- 第 1 页 -
若有興趣, 先得了解一下 comb filter 和 allpass filter:-
In signal processing, a comb filter adds a delayed version of a signal to itself, causing constructive and destructive interference. The frequency response of a comb filter consists of a series of regularly-spaced spikes, giving the appearance of a comb.
Comb filters exists in two different forms, feedforward and feedback; the names refer to the direction in which signals are delayed before they are added to the input.
Comb filters may be implemented in discrete time or continuous time; this article will focus on discrete-time implementations; the properties of the continuous-time comb filter are very similar.
http://en.wikipedia.org/wiki/Comb_filter
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An all-pass filter is an electronic filter that passes all frequencies equally, but changes the phase relationship between various frequencies. It does this by varying its propagation delay with frequency. Generally, the filter is described by the frequency at which the phase shift crosses 90°.
They are generally used to compensate for other undesired phase shifts that arise in the system, or for mixing with an unshifted version of the original to implement a notch comb filter.
They may also be used to convert a mixed phase filter into a minimum phase filter with an equivalent magnitude response or an unstable filter into a stable filter with an equivalent magnitude response.
http://en.wikipedia.org/wiki/All-pass_filter
[ 本帖最后由 himhui 于 08-1-22 12:42 编辑 ]
In signal processing, a comb filter adds a delayed version of a signal to itself, causing constructive and destructive interference. The frequency response of a comb filter consists of a series of regularly-spaced spikes, giving the appearance of a comb.
Comb filters exists in two different forms, feedforward and feedback; the names refer to the direction in which signals are delayed before they are added to the input.
Comb filters may be implemented in discrete time or continuous time; this article will focus on discrete-time implementations; the properties of the continuous-time comb filter are very similar.
http://en.wikipedia.org/wiki/Comb_filter
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
An all-pass filter is an electronic filter that passes all frequencies equally, but changes the phase relationship between various frequencies. It does this by varying its propagation delay with frequency. Generally, the filter is described by the frequency at which the phase shift crosses 90°.
They are generally used to compensate for other undesired phase shifts that arise in the system, or for mixing with an unshifted version of the original to implement a notch comb filter.
They may also be used to convert a mixed phase filter into a minimum phase filter with an equivalent magnitude response or an unstable filter into a stable filter with an equivalent magnitude response.
http://en.wikipedia.org/wiki/All-pass_filter
[ 本帖最后由 himhui 于 08-1-22 12:42 编辑 ]
20 Comb/20 Allpass design
FREQ RESPONSE
Adjusts the frequency response of the currently selected filter (only applicable to Comb Filters). The higher the value, the more the high frequencies are attenuated.
COMBS ENABLE
If checked, the Comb Filters are enabled. If unchecked, they will be bypassed.
ALLPASS ENABLE
If checked, the Allpass Filters are enabled. If unchecked, they will be bypassed.
STEREO ENABLE
If checked, a stereo enhancement algorithm is added to both mono and stereo files. If unchecked, stereo files will maintain discreet stereo dispersion and mono files will maintain mono dispersion.
BANDPASS ENABLE
If checked, the Bandpass Filter is enabled. If unchecked, it will be bypassed.
BANDPASS LOW
Sets the Low bandpass cutoff frequency.
BANDPASS HIGH
Sets the High bandpass cutoff frequency.
[ 本帖最后由 himhui 于 08-1-22 22:44 编辑 ]
FREQ RESPONSE
Adjusts the frequency response of the currently selected filter (only applicable to Comb Filters). The higher the value, the more the high frequencies are attenuated.
COMBS ENABLE
If checked, the Comb Filters are enabled. If unchecked, they will be bypassed.
ALLPASS ENABLE
If checked, the Allpass Filters are enabled. If unchecked, they will be bypassed.
STEREO ENABLE
If checked, a stereo enhancement algorithm is added to both mono and stereo files. If unchecked, stereo files will maintain discreet stereo dispersion and mono files will maintain mono dispersion.
BANDPASS ENABLE
If checked, the Bandpass Filter is enabled. If unchecked, it will be bypassed.
BANDPASS LOW
Sets the Low bandpass cutoff frequency.
BANDPASS HIGH
Sets the High bandpass cutoff frequency.
[ 本帖最后由 himhui 于 08-1-22 22:44 编辑 ]
COMB FILTERS
The Comb Filters can be selected and displayed by pressing the Combs button. Comb Filters create the early first reflections of the chamber. Using a single Comb Filter can create typical echo delay effects. It usually takes three or more to begin creating the many interactive reflections that simulate natural room ambience.
