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Thoughts on dynamic EQ's

Discussion in 'Recording' started by jmm22, Jan 8, 2011.

  1. jmm22

    jmm22 Guest

    I am looking at getting a dynamic EQ, quite possibly Voxengo's GlissEQ, but I do not have a complete understanding of the dynamic aspect. My best interpretation from what I have read is that if the dynamic function is fully engaged, the EQ (say if there is a boost at 2Khz) will only be applied to the peaks and not the average content at that frequency. Is this correct? Any other thoughts or elaboration of dynamic EQ would be greatly appreciated.
  2. RemyRAD

    RemyRAD Well-Known Member

    You sort of have the idea right. Case in point. Dolby B style noise reduction is basically a dynamic equalizer. When recording with it, the lower volume levels get more high-frequency boost than at the higher audio levels. You can hear this by playing an old-fashioned Dolby B encoded audio cassette without the Dolby being engaged for playback. You'll hear as volume levels drop or begin to fade out, the high frequencies start getting boosted more & more. But because this is a "COMPANDER" -based noise reduction system, one must play the recording back with the decoding high frequency dynamic equalizer which, is now dynamically lowering the high frequency response when levels are at their lowest and reducing that when the levels are at their highest. Typically, a dynamic equalizer frequently finds its place as a "De-Esser". You adjust the equalization frequency for the bell shaped curve between 3-6 kHz. Then you set your threshold for the amount you want. So anytime sounds become too rich in that 3-6 kHz region, the compression more highly affects those frequencies. So the more that 3-6 kHz sibilant "S" happens the more the dynamic equalizer can either boost or cut certain frequencies dynamically. Conversely they can also dynamically enhance those frequencies, which you may not necessarily want to do. Another example is FM broadcast limiters. Because high frequencies are boosted during transmission and the higher frequencies are dynamically lowered on playback, the resultant advantage is gaining 10 DB of signal to noise. But because of the constant high-frequency boost, products already rich and high frequencies would quickly distort. So they just simply took a broadband limiter and only made it sensitive for frequencies from 10 kHz on up. So whatever that high energy rock 'n roll cymbal crashes, it's not going to cause any out of band deviation nor splattering nasty distortion. The dynamic high-frequency limiter prevents that. I even modified and used a UREI 1176 broadband limiter that included a little RC network along with a switch. This would allow me to add much more aggressive mid & high frequency equalization to announcers, for commercials, without any irritating or grating overprocessed sound. Although I do feel that dynamic equalizers should only be put in the hands of people that have a thorough understanding of what they're trying to implement. This is a highly specialized type of equalization and I've never really come up with any fully practical use of always having a dynamic equalizer. In many ways, I've had one in software since 1996 and I really don't believe I've ever used it? I personally don't think there are many practical applications for wanting to consider this? If it doesn't already come with your DAW software, I just wouldn't think of spending any money on something I'm not even clear on how to use. I'm not even really hot on that spectral/multiband compression. It certainly has a positive function in
    the broadcast arena. I rarely use multiband compression but I definitely use lots of broadband dynamics processor. It doesn't squish the life out of your recordings as badly as the multiband stuff. So, why do you want a dynamic EQ?

    Dynamically inverted
    Mx. Remy Ann David
  3. Big K

    Big K Well-Known Member

    The Dynamic EQ of the PowerCore range of plugs is, along with the Character plug, the only reason I still keep PoCo in my machine.
    I don't use it that often, but DynEq is a valuable tool for several tasks. DeEssing is one of those.
    Basically, whenever a frequency is temporarily over or under the intended level it comes in handy.
    You can cure things that can't be fixed with volume changes or static EQs. Atm, I am looking at BrinWorx dybamic EQ, but have not tested it, yet.


    To beginners the Multiband compression is truly rather complicated and more can be messed up then improved.
    The sheer number of parameters that can be set/changed is a source of mistakes, already. Once you find one that
    sounds good and you have learned to use it, it becomes a great help, ..again not for everything, but in certain cases.
    If you can't tell, if a piece of music can be improved with multi compression or not, one better leaves it on the shelf.
  4. jmm22

    jmm22 Guest

    Thanks for the helpful replies.

