次世代擴大機(DENON;ONKYO)音場調整Audyssey MultEQ使用須知與注意事項

paneraiben · 發表於 2008-6-20 21:39:56

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先聲明，這是轉載於 MYAV 網兄（tsaident）因覺得不錯才轉過來的

這裡有原本的網址：http://www.myav.com.tw/forum/showthread.php?s=&threadid=312758

次世代擴大機中許多型號與廠牌都用上了這家公司出的音場聲音頻率修正晶片，跟著擴大機一起而來的麥克風經由原廠建議的設置方法、測量您的視聽空間後，利用EQ調整可以改善視聽室中不理想的頻率響應（例如某些頻率的缺陷或是駐波等），從而增加了視聽室裡的皇帝位（SWEET SPOTS）。
在美國的AVS論壇裡對這些功能討論甚多，許多設置上的細節也是要注意的、否則可能得到反效果！誤殺忠良！
在AVS裡Audyssey原廠的工程人員都直接上來與用家討論並提供建議，真令人羨慕！自己因為也有興趣、所以做了一些功課、把一些個人看到認為要注意的地方翻譯一下（翻譯不好的地方請見諒），並附上一些原始連結讓有興趣的人直接閱讀，希望對用家有所助益！我的機器大概還是一堆零件、不知道什麼時候才會到，不過藉此拋磚引玉，希望已經擁有的用家多分享心得，將來自己可以少走冤枉路~~~

原廠連結：http://www.audyssey.com/index.html
AVS 論壇裡專屬討論區：http://www.avsforum.com/avs-vb/show...=795421&page=12

雖然是Onkyo TX-SR705的專屬討論區但是有很多有用的AV擴大機資訊http://www.avsforum.com/avs-vb/showthread.php?t=935808

paneraiben · 發表於 2008-6-20 21:40:53

底下是原廠的人員回覆的一些設置建議： Chris
CTO, Audyssey Laboratories
音場分析麥克風擺設位置：
1.麥克風原始設計是用來設計蒐集反射音的，因此測量時麥克風一定要朝天花板（朝上），否則會收集到錯誤資訊。

2.原廠麥克風回饋是以符合工業用標準¼” instrumentation microphone收音為準，因此務必使用跟隨擴大機而來的麥克風、不要使用其他形式麥克風，以免影響測量結果！

3.很重要的一點：當在測量時麥克風務必架在三角架上高度約與耳齊，不可以手持麥克風！因為手持時會產生一些低頻收音，導致MultEQ濾波器為了補償而將將這些低頻濾掉！另外也不建議將麥克風放在沙發背上或者是靠枕上，若是使用腳架時務必注意麥克風高度應該稍高於椅背上、如此一來才不會收集到椅背的反射音，導致高頻部份產生問題。

4.第一個麥克風位置是用來測量喇叭距離位置、並調整延遲時間用的。也用來設定修飾音頻。因此很重要的就是第一個測量位置務必放置在您主要視聽位置（原來的皇帝位）。

5.MultEQ在從每個喇叭播放測試頻率前、會先測量背景噪音level。為使測量有效、訊號與噪音比須達到某一門檻才會開始計算。如果沒有、各聲道喇叭輸出音量會提高一些再重複測量。如果在測量某一聲道時恰好背景噪音高一點，這時從該聲道輸出的測試訊號音量會提高一些。這並不會影響修飾音場計算後結果！如果背景噪音實在太大、即使提高測試訊號音量後亦如此，這時會顯示錯誤訊訊息、並警告用家無法完成測量！

6.在第一個位置測量後、MultEQ會陸續測量其他視聽位，並不需要一定要剛好在那個視聽位置，理念是說希望多測試幾個視聽範圍的點、讓環境影響聲音品質不良的因素儘量減低。

7.例如我們建議您面對電視或投影機的主要三個位置分別測試、然後在這三位置前面12英呎平行處再測量三個位置，（譯者:這房間也未免太大吧）！正對背牆及側牆處應避免測量。

8. 有些喇叭在偏離其音軸時頻率響應曲線不是很理想，（例如偏離喇叭單體中心想像垂直軸到聆聽者耳朵直線15度）在這些系統中如果測量點太偏離音軸中心點、因為高頻量感不足測量出來結果會導致修正補償過多，致使音場聽起來太亮！雖然很難預測說哪些喇叭有這樣問題，但是我們常觀察到多是一些設計不良、多單體排列在偏軸時有很高的頻率陡降現象。在這樣狀況時、我們建議您儘量麥克風測量位置應該離皇帝位緊密一些、不要分散太開影響測量結果！