我們可以按 COMB FILTERS 的鍵來顯示它的參數, COMB FILTER 用來製造出房間的早期反射。使用一個 COMB FILTER 能夠建出簡單的 ECHO DELAY (延遲效果)。一般情況我們會用3個或以上來做多個互交反射效果, 以模擬房間的自然混響。
The Delay setting of each Comb Filter determines the time to the first reflection of that filter. Larger Delay settings simulate larger rooms.
它的 DELAY 設置決定該 COMB FILTER 的第一個反射時間, 數值越大, 所模擬的房間也越大。
The Feedback setting determines the liveness of the room. Larger values cause the first reflection to continue echoing on for a longer length of time.
Feedback 是決定房間的特性, 如不同物料所影響到的聲音, 數值越大, 延遲的聲音時間也會較長。
The Frequency response setting also plays an important role in simulating the room liveness by controlling how fast the high frequencies decay. Higher values dampen the feedback, rolling off the high frequencies faster.
Frequency response (頻率反應)設置 對房間特性也佔非常重要的角色, 它控制著高頻的衰減時間, 數值越高, 高頻衰減也越快。
Each Comb Filter assigned will be displayed as a vertical line in the display window. The height of the line represents its feedback strength, and the position of the line represents its delay time. Longer times move the position to the right.
每一個 COMB FILTER 會顯示為垂直線, 它的高度代表 FEEBACK 的強度; 所在位置為 DELAY (延遲) 時間, 越靠右邊, 延遲時間越長。
Most lines will be green, but one will be red. The red line is the currently selected and active Comb Filter and the slider controls will reflect its settings. The Previous and Next buttons can be used, as well as the left and right arrow keys, to select a different Comb Filter as the active one. You may then adjust the sliders to change the response of that filter and the overall response of the chamber.
我們會看到 comb filters 的線大多以綠色顯示, 紅色的線表示我們可以編輯它, 按鈕 previous 可選前一個 (向左方) comb filter修改, 按鈕 " Next" 則選 下一個 (向右方) comb filter 來編輯, 也可用鍵盤左右箭頭來控制。
You may add a new filter using the Add button, or delete an existing one using the Delete button. Keep in mind that the more filters added, the smoother the overall chamber can become, but the more intensive the demands are on the CPU.
我們可以用 " Add " 鍵 加入新的 comb filter 或 " Delete" 鍵來刪除每一個 comb filter. 記著, 越多comb filter加載, 混響聲音也會變得越順滑 . 但 CPU資源消耗也隨之增加 (這說明書最後更新應該是 2002年...
)
"Revert"是 取消上一步對 COMB FILTER 或 ALLPASS FILTER 的參數。
When positioning Comb Filters, try to keep the Delay times at random intervals such that there are no even multiples of delays that can directly overlap creating peaks and valleys in the overall chamber response (unless of course that is your intent). In other words placing, one filter at .0100s and the next at .0200s could cause unwanted peaks and valleys in the chamber. Try moving one to .0197s.
當選擇多個COMB FILTER 位置時 (也就是 DELAY 時間), 除非是故意, 應該以不規則方式, 因而重疊或以整倍數時間, 會弄致產生不必要的過大或過小混響聲。 假設相距時間是 0.0100秒 和 0.200秒, 我們最少也要把0.200秒調為 0.0197秒。
[ 本帖最后由 himhui 于 08-1-24 22:26 编辑 ]
The Comb Filters can be selected and displayed by pressing the Combs button. Comb Filters create the early first reflections of the chamber. Using a single Comb Filter can create typical echo delay effects. It usually takes three or more to begin creating the many interactive reflections that simulate natural room ambience.
我們可以按 COMB FILTERS 的鍵來顯示它的參數, COMB FILTER 用來製造出房間的早期反射。使用一個 COMB FILTER 能夠建出簡單的 ECHO DELAY (延遲效果)。一般情況我們會用3個或以上來做多個互交反射效果, 以模擬房間的自然混響。
The Delay setting of each Comb Filter determines the time to the first reflection of that filter. Larger Delay settings simulate larger rooms.
它的 DELAY 設置決定該 COMB FILTER 的第一個反射時間, 數值越大, 所模擬的房間也越大。
The Feedback setting determines the liveness of the room. Larger values cause the first reflection to continue echoing on for a longer length of time.
Feedback 是決定房間的特性, 如不同物料所影響到的聲音, 數值越大, 延遲的聲音時間也會較長。
The Frequency response setting also plays an important role in simulating the room liveness by controlling how fast the high frequencies decay. Higher values dampen the feedback, rolling off the high frequencies faster.
Frequency response (頻率反應)設置 對房間特性也佔非常重要的角色, 它控制著高頻的衰減時間, 數值越高, 高頻衰減也越快。
Each Comb Filter assigned will be displayed as a vertical line in the display window. The height of the line represents its feedback strength, and the position of the line represents its delay time. Longer times move the position to the right.
