From the original SynthMaker forum (2004–2014), with its members’ names and dates.
MDMA ·
So I've been experimenting with the waveshaper component and find out I can have a waveform going like this:
Oposite to a normal waveform winch would look like this:
If Im only reproducing negative values Im forcing my speakers to allways move inwards, I thought there wouldn't be no sound considering there's no +/- movement.
Now my question is:Will this damage my speakers or create phase problems when combined with other sources?
Thanks in advance!
trogluddite ·
Hi there, I wouldn't worry about blowing your speakers - almost all amplifiers will have DC blocking on their inputs that will 'centre' the waveform back around the zero point.
However, you may have problems within your VST host etc. as the offset will eat up headroom, so you'll get overloading/distortion much sooner thatn you would normally - also, anything that has to read the signal level (i.e. meters, compressors, limiters etc.) may be thrown out by the offset and read the volume of the sound incorrectly.
That's not to say that you are doing anything wrong - there are a lot of DSP processes that can push the signal off to one side like this; it's a common problem. If you search for 'DC blocking', you should find a few filter modules on the forum that you can put after the waveshaper to get the signal back in the middle; or just use a high pass filter with a very low cutoff frequency (the offset counts as being a signal at zero Hertz).
MDMA ·
trogluddite wrote: Hi there, I wouldn't worry about blowing your speakers - almost all amplifiers will have DC blocking on their inputs that will 'centre' the waveform back around the zero point.
However, you may have problems within your VST host etc. as the offset will eat up headroom, so you'll get overloading/distortion much sooner thatn you would normally - also, anything that has to read the signal level (i.e. meters, compressors, limiters etc.) may be thrown out by the offset and read the volume of the sound incorrectly.
That's not to say that you are doing anything wrong - there are a lot of DSP processes that can push the signal off to one side like this; it's a common problem. If you search for 'DC blocking', you should find a few filter modules on the forum that you can put after the waveshaper to get the signal back in the middle; or just use a high pass filter with a very low cutoff frequency (the offset counts as being a signal at zero Hertz).
Humm, thanks for the info trogluddite, I'm asking because I've experienced in some songs when I make the bass waveform look like that it tends to sound better when glued to the kick for some reason, so it must have some kind of effect that changes the sound, or maybe its something to do with the phase of both kick and bass, not sure on that, but its good to know that it wont damage the speakers and that need to be carefull with post processing due to early distortion. Thanks
trogluddite ·
MDMA wrote: when I make the bass waveform look like that it tends to sound better when glued to the kick for some reason
You have the ears and instincts of a sound engineer for sure! (and without those, all the technical mumbo jumbo in the world can't hep you) 🙂 But here's some mumbo jumbo anyway!... 😉
If you play a continuous sound with an offset, there's not a lot of difference to hear - but when the audio changes from centred, to not centred (i.e. a sudden DC offset when the note starts), the stepping up (or down) from the centreline causes an impulse. According to the theories, a step like that creates a very short pulse that contains every possible frequency - so no matter how busy your mix, you are sure to hear it! It also means that even if you put a DC blocker in, you'll still get a pulse (takes time for the blocker to react), but the steady part of the sound after will still get leveled out (so you can still avoid any weird level problems). Some of the classic analogue synths had these kind of DC 'thumps', which explains why certain ones are real favourites with fans of hard rhythmic bass - and, just as you say, it helps to line it up with the kick, so that the rhythm is nice and solid. You obviously have good ears, so go with what they are telling you - some DC blocker designs may be 'too good' and kill off something that you like!
And you are also spot on about phase - take a peek at the wave shape of your kicks and look for which direction the wave goes right at the start (usually up), and try to match that with the DC offset on the synth. That way the 'thumps' will add together instead of cancelling out - for maximum 'punch'. If your sequencer has 'invert' buttons on the tracks, that will make it dead easy to get the waves going in the same direction.