paneraiben · 發表於 2008-6-20 21:41:58

檢查測量結果
1一旦MultEQ計測結果完成、資料會儲存在AV擴大機記憶體中

2.很重要的一點、視聽使用啟動MultEQ時一定要用家選擇一種調整曲線（原始設定計測完畢不會自動執行、須由用家去選擇響應頻率調整曲線）。在THX系統中我們建議您使用”FLAT”設定檔，這樣會讓會讓【頻率響應再調整】動作（原本設計用意即如此）。在其他系統裡我們建議“Audyssey”檔用來播放電影， “Flat”檔用來聽音樂。但是因為音樂工業中混音系統並沒像電影工業有一定規格標準，所以可能某些音樂可能在“Audyssey”設定時反而比較好聽！“Front Align”檔設定也會使用Audyssey流程，但是他並未在正面前兩聲道使用FILTER（譯者:應該就是未加料處理的意思）。“Manual”檔並非“Audyssey”設定所以並未使用MultEQ filters。就只是一般EQ調整、所以也會受限於EQ調整的限制。

3.小或大喇叭設定：這是最常被MultEQ使用者討論的問題。首先要了解的是如果您的系統喇叭被偵測為”小”時，這並非對您的系統一種侮辱！這只是代表說在您的房間裡在80HZ頻率或以上偵測到為– 3 dB。即使喇叭廠家宣稱他們能重播更低頻率、這樣狀況仍偶而會發生。事實上將80HZ以下頻率轉移到重低音去負責，對POWER的控制與低頻餘裕來說也是好處。

4.第二個最常問到問題也是跟大小有關：在Denon擴大機裡MultEQ設計為任何喇叭在80HZ或以下能測量到–3 dB便會顯示為“Large”喇叭。對非THX認證的喇叭系統這常是隨意的定義、常引起混淆！他所要代表的意義就是這些喇叭不會處理低頻部份、除非用家指定要將低頻送給這些喇叭處理。由於Audyssey並未有低頻管理、我們必須遵照擴大機廠家的規範，只是將偵測所得資料送給低頻管理系統去處理。

5.如果系統喇叭無法在80HZ以下表現的很好、一定要採取額外步驟以確保測量時低頻訊息沒有喪失，那就是用家必須手動設定喇叭為小。

6.喇叭極性問題：MultEQ會偵測每隻喇叭的絕對極性並回報用家。這只是回報訊息、並不影響後續的運算過程。只是要求用家檢查喇叭正負端是否連接正確。有時候我們會得到假警報，這通常是因為喇叭有個單體（常是中音單體）為了補償分音部分線路而故意接反相造成！如果有相位警示燈亮起只要檢查接線沒問題的話、按一下“Skip”。再提醒一次這些不會對EQ調整運算結果產生影響。

7.重低音距離：在許多主動式重低音喇叭無法取消低通濾波（low-pass filtering），也就是說影音前級的低頻管理系統濾波器位階會在重低音喇叭濾波之上。擴大機內建的低通濾波會對進來信號產生延遲信號、這個延遲信號在MultEQ以acoustical delay顯示。這就是為什麼有時候測量出來的重低音距離比實際位置要遠，這個偵測到的設定不要改變，因為要將衛星喇叭與重低音音場混合設計便是依據這個數據。

8.The design constraints for MultEQ were that it (1) must fit within a small portion of the DSP so that other processes can also run and (2) it must use FIR filters because of the well-known artifacts that IIR filters cause particularly in the time domain response. As it turns out, these two requirements are contradicting. In order for FIR filters to be effective and capable of correcting to low frequencies, they must consist of several thousand coefficients (taps). The problem is that the CPU power required increases with the number of taps, hence the dilemma. What we did at Audyssey was to come up with a different way to partition the frequency axis so that we can use fewer taps and yet not completely give up on low frequency resolution (and therefore low frequency correction). This allows us to take a 512 tap filter that would normally have a resolution of 94 Hz (meaning that any peak or dip narrower than 94 Hz would be missed) and significantly improve its resolving power. The resolution of the filter actually varies continuously with frequency and starts at around 10 Hz. Does this mean that MultEQ can correct an arbitrarily narrow peak or dip at 30 Hz? Of course not. The reality is that in the MultEQ XT version found in receivers, we can correct broader features below 100 Hz better than narrow ones. For example, a lump that is half an octave wide at 50 Hz can be fixed. A narrow dip or peak that is 1/3 or 1/6 octaves wide and centered at 30 Hz will be improved, but not eliminated.
(以上晶片技術問題原文照登~~~)

9.擴大機的螢幕顯示內容圖形有限，因此不能真正顯示出MultEQ改正濾波、真實運算後各頻段情形。顯示出來的可能只像傳統EQ九頻段，實際狀況絕不止於此！所以不要用這數據來判讀真實放大或切除頻率情形。

