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Comment by sjwright | Hacker News Reader

I must say I get rather irritated when people spend time worrying about dubious 'tweaker' methods to improve their audio, when the most under-performing component of most people's sound equipment also has the lowest-hanging fruit: The room itself.

When people ask me where they should spend money to improve the quality of their hi-fi or home theater system, in nearly every case my response will be something like "get a thicker rug" or "put something on this wall to absorb sound reflections, even if it's just a bookshelf."

Beyond that, I'd tend to say something like "stop being so paranoid about what you think you can't hear, and enjoy the damn music."

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stop being so paranoid about what you think you can't hear, and enjoy the damn music.

I'm a composer who works in film/games. I can assure you this is exactly what I'd like people to do when they listen to my music. I spend 99% of my time trying to create good musical ideas, and I spend 1% of my time getting the mix down. I get criticized (rightly) for this quite a bit, but it is hard to care about someone sitting in a >$10,000 labyrinth of sound equipment when I'd rather write a catchy tune.

Then again, when I write sheet music I have to endure some of the most soul-crushingly awful midi sequencing in order to check my work, so perhaps I'm too tolerant to terrible sound quality. Still, I'd rather people listened to the music, not the sound of it.

What's wrong with caring about both sides of it?

A good sounding catchy tune is something work spending that little bit more time on.

I don't necessarily mind effort spent on making sure that music is presented properly-- what I mind is when it supersedes all other concerns about the music.

> A good sounding catchy tune is something work spending that little bit more time on.

But in reality most of your customers want a ton-frakk of compression, loudness and filters on that catchy tune so it ultimately sounds HUGE on the tiniest phone, radio and car speakers... so all that audiophile mixing and dynamics are completely lost anyway.

Agree one-hundred percent about the room (although the prescription isn't always as simple as "get a thicker rug" etc).

The other issue regarding high-frequency sound reproduction is that in most cases, the loudspeaker won't be outputting much beyond 22-25 kHz (assuming very good quality loudspeakers, cheap consumer grade units might struggle to hit a -6 dB point at 18 kHz) and even for the speakers that have usable output at that range, the directivity at those frequencies will be so narrow that your head will have to be locked in the perfect "sweet spot" to hear anything.

I might sound/be stupid for asking, but what's the actual physical response from something at 22 kHz+? I have a hard time picking up a pure sine > 17 kHz. I doubt I'd get any aural response from anything at 22 kHz, so what's the deal?

...of course I mean audible. Or spectral? Not aural, anyway. English is not my first language. Sorry.

That's really good actually, I'm not even sure I know the difference between aural and audible. (<- also, that sentence is a run-on and not good English haha)

The deal is just that you're getting older. Your ears just don't work as well as a 12year old's. Neither do anybody else's your age (within the bounds of typical human variation - probably well over 95% of use _never_ heard 22kHz, not matter _how_ "young" our ears were).

I was once in a small, treated room working with some rather large PA speakers. I was curious how far my hearing range actually extended, and did something very unwise: I played a 20kHz tone and very briefly ramped the volume up and down. I definitely heard it, but I also induced quite a lot of pain. I learned two lessons: 1. my threshold of hearing at 20kHz is near or above the threshold of pain, and 2. don't do that ever again.

heh, your story reminded me of the bar scene in Good Will Hunting:

WILL: The sad thing is, in about 50 years you might start doin' some thinkin' on your own and by then you'll realize there are only two certainties in life.

CLARK: Yeah? What're those?

WILL: One, don't do that. Two -- you dropped a hundred and fifty grand on an education you coulda' picked up for a dollar fifty in late charges at the Public Library.

Yeah I get that I'm getting older. It's just, what's the point of having a stereo that gives perfect playback at 22 kHz if you can't hear it? I'm guessing there must be something since people buy gear like that, or is just a case of deranged audiophiles?

You might not hear a pure 22kHz sine but any sound from, say, a harpsichord will have much off these highs, and some think it is a part off the sound, that one feel without actually hearing it. I'm not endorsing this view, sound islike wine tasting, a lot of hand waving and few solid ground.

There's blind wine tasting, if you want the real deal. Without the hand waving.

  > Agree one-hundred percent about the room

With a username like yours, I'm not surprised. :-)

  > although the prescription isn't always as
  > simple as "get a thicker rug" etc

A prescription is only as good as the likelihood that it will be heeded by the patient. A rug is an easy win; acoustic ceiling tiles and bass traps are a bit harder...

I don't really know much about this, but wouldn't the 22kHz sounds potentially create beats in the lower frequencies?

Acoustic "beat tones" aren't "real" tones— you hear them because of non-linearies in the ear-brain system, but you have to hear the initial tones first. (Well, unless you're talking >>130dB SPL levels where the air starts becoming non-linear, but then lower frequency recording would capture it fine)

If you could hear subharmonic beats from ultrasonics then it would be _very_ easy to demonstrate, alas.

Curious, what does non-linear mean in this context?

IIRC, linearity is when you put a sound wave frequency into the medium (air) a some point, you can predict the frequency of the sound wave at some other place using a linear function - meaning that there is no distortion. Non-linear is when the physics of the medium starts screwing with that function.

