What EQ To Use To Fix Official Releases?

Hello,
 
Some might say what I am about to is sacrilege, and to some degree, I do understand, but it is just time.
I have some albums that were produced in the early 80's that are severely lacking in bass.  Every time I put one of these discs in my car or home stereo, I'm turning up the bass on my EQ drastically to make it sound good.   A good example is Depeche Mode's "Speak And Spell" album.
 
So I decided I want to import these albums into Sonar and through a gentle/appropriate bass boost to these albums.  I am thinking for this album maybe a 3db low shelf between 0 and 60 Hz.
 
Question is, since this is already mastered and released material, is it best to use a Linear-Phase EQ over a normal EQ (like in the prochannel)?

Thank you!
-Adam
 

You might just find that there's actually nothing to boost down there, lol!

sven450
I've done this to fix up bootleg concert recordings.  The cleaner the EQ the better.  Try the LP 64 EQ that comes with Sonar.  Very nice.

 
you know I tried the LP 64 EQ, I just didn't like the sound of it.  I thought linear-phase is best for cleaning up masters or while mastering, but I really like the Pro Channel min phase EQ the best.  I just hope Im not causing any phase issues in what I am doing.

I don't hear any.

I used the minimum phase EQ and check out the results.

I added bass and cleaned up the top end too.   


https://drive.google.com/...XpZYmc&usp=sharing

I have used Ozone to bring old cassettes back to life.  Record them into Sonar and then use Ozone to tweeze the EQ to your ideal levels.
 
Many of the cassettes had low, squishy levels of bass and muted highs. Ozone was able to get it done. IMHO, the Ozoned version sounded better than the original one.... yup, even when the tape was brand new.

Linear vs. minimum phase shouldn't make any difference. The biggest problem is going to be the overall volume boost.
 
Even in a relatively bass-light master (e.g. mastered for vinyl), most of the energy is still going to be in the low frequencies. In order to add 3dB boost down there you'll need to have 3dB of headroom to begin with. Depending on the era of the original recording, you may not have even 1 dB to play with.
 
I'd be curious to see a spectral display of your before and after versions, as well as a volume analysis that shows digital overs. You could be adding significant distortion and not notice it without A/Bing your enhanced master to the (volume-compensated) original.

bitflipper
Linear vs. minimum phase shouldn't make any difference. The biggest problem is going to be the overall volume boost.
 
Even in a relatively bass-light master (e.g. mastered for vinyl), most of the energy is still going to be in the low frequencies. In order to add 3dB boost down there you'll need to have 3dB of headroom to begin with. Depending on the era of the original recording, you may not have even 1 dB to play with.
 
I'd be curious to see a spectral display of your before and after versions, as well as a volume analysis that shows digital overs. You could be adding significant distortion and not notice it without A/Bing your enhanced master to the (volume-compensated) original.

 
question for you in the meantime, I often heard that bass was intentionally reduced because of vinyl - but vinyl is being made again for a lot of bass-heavy current modern recordings.  How is it possible now, but not back in the 80s?

bitflipper
Linear vs. minimum phase shouldn't make any difference.

Technically, there is a difference and the Linear Phase filter should be avoided in this application because the inherent pre-ring can alter the attack of the bass drum.
 
See the excellent FabFilter video which explains this in detail:
 
https://youtu.be/efKabAQQsPQ
 
 

True. In this case a 3dB boost is not going to produce enough pre-ring to be audible.
I guess my point was to just be aware that pre-ringing can occur with a linear phase EQ.
Most of the time it is not a problem because it is at a very low level.
What if next time the OP re-masters a recording and he uses 12dB of boost on the low end?
Perhaps the pre-ring would be audible then?
For me, it just seems to be good practice to not use a Lin Phase EQ when you are boosting low frequencies and low frequency transients exist, such as bass drum.
 
 
For fun I put a single bass drum sample on four tracks, put three EQs all set to exactly 50Hz, 3dB boost, Q=1.
Track 1 = no EQ, Track 2 = Minimum Phase, Track 3 = natural Phase, Track 4 = Linear Phase.
The magnification is zoomed all the way in on all tracks so that the front detail of the track can be seen.
Note that track 4 (Linear Phase) clearly shows the pre-ring. Note that the pre-ring amplitude is -53.4 dB below FS.
In other words, the pre-ring is "down in the dirt" but larger than I expected (!).
 

bitflipper
What was the actual pre-offset for the linear phase track, in milliseconds? 

About 50mS.
I would have expected a pre-ring of 20mS which is the period of 50Hz.
I guess with the Q set at 1 the filter is under-damped.
I guess that if the Q was set to .5 the filter would have then been critically damped and the pre-ring would have better matched the 20mS period of 50Hz.
 

Conclusion: Narrow bandwidth corrective EQ would be better served with a conventional minimum phase filter.
The Linear Phase filter would be well suited for medium or wide bandwidth corrections.
 
The settings used in my example were extreme and not real-world settings. These settings were used to make the pre-ring more visible. 
 
I wonder if the pre-ring could be used as a special effect on guitar? (see edit below, works on bass drum. Not good for guitar)
Put the EQ on a sub. Set the Q=40 so it rings.
Put a gate after the EQ and send the guitar to the sidechain input of the gate.
Set the gate for Ducking mode so that the EQ output is gated off when the guitar plays,  but on during the pre-ring.
I think it would have a mechanical monotone reverse effect sound. The reverse sound would be the frequency that the EQ is set to. You could adjust the frequency so it fits the song.
 
Edit:
I just tried this crazy idea. It works on Bass drum. You have to set the EQ to a bandpass filter so that only the ring comes through. It acts like an oscillator that quickly ramps up in volume right before the bass drum hits, sort-of like a backward recording. Might be good for EDM type music. The latency increases to several seconds with the LP filter doing all that pre-ringing!
It would be best to get the sound set up then record it to a aux then delete the EQ to get rid of the extra latency.