10.由於介面跟記憶體關係、重低音濾波並未加入顯示！這並不代表沒有重低音修正！

paneraiben · 發表於 2008-6-20 21:43:50

AUDYSSEY/SETUP FAQ:
This section was written by Jeremy Anderson
You can access the original post at this link: http://www.avsforum.com/avs-vb/showp...&postcount=151

1.我該如何安排我的喇叭，或者房間處理?
房間要處理到哪種程度，由個人決定，要點就是儘量讓房間頻率響應與喇叭位置達到理想位置讓MultEQ XT一開始能有個比較好的起始點去測量。但這並不一定要你去做許多處理像低頻陷阱之類。.有幾件事要注意是：
A)如果你的主聲道喇叭放置離視聽位置很遠、可能你需要將喇叭稍微tow in。一個經驗法則就是想像你的兩邊高音體中心點幅射出一個80度或90度的錐狀音場兩邊錐狀音場覆蓋整個你的視聽位置。每種喇叭覆蓋擴散範圍不同、有時候或許偏軸效應不同你得到較好或較差效果，至少是好的開始。
B)就像撞球一樣、高音單體指向側牆反射直線到你耳朵、如果在側牆的反射點是硬表面的話、可以掛畫或是布來打亂這個反射面，這樣做可以讓你聽到更多直接音，而不會讓音場混濁，讓喇叭TOE IN一些也有這樣效果！
C)如果中央聲道放置位置低於你的耳朵一英呎以上、請將中央聲道上仰一些、讓高音單體對準你，這樣可以讓對白更清楚，Audyssey在作等化時比較能夠得到好結果。
D)如果您將重低音放在牆角、請嘗試將重低音搬離各牆面至少幾英吋的地方。如果你放的位置比較在房間中間位置，嘗試離開前蘠幾英吋並設法放在大約房間寬度1/3處遠離側牆。如此一來可以避免重低音因為駐波關係在設定時被抵消。
E)如果您的視聽位置離背牆很近、嘗試坐前面一些。坐的離牆壁太近會讓你重低音效果增益太多、導致沒有EQ可以針對你的背牆反射做修正。
2.我需要三腳架來執行MultEQ XT測試嗎?
是的沒有例外！把麥克風放在座位上不僅改變了偵測喇叭距離，也會影響Audyssey做EQ修正的正確性。用手拿著麥克風會會產生噪音(呼吸聲或移動聲) 由於手持麥克風破壞了低頻的EQ修正，通常會導致收音混淆，因為你的身體在麥克風後面。唯一正確執行音場修正方式就是將麥克風固定在三角架上、攝影器材行應該都可以找到簡單幾百元的腳架。
3.我該如放置麥克風以便執行MultEQ XT測試?
一但將麥克風裝在腳架上應該將麥克風高度提高到略高於椅子靠枕上方，以免椅背產生影響到測量，理想上麥克風應放在你的耳朵附近，如果這位置太靠近後牆那應該把麥克風往前移至少12~18英吋這就是執行MultEQ XT.的第一個位置。
第二個測量位置應該在你第一個位置右前方至少三英呎處，一樣麥克風高度應略高於椅背。
第三個位置則在你的左前方三英呎處
第四到第第八測量位置就完全由您現場安排座位而定。第四到第六個位置儘可能做到是第一到第三位置的鏡像位置但是更深入房中央三英呎處。這樣可以讓MultEQ XT更清楚知道您的重低音如何從您的房間週遭牆壁反射，而得到一個更平衡的重低音反應。
4.當MultEQ XT測量時我應該呆在房間內嗎?
MultEQ XT會測量並平衡房間頻率響應，如果你在房間裡面、並且每次測量時你都不在同一個位置上，你的存在是會影響聲音反應的。理想上是你架設好麥克風、走出房外利用遙控器案下測量數值，然後回到房內只改變麥克風位置重複上述動作。

5.ONKYO 705上面使用的Audyssey 調整曲線是什麼?
Audyssey產品提供三種調整曲線：Flat、Front、跟Audyssey。Front曲線在Onkyo環繞擴大機上並沒有。Audyssey曲線是705型號的預設曲線，這區線讓高頻部分衰減一些、確保你聽到比較多直接音，而非房間牆壁反射音。Flat曲線並未使用高頻段衰減。在705上改變聆聽模式到任何THX模式下也會讓MultEQ XT曲線變成Flat。因此THX模式的高頻衰減不會覆蓋Audyssey's的衰減。
不幸的是在ONKYO收音擴大機上無法手動去選擇調整曲線，不像其他廠牌的可以。一個小訣竅可以讓擴大機進入FLAT模式就是”先進入THX模式然後按下RE-EQ按鈕讓THX的衰減關閉”。但是因為只要電源一關、這設定便消失。所以如果你要用FLAT模式時便得如此再做一次！
6.為什麼Audyssey's重低音測的距離與實際距離不同?

