SPL MixDream analog DAW summing

ok. thanks again. i guess i'll just leave it at that.

 

Yeah that almost indescribable minute difference between analog summing and digital summing. It can make all the difference. I don't believe that digital summing in a digital console will re-create the analog summing. I've discussed this with some programmers. You just can't have all the numbers line up perfectly in digital summing. It's all based on time delay multiplexing. But analog summing is all real-time. And there's the real difference. Here's a little secret that folks might be interested in? In 1978 I built up a custom console. It was a split desk. The multitrack monitor mixer section was quite a passive piece. Since we were all working from +4 DBM Ampex MM 1200 outputs, no input buffer was needed. It was all passive. This would then sum into the 2 track output for monitoring. It was really pretty funny since some of the mixes sounded better than it did coming through the entire console electronics. So at times, we would use the monitor mixer mixes. Less electronics, more like a straight wire. And it was single ended as opposed to balanced inputs. Not too different from the concept that Bernie Grubman accomplished with his custom single ended mastering consoles. Sometimes we would print effects & reverb to the machine if we needed some, track availability permitting. And the tonality of the analog summing can be customized through differences in gain staging in the summing amplifier. The more open loop you go, the more opened up the sound becomes. Differences in output level can be compensated by the output amplifiers post summing amplifiers. Of course all of this affects signal-to-noise ratio, distortion & stability but hey, if you are going for a sound, go for a sound. I've heard some beautiful digitally summed mixes through the years. But since I'm still essentially working with an old console, this ain't nothing new to me. It does sort of make up for that cold reality, crispy clarity of cold heartless digital sound.

My Neve is warm & cuddly.
Mx. Remy Ann David

 

A digital mixer doesn't give you analog summing, but it does give you a choice to do digital mixes instead of ITB. I am not saying it is absolute as being better. it may or may not be better. Just another option that is an easier and lesss expensive way to interface with external analog or digital gear than the cost of analog summing and extra converters.

 

yeah it will sum in digital as i understand it, not analog. it was AG's suggestion rather than yours that got me interested in bringing it to the fray.

i'm in exactly the same position as ouzo, i've always known that. i just find it interesting given the other application it opens up if i was to send 16 channels of lightpipe to it, and use it to mix digitally OTB, as opposed to mixing internally. as it then removes the need for midicontrol faders, which was how i was going to configure it. i'm interested in seeing how that sounds as it would be very very easy to A/B. we only have used it for monitoring and routing up to now.

however it does actually claim to have 8 analog buses. i'm not very clear yet as the manual is 425 pages long and doesn't reveal some of the stuff i want to know, exactly what that means.

 

You mean something like 32/64 bit floating point?

If the numbers don't "line up perfectly" its a software bug. Try summing the same set of stems in a bunch of different DAWs: I'm prepared to bet that they all null perfectly, ie: every DAW will produce the same identical and perfect results.

 

We've got two different arguments going on here. The original one (paraphrased) was: what sort of conditions would make it worthwhile to take multiple tracks (or stems) out of the box, convert them to analog, perform analog summing and reconvert to digital? The second argument that got conflated with the first was whether different all-digital summations, done ITB or OTB, are audibly different.

So IIRs' comment about floating-point in response to my post about needing good headroom in an analog summing unit is addressing the second argument in a reply to the first.

In terms of digital summation, there are two other points that cause confusion. The first is that it is not expected that all digital summations will arrive at exactly the same numbers, as the rounding algorithms could well be intentionally different between implementations. What matters is how the result sounds, and it is quite likely that some implementations sound better than others. The second point is that in a properly designed digital system, time delays in the sequential addition arithmetic play no part, as all the additions required for the next sample are performed within one sample time. I am referring here to PCM digital systems; things get more complicated in DSD processing.

 

There may be differences between ITB summing using floating point maths and digital summing in a digital mixer or PT HD hardware using integer maths, but these differences are down at about -140dBFS and I simply don't believe they are significant. Especially if (like Remy) you turn up your nose at 24 bit audio and still use just 16 bits...

 

Lets ignore the OTB digital summing for now as its just confusing the issue.

The way I see it there are two different arguments in favour of analog summing:

1. Summing ITB is flawed somehow, and analog summing is more accurate.

2. Analogue summing adds subjectively desirable colour to an otherwise too perfect digital sound.

As far as I am concerned #1 is BS of the first order, and is a myth perpetuated by people with no understanding of digital audio, or (worse) with a vested interest in selling analog summing devices. Summing = adding together a string of numbers, no more, no less. Anyone who claims any different is either selliing snake oil, or has been conned into buying it.

#2 seems more plausable to me. But I still fail to see why analog 'summing' would be any different from summing digitally and then running the stereo mix through a suitably colourful 2-channel unit. Which (for probably the same money as an 8 channel summing box) might actually provide other useful features like compression or EQ. There are genuine mathematical (ie: non-voodoo) reasons why analog compression or EQ might be technically superior to its digital equivalents (read up on aliasing and Nyquist theory).

 

If its being sold as a cure for imperfections in the digital summing bus, then yes I'm afraid that is my opinion.

Well, sort of. I don't want to imply that anyone here is clueless. And I would certainly never accuse Remy of not being "technically savy"! I always enjoy Remys post's, and find them extremely interesting and informative. But that is precisely why I can't resist stepping in when I think she has it wrong.

I think that there are myths perpetuated about digital audio, many of which used to be true when mix buses had too little resolution, and internal processing used simple naive algorithms, but which no longer hold true in 2010. I don't think digital is cold or harsh anymore. But now we need to deliberately add some of the analog artifacts that we were previously stuck with, like it or not.

