Passive summing box, OTB vs ITB

Discussion in 'Summing Mixers' started by audiokid, Feb 23, 2015.

  1. audiokid

    audiokid Staff

    What do you think of the changes between ITB and OTB, and the demonstration?

    Do you think this is a the best way to allow us to hear an A/B ?

  2. DonnyThompson

    DonnyThompson Distinguished Member

    I don't believe it was the best way to present an A/B demo. I also don't believe that the track/instrument that he chose was the right choice. I'd have rather heard it on something like vocals.

    One of the reasons I thought the bass was a poor choice, is because the bass sample he chose was - IMO - the wrong sample for the song to start with. Of course this is just a personal opinion, ask someone else and they might say it's perfect - but I felt that it sounded too dark and undefined. It's what I call "frumpy" - which is my way of describing loose and muddy. It's also working in a fairly limited bandwidth range... having an instrument that has a fundamental range that rolls off at around 400hz or so probably wasn't the best instrument to choose to demo saturation.

    Unless I'm not hearing this accurately, the source sample sounded as if it was already saturated - either recorded with it, or processed with it. So, he's taking a sample that's already saturated to begin with to a certain extent, and adding even more of it.
    I'm not sure that's the best approach. He might have been better off to start with a sample that was more transparent, and then showing what saturation could do.

    I'm not against slight changes... changes don't always need to be dramatic to make a big difference, but from what I'm hearing, he's making these tracks sound opposite to what he's claiming that he wants.

    I'm also not against saturation, but I'm not sure that, if you are sending the track OTB, that the little passive device he was using is the best way to go. In that workflow, I'd rather hear something with some voltage to it... but, that's just me.
    Saturation is one of those current digital mixing trends that I think is being overdone a bit. I like the sound of a nicely saturated track as much as anyone else does, saturation can be one of those double-benefit additions - if it's done tastefully, it has the advantages of both smoothing out and warming up a track, as well as making the track pop out a bit more in the mix. But when it's overused, it becomes a smeary mess, wiping out clarity and definition (especially on an instrument like bass).
    It seems like there's perhaps too much of it being used nowadays.

    I don't believe that he was doing anything OTB that couldn't also have been done ITB, and given the passive summing device he was using, the ITB options would probably be the better choice.

    Personally, I liked the Slate processing better, but using the RC Tube setting didn't add definition, if anything, I felt that it accentuated the loose sound.

    Also - and this is just the musician in me talking - the bass sample is lagging from a performance aspect. It's not in sitting in the pocket... and that would drive me crazy to have to work with.

    IMHO of course.

  3. Boswell

    Boswell Moderator Distinguished Member

    Funny, I was sure I replied to this yesterday, but nothing has appeared. I didn't automatically look at the thread until I saw Donny's post was there just now. Maybe I didn't hit "Post Reply". Oh well ..

    It was a pretty rubbish demo in my opinion. The first time through I listened on headphones, and couldn't believe how undefined the bass was. I found it hard to tell any difference between his A and B. When I got back to my studio last night I listened on my monitors, and things were even muddier. Using a sub made the bass overwhelming (on my standard settings). Turning the sub off reduced the amount of LF but didn't make it defined.

    What's this guy promoting? If it was how to introduce saturation to tighten the bass in a mix, it was a failure. If it was to show how much better the bass was when put through a passive external box, it was, well, ... a failure.
  4. DonnyThompson

    DonnyThompson Distinguished Member

    Yup, pretty much my thoughts, too.

    I mean - unless the audio we are hearing is different from what he is hearing - but there's no excuse for that, either, if that's the case. If you are going to make a video where the main subject/presentation is to A/B audio tracks, you'd better be sure that what you are hearing is what the listener is hearing, as well.

    So, if this is the case, and the audio on the public version is different from that of what he was hearing - to add to what Bos has considered to be "fails", IMO, there's another "fail" there, too.

    It's not enough for you to tell me how "awesome" something sounds, regardless of what type of processing is being used. You have to allow the listeners to hear the difference for themselves, and make their own judgements.