Audyssey所測量的是acoustic distance而不是實際距離。這個數據可以受到幾個因素影響:
例如重低音的分頻點控制（譯者：就是幾赫茲以下送給重低音處理）會產生延遲、因此會改變acoustic distance。.將重低音或者麥克風放在牆角也會改變acoustic distance。最主要因素是重低音的相位！重低音距離設定數值、其作用有點像是可變相位控制一樣，Audyssey使用這個數值來確保重低音與其他喇叭相位相符。（也就是來自重低音聲音與其他喇叭聲音同時到達聆聽者位置）我們不建議您更改這數值！然而你可以嘗試改變上述幾個因素然後在重新測量一次，看看數值是不是跟實際距離比較接近！

7.Audyssey偵測出我的喇叭都是大、全頻段，我應該就讓它這樣嗎?
ONKYO裝置的Audyssey MultEQ XT有一個眾所皆知的問題就是：即使是書架型喇叭，只要60HZ以下的門檻有一定音壓強度，擴大機都偵測喇叭為大型喇叭！我們建議是除非你的喇叭在至少35HZ以下時輸出音壓能有－3db水準，不然不要讓它設為大型喇叭、應該手動改為小。

paneraiben · 發表於 2008-6-20 21:44:28

8.我該如何設定我的喇叭分頻點 (幾HZ下給重低音負責)?
分頻點是一個把聲音逐漸從喇叭轉移到重低音的裝置，意思是需要一點餘裕空間好讓這轉移逐漸進行。有一個好準則就是看看你的喇叭頻率響應曲線，看看他最低工作頻率是多少、或者是再哪一個頻率點輸出音壓掉到－3db，找出這個點然後再加上20HZ把這數值當作重低音分頻點。

原文如下

A good guideline is to look up the frequency response of your speaker and find its lowest frequency (or the point where it drops off -3dB), then add about 20Hz to that to use as the crossover setting. That said, the crossover's slope (i.e. how quickly it transitions) is pretty steep, so you might be able to get away with adding as little as 10Hz to your speaker's lowest reproduceable frequency. Start with 20, then tweak to preference to get the best transition.
9.我應該改變Audyssey所測的喇叭距離嗎?
Audyssey似乎可以偵測喇叭距離與實際距離相當接近，但有些人仍認為這不是喇叭中間音像最佳設定。你可以用Digital Video Essentials測試碟中一系列測試音（這些測試音音場都是在喇叭正中央），一次改變設定距離約半英呎慢慢感覺音場聚集在中央（意即在這樣設定下喇叭相位正確）。如果聲音變得越分散或者難以聚焦，那表示改變距離設定後讓喇叭與其他喇叭相位不正確了。
While Audyssey does seem to properly detect speaker distances close to their actual physical distances, some have found that this is not the best setting for between-speaker imaging. The calibration disc has a series of test tones that are placed equally between channels. Using these tones, you can tweak speaker distance a half-foot up and down to listen for the setting that makes the sound "hang" in space between the speakers (which means it is in phase at that setting). If the sound becomes more diffuse or harder to pinpoint, it is because changing the setting is putting it out of phase with the other speaker.
要改變喇叭距離設定、面對前牆依照下列步驟去做：
A)在前左聲道與中央聲道播放特定頻率測試音、然後一點點慢慢改變設定值前後移動中央聲道、看看是否在某距離設定時、讓你感覺聲音更聚焦在兩支喇叭中間！然後在前右聲道與中央聲道重複這動作，選擇一個讓兩邊聲道聽起來最佳的設定值作為中央聲道距離設定值。
B)在右前聲道與右環繞聲道中間播放測試音頻，然後上下調節右環繞喇叭距離，找出側牆喇叭距離的最佳位置，因為環繞聲道位置通常高於主聲道喇叭、或許無法找到一個完美的設定，但你應該可以找到一個從側方向來較佳的音場位置！
C)重複B)的動作在左環繞部份，如果你只有5.1配置、那到這裡你就完成設定了
D)For 6.1/7.1 setups, put your receiver into DPL-IIx Movie mode and play the tone between the right surround and the rear surround (since DVE only has 6.1 tones), or change DVE to the DTS track and use DTS-ES Matrix mode, then bump right rear surround distance up and down slightly until you hear solid placement of the sound between the two. Then repeat using the tone between left surround and rear surround, changing the distance setting for the left rear surround. If you only have 6.1, bump your rear up and down to listen for the setting that works best with both tones.