I believe that it means that the superposition principle (http://en.wikipedia.org/wiki/Superposition_principle) doesn't hold: the net response at a point is not just the weighted sum of the individual responses.

so without very high power sounds and the nonlinearity business the whole "Sound from Ultrasound" wouldn't work? Huh, I guess all this time I misunderstood it.

for those curious http://en.wikipedia.org/wiki/Sound_from_ultrasound

Well, what I can think of is that of course you need to sample at > 2*max frequency if you do uniform sampling to avoid aliasing (by Nyquist), but that's not the same as playback.

Yes, there will be inter-modulations from higher frequencies. There are also from the audible spectrum but if the amp is linear enough they will be low.

I agree. It should be about the performance, not the sonics. There are plenty of old Motown and even Beatles recordings with distorted vocals, bad edits, etc. Your brain passes right over them because of the emotional content of the music.

This.

I worked out a long time ago, that I enjoy listening to _music_, not HiFi gear.

My advice to people who ask how to make their system sound better? Buy some music you enjoy more…

I can enjoy a wonderful performance of a great tune played through my laptop speakers - much more that I enjoy test tones or gear-demo-tracks through sound gear worth something north of a new car…

(not that I haven't been "that guy" in my past…)

> My advice to people who ask how to make their system sound better? Buy some music you enjoy more…

Good advice, but you do need some baseline quality equipment to start with. Got my car with one speaker blown out, speakers wired semi randomly (left-right and front-rear faders don't work as they should), also powering line-in source from cigarette lighter results in funky background noise. Sounds great--when a good tune is playing and I'm able to recognize it ;-)

That's because they focussed on the most likely end-user experience:

>While Motown shortened song to fit into radio time, the company also produced records specifically with car radio audio quality in mind. Motown recording engineers set up car speakers in the studio so that they could simulate and perfect how a song would sound emanating from a car radio

- what's the point of engineering things to a set of conditions virtually none of your target audience possesses?

http://web.wm.edu/amst/370/2005/sp3/machinery_marketing.htm

I'd disagree, at least among the people I know: they all have cheap HTIB systems and the single biggest, most cost-effective improvement you can make from there is to buy better speakers.

Then you can worry about your room.

No, even in that case, the room can still overpower the speaker. A $200 HTIB system in a properly treated room will sound a lot better than $28,000 Wilson Watt Puppies in a bathroom for example.

Sure, but that's a rather contrived example-- most people have a fairly normal room, and the average joe would be best served by getting a good pair of speakers, and a reasonable amplifier and DAC, before worrying seriously about room acoustics.

A fairly normal room is pretty awful these days, particularly with the trend towards timber flooring and sparse furnishing.

I'd even skip the dac (I mean I might not.... but a decent amplifier, and I just mean decent, like something that still works from the 70's or 80's) and a decent pair of tower speakers (needn't be expensive), and, well, just don't use the shittiest cables you can find (I mean as long as they are thicker than a few human hairs you're okay)- it'll sound far, far better.

Or get some half decent headphones.

Hum, my experience (I was sound engineer in a previous life) is that the first thing to fix bad sound is to flatten the equalizer and to remove bass enhancer. Then I'd put the speakers on a solid table in a relative symmetry regarding the listener, while checking they have the correct phase. All the rest is rarely necessary.

You might be surprised how much of a difference EQ can make. As an experiment I once used 12 bands of parametric EQ to adjust the speakers in a cheap, old LCD monitor. Sure, you're not going to get any better bass response than before, but stereo imaging (nonexistent before EQ, perfect phantom localization after), spectral balance, clarity, distortion (due to not exciting resonances in the monitor), etc. were significantly improved. Most people could have added an EQ'd subwoofer to those tinny LCD speakers and been completely satisfied.

One of the many things EQ can't fix, of course, is room reflections, which can be helped by room treatments and speakers with a directivity better suited to the room.

Of course EQ can help with room reflection! In a square room you'll have a resonance at a given frequency, and you can mitigate a bit this problem with an EQ. But usually EQs are used too add bass and do more harm than good.

By room reflections I mean higher frequency reflections that result in comb filtering and spatial and temporal smearing of the sound, rather than lower frequency resonances that result in the standing waves you mention. EQ can reduce the effect of room resonances, but it still can't fix the extended decay time at those frequencies[0].

[0] DRC can improve this, but only within a small sweet spot.

I should point out that after room treatment, my next recommendation tends to be an amplifier with Audyssey MultEQ in-room calibration. I've never heard a listening environment that didn't sound unambiguously better with it enabled.

Did you read the article? Are you sure it wasn't just unambiguously louder? ;)

Yes. Because one of the settings shown after the full room color sweeps is dB, and the sweeps will often set various speakers a bit quieter. (The goal of Audessey calibration is to eliminate frequency resonance hot spots in common listening positions, as well as get flat response from your speaker setup.)

Audio tweaker with hacker leanings but without carpentry skills? Start your engines: http://drc-fir.sourceforge.net/

We have a lot in common.

