New YouTube Video - Matt's Chats: Audio Facts, Myths, & Scams

[SuicideSquid]

Hey guys,

Recently I started uploading a weekly segment to my band's YouTube page, in an effort to keep some regular content flowing (when you just post music videos and live clips, and you only play live a couple times a year, it can be hard to feed the beast).

Today's episode is all about audio, I thought you guys might enjoy it - I give a basic summary of how recording and playback works, talk a bit about psychoacoustics and why it's so difficult to accurately compare sound quality between two devices, and then talk about a few common myths, like speaker cables, and how to insulate yourself from being fooled by such scams.

I've already recorded a "Part 2" about vinyl vs. digital, which I'll be posting next Monday.

Hope you enjoy it! Other videos are mostly focused on music (and particularly progressive and post rock music), including a best of 2025, ranking Haken's discography, defending Dream Theater's the Astonishing, and talking a bit of inside baseball about streaming vs. physical album sales vs. piracy.

 

[MattHooper]

Cool. I will have a watch.

 

[SSS]

Viewed the entire video and there is some truth in it. Told in easy understandable way it clarifies some audio topics. As educated in technical stuff and having a lifetime audio experience with LPs, tape, CDs, PC based replay I can also state that Matt is basically right. One exception perhaps, power amplifiers which can not deliver high current into a reactive load can make a difference in sound performance. The most sound influencing item was and is still the loudspeaker. These transducers create the physical air pressure in various ways which then heard as different timbre. The todays electronics is transparent if not really bad designed which can of course happen.

 

[Kaz2480]

Nice video! I have thought about starting a thread with the topic similar (at least very adjacent) to your title - along the lines of "What are the requirements of a good stereo system?". As an engineer with 40+ years' experience, I've driven approaches to developing high-quality requirements lists. When I've applied this to building a stereo system, I've asked myself the past few years - what is really needed to playback the vast majority of the music I listen to? 20 Hz-20k Hz has been a long "gold standard" of all our equipment. But what do we really NEED? Even at 20, some of our hearing range has begun to diminish. I can hear up to 13K Hz today in my early 60's. So the next question I asked myself is - what do I NEED to hear? What is the frequency content range of the music I listen to? If you search for charts of musical instrument frequency ranges, you'll find approximately two or three instruments produce fundamentals down to 20 Hz and very little goes beyond 10k Hz to 12k Hz (or there abouts - and all the charts/data I've found have a slight differences for similar instruments listed). Classical music would likely have the most demand for the largest range of frequencies - but how many scores have been written that require 20 Hz or 15k-16k Hz to be played? Of course there are harmonics for many instruments that extend from about 10k Hz to 16k or 18k Hz, but how much of that sound is truly processed by our brain...of course if you can't hear it, what does it matter? I know there has been work on "sympathetic" frequencies even beyond 20k Hz that are believed to have a psychoacoustic effect, but that will very likely be individually dependent, if it really has any effect - I do not wish to go down this rabbit hole. To answer this 2nd question of mine, I have analyzed a number of different music genres through a couple audio spectrum analyzer software tools. I'm looking at 35 Hz to about 12k Hz, across Fleetwood Mac, Sade and Art Blakey, to name a few.

So now, given my hearing range (and many people beyond age ~40) along with the frequency content of most of the music I listen to, I find it hard to convince myself I need equipment that can deliver frequencies beyond mid 30's to ~11k Hz. Each individual will have their own limits as well, but I can almost guarantee it's not 20-20k for the very large majority of the general public. These results have led me to build my own single driver, full-range speaker pair - and they sound better than any other pair I have on hand (inexpensive Elac bookshelves and older Mission 770 Freedom II...of course not in a blind test, as Matt suggests, but switching instantly from one to the other. My son has even heard sounds from music he listens to that he's never heard before through this pair.

Considering my observations and comments above, is the 20-20k Hz requirement for our equipment a "myth"...or maybe a "scam" of sorts? Food for thought!

 

[DVDdoug]

Considering my observations and comments above, is the 20-20k Hz requirement for our equipment a "myth"...or maybe a "scam" of sorts? Food for thought!

I'd say it's an "ideal".

For electronics it's easy, so why not cover the full traditional-theoretical audio range?

With speakers there are cost trade-offs, especially on the low end. Flat all the way to 20Hz must not be THAT easy because most speakers seem to roll-off a bit.

