Apple HomePod – The Audiophile Perspective and Measurements • Hacker News Board

Re: Apple HomePod – The Audiophile Perspective and Measurements

#41

Post by 52-6F-62 » Mon, Feb 12, 2018, 6:09 PM UTC

mrob wrote: post #36

>I'm an EDM guy and demand a certain performance to 20hz, which homepod lacks. I've checked a lot of dance music and never found anything with meaningful 20Hz content. It's extremely rare for "deep bass" to be lower than 40Hz. The only genre I can think of that often has very deep bass is pipe organ music. EDIT: Movie soundtracks also commonly have <40Hz content for sound effects.

I always understood ~20Hz to be relegated more for inaudible movie effects like you mentioned. Usually contributing to the feeling of dread, fear, and anxiety in horror movies, etc.

It’s news to me that one might need 20Hz for purely an audio track, especially in the home. I would understand at a concert or something but to demand it from a single small self-contained unit like that sounds like looking for love in all the wrong places.

Re: Apple HomePod – The Audiophile Perspective and Measurements

#42

Post by wl » Mon, Feb 12, 2018, 6:10 PM UTC

colanderman wrote: post #28

oflannabhra wrote: post #25

I'm no audiophile, and I don't plan on getting a HomePod, but the interesting tidbits to me were the following: >Apple uses Balanced Mode Radiators (BMRs) instead of industry typical tweeters. They have a response range of ~250Hz-20kHz, whereas typical tweeters have a range of 2kHz-20kHz. Here is gif of a BMR compared to other speaker technologies [1] >Apple applies Equal-loundness contours[2] to equalize absolute en…

> That is, the dB of sounds in the 2KHz-5KHz is decreased by several decibels, because the human ear is more sensitive to them. I would expect recorded material to already account for this. Does anyone know why Apple finds it needed to further apply sound shaping to recorded sound? (That is, I would expect audiophile-grade equipment to best mimic the monitors on which most recordings are mixed, which presumably is a…

The perception of equal loudness changes with both sound pressure level (SPL) and frequency. Are you playing the music louder or quieter than the SPL it was mixed at? Then the balance changes.

Re: Apple HomePod – The Audiophile Perspective and Measurements

#43

Post by jtbayly » Mon, Feb 12, 2018, 6:11 PM UTC

colanderman wrote: post #28

oflannabhra wrote: post #25

I'm no audiophile, and I don't plan on getting a HomePod, but the interesting tidbits to me were the following: >Apple uses Balanced Mode Radiators (BMRs) instead of industry typical tweeters. They have a response range of ~250Hz-20kHz, whereas typical tweeters have a range of 2kHz-20kHz. Here is gif of a BMR compared to other speaker technologies [1] >Apple applies Equal-loundness contours[2] to equalize absolute en…

> That is, the dB of sounds in the 2KHz-5KHz is decreased by several decibels, because the human ear is more sensitive to them. I would expect recorded material to already account for this. Does anyone know why Apple finds it needed to further apply sound shaping to recorded sound? (That is, I would expect audiophile-grade equipment to best mimic the monitors on which most recordings are mixed, which presumably is a…

Because you are changing the volume. If you read about it further, it's adjusted on the basis of how loud you turn it up.

Long and short of it is that if you turn the volume up, and your want it to sound the "same" but louder than before, you need to turn different frequencies up more than others, to account for the human ear's varying sensitivity to different frequencies.

Re: Apple HomePod – The Audiophile Perspective and Measurements

#44

Post by tomxor » Mon, Feb 12, 2018, 6:13 PM UTC

There is no way i'm believing this thing actually sounds good unless Apple are using some tech that is not a normal transducer based loud-speaker...

First off: This guy is talking about "measurements" not perceptible quality, and anyone who has reasonable experience in audio quality will know that amp specs and measurements have almost zero correlation to audible sound quality and musicality (THD anyone).

Second: An all in one active load-speaker this small, singular and low powered will never sound "good" compared to the same money spent on actual audio (a basic integrated amp and some bookshelf speaker).

These types of devices are always a bag of compromise for audio quality, in the form of "everything must be small" (speaker diaphragms and drivers suffer because you need both large and small ones to comfortably reproduce the frequency spectrum without seriously fucking with the audio signal), battery powered (D-class amps), and finally mono for some bizarre reason, because who cares about sound anyway.

Re: Apple HomePod – The Audiophile Perspective and Measurements

#45

Post by butisaidsudo » Mon, Feb 12, 2018, 6:17 PM UTC

colanderman wrote: post #28

oflannabhra wrote: post #25

I'm no audiophile, and I don't plan on getting a HomePod, but the interesting tidbits to me were the following: >Apple uses Balanced Mode Radiators (BMRs) instead of industry typical tweeters. They have a response range of ~250Hz-20kHz, whereas typical tweeters have a range of 2kHz-20kHz. Here is gif of a BMR compared to other speaker technologies [1] >Apple applies Equal-loundness contours[2] to equalize absolute en…

> That is, the dB of sounds in the 2KHz-5KHz is decreased by several decibels, because the human ear is more sensitive to them. I would expect recorded material to already account for this. Does anyone know why Apple finds it needed to further apply sound shaping to recorded sound? (That is, I would expect audiophile-grade equipment to best mimic the monitors on which most recordings are mixed, which presumably is a…

You'd think so, but recordings are usually mixed to sound good out in the wide world. The most famous mixing monitors are famous for sounding awful.(https://www.soundonsound.com/reviews/yamaha-ns10-story) The thinking there is if you can make the song sound good on those monitors, it'll sound good anywhere.

