The "other" reason most ITB mixes don’t sound as good as analog mixes

[sound_forward]

Reading all those info in other thread about gain staging etc...

Am I the only one who thinks that mixing ITB sounds "bad" because the simple fact that AD/DA converters are not capable of perfectly reproducing analog sound source?

I confess that I do not have experience with absolute highend converters (prism, lavry, dad...) but every other AD/DA converter I have tried cannot cope with original analog signal. Something is always lost, and that little "something" is a big deal when trying to mix 32channels of audio.
But this "something" is only evident after recording analog source. If I record digital source, the recording is perfect. (once I tried DA/AD loop, 5 cycles, and it was perfect).


I will try to explain what this "something" is.
I produce electronic music, and all my synths (mostly analog), samplers (mostly vintage) and fx go straight to analog desk, they do not touch AD/DA converters until the final master.
Everything sounds the way I want and mixes by itself. No EQ needed, no compression needed, the sound is alive and 3D.

When I record individal tracks to DAW and play it back to analog desk, sound is changed. 3D is lost, fatness gone, but the biggest difference is that mix does not mix by itself anymore. There is not right level anymore, it is to loud or to quiet. The biggest problem are quiet sounds like reverb, tiny delays, quiet instruments...They are pretty much impossible to find the right level ITB. This is why I hate digital and ITB.

My question is...

If I find a single stereo AD/DA converters that can truly reproduce analog source (be it tapemachine, minimoog or voice), does it mean that ITB summing will become perfect? Equal to analog?

Or in other words, did anyone here at gearslutz tried this test with top notch converters...

8/16/24 analog sources (tape machine) straight into clean analog desk or summing box and then recorded with AD converters.

VS

8/16/24 analog sources (tape machine), each channel recorded one by one into AD converter and then mixed ITB.

Results?

P.S. I do not care for this ITB vs OTB summing tests where OTB means digital playback thru analog summing box.

[Brad McGowan]

My friend, you have basically summed up perfectly all the same conclusions I've come to myself in the last year after having spent countless hours A/B'ing analog recordings to digitized recordings in numerous permutations (I provide a link to some tests I did in a bit). I wholeheartedly agree that the reason that ANY digital recording sounds "bad" is because modern PCM conversion (especially at 44.1k and 48k sampling rates) cannot reproduce an analog signal in a manner that is 100% acceptable to me. I say "any digital recording" because I've found that this behavior is not limited to purely ITB mixes, but instead occurs with any recording where individual tracks are digitized before they are mixed (summed) together. The negative artifacts are most pronounced at 44.1k and 48k. Working at 88.2k or 96k seems to alleviate some of the "bad" stuff. I believe George Massenburg strictly works at higher sampling rates for very similar reasons.

I confess that I do not have experience with absolute highend converters (prism, lavry, dad...) but every other AD/DA converter I have tried cannot cope with original analog signal. Something is always lost, and that little "something" is a big deal when trying to mix 32channels of audio.
But this "something" is only evident after recording analog source. If I record digital source, the recording is perfect. (once I tried DA/AD loop, 5 cycles, and it was perfect).

I have experienced the exact same thing. Something does indeed change. To my ears the A/D conversion process doesn't accurately convey the sense of space, depth, and realness that exists in the orignal analog source. I have even found this to be true using high end Mytek conversion so I know the issue isn't limited to lower end gear. And like you have pointed out, once you have a digitized source you can easily convert and reconvert that signal with multiple ADDA loops and suffer no additional audible degradation. Those transfers are perfect. That's because you already degraded the signal to the point of no return during that initial conversion from the analog realm to the digital realm, and this is why I now strongly believe that the first time you convert should be as late in the game as possible (during mastering) and should be with the best converters you can get your hands on. You only have one shot to get it right.