10.為什麼重低音的峰值切削設定如此低?
一個人們常犯的錯誤是把重低音的增益或音量調太高了、如此一來重低音的哼聲與躁聲被放大了。如果Audyssey把subwoofer trim設定的很低、請嘗試將重低音的增益或音量降低然後再測一次！或者你也可以用SPL meter檢查一次、這樣你就不用Audyssey流程重跑一次。理想上subwoofer trim儘可能接近0、而此時你的重低音gain在其最大1/3處！

11.為什麼我的所有聲道TRIM值都很低?
Audyssey試圖讓所有喇叭在你的擴大機相對音量值調在0時、你聽到是參考播放音量值reference playback level(也就是說你的喇叭此時音壓105db，重低音音壓115db)但是因為各廠喇叭效率不同，這些音壓強度會因為喇叭廠牌、房間音響效應、等等因素而改變。如果你不在乎0是參考播放音壓或者是你用絕對音量讀數、那你可以把所有聲道值等量提高到接近0如果你喜歡地話。然而因為ONKYO 705的最大音量值是決定於你所設定的maximum channel trim，如果你設定highest channel trim +2、那最大音量會從相對音量+18減到+16。因此你不會因此從擴大機得到額外輸出音量！很多人可能注意到Audyssey設定TRIM值低約2-3dB來達到reference level at 0。你可用SPL meter再測一次調整各聲道道音壓值到75db。

paneraiben · 發表於 2008-6-20 21:44:51

12. Audyssey在測量時冷氣突然打開、小狗叫了一下、或出現躁音我得重新測量嗎?
原文大意指的是最好在安靜環境下來測量、把冷氣關了、小狗抱出去、再開始測量！

13.Audyssey MultEQ XT到底在做些什麼?

MultEQ XT讀取數百個數據來測量你房間的頻率響應特性、把這些數據運算後然後加上一個反向濾波，也就是說它偵測到某個頻段有峰值他會使用反向濾波去消除這個峰值，反向亦然某頻段有凹陷他便做一個放大動作。如此一來讓你的房間達到一個比較平坦的頻率響應曲線！
對重低音部分來說，他希望你聽到的是重低音的第一次直接音、而非低音自房間反射回來的音波！（就是一般人所說的緊實的低頻）這就是為什麼偵測麥克風放置位置如此重要的原因！
此外MultEQ XT分析一大片區域，然後把每個位置的數值運算後加上反向濾波，如此一來確保你的每個視聽位置都可以聽到一般相同的聲音。

For more information, see www.audyssey.com

16.我需要每個訊源都做一次Audyssey MultEQ XT分析嗎?
只需要做一次便夠了、他測的是喇叭的表現而非訊源所以一次就可以。

17.如果測出來的低頻分頻點是80HZ而我的喇叭設定分頻點是高於這值、這中間的聲音會不見嗎?

低頻分頻點只影響重低音輸出聲道(the .1) 不是整體聲音
The 705 defaults to the THX LFE cutoff of 80Hz and Audyssey doesn't adjust that setting. However, the LFE channel by its very nature is brickwall filtered during encoding at 120Hz. If you want to accurately reproduce the entire LFE channel, set LFE cutoff to 120Hz. However, few sound mixes have audio above 80Hz in the LFE channel, which is why THX recommends the 80Hz cutoff. Also, because the LFE channel receives a +10dB boost during decoding, the THX recommended 80Hz cutoff is there to reduce the chance of humming/noise above 80Hz from the LFE channel. Chances are that you will not notice a significant difference, if any, by changing LFE cutoff from its default of 80Hz, but doing so has no effect on the bass redirected from the other channels

17. 雖然我很小心的擺放麥克風及處理我的房間、我還是不喜歡Audyssey平衡後的聲音，我可以改變它嗎?
這是你的系統、你的耳朵、你是要感到滿意的人！如果你不喜歡就改變數值設定！
我門必須針對不同廠牌擴大機喇叭等等來做考量、一個習慣於聽清亮音色的人乍聽中性真實的聲音可能會不喜歡，雖然說這是比較正確聲音！而一位習於搖滾低頻者、可能會覺得調整後低頻量感不足！我們建議您不管系統改變還是Audyssey調整後的聲音、給自己個幾天時間、聽你所習慣聽的各式音樂或電影（或許乍聽之下低音好像不足、但是深入聆賞後發現其實低音音符變的比較清楚）然後評估优缺點！如果幾天後你還是不滿意、當然可以改變它！
If anyone can think of any other setup/Audyssey questions to address, let me know. (Please forward all comments pertaining to this section to Jeremy Anderson)

