(and that was, what voitech meant, when he told me in very short back then... now I understand it)
This is what Chat GPT wrote:
"You're dealing with the difference between minimum-phase and linear-phase impulse responses (IRs) and how preringing affects the sound. Let me break it down for you:
1. Linear-Phase vs. Minimum-Phase IRs:
Linear-Phase IRs: These typically exhibit the "preringing" you've noticed. The peak of the waveform is in the center, and the IR is symmetric because it treats phase information equally across the entire frequency spectrum. This means that the phase shifts across frequencies are consistent (hence "linear-phase").
Pros: No phase distortion. All frequencies are handled evenly, which is often ideal for precise frequency response corrections.
Cons: Preringing—the ringing or oscillations before the main impulse occurs, which can be particularly audible in signals rich in transients (like drums).
Minimum-Phase IRs: These IRs are "shifted forward," meaning the largest peak occurs at the beginning, with no preringing. The phase information is adjusted to minimize delay.
Pros: No preringing. This often sounds more natural, especially for transient-rich signals.
Cons: Phase distortion. Some audible phase shifts can occur, especially with wide frequency content.
2. Preringing and Perceived Sound Differences:
Preringing is a common phenomenon in linear-phase filters. You mentioned that cutting off the preringing (the pre-ringing part of the waveform) doesn’t seem to change the sound significantly. This can often be true, especially with less transient-heavy signals. In many cases, the preringing isn’t immediately noticeable in music or natural material, but with strong transients (like drums), it can sound unnatural.
When you cut off the preringing in an IR, you're effectively turning a linear-phase IR into a minimum-phase IR. The resulting phase distortion is usually subtle and often acceptable in many practical cases. However, if the signal is sensitive to phase shifts, you might hear a difference.
The audio developer you mentioned might be suggesting that in pure linear-phase filter theory, preringing is a natural consequence of maintaining a flat phase response across frequencies. There is no such thing as a "perfect" linear-phase IR without preringing—the two are inherently linked.
3. Conclusion:
You can absolutely use minimum-phase IRs or modify a linear-phase IR to a minimum-phase IR (for example, by trimming off the preringing).
The key difference between these approaches lies in phase distortion and possible preringing. Depending on the type of signal you're processing, this can either be audible or not.
There is no "wrong" way here—it really depends on what works best for your specific case (e.g., music production vs. audio analysis). If the sound without preringing is better for you and you don't notice significant phase issues, then that's a valid approach.
If you'd like, I can go into more detail or give you tips on how to further analyze and process your IRs!"
This is what Chat GPT wrote:
"You're dealing with the difference between minimum-phase and linear-phase impulse responses (IRs) and how preringing affects the sound. Let me break it down for you:
1. Linear-Phase vs. Minimum-Phase IRs:
Linear-Phase IRs: These typically exhibit the "preringing" you've noticed. The peak of the waveform is in the center, and the IR is symmetric because it treats phase information equally across the entire frequency spectrum. This means that the phase shifts across frequencies are consistent (hence "linear-phase").
Pros: No phase distortion. All frequencies are handled evenly, which is often ideal for precise frequency response corrections.
Cons: Preringing—the ringing or oscillations before the main impulse occurs, which can be particularly audible in signals rich in transients (like drums).
Minimum-Phase IRs: These IRs are "shifted forward," meaning the largest peak occurs at the beginning, with no preringing. The phase information is adjusted to minimize delay.
Pros: No preringing. This often sounds more natural, especially for transient-rich signals.
Cons: Phase distortion. Some audible phase shifts can occur, especially with wide frequency content.
2. Preringing and Perceived Sound Differences:
Preringing is a common phenomenon in linear-phase filters. You mentioned that cutting off the preringing (the pre-ringing part of the waveform) doesn’t seem to change the sound significantly. This can often be true, especially with less transient-heavy signals. In many cases, the preringing isn’t immediately noticeable in music or natural material, but with strong transients (like drums), it can sound unnatural.
When you cut off the preringing in an IR, you're effectively turning a linear-phase IR into a minimum-phase IR. The resulting phase distortion is usually subtle and often acceptable in many practical cases. However, if the signal is sensitive to phase shifts, you might hear a difference.
The audio developer you mentioned might be suggesting that in pure linear-phase filter theory, preringing is a natural consequence of maintaining a flat phase response across frequencies. There is no such thing as a "perfect" linear-phase IR without preringing—the two are inherently linked.
3. Conclusion:
You can absolutely use minimum-phase IRs or modify a linear-phase IR to a minimum-phase IR (for example, by trimming off the preringing).
The key difference between these approaches lies in phase distortion and possible preringing. Depending on the type of signal you're processing, this can either be audible or not.
There is no "wrong" way here—it really depends on what works best for your specific case (e.g., music production vs. audio analysis). If the sound without preringing is better for you and you don't notice significant phase issues, then that's a valid approach.
If you'd like, I can go into more detail or give you tips on how to further analyze and process your IRs!"
Statistics: Posted by mccy — Mon Oct 14, 2024 8:21 pm — Replies 0 — Views 54