Some say the problem with digital is ITB summing. Others say it is intersample peak distortion and gain staging. Other say it is lack of distortion and color. The problem to my ears is simply that current PCM-based A/D conversion changes analog audio into something that is musically degraded. It's as simple as that for me. Dave Amels of Bomb Factory and Anamod fame, has made similar statements in these forums. He knows a thing or two about DSP processing. I've found DAW summing to be perfect. It's flawless. It works beautifully. If I want color it's super easy to hang a transformer coupled piece of hardware on my 2-buss. If I could have converters that captured an analog source perfectly then I would have no hesitation mixing ITB. Total recall is an absolute dream. Who doesn't want that? IHMO the loss happens before the signal gets to that DAW summing bus.

Here's a test I performed that is very similar to what you are asking for. I think I linked the right one. If not then I'm pretty sure it's in that thread somewhere. I suggest reading the whole thread if you have the time because I posted a number of small tests regarding related issues that you may find interesting (i.e. summing of tracks pre and post conversion)

http://www.gearslutz.com/board/4249653-post218.html

I know some say digital has arrived. I will say digital has arrived when there are many affordable A/D converter products on the market that accurately reproduce an analog source in a musical manner. One or two products from boutique manufacturers costing $10k or more is a teaser at best. Maybe we should start a pool to guess the year I'll make the switch back to digital.

Brad

[Everbeatz]

Great ITB-OTB topic continuity!

I hope this one will eventually point out what problems are and what should be improved as there's always space for that.

ITB didn't reach its full potential, it's rather a new technology. I strongly believe that one day it will reach analog in both sonic and musicality department.

The negative artifacts are most pronounced at 44.1k and 48k.

So true - and the big part of those artifacts is distortion that accumulates resulting in harsh sound no one likes

To me - even upsampling to higher sample rates helps to some extent but that doesn't fully avoid all troubles with actual representation of analog source. Not to mention further processing with plugins ending up with reconstructed waveforms with various forms of phase problems and distortion.

If you dig into science more everyone can see that it is capable of modeling and simulating various processes that can be found in nature - far more complex than modeling what's happening inside analog desk for instance. To me, it all comes down to one thing - is this a marketing/production strategy and having advanced digital products kept in reserved state so those will be delivered to a market one day?

Most of highend digital products came out from science laboratories and institutions - actually just a small portion of it...is this all just a matter of patience?

[Brad McGowan]

Unfortunately since the market for musically "real" sounding A/D conversion is relatively small (at best), it's just a handful of people that are really pushing the envelope and developing the technology. That usually translates into big bucks for the end user that really cares about what's happening to their analog signals. Real progress will eventually happen is when you see a $199 8-channel converter from one of the bigger large scale manufacturers (Behringer?) that sounds like what some of us are dreaming about. Then we can say that digital is mature.

I'm still very interested in checking out one of those Korg DSD recorders. And I have high hopes for the next generation of 32-bit converters on the horizon. I anxiously await the day that I can come to this forum and say that I've found a converter that is reasonably priced and doesn't degrade audio in a way I find unacceptable.

I find it pretty sad that most people still work at 44.1k, especially considering that quad core processor computers and 1TB hard drives are fairly common these days. I'm guessing most folks just don't take the time to properly investigate what's happening to their audio at those low sample rates. Or maybe they just don't care considering that the kids on the street are listening to MP3's on iPods.

Brad

[HomeProducer]

most likely your problems arise because

your recorded material is 0.5-1 dB quieter than the source!

That's all.

I don't have these problems.
My recorded stuff sounds as deep as the source.

[HomeProducer]

Nothing is wrong with digital summing either.

Please provide a mix made ITB and OTB and lets compare the results in a blind test.

I would like to hear the flatness of the ITB mix.

[Brad McGowan]

Try this:

- Record a live acoustic instrument to a professional analog recorder.
- Rewind the tape and transfer the recording into your DAW of choice through an A/D converter at 44.1kHz
- Set up your DAW to monitor the A/D input(s) on a D/A output.
- While transferring the audio, A/B back and forth between monitoring the repro head of the tape deck and monitoring the D/A output of the DAW, thus comparing the analog source to the digitized transfer (you will need a console or a monitor controller with multiple inputs to do this properly)
- Repeat the exercise at 48k, 88.2k, and 96k.

Honestly tell me you don't hear a difference between source and "copy" at 44.1k and a lesser difference as the sample rate increases. I've made this offer before, but anyone in the SF Bay Area is more than welcome to stop by my studio and I will perform this test for them. It's eye opening if you've never had the opportunity to do it.

