*** 免費 *** 房間音響測試軟件

[是旦]

我朋友用呢隻
TrueRTA 3.2

聽講check完之後, 係用人手執執間房, 令到接收到既signal (20hz~20KHz)都係一樣

[Racingboy]

我朋友用呢隻
TrueRTA 3.2

聽講check完之後, 係用人手執執間房, 令到接收到既signal (20hz~20KHz)都係一樣

唔明 ？

[是旦]

我朋友用呢隻
TrueRTA 3.2

聽講check完之後, 係用人手執執間房, 令到接收到既signal (20hz~20KHz)都係一樣

唔明 ？

條curve邊段唔夠多, 就移燈換位, 吸下D高音, 反下D低音, 執靚條curve

[Romrom-100Fun]

[拓荒者]

[咖喱啡]

[Racingboy]

我朋友用呢隻
TrueRTA 3.2

聽講check完之後, 係用人手執執間房, 令到接收到既signal (20hz~20KHz)都係一樣

唔明 ？

條curve邊段唔夠多, 就移燈換位, 吸下D高音, 反下D低音, 執靚條curve

哦 ！即係同 LoFi 嗰啲軟件一樣！

[LoFi]

E 個軟件，已於２００５年１２月２２日 update 至 version 3.27 。

新軟件加入了不少新 feature ，包括可提供俗稱的 waterfall plot (cumulative spectral decay) （見下圖）。






Waterfall plot ，用於測試 room acoustics 時，聽講係可以 check 倒是否有大量不良的殘響。

In the early days of hi-fi, when two loudspeakers which "measured the same" sounded entirely different, the popular notion (even amongst early designers) was that loudspeaker measurements were completely meaningless ...

It was not until the late Richard Heyser ...

His great breakthroughs related to the effects of phase upon the sound of a loudspeaker ...

This brings us to the next important loudspeaker measurement which is called the Waterfall plot (or Cumulative Spectral Decay to scientists and engineers).

This plot displays how loud the speaker is at all frequencies ... at each instant in time.

These plots are shown one after each other, like cards in a deck.

The effect is like looking at a cliff face. The steeper the cliff the better.

When the sound system tries to play a note that suddenly stops, the sound does not suddenly stop.

The main effect is that sound echoes around the room for 1/3 second or so.

The loudspeaker enclosure walls, driver cone, etc. also continue to vibrate for a fraction of a second.

The waterfall plot shows the relative frequency response of this lingering sound, as it decays. Room resonances persist the longest. ...

Why do we care about any of this?

For two reasons:

(1) the change in the shape of the frequency response of the decaying sound adds coloration not present in the original music, and

(2) resonances at the higher frequencies can also affect the transient response.

An ideal waterfall plot would show a sequence of curves that are all smooth and flat across the frequency band, and that drop uniformly in amplitude to near zero in 1/3 second or so.

A more rapid decay at higher frequencies may be preferable for good transient response.

The waterfall plot is useful in identifying unwanted resonances, and sometimes something can be done to eliminate or reduce them. ...

Arthur C Ludwig Sr 係邊個 ?

... Now retired, I have had a very enjoyable 35-year career working at the NASA Jet Propulsion Lab (during the Apollo era),

as a visiting professor at the Technical University of Denmark,

and with a great group of engineers at Toyon, a small research firm in Santa Barbara.

My specialties are electromagnetics, signal processing, and systems engineering. ...

[1993]

[chowchow]

Lofi 大大

JPL

[tonyling]

[咖喱啡]

[藤原拓海]

不過都係唔識用

[lazy pig]

:a012:

不過都係唔識用

x 2

[Racingboy]

LoFi