Clipping Comverters During Mastering

[Gold]

I use a plugin for clipping ITB because I can then back off the amplitude a little afterwards and then bounce the file. I don't like having actual overs (samples at 0 dB) in digital files.

If I hard clip I follow it with a limiter and can set the ceiling for less than 0dBfs.

 

[L´Andratté]

If I hard clip I follow it with a limiter and can set the ceiling for less than 0dBfs.

Because just turning down level would reduce loudness/perceived volume again?

 

[thor.zmt]

Folks,

Ok, let me talk a bit about the use of intentional overload with music.

I'm old enough and because of coming from former eastern europe another decade plus behind my age for experience with old analogue systems.

Plus, even the best studio's and band's generally had very limited access to equipment, a lot of stuff we got was second hand western gear blown out by studios and PA rental companies. So in the late 80's we were running a lot of early 70's gear.

Now clipping...

Hard clipping is often considered bad, however if what is clipped are short transients AND clipping recovery is "clean" and instant, the clipping is not really audible. The increase in RMS levels however is. On top, while amplifiers clip hard, tape clips soft.

Soft clipping is sonically a little different and I found hard clipping "brighter" and soft clipping paradoxically sounds "louder" than hard clipping.

Back in the 80's in eastern europe access to compressors was rather limited. Having a multiband compressor? Such a sting exists?

We all know that compressors have timing and while it is not hard to optimise timing for a single instrument, making it work for a full mix is hard. Multiband compressors help but have other problems.

For a studio job, you can individually compress tracks if needed, during recording. Then pushing levels on tape give a more dense sound.

For live sound this does not work too well. We didn't have enough compressors to put one on each tom and drum etc. Clipping the mixer channel and running the fader a bit low crushes the tops of transients.

Next, if you use speakers that have good thermal handling and are inherently damped, clipping peaks can be very hard to hear.

We were often running true horns, EV Eliminator or bigger EV "Bima" (some of the TL series horns) for bass and/or bass/lower mids.

Unlike vented boxes without low pass features build in, horns are bandpass designs acoustically, so clipping the bass and lower mid the upper harmonics are filtered acoustically.

So clipping is fairly moderate in audibility, as long as you keep upper mids and treble clean. Also, when the amp clip's and suddenly the electrical damping of the speaker disappears, hors remain subjectively "tight", vented boxes loose it. You do need to make sure to not burn out the drivers. Once vented systems and "full range" boxes plus subs became more prevalent, this was a sonic and reliability disaster.

So hard clipping can be used, but needs care.

I think a soft clipper at an AD input is a good idea. Very good.

I could also see a multiband soft clipper that only clips "sub" and "mid-bass" as interesting. Set the crossovers at 80 & 320Hz and have separate thresholds and compression ratios for those bands. Maybe add a sub 40Hz band where you only mix the > 40Hz content back in suppressing fundamentals. Probably something like this already exists as plugin.

Thor

 

[thor.zmt]

In most situations it’s the analog stage prior to the converters that is clipping.

This is not my experience.

Most ADC IC's use 3.3V or 5V single rail and accept 1V or 2V RMS differential for 0dBFS digital (PCM) output, which is likely set as 3-6dB below actual modulator hitting 100%.

Often an attenuator is used, like ~10dB (3:1), so with 12V rails for the analogue circuit we are looking at easily 14V RMS into the attenuator and lowpass, where 6V are sufficient, so the analogue stage in this case clips at +7dBFS.

So the common AD driver circuitry clips well after the IC.

If you did get an “illegal signal”, most converters now do a high enough upsampling level that it wouldn’t result in aliasing.

????

What does this have to do with clipping?

Thor

 

[thor.zmt]

I think a soft clipper at an AD input is a good idea. Very good.

Here a very simple circuit that is fairly clean at -3dBFS (0.008%) and needs ~ +6dBFS equivalent input before we get overs in the ADC which still have rounded edges.



The ADC here is assumed a AKM AK5393. Open the switch and the soft clipping is off and THD is not affected. I think such a circuit makes a lot of sense.

Tina TI allows a wave file to be loaded as generator and to be played, so it is possible to listen to the result of this circuit...