Brad

[OurDarkness]

Pardon my French but the amount of bogus info and unsubstantiated opinions infesting various fora regarding ITB vs OTB is staggering.

[Brad McGowan]

Ain't that the truth!

Brad

[work2do]

Originally Posted by sound_forward

Am I the only one who thinks that mixing ITB sounds "bad" because the simple fact that AD/DA converters are not capable of perfectly reproducing analog sound source?

There are so many good ITB mixes out there from some big time and small time engineers who use 192's so who knows. I think the understanding of ITB techniques and limitations the we had w/ tape and consoles is lacking.

[Lawrence]

Brad,

I don't disagree with your conclusions. I would only ask that - in your view - is the degradation you hear as a result of sampling so much that it's actually problematic? Not if analog sounds subjectively better in a same case scenario than sampling but can sampling sound good also.

Take Tony's 48k recording/mix demo song for R&B Masters II as an example. Are there sonic problems there that would make people shy away from 48k recording? It's one of many examples that sounds perfectly fine to me. Would it have sounded even better recorded to tape and mixed on a console? Maybe.

Thanks.

[Ethan Winer]

Originally Posted by HomeProducer

most likely your problems arise because your recorded material is 0.5-1 dB quieter than the source!

This is not a joke, and it's surely one big reason people think they hear all kinds of differences that don't really exist. With a proper blind test where the levels are carefully calibrated, all of those audible differences usually disappear.

My recorded stuff sounds as deep as the source.

Me too. When my stuff sucks, I know it's me and not my "digital" gear.

What kills me about these discussions is people obsess over infinitesimal amounts of distortion in a converter, and 0.1 dB deviances in frequency response, while praising analog tape which is literally ten times worse than even a consumer grade sound card. Tape hiss, print-through, tape modulation noise, 3 percent distortion, head bump, flutter - not to mention the cost of blank tape and the time and expense to maintain an analog recorder.

But some people gladly overlook all of those shortcomings of tape anyway, because it's cool to love tape.

Watch for my op-ed column in Sound on Sound magazine on exactly this topic in a few months.

--Ethan

[jayalanthomp]

Excellent points! I believe there has been a lot of hype concerning digital recording that has resulted in our pockets being picked on a regular basis over the past 20+ years. Add up all of the money you have spent on plugins for example- especially the ones you no longer use, or can't use because of the constant changing of operating systems. You can't give away a digital multitrack tape machine today, yet in 1989 they went for over 100K and you weren't considered one of the real players unless you had at least one in your facility. Think about all of the debt that people went into to try to keep up with the hype- and the broken marriages that may have resulted.

I am very thankful that people (me included) are beginning to wake up and come out the matrix.

Peace,

Jay

[indie]

I agree with you Brad. However, I would say that Prism and Radar converters and FREAKING close. But close is not perfect at all.

[TranscendingM]

Originally Posted by konkaos

There are so many good ITB mixes out there from some big time and small time engineers who use 192's so who knows. I think the understanding of ITB techniques and limitations the we had w/ tape and consoles is lacking.

Again this comment is a reflection of the crux of what I was getting at in the original thread: the "understanding", the "limitations" or simply the education is lacking. You can post threads til you're blue in the face as to why this mix isn't as good as that mix but all you are doing is posting symptoms of an issue and not the issue itself.

A proper DAW doesn't sum wrong per say. It just doesn't sum like analog. This is niether good or bad. Anybody who took the time to understand audio fundamentally would then know what to apply or do in "ITB world" to straddle what's good about the "analog world" and the benefits of digital.

[Lawrence]

Originally Posted by indie

I agree with you Brad. However, I would say that Prism and Radar converters and FREAKING close. But close is not perfect at all.

That was my point. Is there really any such thing as "perfect" on any recording medium?

[Raider]

Or maybe they just don't care considering that the kids on the street are listening to MP3's on iPods.

That's the crux of it.
MP3 killed any chance of higher fidelity progress.
The consumer wants good songs, good performances of those songs and they want them for free. .001% is the obsessive audiophile market.