    To quote George Mallory, because it's there. :tongue: But to elaborate, one learns of new tools and assumes there is a purpose to them, and then one wonders if that purpose might be beneficial. Of course this kind of end-user thinking is the very lifeblood of plug-in developers. :smile: The dynamic EQ's I have scouted also function as normal EQ's, in which case, the dynamic component can remain in a perpetual state of readiness for the day when I figure out some way to use it in some beneficial way. But I am glad to learn they are hardly a necessity. There are enough parameters to control as it is.
  5. RemyRAD

    RemyRAD Well-Known Member

    Yup and that's a good reason to want to know about dynamic equalizers. Back in the 1960s radio era CBS laboratories were quite popular for their broadcast limiters & compressors. They had a unique processor known as a "dynamic presence enhancer". This was nothing more than a compressor that had an equalizer in the sidechain of the level detector. The equalizer in the sidechain had some of the midrange sucked out. This was really the inverse of a "De-Esser". By making the detector less sensitive in the midrange presence frequencies, the compressor would pull those frequencies dynamically up more so than higher & lower frequencies while adding density to that midrange frequency spectrum. Dynamic equalizers can also be utilized to add more punch to your mix. At a now-defunct hit recording studio I used to work at in New York City their motto in-house was "An ounce of Punch is worth a Pound of Sound". Something I have always lived by. Multiband compressors are basically dynamic equalizers. It's just a full house of multiple dynamic equalizers. And there can be a lot of reasons to use them. Every radio & TV station does and has used them since the mid-1970s as the last stage before the transmitter. So basically the radio & TV stations are adding additional stereo bus processing that you already added to your stereo bus. This can aid in evening up a not well balanced mix. And so it's popularity reigns supreme.

    I get wet when it reigns
    Mx. Remy Ann David
  6. IIRs

    IIRs Well-Known Member

    Dynamic EQ is a favorite trick of mine. But usually as a way to fix problems that normal EQ or dynamics can't deal with. If you track everything perfectly to begin with like Remy you will probably never need one. ;)

    Anyway, there seem to be a few different approaches to dynamic EQ. I've not tried the Voxengo one, but as I understand it the dynamic behaviour is largely preset: dial in a boost and you get upward expansion, or dial in a cut for downward compression. I'm sure it sounds great, but it doesn't provide as many problem solving options as my own design IQ4gui (click my sig)

    IQ4 exposes all the various filtering and dynamics parameters, so you can set up any dynamic behaviour you choose, and combine it with static gain in either direction. ie: you can combine a boost with downward compression, so that a specific frequency is compressed with make-up gain. Or you can combine upward expansion with a cut. And you can specify the threshold, ratio and ballistics for each band.
  7. IIRs

    IIRs Well-Known Member

    I just skim-read the Gliss EQ manual: turns out it doesn't react to volume changes like a compressor, it actually responds to transients like a transient designer. This means it is actually a totally different beast to my IQ4, or to other processors called "dynamic EQ" such as the hardware BSS DPR901.
  8. jmm22

    jmm22 Guest

    I'll be sure to give your IQ4 a try IIrs. Thanks for the reminder.
  9. CG1

    CG1 Member

    AH... THERE you are! What an excellent design! I've always wanted to say 'thank-you'! It is about the only thing in software that effectively emulates what I've been doing in hardware for ages. The Sonalksis does similar - but is considerably heavier on resources.

    Thank-you - I've just recently recommended the IQ4gui to several others.
  10. Mario-C.

    Mario-C. Active Member

    Dynamic EQs are incredible especially if they can do compression and upward/downward expansion both below and above thereshold ... ToneBoosters FLX can do this, there's so much control, it rocks.
  11. Mo Facta

    Mo Facta Active Member

    I use IIRS's dynamic EQ often. I've thanked you before but thanks again!

    I find it incredibly useful for eliminating annoying ringing frequencies. It's a lot more surgical than a regular MBC because of the adjustable Q width. I also love the listen function. It's just a great processor. Thanks for making it available for free!

    Cheers :)

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