Marrying Hi-Fi with Pro Audio - Paul Hales | Pro Audio Technology Origins | What Matters (S3:E14)

[@bradlee2594]

Interesting guy, Paul Hales. Would love to hear more about his thoughts on room correction and how he sets up a room using his products. I know one of the amp/controllers has a simplified setup method, but I'm more interested in the other products where the simplified method is not an option.

[@DeepHorizon3773]

All new Popori Acoustics Loudspeakers will be at the 2024 Capital AudioFest in Room 840. You don't want to miss this one...maybe the New Holy Grail of Speakers ?!

[@SuperMcgenius]

Yes, so many hifi speakers struggle with dynamic range, soon as you get into the upper 90s it’s all over with compression

[@Daniel_Ho_Status_101]

I'm curious to learn more about comb filtering. Years ago, I learned from a well respected Canadian audio journalist (with the initials A.L.) that comb filtering created measurement artifacts that anyone with 2 ears and a brain didn't hear. I thought that was settled. Then the measurement influencers started harping about how M-T-M and other center channel configurations were to be avoided because of comb filtering. "Listen to pink noise, move your head around, can't you hear the cancellations?" Except I don't listen to pink noise for entertainment, and music sounds just fine through such loudspeakers. I'd like someone knowledgeable about the topic to get to the bottom of it. A Soundstage Network article would be appreciated.

[@dougschneider8243]

It's a good idea for a topic for one of my videos. But let me help out a bit to give you a brief description of what comb filtering is: Let's just use whatever stereo speakers as an example. Now let's say they're both playing identical signals. If you stuck a microphone right at an ideal listening distance away, perfectly in the middle (which would be the listening position for an audiophile listening alone), those two signals will combine constructively, reinforcing each other. But let's say that you move the microphone a little bit to one side -- now, the signal from one speaker will arrive earlier than the other because it has to travel a shorter distance. When that happens, instead of ideally combining, you'll get both constructive and destructive interference, meaning combining and cancelling, the result being peaks and valleys in the frequency response that weren't there when the two were combining ideally. Imagine the teeth of a comb -- that's comb filtering. Just by giving you that above example shows you that in any stereo system, comb filtering happens, because you have a lot of the same musical information coming from the left and right channels, yet oftentimes someone's head is not ideally in the middle -- we're human after all -- so you get constructive and destructive interference. So, in ways, we get used to hearing a lot of comb filtering going on when two speakers are playing. Now let's bring the example to just one speaker. And, for the best example, something with an MTM array, meaning two midranges, with one above and the other below a tweeter. There might be woofers above and below those midranges, or the midranges might really be midrange-woofers that also reproduce the bass. But here's the point: The tweeter acts as one sound source, so its output is reflecting around the room but also going straight to the ears. But the drivers above and below are two sound sources producing the same signal. Providing your head is perfectly between them vertically (so aligned with the tweeter), their signals, which are identical, will arrive at the same time, so all is good. But if your ears are not exactly at tweeter level, that means they'll be closer to one driver than the other and you'll get comb filtering, because one signal is delayed respective to the other because of distance differences. Now combine that problem with one speaker with what I said about stereo listening -- if your head is not exactly centered between the left and right speakers, now you have even more comb filtering going on between the two speakers as well. In short, the outputs from a stereo set of speakers can become a real mess because of comb filtering happening from one speaker and between two speakers. And that, in a nutshell, is the definition that combs up with regards to comb filtering -- two identical signals arriving at your ears, but at different times.

[@SuperMcgenius]

Martin columns book on loudspeaker. Design was way more in-depth than Vances book that helps me shape better designs for a scientific analysis. I think it was in the late 80s or early 90s that I started to read about what Floyd was doing, which was a further step in the right direction. I built my first loudspeakers when I was 11 years old, it wasn’t that they sounded great, but that I had built some thing.

[@proaudiotechnology4345]

I got you. If Soundstage has me back, I think I can explain it in a way that might add some clarity.