[Ethan Winer]

Just to clarify a few points:

Originally Posted by TranscendingM

A proper DAW doesn't sum wrong per say. It just doesn't sum like analog.

Originally Posted by Lawrence

That was my point. Is there really any such thing as "perfect" on any recording medium?

Analog summing adds two or more voltages, and is mostly flawless. The only problems occur at the upper and lower limits. At the bottom of the range you get noise, and at the top you get distortion. A good line-level analog mixer should be very clean right up to the sudden onset of gross distortion. By "clean" I mean the sum of all distortion artifacts is below the threshold of audibility. Unless it has transformers, in which case distortion might rise before the amp circuits clip. This of course depends on the quality of the transformer.

Digital summing also adds two or more signals, and current summing methods that use 32 bits are indeed perfect. Or so close to perfect that nobody could possibly hear the errors. Errors in summing can be expressed as distortion some number of dB below the music. I'll take a wild guess and say those distortions are down 200 dB or more. Only an audiophile magazine writer can hear artifacts that soft.

Digital recording may not be perfect when measured at a high resolution. But audibly, current technology is perfect enough to not matter.

--Ethan

[mixmixmix]

TranscendingM, your opinion mirrors mine. Digital summing is simply different. It will never sound like analogue - just like guitar will never sound like saxophone.

However, hybrid setups is the future - digital recording and some processing, analogue summing and some outboard.

Also, ITB reverb and delay is 2D, unlike outboard which gives convincing emulation of 3D. That again calls for analogue summing.

ITB brainwashed whole generation in audio industry. The problem is that majority of people who use ITB summing either don't want or can't compare ITB vs. OTB summing in their own studio with their own material. Add denial and confusion from many conflicting opinions and agendas - it's a big conceptual mess right now.

But, luckily the one who wants to hear, WILL hear.

Amen.

[Wow]

Originally Posted by Ethan Winer

Digital recording may not be perfect when measured at a high resolution. But audibly, current technology is perfect enough to not matter.

--Ethan

W

[TranscendingM]

Originally Posted by Ethan Winer

Digital recording may not be perfect when measured at a high resolution. But audibly, current technology is perfect enough to not matter.

--Ethan

True, and I'll add further that "perfection" is a strange beast regarding sonics. As you point out, ironically Digital is more perfect than analog. But what kind of perfect do we mean? There's technically perfect or in other words representation; linearity. Then there's aesthetically perfect. The kind of "perfect" you would hear putting the finishing touches at the end of a great mix session, let's say. Well designed analog has a lot of that kind of perfect. It's knowing and understanding those fundamentals that allows one to create aesthetic perfection both OTB and ITB. Picking apart minute tech specs will not get you to a great mix. Learning the fundamentals of audio however is all about being a better engineer. Then, respectively & ultimately hands on practice makes you a better mix engineer.

[xq3js]

by listening to those back street boys' and mariah carey's new stuff, i am convinced that the "**** sounds better" debate is completely waste of time

[Lawrence]

@Ethan

By "perfect" I was talking about capturing (recording) not summing. Is there any such a thing as a "perfect" capture of an analog music waveform? I was under the impression that any man made recording devices themselves add certain levels of distortion/change as imperceptible as they may be.

In that regard I've never considered any recording perfect.

[ears2thesky]

I think the issue at hand is the summing process itself--not whether individual tracks are digitized. Obviously staying all analog until the stereo mix is digitized will sound different than digitizing individual tracks right after the mic pre. I think what we are talking about here is the actual combining process of individual tracks. The issue is not how to get good kick and bass sounds into your computer but how the tracks sound when mixed together.

One aspect I haven't seen mentioned is the process of combining tracks into a stem. ITB? OTB? Stay ITB until final mixdown? Both submix and mix OTB?
As far as OTB: passive or active summing?

[WiZKiD]

The bottom line here is the medium of exchange. Digital. It's common knowledge among engineers that it doesn't sound as good....but it's the common consumer who matters and will be catered to be kept happy...Not us. As long as they are purchasing MP3's, A/D, outboard gear, ITB, OTB, can vary heavily because it doesn't really matter how "analog" we think it sounds. Tape machines are so cheap these days it makes me laugh. (why I use one).