每一個 COMB FILTER 會顯示為垂直線, 它的高度代表 FEEBACK 的強度; 所在位置為 DELAY (延遲) 時間, 越靠右邊, 延遲時間越長。
Most lines will be green, but one will be red. The red line is the currently selected and active Comb Filter and the slider controls will reflect its settings. The Previous and Next buttons can be used, as well as the left and right arrow keys, to select a different Comb Filter as the active one. You may then adjust the sliders to change the response of that filter and the overall response of the chamber.
我們會看到 comb filters 的線大多以綠色顯示, 紅色的線表示我們可以編輯它, 按鈕 previous 可選前一個 (向左方) comb filter修改, 按鈕 " Next" 則選 下一個 (向右方) comb filter 來編輯, 也可用鍵盤左右箭頭來控制。
You may add a new filter using the Add button, or delete an existing one using the Delete button. Keep in mind that the more filters added, the smoother the overall chamber can become, but the more intensive the demands are on the CPU.
我們可以用 " Add " 鍵 加入新的 comb filter 或 " Delete" 鍵來刪除每一個 comb filter. 記著, 越多comb filter加載, 混響聲音也會變得越順滑 . 但 CPU資源消耗也隨之增加 (這說明書最後更新應該是 2002年...
)"Revert"是 取消上一步對 COMB FILTER 或 ALLPASS FILTER 的參數。
When positioning Comb Filters, try to keep the Delay times at random intervals such that there are no even multiples of delays that can directly overlap creating peaks and valleys in the overall chamber response (unless of course that is your intent). In other words placing, one filter at .0100s and the next at .0200s could cause unwanted peaks and valleys in the chamber. Try moving one to .0197s.
當選擇多個COMB FILTER 位置時 (也就是 DELAY 時間), 除非是故意, 應該以不規則方式, 因而重疊或以整倍數時間, 會弄致產生不必要的過大或過小混響聲。 假設相距時間是 0.0100秒 和 0.200秒, 我們最少也要把0.200秒調為 0.0197秒。
[ 本帖最后由 himhui 于 08-1-24 22:26 编辑 ]
观众反应
ALLPASS FILTERS
The Allpass Filters can be selected and displayed by pressing the Allpass button. Allpass Filters create the density and reflection diffusion of the chamber. Without the Allpass Filters the individual reflections of the Comb Filters may be heard intact, and can create a kind of course and rough sound. By adding the Allpass Filters at various delay points in the chamber, individual reflections become diffused and blended together, creating the smooth decay trails that are normally associated with room ambience.
Once again, more can create smoother chambers, but at the expense of CPU time.
The delay times of the Allpass Filters are much shorter than the Comb Filters, and you can create actual resonant tones by placing them too close together.
當我們要調校 ALLPASS FILTER的參數時, 只按"ALLPASS"這鍵便可。它是用來建立混響的密度和反射擴散, 如果沒有了 ALLPASS FILTER, 我們所聽到 COMB FILTER 的聲音會較為粗糙, 加入 ALLPASS FILTER 在不同 延遲位置 (時間), 每個反射聲音得以擴散和融合, 建出和房間混響順滑和有調理的衰減聲音。
ALLPASS FILTER 的延遲時間比 COMB FILTER 要短得多, 我們可以把它們按排得很接近來凝造出真實哄鳴音色。
[ 本帖最后由 himhui 于 08-1-24 19:03 编辑 ]
The Allpass Filters can be selected and displayed by pressing the Allpass button. Allpass Filters create the density and reflection diffusion of the chamber. Without the Allpass Filters the individual reflections of the Comb Filters may be heard intact, and can create a kind of course and rough sound. By adding the Allpass Filters at various delay points in the chamber, individual reflections become diffused and blended together, creating the smooth decay trails that are normally associated with room ambience.
Once again, more can create smoother chambers, but at the expense of CPU time.
The delay times of the Allpass Filters are much shorter than the Comb Filters, and you can create actual resonant tones by placing them too close together.
當我們要調校 ALLPASS FILTER的參數時, 只按"ALLPASS"這鍵便可。它是用來建立混響的密度和反射擴散, 如果沒有了 ALLPASS FILTER, 我們所聽到 COMB FILTER 的聲音會較為粗糙, 加入 ALLPASS FILTER 在不同 延遲位置 (時間), 每個反射聲音得以擴散和融合, 建出和房間混響順滑和有調理的衰減聲音。
ALLPASS FILTER 的延遲時間比 COMB FILTER 要短得多, 我們可以把它們按排得很接近來凝造出真實哄鳴音色。
[ 本帖最后由 himhui 于 08-1-24 19:03 编辑 ]