- Creating a 20khz square wave with sound forge 9.0 pro#
- Creating a 20khz square wave with sound forge 9.0 windows#
Also, in the case of same synthetic generated signals, there can be no AD stage, then the ringing would happen due to the player filter, but I also think this is not very common, or likely to happen in commercial CD's. However, I don't think this is likely to be the case. I say most likely because if the CD player filters at a lower frequency than the AD filter, it will eliminate the AD filter ringing, but will introduce its own. So, if there is any ringing, it is already present in the recorded signal, and (most likely) not produced by the cd player brickwall filter. However, this AD pre-filtering can also produce ringing, if there was any content at the filtering frequencies in the original signal. Thinking a little bit more about this, in a properly recorded cd signal, there should be no content at these frequencies, because it must have been filtered at the AD stage in order to avoid aliasing. Also, for this ringing to appear, the signal must have content at these frequencies. So, if there is any ringing, it will appear at these frequencies. In CD brickwall filters, the discontinuity happens near 22 KHz. The more abrupt the discontinuity (~ higher slope, or steeper filter), the greater the time-domain ringing. If there is sonic "content" in the original signal at the frequency this discontinuity exists, pre or post ringing will appear. Ringing in filters happens whenever there is an abrupt discontinuity in the frequency response of the filter. The only thing you could have heard me saying is that pre-ringing due to brickwall filtering at CD's is not audible. I thought KikeG said that pre-ringing is not audible What about the variety you get in the brick wall filter for CD? The later work like real world analog filters, and show no pre-ringing, whilst the former do.
Creating a 20khz square wave with sound forge 9.0 pro#
FIR filters usually are designed to be linear phase filters.ĬoolEdit Pro allows you to use linear phase filters (FFT filter, graphic equalizer, quick filter) and minimum phase filters (parametric equalizer and scientific filters).
IIR filters behave usually like analog filters, (better say that analog filters work like IIR filters), being minimum phase. If I'm not wrong, analog equalizers are minimum phase, and use a less steep, softer style of filter. If you use instead a minimum phase filter, you will get almost no pre-ringing, only post-ringing, which is much less audible. The pre-ringing is due to the use of a linear phase filter. The smearing is due to the steepness of the filter. There is no reason why a slight variation of the transition band should tranlate into such a big difference in time smearing. I'd say this is due to SoundForge implementation. Remove the 2 Hz component in a 120 bpm song, and there is no more rhythm audible ! Even if those low frequencies (someone in depht in Lame, can you tell us the size of the block, in ms, needed to accurately encode transients ?) are not audible directly as tones, their absence is audible. Quite funny isn't it ? It must be the lowest highpass audible. So transient are smeared because they lack their sub bass components !
Creating a 20khz square wave with sound forge 9.0 windows#
That's where low frequencies come into play : using too short windows smear transients because the frequencies below the size of the window can't be taken into account, while they are needed to focus the transient. It must have something to do with the size of the window used by the filter to analyze the sound. That was the original question and it was not answered. I once used this Namlook sample in in order to show the peak level increasing after a lowpass, because the person pretended that the square wave was not a real-life example.īut they both miss the point : using Shibata's equalizer actually smears transients. I don't remember about pure square waves in a CD, but Front242 - Mutilate (from 06:21:03:11 Up Evil CD) or Pete Namlook - Entity2840 must be close to it in their way of cutting the signal. Example : there are many pure sinewaves used in Kraftwerk-Airwaves and all the Radioactivity album. Mike Walker is wrong : a square or sine wave is sound. Mirandax is right of course, there are low and high frequencies in transients. If it wasn't so old, I would have register and answered. That transient discussion in the second link makes me sick !