The fact is...playing fields are way more level in the present. There's probably some 16 year old with parents in the industry, some knowledge, and a UAD card w/ Logic in the bedroom that has just as much a chance to produce or create a hit song as me. Colbie Caillat was a great example of that.

[Nolet]

Wait for it.....I feel something coming.....

[indie]

Originally Posted by Lawrence

That was my point. Is there really any such thing as "perfect" on any recording medium?

I meant perfect replication of what analog tape picks up.

[TranscendingM]

Originally Posted by indie

I meant perfect replication of what analog tape picks up.

Yeah, this is why at times, semantics are important.

Technical perfection: more or less 1:1 replication.

Aesthetic perfection: musicality; non-linearity; sonic "mojo". "It" factor.


By technical definition, there's nothing wrong with "digital".
By aesthetic definition, digital doesn't impart character.

[Brad McGowan]

I haven't read all the latest responses so I apologize for delaying my response to some of your comments and questions. I don’t think the OP is trying to turn this into an ITB vs. OTB discussion or a debate about the merits of working one way or the other. I think he’s simply drawing attention to the fact that if there is any “B” in the equation at all (that would be A/D conversion) then there is something funky happening to his analog sources. I totally agree with him. This isn’t about tape vs. digital or how tape does or doesn’t have linear response or sounds cool or not cool. It’s a very fundamental issue that is blind to any of that. The issue is that the current crop of PCM-based converters doesn’t reproduce an analog source or mix of analog sources in a way that some of us hear as musically equivalent to the source material. I suggested using a tape deck as a source because a) it’s analog and b) you can rewind and replay the same sound to repeat a listenting test. It can be the most non-linear, distorted, and poorly aligned tape deck out there. It won’t matter because it’s an analog source by definition. And the point is whether or not an A/D converter is faithful to the analog source material (whether or not analog tape is musically faithful to an acoustic event is another debate entirely). I have yet to hear one I can afford that is. I know perfect conversion doesn’t exist. But 44.1k is a joke compared to the actual source. I blindly accepted it for a long time as “good” sounding. I was really surprised when I finally came out of the cave of blissful ignorance and actually took the time to listen with my own ears. Honestly—operating a tape deck and mixing through a console with no recall is not nearly as convenient as working in a DAW for some projects. However, the sound changes in a way I don’t like the instant I convert audio. Why would I want to accept what I personally consider a sonic compromise when there are ways to avoid the problem entirely?

To my ears PCM digital does not give you 1:1 replication.

More later…

Brad

[MichaelAngelo]

Originally Posted by TranscendingM

True, and I'll add further that "perfection" is a strange beast regarding sonics. As you point out, ironically Digital is more perfect than analog. But what kind of perfect do we mean? There's technically perfect or in other words representation; linearity. Then there's aesthetically perfect. The kind of "perfect" you would hear putting the finishing touches at the end of a great mix session, let's say. Well designed analog has a lot of that kind of perfect. It's knowing and understanding those fundamentals that allows one to create aesthetic perfection both OTB and ITB. Picking apart minute tech specs will not get you to a great mix. Learning the fundamentals of audio however is all about being a better engineer. Then, respectively & ultimately hands on practice makes you a better mix engineer.

I think most posters here are missing the point. The audio business is about "ART" meaning what ever distortion or colouration makes people smile is the "better" one.. That being said I don't think anyone would argue that a tape machine and a SSL "sounds more musical and cooler" and certianly gets you more involved in the performance and or emotion of the artist.

This ITB or OTB is not the issue, the issue is musicality, depth, width, tone, texture etc etc... Bottom line is digital is cold sounding, analog is warmer, more musical (because of its musical distortions,noise, etc) .. So there fore because production flexibility generally outweighs sonic integrity, we will stay in this digital domain...Think musical, not does this system capture its source perfectly, but does it add a musical ingredient..that is pleasing ....

Just get some records and listen to them for a few days... and then come and post and talk about sample rates and ITB vs OTB ....