Thor

 

[Ricardus]

Hard clipping also tends to sound better on things that don't have "notes." I've found it sounds great on drums and percussion, but less so on "musical" content."

 

[ruairioflaherty]

This topic always devolves into noise. Without fail.

Clipping is way overused in modern recording, mixing and mastering in my opinion. That however does not in any way negate the fact that sometimes it is exactly the right tool for the job. I use a digital clipping plug in, the oversampling filter matters greatly.

In a mastering context clipping kick and snare transients with a zero time constant can take a load off of the limiter.

I applaud Wayne for coming at this with a new take. It's wishful thinking but if I had the time I would build up this circuit to listen here.

 

[ZenSix]

This discussion is way over my head so my input is rather questionable...

My Apogee Symphony MKII has a built in "Soft limit" which is obviously different from a clipper but may produce some of the same sonic opportunities the OP is looking for...

In a purely digital plugin world the Pulsar Modular P42 is rather good at this...lots of ways to drive the saturation and signal to clip.

I have experimented with 32 bit float files and clipping is fairly non-existent in the normalized files regardless of how clipped it was recorded...again a different beast.

Are we looking for just "louder" or perceived louder?

I imagine the mastering guys get all kinds of hot driven tracks that need to be tamed so there has to be some professional analog device and/or ADDA and/or algorithm to accomplish this...MAS Overstayer? Weiss DS1-MK?

What happens when you max out the sample rate and clip?

Symphony sounds ok, not my favorite converter to clip. I prefer Lavry, Bettermaker, or Prism Sound. Lavry and Prism have bigger low end while clipped (which can be too much for bass heavy music), and Bettermaker sounds more tight in the low end and gives a pop music vibe (works great for EDM). All of these converters give a much bigger sound with some really nice harmonic distortion than a digital limiter.

On my mixes I go through DA converters into Dangerous LT and 2Bus+ (hit the transformer a little bit), into Bettermaker Mastering Compressor, stereo Pultec EQP-1A clone, then I clip the AD converter, back into the box and finish with a FabFilter Pro L2 with 1-2db gain reduction. Gives me a very loud mix without destroying transients and substantially brings up the average RMS level.

Ordering an IGS Tubecore 3U soon, going to experiment with placing this in the chain and see if it works in my flow.

 

[elskardio]

Hard clipping also tends to sound better on things that don't have "notes." I've found it sounds great on drums and percussion, but less so on "musical" content."

My friend swears by his old Apogee Rosetta for drums recording. They have a “soft limit” function… I guess some sort of diode clipper.

 

[living sounds]

Symphony sounds ok, not my favorite converter to clip. I prefer Lavry, Bettermaker, or Prism Sound. Lavry and Prism have bigger low end while clipped (which can be too much for bass heavy music), and Bettermaker sounds more tight in the low end and gives a pop music vibe (works great for EDM). All of these converters give a much bigger sound with some really nice harmonic distortion than a digital limiter.

Well, which Lavry, which Prism? They all have different topologies. The AD-2 "Dream" converter uses an older Cirrus chip with two-stage gain ranging. The Gold MK3 is supposedly discrete, but it does also use a two-stage gain ranging arrangement of sorts . The new Savitr seems to use an ESStech chip. Savitr and MX also have an actual selectable pre-conversion clipping stage, while the older ones offer a digital post-clipping "saturation" algorithm.

 

[Tubetec]

If you go back into the beginings of radio the compressor hadnt even been invented ,
the designers of sound equipment intentionally looked for ways to soft clip the sound to prevent overload of the transmitters during transients, they just so happened to be using tubes .
Its pretty much the same if you have a bunch of vintage preamps with iron and tape in the signal path ,
With proper gain staging the transients can to be very effectively controled .

The modern desktop audio interface mic preamp reproduces these transients perfectly , you have no EQ to kill the low end with close micing , So you end up sending a bass heavy sound to the covertors , at best your going to end up with a signal to digital thats badly out of shape sonically without using VST's to correct it in the return path .


I get the impression from what Ruairi said its often a problem that occured during the tracking that hes left dealing with .

These transient events were taking about happen a lot in musical performances , handling things right in the analog domain means less chance of the need for 'post pro' fixups .