  5. Kurt Foster

    Kurt Foster Distinguished Member

    is this guy famoose? who is he?
  6. audiokid

    audiokid Staff

    Same here. Glad you guys are all on the same page.

    One point we've all not mentioned, which really sums up why I posted this ... when I do any A/B, I never do it like this. I always copy the A/B on a new track, nulling attempt and what ever else I can do to get them both as close as I can before I even begin, then loop the exact parts on a 2 bar measure so they are seamless beat matched perfect as I can get it. I don't talk either and I clinically listen to them as they run in the timeline. This guy is talking, pausing and going between two tracks like he's never done a comparison helpful for him in his life.
    Talk about wrong.
    This is a ridiculous example of how you should never compare audio.
    As bad as it all is, the ITB sounded much better . I'm with all of you!
  7. Kurt Foster

    Kurt Foster Distinguished Member

    i admit to being a snob when it comes to ewwutoob tutorials. i tend to give the ones put up by someone with a track record more credit than ones put up by someone i have no idea who they are. that's why i was asking who this guy is? i admit i'm not that informed to current trends and who's doing what. i'm still trying to figure out where this stuff is getting played.
  8. audiokid

    audiokid Staff

    I was approached by a manufacture who made these passive boxes yesterday. Before I advertise anything, I research it. No point in pushing something we don't like here, or that I wouldn't use.

    Through research stemming from the testimonials of the Manufacturers site, I found this video. I have know idea who it is so I'm like you Kurt, left scratching my head.
    Because it was a referred link in my quest to learn more, I followed it and after seeing this, I couldn't help but post it. I know we are very interested in these passive summing boxes. I think it may be the same one you may have bought or similar?

    They look like a cool deal. I wonder how something would sound using my m-2b or the SPL Premiums that have Lundahls on both front and back. Whatever this guy used, sounded like mud.
  9. Kurt Foster

    Kurt Foster Distinguished Member

    why should true passive summing box's should be that expensive? i asked around a lot and no one could tell me why something like the LittleOne 8 i bought isn't as good as anything else. the price goes up when you add transformers at the front end or amps at the 2-bus at which point it's no longer a passive system ....

    i like the idea of a passive box that i can choose what i use for make up gain. and there's other uses for a passive summing network during tracking.

    imo, a truly passive summer shouldn't make anything sound like mud or anything else .... that would be the fault of something / someone else.
  10. audiokid

    audiokid Staff

    These ones I am referring to are a few hundred. They appear well made . I'd like to get a few here but I think my OP pretty much blew that lol.
  11. Kurt Foster

    Kurt Foster Distinguished Member

    Xicon metal film resistors vs Vishay resistors (mil spec).?

    priced about the same

  12. Boswell

    Boswell Moderator Distinguished Member

    Don't knock the importance of resistor specifications. Figures that few resistor manufacturers release include curves that show the change of resistance with terminal voltage, which in certain types of precision resistors can be significant, especially surface-mount types. This property is a recipe for distortion, of course, and the higher the signal levels, the greater the distortion. It's one of the reasons I remain to be convinced about high-voltage summing boxes.
  13. audiokid

    audiokid Staff

    Me like my neos :love:
  14. audiokid

    audiokid Staff

    Bos, The m-2b obviously has a good rail. So, would one of these little passive boxes be like having a big rail summing box then?
  15. Makzimia

    Makzimia Active Member

    I'm glad I am not the only one who thought that demo was lame. Figured at first it was just because I was listening on my PC speakers.
  16. DonnyThompson

    DonnyThompson Distinguished Member

    @Kurt Foster @Chris @Boswell

    I guess I'm one who doesn't care as much about someone being famous, as long as they know what they are talking about, and present their subject in a clear and concise fashion. I'd be just as interested in something that the people here on RO would have to say as I would be from someone famous - as long as the person who is famous wasn't endorsed by - or shilling for - a particular manufacturer.

    I've learned just as much from "common" studio guys like us as I have from people like Pensado. Being "famous" is not a prerequisite for me to listen and consider what someone has to say.

