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Junior Varsity
What is the audible effect of 180 polarity change between HF and mids?
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<blockquote data-quote="John Roberts" data-source="post: 41497" data-attributes="member: 126"><p>Re: What is the audible effect of 180 polarity change between HF and mids?</p><p></p><p>You can educate yourself about the audibility of stuff like this with tone bursts. Back in the '70's when I was designing dynamic processors like companding noise reductions and compressor/limiters, I built my own tone burst generator. Basically a glorified on/off (actually variable amount of off) gate that started and stopped at zero crossings for adjustable on and off times. I even made sure it presented even numbers of positive/negative cycles. (if you don't gate at zero crossings you will hear HF clicks. If you don't present full cycles you will get DC content that will cause cap coupled paths to bounce up and down. ) </p><p></p><p>As you progressively shorten the number of cycles presented of a sine wave burst, the sound character becomes less dominated by the fundamental pitch of the sine wave, and more influenced by the characteristic frequency of step function defining the on/off gate or burst time. This is kind of predicted by mathematical analysis of the waveforms and the step function it is multiplied by, but simply put a short one or two cycle long tone burst sounds more like a click or thump than a tone. </p><p></p><p>The majority of sound energy we receive is tone like, and steady state EQ matters for that. But there is a lot of information in the transients that is not tone like and not so easily corrected. </p><p></p><p>I suspect listening to tone bursts in loudspeakers could be revealing, while not immediately obvious which one is more accurate when two speakers sound different. Maybe develop a baseline for what the short burst should sound like first by spending some time with high quality headphones listening to bursts.</p><p></p><p>I found the completely adjustable on time, rep rate, and amount of attenuation when gated off, helped me parse out quirky behavior in dynamic circuits that might reveal themselves on only a single note in a musical passage. </p><p></p><p>JR</p><p></p><p>PS: My old tone burst gate, could also be used to gate musical inputs so I could artificially increase the dynamics or peak to average (crest factor) of pre-recorded music to better stress and isolate transient response flaws in dynamic processors. I don't expect loudspeakers to have the same kind of quirks related to dynamic level changes. I suspect speakers to instead have more static dead spots or unwanted honks on spot frequency content (like the length of a burst in combination with a sine wave carrier pitch). Of course this is mostly speculation about speakers on my part. I am not a speaker guy. (They're too hard <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":-)" title="Smile :-)" data-smilie="1"data-shortname=":-)" /></p></blockquote><p></p>
[QUOTE="John Roberts, post: 41497, member: 126"] Re: What is the audible effect of 180 polarity change between HF and mids? You can educate yourself about the audibility of stuff like this with tone bursts. Back in the '70's when I was designing dynamic processors like companding noise reductions and compressor/limiters, I built my own tone burst generator. Basically a glorified on/off (actually variable amount of off) gate that started and stopped at zero crossings for adjustable on and off times. I even made sure it presented even numbers of positive/negative cycles. (if you don't gate at zero crossings you will hear HF clicks. If you don't present full cycles you will get DC content that will cause cap coupled paths to bounce up and down. ) As you progressively shorten the number of cycles presented of a sine wave burst, the sound character becomes less dominated by the fundamental pitch of the sine wave, and more influenced by the characteristic frequency of step function defining the on/off gate or burst time. This is kind of predicted by mathematical analysis of the waveforms and the step function it is multiplied by, but simply put a short one or two cycle long tone burst sounds more like a click or thump than a tone. The majority of sound energy we receive is tone like, and steady state EQ matters for that. But there is a lot of information in the transients that is not tone like and not so easily corrected. I suspect listening to tone bursts in loudspeakers could be revealing, while not immediately obvious which one is more accurate when two speakers sound different. Maybe develop a baseline for what the short burst should sound like first by spending some time with high quality headphones listening to bursts. I found the completely adjustable on time, rep rate, and amount of attenuation when gated off, helped me parse out quirky behavior in dynamic circuits that might reveal themselves on only a single note in a musical passage. JR PS: My old tone burst gate, could also be used to gate musical inputs so I could artificially increase the dynamics or peak to average (crest factor) of pre-recorded music to better stress and isolate transient response flaws in dynamic processors. I don't expect loudspeakers to have the same kind of quirks related to dynamic level changes. I suspect speakers to instead have more static dead spots or unwanted honks on spot frequency content (like the length of a burst in combination with a sine wave carrier pitch). Of course this is mostly speculation about speakers on my part. I am not a speaker guy. (They're too hard :-) [/QUOTE]
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What is the audible effect of 180 polarity change between HF and mids?
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