Fast Layer 3 EQ cuts high frequencies ?

[Pat83]

Does the intern "Fast Layer 3 EQ" cut frequencies above 16kHz?
I've read many different opinions about this. Does someone know this for sure? I'm using Winamp 2.91. Thanks

[Sawg]

Winamp 2.91 is not supported, please upgrade to Winamp 5.53

Fast Layer 3 EQ is meant to be fast (by taking advantage of how MP3s are encoded) and not good.

[Pat83]

Thanks, but I didn't want to know if it's good or bad.
I just wanted to know if it cuts the high frequencies above 16kHz?

I've downloaded Winamp 5.53 and it has the "Fast Layer 3 EQ" too. Does it cut or not?

[Rocker]

does it matter? most people can't hear over 16kHz anyway.

if you were after sound quality you wouldn't be using mp3 at all.


we don't use fast layer 3 anymore by default because it is bad and inaccurate.

it was common back in the day to run a high pass filter before encoding(so the encoder didn't waste bandwidth on what you can't hear)

[Pat83]

So it's true. The "Fast Layer 3 EQ" actually does cut high frequencies.

(btw,I can hear over 20kHz. I did various listening tests.)

[Pat83]

Here in the Winamp forums I've read:
"I prefer the standard equalizer (Fast Layer 3 checked), it seems that equalize the sound correctly, exactly the way i adjusted the equalizer.
The musics i tested were genre House, Trance and Rock. I hear difference in bass and treble, the treble is more clear, seems less distortion, the bass is stronger, with "Fast Layer 3 EQ" option checked."

In Hydrogenaudio forums I've read quotes like this:
"The fast layer 3 EQ also had, reportedly, good quality. No need to turn it off. Only the generic EQ was crappy."

So whats the truth? FL3EQ isn't bad at all?

I've done some tests.
I've come to the conclusion that "Fast Layer 3 EQ" doesn't cut high frequencies.
I can hear Test tones like 18kHz - 20kHz with FL3EQ on. If FL3EQ would cut, I wouldn't be able to hear them. Right?

[Pat83]

I promise it's my last post about this topic.
I made further tests. I used different mp3 test tones and udial.mp3 @ 320kbps.

Results:
15kHz test tones @ 44100kHz & 48000khz
FL3EQ = fine
4Front = fine
No EQ = fine

16kHz test tones @ 44100kHz & 48000khz
FL3EQ = fine
4Front = fine
No EQ = fine

18kHz test tones @ 44100kHz & 48000khz
FL3EQ = distorted
4Front = fine
No EQ = fine

20kHz test tones @ 44100kHz & 48000khz
FL3EQ = distorted
4Front = fine
No EQ = fine

udial.mp3
FL3EQ = distorted
4Front = fine
No EQ = fine

"Fast Layer 3 EQ" definitely does cut high frequencies above 16kHz!!!


Test it for yourself:
Play this tones only at low volume! It can hurt your ears and speakers!

16kHz Test tone 48000kHz (Fine with FL3EQ & 4Front)
h**p://www.zshare.net/audio/10323014076a315d/

18kHz Test tone 48000kHz (Disorted with FL3EQ & fine with 4Front)
h**p://www.zshare.net/audio/103230474a0b6cc6/