    All that being said, the video was still bad - whether the guy is "known" or not.
  17. Boswell

    Boswell Moderator Distinguished Member

    Not really - the important point is the difference between passive and active boxes. Passive boxes by their nature need make-up gain, and you are free to use what you like for that - a clean pre-amp, a transformer-based pre-amp or even a valve (tube) pre-amp. You can change it depending on the material you are mixing. The active boxes contain their own make-up gain, and once you have bought it you are stuck with what the manufacturer chose to include, which, I have to say, is usually a very good, transparent amplifier. High-rail active boxes are just a variant of this, and aim to give more headroom above the noise floor.

    What I was drawing attention to is the little-known property of most resistive materials that their resistance is not exactly constant but varies not only with temperature but applied voltage and frequency. Temperature is not usually a problem as it is a slow-changing effect and so does not in itself change a waveform, and frquency-dependent resistance does not usually rear its head in audio. However, voltage-dependence is a very real effect, as it means that the summing current flowing in a resistor is not a strictly linear function of the voltage across it. In itself, this is like a re-wording of the definition of distortion, but, as with things like tape and transformer saturation and valve transfer curves, there is "good" distortion and "bad" distortion.

    While most through-hole resistors are linear within the errors of measurement over a range of 10V or so, a lot of surface-mount components are measurably non-linear under the same conditions. However, unless you are very careful, even through-hole resistors can show non-linearity at 50V or more. That said, I'm sure that Neos with their +/-60V rails and other manufacturers of high-rail audio devices are well aware of these problems and carefully specify and then select components to give the performance they require. As an aside, I've recently been engaged on some high-voltage designs and at critical points in the circuit have chosen to use several resistors in series so the voltage across each one and its power dissipation stay within a reduced range.
    DonnyThompson likes this.
  18. DonnyThompson

    DonnyThompson Distinguished Member

    Bos...At any point in an active summing system is a starving voltage processed used? I'm just curious to understand more about it, I know that you mentioned that most high end models are built to pass signal as transparently as possible, but what about valve-based or FET summing devices? Is color added through the tube itself, or is voltage starving ever implemented to gain a color/character?
  19. Boswell

    Boswell Moderator Distinguished Member

    I don't know the full range of commercial summing devices, but it's up to the individual manufacturers to choose how they do the make-up gain. I'm sure that if there were a marketing advantage to be gained from claiming a particular box used starved-plate techniques in their summing amps, then certain manufacturers would do so.

    Although the innards are quite dissimilar, there's not a lot of difference between what's involved in choosing a summing amp and choosing, say, a microphone pre-amp. You go for measurable specs like dynamic range and noise levels, and then there are unquantifiables like "character" and "colour". It's odd that you may want those things in a pre-amp and absolutely not in a summing amp. You have to go with what sounds right in the application that you need it for.
    DonnyThompson likes this.
  20. DonnyThompson

    DonnyThompson Distinguished Member

    I have to admit I'd never considered that before, but it makes total sense when you put it that way. What really clarified the jist of it for me was this:

    "...There's not a lot of difference between what's involved in choosing a summing amp and choosing, say, a microphone pre-amp. You go for measurable specs like dynamic range and noise levels, and then there are unquantifiables
    like "character" and "colour"..."

    I take the description of "Unquantifiables" as relating to an individual's perception of what we hear that is pleasing to us - which is why some people like certain preamps like Neve 1081's, Harrison 32's, etc., where some might prefer SSL or other "clinical" types of sound - along with tube mics and/or pre's vs. SS or FET, because those particular sounds are pleasing to them - where as others want the signal to be as transparent as possible...

    I don't think there is any right - or wrong - in this scenario. It's all about what someone likes... and that makes it unquantifiable, because perception is individual and often difficult to describe.
    "Quantifiable" would be a certain sound that we would all agree on as being bad, or, even great. There are concrete reasons as to why it sounds that way to us, whether it's the quality in the build, or the components, where factors like noise, limited bandwidth/frequency response, or poor conversion, can actually be mathematically measured. Those aren't "perception" factors, they are...well... "quantifiable". ;)

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