Just draw a simple saw wave ( sample editor )
Go to instruments tabs , choose a filter , disable envelope , enable lfo …choose sine and set amount to 18 …
Boy O boy …it sounds like a square wave lfo …from one extreme to anothere extreme …=.nothing ,the negative phase of the sine lfo ( inverted )is not applying any modulation , only the positive phase of the cycle is …just look at the indicator and hear for yourselves ,
no option to set the intial cutoff point , every possible lfo waveform with a modulation amount obove 10 sounds the same …the saw lfo sounds like a square
WHen an lfo is assigned to pitch , the actual shapes of the lfo makes more sense , a saw lfo is actually a saw , but only an upwards saw with no possibility to inverse it by applying a negative mmodulation amount , which is marginallly small
I think this is one of the weakest , parts of renoise …
We need , accurate lfo shapes when applied to cutoff , an initial cutoff point ( when not using te envelopess , and a bigger modulation amouint when modulating pitch .
The instrument editor had a huge overhaul in this release , which can’t be said of the lfo and filters
We need Dblue in here with tests, graphs, and screenshot proof
Can’t say I use the instrument lfo’s much, but I believe you if you say they’re crap.
Hey, we need to save some cool stuff for upcoming releases as well
As mentioned a few times before, we deliberately did not touch the instrument modulation devices for this release. Too much work for the 2.7 release. They where only made this way to be fully backward compatible with the old instruments.
Expect lot of changes for this in upcoming releases…
The instrument LFOs are actually applied on top of the envelopes. This makes a lot of sense, because it allows you to create a main envelope which dictates the overall behaviour of your sound (some kind of fade or sweep, for example), while also having an LFO applying some extra little modulations on top.
If you’re only using the LFO by itself, then I agree that the behaviour can seem a bit strange at first, but the only thing you have to do here to ‘fix’ things is create an envelope with a single point positioned at a sensible starting frequency. For example, if you create a cutoff envelope and put a single point at around 7kHz, and set the LFO amount to around 64, then the LFO will modulate the frequency around this center point and behave as you expected.
If you do not have a cutoff envelope defined, then the initial cutoff frequency is assumed to be 0kHz. The LFO is still actually working normally in this case, but it’s modulating the frequency around a center point of 0kHz, and so you will only ever hear the positive phase of the LFO cycle when using a lowpass filter. If you switch the filter from lowpass to highpass, then you will only hear the negative phase of the LFO cycle, because the highpass obviously works in reverse.
The pitch LFO operates in the same way, it’s just that a default center point of 0 works out great for pitch, so it doesn’t result in a behaviour that feels buggy to you at first.
For the filter, a default cutoff frequency point of 0kHz is perhaps the only ‘bad’ thing here. A more central default cutoff frequency (somewhere between around 8kHz - 10kHz, for example) might be a better starting point, but all this stuff will be overhauled later anyway as Pysj has already mentioned.