|
|
|
10-07-2019, 10:54 AM
|
#1
|
Human being with feelings
Join Date: Mar 2018
Posts: 24
|
why does previously limited wav overdrive when EQ adjusted down?
I outputted a mastered mix as a wav, and put it on my website. Listening on other devices, I felt it was too bassy.
For long-winded reasons, instead of remastering, I brought the wav into a new Reaper project. I applied two instances of TDR Nova to reduce the low frequencies (one was a steep HPF at a v low frequency, the other a gentle HPF higher up). The thing went over 0dBFS, to about +2.
I sacked Nova, and tried ReaEQ. Same thing, although with slightly lower overdrive values.
All I've done is reduce some frequencies.
Without the EQ plug-ins, the track peaks at 0, as I'd expect, given that I set it there before outputting in the first place.
Any thoughts?
|
|
|
10-07-2019, 11:20 AM
|
#2
|
Human being with feelings
Join Date: Sep 2008
Location: Calgary, AB, Canada
Posts: 6,551
|
Filters don't just roll off - there's a resonant peak at their cutoff frequency. For low Q values (shallow), this isn't noticeable and they behave exactly as you'd expect. As you increase the Q you start to get a little bump, and at very high (steep) values it can be a huge spike.
The good news is that you can just turn the mix down to fix it.
Side note: IMO you shouldn't limit to 0dbfs anyway, because various formats will add a bit of level when you encode them. MP3s are particularly bad - I played with it a while back and if memory serves a 320k MP3 was adding 1db or so, all the way up to 4db at 128k.
|
|
|
10-07-2019, 11:41 AM
|
#3
|
Human being with feelings
Join Date: Mar 2018
Posts: 24
|
Ahh ... that's v helpful, thanks. I was wondering about just nudging the level down over all, but was worried in case something had gone bonkers. Cheers.
|
|
|
10-08-2019, 05:10 AM
|
#4
|
Human being with feelings
Join Date: Sep 2009
Location: Oz - Blue Mountains NSW, formerly Geelong
Posts: 943
|
Note that even without a resonant peak in a filter's response you can still get an increase in the waveform's amplitude. e.g. a square wave fed into, say, a 4th order butterworth (no peak) filter the increase can approach 2dB.
Of course, this applies to real circuits, not just software. Long before we had computers to simulate such things I used to demonstrate this to electronics engineering students.
To understand all this you need to understand Fourier analysis and phase shift in filters...
__________________
It's "its" except when it's "it is".
alanofoz, aka Alan of Australia
|
|
|
10-08-2019, 06:30 AM
|
#5
|
Human being with feelings
Join Date: Jun 2013
Location: Krefeld, Germany
Posts: 14,688
|
Quote:
Originally Posted by Cup
Without the EQ plug-ins, the track peaks at 0, as I'd expect, given that I set it there before outputting in the first place.
|
Beware that peaks at Zero db (or even much higher) within a DAW don't "overdrive" anything or hit any limit, It's just another mark in the dB meter, and does not harm at all (only at the point when rendering to an output file, but there you'll see a different display showing the results).
-Michael
Last edited by mschnell; 10-08-2019 at 12:12 PM.
|
|
|
10-08-2019, 09:22 AM
|
#6
|
Human being with feelings
Join Date: Jul 2011
Location: Brooklyn
Posts: 2,613
|
To add to the previously mentioned, an eq has many different possibilities of filters that it can be set at. And how much a resonant freq is raised when the set freq is lowered will vary from barely, if at all perceptibly, to a lot. If you change the band's type of eq you can see how differently they affect the surrounding freqs.
__________________
The reason rain dances work is because they don't stop dancing until it rains.
|
|
|
Thread Tools |
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -7. The time now is 10:07 PM.
|