調校分頻點一問。

chhanthony

如果係咁LFE中80-120hz會消失 : 係~最後 subwoofer 輸出最高係80Hz(LFE channel)
而唔會由主聲道去幫手 ...
bbsai 發表於 2011-3-15 18:27

bbsai兄

FYI

杜比數位的節目也許包括只含低頻資訊的LFE聲道， 但是這個聲道並不直接等同於超重低音揚聲器輸出。節目本身也許包含LFE聲道， 但是解碼器（ 功放） 可以不提供超重低音揚聲器輸出，這是因為所有的低音資訊（ 包括LFE聲道） 可以通過主揚聲器來還音。反過來同樣成立

http://en.wikipedia.org/wiki/Low-frequency_effects
source from http://en.wikipedia.org/wiki/Bass_management

相信係前文嘅英文版本
http://www.dolby.com/uploadedFil ... essional/38_LFE.pdf

Dolby Digital programs may include a bass-only LFE channel, but this channel
does not correspond directly to a subwoofer output. It is possible for a program to
contain an LFE channel, but a decoder may provide no subwoofer output because
all of the bass information in the program, including the LFE channel, can be
reproduced by the main speakers.

以上文中提及
如果唔用sub-woofer的話LFE會由主聲道處理,而唔會無O左LFE嘅訊號
如果以上說法係真, 我相信將LFE crossover set做80hz係唔會令到LFE中80-120hz頻段消失
而係交由主聲道處理

bbsai

bbsai兄

FYI




source from

相信係前文嘅英文版本




以上文中提及
如果唔用sub-woofer ...
chhanthony 發表於 2011-3-15 19:46

好有趣喎~~~
^^
意思係唔係無 subwoofer, 就會用 FL/FR 呢??

不過 LFE channel dts/dolby 有分別, dts 上限係80Hz, dolby 上限係120Hz.

bbsai

剛剛搵到有d料, 可能係 dolby 所講既嘢....

http://www.yamahaproaudio.com/do ... _papers/m2tb_en.pdf

page 16/74

Recording response
(media)

LFE: none or added to
L/R (<120Hz)

chhanthony

好有趣喎~~~
^^
意思係唔係無 subwoofer, 就會用 FL/FR 呢??

不過 LFE channel dts/dolby 有分別, dts  ...
bbsai 發表於 2011-3-15 20:03

see this interesting

http://www.dolby.com/uploadedFil ... el_Music_Mixing.pdf

4.4 Bass Management

Bass-management allows the user to redirect low-frequency information from any of
the five main speakers to the subwoofer. This is important since the five main
speakers in home theater systems (satellite/sub speaker arrangements) are typically
not designed to reproduce frequencies much below 80 Hz . Even though bass
management is not required when monitoring in a studio with full-range speakers and
a subwoofer, it is useful for checking how redirected low frequencies from any of the
main channels may interact with the LFE-channel information. Remember that the
consumer is likely to use some form of bass management, so proper bass management
is necessary to emulate a consumer home theater system.
Historically, the LFE channel for cinema applications has a range that extends up to
120 Hz. Some less expensive consumer receivers offer only a fixed bass-management
crossover frequency (often at 80 Hz) using one filter after the summation of the LFE
and the main channel information (see Figure 4-6). This results in a situation where
bass content between 120 and 80 Hz in the LFE channel is lost.

For this reason, it is recommended that the LFE channel be rolled off at 80 Hz during
5.1-channel music mixing.

The bass management feature on some consumer processors offers other
combinations of redirection. For example, when the consumer does not have a
subwoofer in the system, the LFE content can often be sent to the L and R main
speakers. The 5.1-channel music producer may want to monitor the effects of these
processes while still in the studio to ensure a desirable result.

Again, the goal in production and home playback is to hear all the bass accurately,
regardless of which speaker reproduces it. When using full-range speakers with good
bass response, there is theoretically no need for bass management, even when using a sub
for monitoring the LFE channel. However, the track should still be listened to at some
point with bass management engaged, to emulate what the consumer will hear at home.

kennyko

其實.....lx73可以係邊到set 分頻點呢? 我唔識搵....

ttkai322

想請教下，係 608 內set 80 話，佢顯示係 80(THX)，係咪即係d 喇叭要有 THX 先好用 80呢? thanks

Big_McIn

想請教下，係 608 內set 80 話，佢顯示係 80(THX)，係咪即係d 喇叭要有 THX 先好用 80呢? thanks ...
ttkai322 發表於 2011-3-16 16:14

唔一定要有THX，5聲道喇叭越細就越要以80Hz為起點，甚至90或100Hz。

但有THX認証又不是一定要set 80Hz，呢個只是標記。

ttkai322

唔一定要有THX，5聲道喇叭越細就越要以80Hz為起點，甚至90或100Hz。

但有THX認証又不是一定要set 80Hz， ...
Big_McIn 發表於 2011-3-16 16:31

明白，多謝指點

我最近set 呢點都set 到頭都爆...
都仲未去set db....

thundersnow

回復 45# kennyko


    Manual Setting 入面揀 SP setup

bbsai

唔一定要有THX，5聲道喇叭越細就越要以80Hz為起點，甚至90或100Hz。

但有THX認証又不是一定要set 80Hz， ...
Big_McIn 發表於 2011-3-16 16:31

同意~
早期THX standard 唔係80Hz的~