It is said that in most cases 192 kbit .mp3 is indistinguishable from >192, and blind tests support that. Granted, there are instruments like castanets which make it easier to hear the difference. In general though, I can't distinguish 128 from 192 and I listen to music a lot. Also it's unlikely that my hearing is already damaged because I try to keep volume low.

But I've noticed that where I put the speakers makes a huge difference. I can easily tell the difference from speakers on the floor versus speakers on my desk. Where I'm at the moment also matters a lot. If I lie on the floor, floor speakers don't sound as bad anymore.

In the end, I use headphones. Midrange Audio Technica ones, and I'm probably already overpaying a bit. But I bought them for build quality and comfort, and I wasn't disappointed. I can have wear them for hours (Not healthy I guess, but I'm used to wearing them even with no music being played). Headphones have the advantage that it suddenly stops to matter where your speakers are and where are you relative to them.

This effect isn't sooo surprising seeing as it even occurs with dumb mono guitar cab speakers and is very, very, VERY clearly audible there, even just moving your head a few cm in or out of the cones' axis.

Is the 192 the bitrate or the frequency response? I thought 192 in MP3 was the bit rate, not the maximum frequency response...

Amen. Someone got the point of the article.

> Stop being so paranoid about what you think you can't hear, and enjoy the damn music.

Yes. Do a couple of blind tests with your acoustic system first.

> It's true enough that a properly encoded Ogg file (or MP3, or AAC file) will be indistinguishable from the original at a moderate bitrate.

Disagree. This claim seems to be ungrounded compared with others.

I can believe limitations with bit depth and sampling rate (although I'll take a chance to test myself if I get near good enough acoustic system). However, I definitely could discern in a blind test whether music I listened to was stored using lossy format with reasonable bitrate. It's usually quite audible with rock music that involves cymbals.

There's a specific "bug" in the mp3 encoding scheme which means that you get a pre-echo effect on fast attack waveforms. It's inherent in the encoding, so it can't be eliminated (although the higher the bitrate, the less obvious it is IIRC). If you how know to listen out for it then you'll spot it immediately.

AAC / Ogg don't have that limitation & at high enough bitrate should be indistinguishable from the source in a blind listening test, as demonstrated in a number of Hydrogen Audio listening tests down the years, unless of course you're using crappy encoders at which point all bets are off...

(Really, LAME is very good indeed these days. I eventually decided that I was going to get with the program and just encode all my CDs (backed up to flac files) as mp3 for portable listening. It's good enough, and I've decided not to listen for the pre-echo artifacts so that I won't notice them :) )

Well, actually it was that long cymbal sounds “fade” quicker and just sound different with lossy music.

IIRC I distinguished an mp3 encoded by iTunes with bit rate 192 or 256 kbps from its original in Apple Lossless (both played on same cheap acoustic system). I probably should test with AAC or Ogg, too. Although I have a feeling that it's pretty much impossible to keep intact those rich in high frequencies cymbals while keeping compact file size.

> I've decided not to listen for the pre-echo artifacts so that I won't notice them :)

You're much better at controlling your mind. =) After I once verified that the difference is audible even on cheap speakers, I can't switch back to lossy formats. It means constant wondering if that how it's supposed to sound or not…

That's, by the way, why Apple's idea of having ‘Mastered for iTunes’ label[0] IMO is worthwhile—at least you can be sure that mastering engineer listened to it this way. =)

[0] http://arstechnica.com/apple/news/2012/02/mastered-for-itune...

It's certainly true. Ogg is far less audible than mp3 - it's actually very decent at bit rates as low as 64kpbs.

"I distinguished"

Was this in a blind test?

Please refer to my comment above[0]. Yes, it was a blind test. The person helping me might've looked up bit rates, so it was not a double-blind experiment, but I could not (nor did I want to) see what's being played, and relied only on hearing.

[0] http://news.ycombinator.com/item?id=3669893

Might be interesting to try AAC or Ogg Vorbis & see if they're any better. In these days of ever increasing cheap portable storage carrying a bunch of flacs around isn't quite as nuts as it used to be of course.

(Cymbals seem to be a particular bugbear for mp3 encoding; cymbal-heavy tracks tend to suffer the most from obvious encoding artifacts once you know what to listen for.)

A thousand times this. I never cease to be amazed at the number of people who will vocally argue the benefits of solid-silver wundercable, but who've never heard of mirror points or bass traps. $20,000 hifi systems in rooms with bare wooden floors and bare concrete walls. Subwoofers in untreated cubic rooms. People praising the transient response of their PMC MB2s in a room with chronic flutter echo. It's utterly dispiriting.

I agree the damn room matters so much more. Also the distortion of most speakers is already the bottle neck in most people's systems.

Alan Parson's makes this point, too: http://boingboing.net/2012/02/10/alan-parsons-on-audiophiles...

Exactly! I could not have put it better myself!

" … when the most under-performing component of most people's sound equipment also has the lowest-hanging fruit:"

And I was _so_ sure the next sentence was going to be something like:

"No, do not have any suggestions that will make your sound equipment make Justin Bieber sound better…"

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