Yuroun ·
Trog, great explanation. Well done 🙂
MDMA ·
trogluddite wrote: And you are also spot on about phase - take a peek at the wave shape of your kicks and look for which direction the wave goes right at the start (usually up), and try to match that with the DC offset on the synth. That way the 'thumps' will add together instead of cancelling out - for maximum 'punch'. If your sequencer has 'invert' buttons on the tracks, that will make it dead easy to get the waves going in the same direction.
Thanks a lot for the explanation mate. It really makes scence, I have experienced before that when I invert polarities things start sounding punchier or less punchier depending on that fact, in fact the first and only synth I comercialised was a sampler combiner tool: http://www.minddoctorsmakeacid.com/synths/ And the phase inverstion button I added really helps to combine sounds together in order to get more punch. I can now use this with more understanding for my next projects. Thank you!
PS-Are you portuguese by any chance?
trogluddite ·
Thanks guys, it's always good to know when my 'mumbo jumbo' is useful (or not)! 🙂
MDMA wrote: sampler combiner tool
That looks cool - always so good when you can make a custom sound quickly, so you don't lose the 'flow' when working on a new tune.
MDMA wrote: PS-Are you portuguese by any chance?
No, English - and like most Englishmen, I only really speak/understand English. 😊 It would be good if our schools would teach us to understand other languages better - seems wrong that always we expect other to use our language.
Xtinct ·
trogluddite wrote: seems wrong that always we expect other to use our language.
That dosn't sound very English 😉
MDMA ·
trogluddite wrote: MDMA wrote: PS-Are you portuguese by any chance?
No, English - and like most Englishmen, I only really speak/understand English. 😊 It would be good if our schools would teach us to understand other languages better - seems wrong that always we expect other to use our language.
True! I only asked because we use the word trogludita and thought you were using and adaptation of the word for your name.
trogluddite ·
Xtinct wrote: That dosn't sound very English
He he, our old "colonial and empire" habits are taking a long time to die - still we are deluded and think we rule the world!
MDMA wrote: trogludita
In English, is normally spelled "troglodyte" = Cave Man (I used to go underground to explore the caves around here).. I used instead '-luddite". Luddites were some people in England at the 'Industrial Revolution' who sabotaged the machines because they wanted to be creative craftsmen instead of slaves to the factory owners.
Dell ·
MDMA wrote: If Im only reproducing negative values Im forcing my speakers to allways move inwards, I thought there wouldn't be no sound considering there's no +/- movement.
There will always be sound from your loudspeakers for the cone is moving from the starting point (where the voice coil sits when there is no signal present) inwards.
Bear in mind if the xmax of your loudspeakers is +/- 12 mm, it means 12 mm forward and 12 mm reverse.
The starting point of the voice coil would translate to 0 mm.
Cheers!
MDMA ·
Dell wrote: MDMA wrote: If Im only reproducing negative values Im forcing my speakers to allways move inwards, I thought there wouldn't be no sound considering there's no +/- movement.
There will always be sound from your loudspeakers for the cone is moving from the starting point (where the voice coil sits when there is no signal present) inwards.
Bear in mind if the xmax of your loudspeakers is +/- 12 mm, it means 12 mm forward and 12 mm reverse.
The starting point of the voice coil would translate to 0 mm.
Cheers!
Thanks mate, it makes sence!
Leslie147 ·
... and absolute polarity of sound, or an electronic signal that represents it, is an interesting topic that doesn't really appear to have been resolved.
Opinions seem to be divided as to whether the initial transient in the sound of a kick drum really must be positive for it to appear realistic when reproduced over loudspeakers. Douglas Self almost, but not quite, says this ... his view seems to be to preserve the phase of whatever was presented by the microphone that recorded the sound, which is a conservative approach, but that doesn't apply to synthesisers.
I wonder if those that sit in seats behind the band get the polarity of the kick drum sound reversed. Nowadays, that probably depends on how they're served by the PA system.
Chris
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