exhibit this change when new, so your contributor who talks of shoes is right!
Following the run in period the material is quite stable for tens of years until fatigue sets in.
With woofers the free air resonance of the drive unit will drop by 10 to 15% following the run in period. This is common to most woofers but the time it takes to settle down varies due to different surround matterials.
If you consider that the cabinet, whether transmission line, reflex or sealed box is designed for a drive unit with specific parameters following the run in period, then a new drive unit has effectively the "wrong" parameters. Because the resonant frequency is too high when new, the low end often sounds lacking in dynamics and bass extention...because of the missmatch with the cabinet.
With tweeters, the resonant frequency is too high when new and this produces a missmatch with the crossover (which has been designed for the post run in parameters).
This often leads to a harsh upper midband quality and a lack of stereo "spaciousness" (if the speaker has any in the first case!)
The harshness is due to the missmatch with the crossover before run in and can be seen when measuring responses through the crossover region. The lack of spaciousness is due to the two tweeters not running in at exactly the same time and effectively not being matched during the run in period.
Hope that helps!
Those that cannot hear it are either using speakers that are so badly tuned that the missmatch is a small variation compared to the poor design or will not let themselves hear it on principle!
Kindest Regards
Peter
Peter Thomas
Managing Director
Hi Hugh,
The effects of 'running in' is very obvious with high end speakers and is well supported by physics, so we're on a winner here!
The change is greater or lesser depending on the type of surrounds used to support the diaphragm of the drive unit. This applies to all kinds of drive units but effects them in different ways. Most flexible materials exhibit this change when new, so your contributor who talks of shoes is right!
Following the run in period the material is quite stable for tens of years until fatigue sets in.
With woofers the free air resonance of the drive unit will drop by 10 to 15% following the run in period. This is common to most woofers but the time it takes to settle down varies due to different surround matterials.
If you consider that the cabinet, whether transmission line, reflex or sealed box is designed for a drive unit with specific parameters following the run in period, then a new drive unit has effectively the "wrong" parameters. Because the resonant frequency is too high when new, the low end often sounds lacking in dynamics and bass extention...because of the missmatch with the cabinet.
With tweeters, the resonant frequency is too high when new and this produces a missmatch with the crossover (which has been designed for the post run in parameters).
This often leads to a harsh upper midband quality and a lack of stereo "spaciousness" (if the speaker has any in the first case!)
The harshness is due to the missmatch with the crossover before run in and can be seen when measuring responses through the crossover region. The lack of spaciousness is due to the two tweeters not running in at exactly the same time and effectively not being matched during the run in period.
Hope that helps!
Those that cannot hear it are either using speakers that are so badly tuned that the missmatch is a small variation compared to the poor design or will not let themselves hear it on principle!
Kindest Regards
Peter
Peter Thomas
Managing Director
Так же следом я обнаружил следующую информацию, обьясняющую почему это стоит делать:
Peter Thomas, PMC wrote:The simple answer is that the crossover circuits are designed assuming a specific free air resonance of the drive units. So, the cabinet design will take the bass unit resonant frequency, say at 25Hz. When the drive unit is new its free air resonance will be higher (by up to 10%) and therefore incorrect for the designed cabinet. I don't believe that ATL's are any more sensitive to this than infinite baffle and reflex, but the lower distortion and extended LF allows you to hear the effects more readily in the ATL. Certainly a new bass driver will have an excessively damped bass which sounds dry and lacking in weight until run in.
The tweeter will also have a higher resonant frequency when new and the crossover which is designed to work optimally with a certain load impedance and to minimise the effects of that resonant frequency will not accurately filter the tweeter output to match the woofer crossover. This usually results in a rather harsh and edgy hi frequency response that mellows as the units run in and match the parameters that the crossover expects.
All drive units change their characteristics when they are used initially so it should effect all designs........my experience is that the cleaner and more revealing the speaker design, the longer and more noticeable is the burn in period.
Еще я встречал вот такие измерения, проведенные тоже инженерами компании PMC.
Here are some graphs of pre and post run-in data. The waterfall plots show the inherent resonances in the drive unit pre and post burn-in. The effect is obvious if you overlay the two plots and switch between them -- the resonances clearly reduce after burn-in. For anyone not familiar with waterfall plots, the waterfall shows the output from the drive unit after the input signal is switched off at 0ms. All output thereafter is the speaker resonating...the mountain range effect indicates the primary resonances.
Original Driver:
After 8-hours run-in:
The two plots below indicate the changing free-air resonant frequency for PMC's 5-inch and ten-inch woofers as the compliance of the surround alters. The two lines on each plot are for the original (black) and 8-hour run-in (red) drivers. The free-air resonance shows up on the impedance plot very nicely and reduces in both cases. Pete tells me that these measurements were taken after 8-hours of medium level use, which is the period of greatest change, but that the changes continue to settle down further over about 40 hours and are then fully stable for the life of the driver.
10-inch driver, free-air resonance changes from roughly 45 to 40Hz:
5-inch driver, free air resonance changes from roughly 50 to 45Hz:
Что можете сказать, какие ваши наблюдения на этот счет?
Или возможно у вас есть какие либо измерения и вы могли бы ими поделиться до и после "прогрева" студийных мониторов или АС?
Любой диалог приветствуется, так же прошу заранее быть более сдержанными и не переходить на личности, уважать ваших собеседников и коллег.
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