When I studied a little about lossy compression (MP3) I learned about masking (drowning out). The highest frequencies are usually weak harmonics that are masked by stronger not-quite-as-high frequencies. So even if you can hear loud 20kHz pure tones in a listening test you don't usually notice if those highest harmonics are lost. But I wouldn't use that argument to justify a speaker with a limited range unless there are also economic/cost justifications.

20Hz isn't necessary for most music (or most recordings) but when there is low frequency content I'd say it's better if you can avoid filtering it out. (But my large-ported DIY subwoofers are only "tuned" down to around the 30Hz range.)

 

[SuicideSquid]

So now, given my hearing range (and many people beyond age ~40) along with the frequency content of most of the music I listen to, I find it hard to convince myself I need equipment that can deliver frequencies beyond mid 30's to ~11k Hz. Each individual will have their own limits as well, but I can almost guarantee it's not 20-20k for the very large majority of the general public. These results have led me to build my own single driver, full-range speaker pair - and they sound better than any other pair I have on hand (inexpensive Elac bookshelves and older Mission 770 Freedom II...of course not in a blind test, as Matt suggests, but switching instantly from one to the other. My son has even heard sounds from music he listens to that he's never heard before through this pair.

Considering my observations and comments above, is the 20-20k Hz requirement for our equipment a "myth"...or maybe a "scam" of sorts? Food for thought!

Broadly speaking, there's very little "musical" content in the top octave (10kHz-20kHz) or the bottom octave (20Hz-40Hz). The bottom note of a bass guitar or contrabass is a low E, 40Hz. The bottom note of a piano is lower, but mostly what you hear are the harmonics and not the fundamental. Unless you're listening to a lot of pipe organ music, there's just not much going on down there. Same with the 10-20kHz region - as you note (and I think I made passing reference to in the video), lots of folks have lost the top end of that range (and often don't even realize). There's still relevant sonic information there - particularly frequencies in that range help to inform our brains about the space in which a sound is being recorded (why audiophiles often refer to speakers with hyped top-end as having "air"), but it's not nearly as important as what's below it.

IMO, if you can get a speaker that's pretty close to flat from 40Hz-10kHz and then maybe droops on the low-end and gets a bit squirrely on the high end, you're going to be way happier with that speaker than with one that can play at full volume at 20Hz and 20kHz but has uneven response over the range where our ears are the most sensitive.

 

[Kaz2480]

I'd say it's an "ideal".

"Ideal" - I agree, absolutely! My point is, for most product development engineering efforts, it costs much more, in time and money (as well as an ultimate increased "cost-of-goods"), to achieve the ideal performance. I have witnessed many development efforts driven by unnecessary performance goals just to approach or reach the ideal limits, or to advertise "we're better than our competitor and closer to ideal". This goal is perfectly fine, and clearly has a place, as it should, in product offerings and options. But the reality is more often that the performance exceeds the true need(s) of the user. If the general public believes all their components in their system need to pass audio signals flat from 20 Hz to 20k Hz, then I would call this a "myth".

My reply to the original thread was intended to generate some good thoughts, as those of you that have kindly posted have provided, on the very adjacent topic of - what do most listeners actually need from their equipment to reproduce and enjoy the music they are most likely to listen to at a fidelity level that meets their needs. Matt makes some very good observations about this topic - thanks for staring the conversation!

 

[Kaz2480]

Broadly speaking, there's very little "musical" content in the top octave (10kHz-20kHz) or the bottom octave (20Hz-40Hz). The bottom note of a bass guitar or contrabass is a low E, 40Hz. The bottom note of a piano is lower, but mostly what you hear are the harmonics and not the fundamental. Unless you're listening to a lot of pipe organ music, there's just not much going on down there. Same with the 10-20kHz region - as you note (and I think I made passing reference to in the video), lots of folks have lost the top end of that range (and often don't even realize). There's still relevant sonic information there - particularly frequencies in that range help to inform our brains about the space in which a sound is being recorded (why audiophiles often refer to speakers with hyped top-end as having "air"), but it's not nearly as important as what's below it.

IMO, if you can get a speaker that's pretty close to flat from 40Hz-10kHz and then maybe droops on the low-end and gets a bit squirrely on the high end, you're going to be way happier with that speaker than with one that can play at full volume at 20Hz and 20kHz but has uneven response over the range where our ears are the most sensitive.

Thanks for your thoughts on my comments!