貼完~~多謝觀賞~敬請指教
有些比較技術性的東西怕自己翻譯把原意給弄錯了~~
所以原文照登比較好~~
主要還是希望用家能多提出使用心得
做出屬於台灣劇院調挍數值~~
謝謝~~

fly · 發表於 2008-6-22 16:47:06

雖然目前沒有次世代擴大機
但是先認識功能總是好的。
感謝大大的翻譯。

wil-wil · 發表於 2008-11-27 21:49:40

Audyssey Setup – One Step at a Time (轉載)
http://www.avsforum.com/avs-vb/showthread.php?p=14456895#post14456895

The below step-by-step instructions are based on information collected from the Audyssey FAQ, located here:
http://www.audyssey.com/faq/index.html and the AVS Forum Official Audyssey thread, located here: http://www.avsforum.com/avs-vb/showthread.php?t=795421

Disclaimer:
The following procedures may not work in all cases, as there are too many variables to account for in this document.
If you feel further assistance is required, please visit the AVS Forum Official Audyssey thread, linked above.

I.Room Setup
Lower the noise floor of the room (<45dBA) by turning off the HVAC system, projector, etc.

II.Microphone Setup
A. Use the microphone that came with the unit.
1. Use of a different microphone will cause incorrect frequency response measurements because of different internal calibration.

B. If you feel the urge to use another microphone, re-read section A.

C. Mount the microphone on a tripod.

D. Point the microphone at the ceiling.

E. Place the microphone at ear height when seated.

F. If the seat back is higher than your head, ensure the microphone is above the seat back.
1. If the seat back is a few inches behind the microphone, this will cause additional reflections.

G.Place the microphone in the primary listening position for the first measurement.
1. Audyssey uses this measurement to set the speaker distances and levels, so the microphone should be placed in the seating position used the most.

wil-wil · 發表於 2008-11-27 22:00:10

III.Subwoofer Setup
A. Determine the optimal placement of the subwoofer within your room using common accepted practices. (location, location, location)
   1. Here are some useful references for subwoofer setup:
         a. Audioholics subwoofer placement article:
         http://www.audioholics.com/tweaks/get-good-bass/subwoofer-placement-the-place-for-bass-part-1
      b. Harman multiple subwoofer placement white paper:
         http://www.harman.com/wp/pdf/multsubs.pdf

B. Disable the Low-Pass Filter (LPF) on the subwoofer, if allowed.
   1. Disabling the LPF will result in more accurate subwoofer distance measurements.
   2. If the LPF cannot be disabled, set it to the highest frequency allowed.

C. Ensure the subwoofer(s) are at least 3 – 5 inches (7 – 13 cm) from the wall.
   1. Reverberating walls may result in inaccurate subwoofer distance measurements.

D. Set the subwoofer polarization (0 or 180 degrees) using common accepted practices.
   1. If you have two subwoofers, ensure their polarization settings are the same.

E. If the subwoofer has a phase control (in addition to the polarization control), set it at “0”
   1. Phase controls on subwoofers apply "delay" at one frequency rather than the needed group delay that is frequency independent.
      So, it is best to just leave them at “0”.

F. If the sub has an EQ system, use it to tame large peaks before calibrating with Audyssey.
1. Narrow peaks or dips in the response below 100 Hz that are 1/3 or 1/6 of an octave wide can be improved—but not eliminated—by Audyssey Mult EQ XT.
      a. In these situations, the built-in subwoofer EQ systems might be useful.
2. Velodyne’s SMS and JL Audio’s ARO are two examples of EQ systems.

G. Calibrate the subwoofer volume
1. Set the volume control on the subwoofer at the middle of the adjustment range allowed.
      a. Please note this “starting point” may not work with all subwoofers.
2. Place the microphone at the primary listening position (the center of the listening area) and run through the calibration process for the first measurement
      —until all speakers have been measured once.
3. After the first measurement process is complete, select "Calculate", then "Save" or "Store", then go to "Check Parameters".
      a. Audyssey will calculate the speaker distances and trim levels from this first measurement.
      b. Each manufacturer has a slightly different interface, so the terminology may not exactly match.
4. Check the subwoofer trim levels in the receiver / processor menu.
      a. If the subwoofers trim level is at the maximum limit of the cut or boost adjustment range allowed, you need to adjust the volume control on the subwoofer
         and repeat step #2. Specific instructions will follow.
      b. For example, Denon receivers have a trim adjustment range from -12dB to +12dB.
      c. Trim adjustments are a tool used to achieve the goal of producing a specific SPL from each speaker / subwoofer when the system is played
         at reference level.
5. If the subwoofer trim level is at the maximum boost, turn up the subwoofer volume a bit and repeat step #2
6. If the subwoofer trim level is at the maximum cut, turn down the subwoofer volume a bit and repeat step #2
7. A suggestion for tweakers is to set the subwoofer trim level in the range of ±3 dB.
      a. This is only a suggestion for the tweaker who likes to play around.
      b. Audyssey’s position is to perform steps 4 to 6 above.