The question that I myself am genuinely curious about is: given that digital summing is 'perfect', is there any specific advantage to adding your analog flavour via a summing bus, compared to (eg a nice comp on the digital 2-bus? My gut feeling is: no there isn't. If you're going to spend the cash, get a good stereo comp or EQ that you can also use while tracking. But I haven't been able to try a test. I'm not even sure a proper test is possible... but if you lined up levels VERY carefully you could sum X number of channels via a summing box / desk, then sum the same stems ITB and run that mix through two channels of the same device. I was planning to try it out with a 16 channel Midas XL3 expander module that a friend offered to lend me, but unfortunately his PSU proved to be noisy as hell, and siting it outside the control room would have been too much hassle for a 6-month loaner.

Disclaimer: while I did get to record onto 2 inch tape a few times in my capacity as a guitar player back in the 90s, I have never engineered any recordings in a proper analog studio. My own modest studio has been open for only a year, is 100% ITB, and is a long way from earning me a living at the moment. But I have mixed rather a lot of live sound over the years, and the last 2 or 3 years have seen digital live consoles start to become more common than analog, at least at the higher end. There are some common models that are generally agreed to sound bad (naming no names) but I have been fortunate to be using mostly Soundcraft Vi6 desks recently: these have Studer pre-amps, bags of internal headroom, internal EQ and dynamics that sound really good, built-in lexicon FX, and 5 touch-screens to control them all. They are a joy to work with, and sound great. :biggrin:

 

Hello everyone,

I've been enjoying reading this thread as well. Perhaps none of you really know me well, I also have a small home studio that I have used for my own creative reasons throughout the years.

My background reflects as a recording artist since the late eighties. When I started my creative venture I was a teenager in my parents basement. At that time all I had was an Ensoniq EPS sampler, ESQ-m module that I had worked a couple years to buy, SM58 and a cassette tape deck. I had little money and lots of support from my parents who were artists as well. They did not fund my venture, but were supportive. I had done some work with recording my own music but really lacked the budget to get a pro sounding studio at home. At times I would save a few hundred and record in a small midi studio in Minneapolis called Film in the Cities. They actually offered a few classes in recording there, which I did take. I never really had the passion or the wit to become a professional recording engineer, I have always been into recording for my own enjoyment as a recording artist.

Anyway, I just can't help but want to give my opinion on this subject as well. I had in 2007 decided to update my ancient digital recording system to a more robust DAW. First I had to decide which platform and software to buy, which was a bit of a headache. I had been very absorbed trying to learn and develop an understanding of the software and interface that I had decided to buy. This tends to be a somewhat difficult task, depending on how much time you devote to using and learning it. For me catching up to the modern software has proven to be a bit painstaking.

To make a long story short, after using my DAW for a few years I can certainly notice a difference between mixing ITB and sending the outputs to the Analog realm and dealing with it accordingly. I especially notice when listening to a CD of mixes done ITB compared to ones done on my mixer, to me its shocking. Of course many will comment on the importance of having a decent signal chain, AD conversion and Monitors for listening critically and mixing. Certainly, for me at least, owning a decent professional analog mixer (Soundcraft, Allen+Heath,ect...) has always been a major goal of mine as well, one that has always been put off since I have rarely had the money to really afford one. I had to settle with less for now. My opinion is this, in many ways the analog mixer is really the most critical link to your sound, that is if that is what you prefer and what you enjoy hearing. I must say that overall the analog gear has always had more of an appeal to my ears even though digital has made so many amazing advances in recent years. Perhaps they will master ITB digital mixing better someday soon so you cannot tell the difference, but for now my vote is strongly in favor of the analog realm!

 

That's analog mixing however. We are talking specifically about summing.

I absolutely agree that analog and digital mixing are different, and require different approaches. I am sure that, while Remy can undoubtedly produce good mixes ITB, she can produce even better mixes using her warm cuddly Neve... but it is my opinion that the mix bus of her Neve is less of a factor than the analog EQ and dynamics she would be using, and that both of these would be much less significant than her abilities as an engineer, and her familiarity with said equipment.

If you dropped me into her studio (or any other studio full of analog gear I was unfamiliar with) I suspect the results would be reversed and (at least at first) would be inferior to my ITB mixes using the collection of plugs I have built up over years.

 

Can you really tell the difference? If you are listening to a commercial radio station, can you tell which songs were mixed with an SSL, and which were produced entirely in Logic or Pro-Tools?

 

IIRs, with all due respect I really love the simplicity of digital mixing and the ease of which your mixes eliminate any chance for noise to enter. If I could have a digital mix that could sound the same as an analog one I would most certainly favor it, no question about it. The fact of the matter is that I tend to notice a change in overall depth of the mix. Ya know, this kind of thing is really hard to put into words, and I am sure everyone would see it differently. Its very difficult to describe, this is one reason there is so much debate and controversy over this topic. I can only tell the difference in my own mix comparisons, that is Logic Pro's internal digital mix as opposed to mixing out the firestudio individual outputs on the analog console in my little home studio. Certainly I cannot tell what's being used in radio broadcasts, nor do I really care, its far beyond the scope of my experience. But what I do know is what I like when I hear it. I like analog even if it means more noise and more work to get a final mixdown, it makes the overall depth and punch so much more dynamic to my ears, even if its way more subtle than most listeners can tell.

 

Thats great jammster, I have no argument with any of that. Subjective preferences are what music is all about.

 

What calculating errors? And why would many channels make a difference? Would your calculator start to produce randomly erroneous results once your shopping list passed a certain length? You can't just assert that there are errors without providing evidence for that assertion. Every test I have ever conducted myself, or that I am aware of others conducting, indicates that digital summing is absolutely 100% perfect. Indeed, I think it would make more sense to go out of the box for compression and EQ, then back in for digital summing!

Or it could be entirely placebo. Can you reliably tell between analog and digitally summed mixes in blind testing?