 

[ruairioflaherty]

I get the impression from what Ruairi said its often a problem that occured during the tracking that hes left dealing with .

Very little of the clipping I deal with in source material happens by accident, It's mostly intentional from the artist.

I use clipping on transient peaks only, basically on noise where the clipping effect is preferable to a limiter with a time constant. Always in conjunction with a digital limiter following.

 

[gyraf]

I use clipping on transient peaks only, basically on noise where the clipping effect is preferable to a limiter with a time constant.

This also for clipping with e.g. the G21?

/Jakob E.

 

[ruairioflaherty]

This also for clipping with e.g. the G21?

/Jakob E.

Ah, no! That's a whole other deal, much more tone shaping etc than about pure level chasing. With the G21 I'm often working much more into the body of the sound.

 

[fazer]

This has been one of the more interesting threads I’ve read. Lots of information to experiment with.

 

[Whoops]

Well, which Lavry, which Prism?

I have extended experience with Lavry converters and what I can say is that both the Lavry Blue or the Lavry Gold sound pretty good when you hit the Red (clipping).
Clipping those converters it's a very good Free Limiter,
how much you clip depends up to you, of course any converters or any circuit will start to sound heavily distorted if you push it too hard but if you use them with just a touch of Clipping it sound great on Rock/Pop/Electronic Music.

Like Ruairi have said "sometimes it is exactly the right tool for the job"

 

[Philbo King]

I'm not a fan of the clipping sound, and never use it in my mixes. I find it is very much like the natural preference for loudness; it seems superior at the first listen, but becomes tiring to listen to over time, and I end up actively avoiding that music.

It is great for disposable music like hiphop, rap and EDM, cash cow stuff destined to be landfill fodder. But music as art, things that will be enjoyable in 20 years, not so much...

If it brings in your clients, go for it, you gotta feed your family after all. And labels do like noise, apparently. But, consider that 70% of the current music market consists of 'oldies' mixed in the 50s-80s. Perhaps there's a good reason for that?

Let the flaming commence...

 

[ruairioflaherty]

I'm not a fan of the clipping sound, and never use it in my mixes. I find it is very much like the natural preference for loudness; it seems superior at the first listen, but becomes tiring to listen to over time, and I end up actively avoiding that music.

It is great for disposable music like hiphop, rap and EDM, cash cow stuff destined to be landfill fodder. But music as art, things that will be enjoyable in 20 years, not so much...

If it brings in your clients, go for it, you gotta feed your family after all. And labels do like noise, apparently. But, consider that 70% of the current music market consists of 'oldies' mixed in the 50s-80s. Perhaps there's a good reason for that?

Let the flaming commence...

You've got it all figured out, well done you.

 

[user 37518]

You've got it all figured out, well done you.

He is new, be gentle.

PS I also think that clipping the converters is barbaric.

 

[Newmarket]

I'm not a fan of the clipping sound, and never use it in my mixes. I find it is very much like the natural preference for loudness; it seems superior at the first listen, but becomes tiring to listen to over time, and I end up actively avoiding that music.

It is great for disposable music like hiphop, rap and EDM, cash cow stuff destined to be landfill fodder. But music as art, things that will be enjoyable in 20 years, not so much...

If it brings in your clients, go for it, you gotta feed your family after all. And labels do like noise, apparently. But, consider that 70% of the current music market consists of 'oldies' mixed in the 50s-80s. Perhaps there's a good reason for that?

Let the flaming commence...

It may not be your thing, and it's not particularly mine, but it's objectively true that some hip hop and rap from decades ago still stands up well today.

 

[living sounds]

I have extended experience with Lavry converters and what I can say is that both the Lavry Blue or the Lavry Gold sound pretty good when you hit the Red (clipping).
Clipping those converters it's a very good Free Limiter,
how much you clip depends up to you, of course any converters or any circuit will start to sound heavily distorted if you push it too hard but if you use them with just a touch of Clipping it sound great on Rock/Pop/Electronic Music.

Like Ruairi have said "sometimes it is exactly the right tool for the job"

Recently tried it with the LG again, you are right. I also use a Pendulum diode limiter, and the combination of the two can do a lot.