Note:
This process is for checking the trim levels only.
After you have completed the subwoofer setup, be sure to start the measurement process over, following the guidance in section V to use all six or
eight measurement positions available.

wil-wil · 發表於 2008-11-27 22:05:33

IV. Dual mono (LFE) Subwoofer Setup
A. Place the subwoofers symmetrically within the room, if at all possible.

B. Place the subwoofers at identical distances from the primary listening position, if at all possible.
1. When two subwoofers are driven as one unit, proper time alignment is critical.
2. The two subwoofers will not be properly time aligned unless they have the same physical distance from the primary listening position.
3. Adjusting the physical distance of the two subs effectively adjusts their time delay.

C. The above advice applies only to sealed rectangular rooms without any openings.

D. As an alternative to locating the subs at equal distances from the main listening position, you may insert an electronic device between the receiver /
processor and the nearest subwoofer.
1. This device should introduce a time delay such that its output sound reaches the main listening position at the same time as the farthest subwoofer.

E. Attempt to match the output level of both subwoofers.
1. Play the receiver / processor internal LFE test tone while adjusting the volume control on the subwoofer.
2. Turn on one subwoofer and adjust the output level using an SPL meter to 80 decibels.
a. If you do not have an SPL meter, adjust the level by ear.
3. Turn off the first subwoofer, turn on the second subwoofer, and repeat the procedure.
4. Turn on both subwoofers and calibrate with Audyssey.

F. Follow the steps in subwoofer setup (above) for each subwoofer.

wil-wil · 發表於 2008-11-27 22:11:45

V. Microphone Placement (Measurement Positions)

Use the maximum amount of measurement positions allowed by the Audyssey version.
- If you are using MultEQ or MultEQ XT you should use all six or eight measurement positions available.
Avoid taking measurements too far off to the side and/or outside the front Left and Right loudspeakers, even if seats are located there.
- Frequency response in these locations will exhibit reduced high frequencies.
- Audyssey would adjust the room correction filters according to this measured response, resulting in unnecessary compensation.
Avoid taking measurements too close to the back wall, even if the only seating is located there.
- Move the microphone at least 1 foot (30 cm) from the back wall before measuring.
Audyssey uses the first measurement point to calculate the distances of each speaker and subwoofer.
Distance measurements are really time measurements that ensure temporal coherence.
It is a critical part of calibration because—without it—you have frequencies arriving at different times:
This is called non-constant
group delay, and is a form of distortion.
The distances are calculated so the sounds from all speakers and subwoofers arrive at the first measurement position at the same time.
When calibrating only a primary listening position, use the following placement methodology:
- The first microphone position (#1) must always be in the center of the listening area.
- For measurement #2, move the microphone two feet (60cm) to the left of position #1.
- For measurement #3, move the microphone two feet (60cm) to the right of position #1
- For measurement #4, move the microphone two feet (60cm) forward of position #1.
- For measurement #5, move the microphone two feet (60cm) forward of position #2.
- For measurement #6, move the microphone two feet (60cm) forward of position #3.
- For measurement #7, move the microphone one foot (30cm) to the left of position #1, and one foot (30cm) forward of the line formed by measurements #1, #2, and #3.
- For measurement #8, move the microphone one foot (30cm) to the right of position #1, and one foot (30cm) forward of the line formed by measurements #1, #2, and #3.
Here is a visualization of eight measurements surrounding the primary listening position.
- The first microphone position (#1) is where the silhouette of the head is located.
- After the first measurement, the order in which you make the measurements does not matter.
  The order in the steps above only serves to ensure each location is measured.
- The below diagram shows the optimum microphone placement for a typical living room.
  In general, Audyssey does not recommend putting the microphone in "every seat", except in a dedicated theater with seat rows.

In typical living rooms, placing the microphone in every seat will not give you the best results because the seats can be off axis or close to the wall.
Audyssey recommends following a pattern close to what is in the diagram even if you only have one listening position.
The most common problem with EQ systems is that they base their data collection on a single point in the room and that usually results in very poor performance.

[ 本帖最後由 wil-wil 於 2008-11-27 22:14 編輯 ]

wil-wil · 發表於 2008-11-27 22:15:33

VI. During Calibration
A. Do not make any sudden noises during the “chirp” measurements.
   1. Audyssey measures for a few milliseconds (ms) after each “chirp” is finished, but then has to wait for the DSP to calculate,
      so the microphone is not active until a few ms before the next set of chirps.

B. Do not stand in between the speaker and the microphone or anywhere that the sound is either reflected off of you or absorbed by you.
1. The natural room acoustics must not be substantially affected.

C. Be prepared for the “chirp” measurements, as they are quite loud, and can startle you.

D. If a phase warning is shown, check the speaker wiring, and press “Skip” to continue with the calibration.

VII. After Calibration
A. Raise the speaker crossover settings, if desired.
   1. Raising the crossover frequency from the calibrated setting does not affect the channel correction implemented by Audyssey.
2. Lowering the crossover frequency from the calibrated setting is not recommended.
      a. Audyssey will not provide correction to the satellite speakers lower than the frequency it measures as the -3 dB point.
3. Setting the speakers to “Small” with a 60 Hz – 80 Hz crossover is a good starting point, assuming the calibrated crossover setting is 60 Hz or lower.
4. For additional details about the speaker setting process, see “Note 1” below.

B. Raise the low-pass filter setting (usually incorrectly identified as a crossover) of the LFE subwoofer in the receiver / processor to 120Hz, if allowed.

C. If the satellite speaker distance settings (excluding the subwoofer) were not measured accurately, and are markedly different from what you get with
   a tape measure, start all over.
   1. Incorrect distance measurements for the satellite speakers indicate a procedural error, and the associated EQ results are likely to be poor.

D. Do not change the distance setting of the subwoofer.
   1. Inaccurate subwoofer distance settings are the result of measured delays between the time when the receiver outputs the test tone and
      it is received at the microphone.
      a. Any filters and/or active circuitry in subwoofers can delay this signal.
      b. Audyssey simply measures the time delay and compensates for differences in the arrival time of sound from the various speakers and the subwoofer.
         It is best to compensate for these differences regardless of why they occur.
2. The subwoofer / satellite speaker time alignment blend is based on this measurement.
3. Inaccurate subwoofer distance measurements usually occur when the subwoofer’s Low-Pass Filter (LPF) is not disabled.
      a. The LPF, by nature of its design, introduces additional delay to the signal; Audyssey detects and corrects for this delay.

E. Disable any Night Modes, DRC (Dynamic Range Compression), and D. Comp (Dynamic Compression) in the receiver /
processor as well as the DVD / BD player.
1. If these features are not disabled, they could possibly cause adverse interaction with Dynamic EQ and Dynamic Volume.
2. You may need to temporarily turn off MultEQ to access these parameters in your receiver / processor.
3. You may also need to select a specific soundtrack type before a given parameter will appear in the menu for adjustment; check the manual to be certain.

F. If your receiver / processor has the THX Loudness Plus feature, turn it off if you plan to use Dynamic Volume.

G. Select one of the target curves created by Audyssey.
1. In a THX system, the “Flat” curve should be used when THX post-processing is on, and the “Reference” curve should be used
      when THX post-processing is off.
2. In other systems, the “Audyssey” curve should be used for listening to movies, and the “Flat” curve should be used for listening to music.

H. If desired, trim adjustments can be made in the receiver / processor, so that all speakers measure at 75 dB with an SPL meter (set at “C” and “Slow”)
   using the internal test tones. See “Note 2” below.
1. Audyssey will monitor these changes.
2. The changes are monitored so that Audyssey and its features (Room correction curves, Dynamic EQ and Dynamic Volume, etc.) work as designed.
3. If you were to make changes to the settings on a subwoofer, Audyssey would have no knowledge of this, and those features would not operate as designed.

[ 本帖最後由 wil-wil 於 2008-11-27 22:27 編輯 ]

wil-wil · 發表於 2008-11-27 22:27:36

Note 1:
Audyssey does not set the crossovers; it simply measures the -3dB frequency point of each speaker.
This information is passed to the receiver / processor for calculation of the speaker settings and crossover points, if applicable.
Unfortunately, Audyssey does not report the -3dB frequency point measured for each speaker.
The only information available to you is whether or not the speaker was designated “Large” or “Small”, and any crossover point selected for “Small” speakers.

Receiver / processor manufacturers use a specific Frequency Decision Point (FDP) to classify speakers as “Large” (full-range) or “Small” (less than full-range).
The selection of the FDP varies among manufacturers, and may be 40 Hz, 80 Hz, or another frequency.
If the -3 dB frequency measured by Audyssey is below the FDP, the speaker is classified as “Large’.
If the -3 dB frequency measured by Audyssey is above the FDP, the speaker is classified as “Small”, and a crossover frequency is selected.

Each receiver / processor has various crossover points from which to choose.
Typically, the first crossover setting above the -3 dB point measured by Audyssey is chosen.

For example: If your receiver has crossover settings of 40, 60, 80, 100 and 120 Hz, and the speaker is set to “Small” with an 80 Hz crossover,
that is an indication the - 3dB point is somewhere between 60 and 80 Hz.