A lot of songs are mixed with less bass than ideal, because the engineer knows that everyone and their grandma has that bass boost button permanently down on their stereo. Or people are using beats headphones that crank the low end.

The ideal mix also changes over time. Part of that is fashion. Every period has its own ideal sound. But another part is the equipment the average listener has.

Ever have a beater car with a terrible stereo? Music from the 60s will still sound great because it was mixed to sound good on transistor radios. You can hear the bass guitar even though there's no low end on your setup. Anyone who had a K car in the 90s has a love for CCR. That's a fact.

In previous decades music was mixed to sound good on wood encased speakers, which have their own resonance characteristics. For modern music, you assume plastic. You also have to assume that a large portion of listeners are going to be using apple earbuds, or some other cheap earbud.

When working on a mix, you usually have a few different speakers to choose from in the studio. But the final test is always how it sounds in a car.

Re: Apple HomePod – The Audiophile Perspective and Measurements

#46

Post by glhaynes » Mon, Feb 12, 2018, 6:21 PM UTC

hudo wrote: post #24

Even measurements on the paper looks great when we talk about how it actually sounds, this review explains it the best https://www.youtube.com/watch?time_continue=12&v=uzbTRMIFL-4 That's the difference with "mainstream" companies (sony, panasonic, ...,apple?) and hifi one (rotel, nad, marantz, ...): sony will probably send the amp/speaker to production after it looks ok in measurements, while hifi companies always li…

Sorry, can't watch the video at the moment, but: if anything, the hifi companies are tweaking for an "incorrect" response, then, right? Which it seems at best might sound "better" for one type of music but it seems like would thus have to sound worse for others. If not, it seems like all editing stations ought to have an EQ that applies the universally-superior-sounding shape to all output. (Of course this assumes speakers aim for flatness…)

Edit: this other thread on this same post is already discussing this topic - https://news.ycombinator.com/item?id=16360296

Re: Apple HomePod – The Audiophile Perspective and Measurements

#47

Post by colanderman » Mon, Feb 12, 2018, 6:23 PM UTC

wl wrote: post #42

colanderman wrote: post #28

Earlier quoted context omitted.

> That is, the dB of sounds in the 2KHz-5KHz is decreased by several decibels, because the human ear is more sensitive to them. I would expect recorded material to already account for this. Does anyone know why Apple finds it needed to further apply sound shaping to recorded sound? (That is, I would expect audiophile-grade equipment to best mimic the monitors on which most recordings are mixed, which presumably is a…

The perception of equal loudness changes with both sound pressure level (SPL) and frequency. Are you playing the music louder or quieter than the SPL it was mixed at? Then the balance changes.

Thank you, that makes a lot of sense.

Re: Apple HomePod – The Audiophile Perspective and Measurements

#48

Post by jtbayly » Mon, Feb 12, 2018, 6:25 PM UTC

tomxor wrote: post #44

There is no way i'm believing this thing actually sounds good unless Apple are using some tech that is not a normal transducer based loud-speaker... First off: This guy is talking about "measurements" not perceptible quality, and anyone who has reasonable experience in audio quality will know that amp specs and measurements have almost zero correlation to audible sound quality and musicality (THD anyone). Second: An…

This device is not battery operated. FYI.

Re: Apple HomePod – The Audiophile Perspective and Measurements

#49

Post by colanderman » Mon, Feb 12, 2018, 6:27 PM UTC

butisaidsudo wrote: post #45

colanderman wrote: post #28

Earlier quoted context omitted.

> That is, the dB of sounds in the 2KHz-5KHz is decreased by several decibels, because the human ear is more sensitive to them. I would expect recorded material to already account for this. Does anyone know why Apple finds it needed to further apply sound shaping to recorded sound? (That is, I would expect audiophile-grade equipment to best mimic the monitors on which most recordings are mixed, which presumably is a…

You'd think so, but recordings are usually mixed to sound good out in the wide world. The most famous mixing monitors are famous for sounding awful.( https://www.soundonsound.com/reviews/yamaha-ns10-story ) The thinking there is if you can make the song sound good on those monitors, it'll sound good anywhere. A lot of songs are mixed with less bass than ideal, because the engineer knows that everyone and their grandm…

I agree with everything you said, but were Apple compensating for that, I'd expect them to use a curve weighted to crappy studio monitors/Beats headphones/etc.

A couple other commenters noted that perception-weighted curves vary with total SPL; louder sounds sound different. I had never thought about that before but that makes sense to me, that Apple would apply a dynamic adjustment that studios can't.

Re: Apple HomePod – The Audiophile Perspective and Measurements

#50

Post by S_A_P » Mon, Feb 12, 2018, 6:29 PM UTC

mrob wrote: post #36

>I'm an EDM guy and demand a certain performance to 20hz, which homepod lacks. I've checked a lot of dance music and never found anything with meaningful 20Hz content. It's extremely rare for "deep bass" to be lower than 40Hz. The only genre I can think of that often has very deep bass is pipe organ music. EDIT: Movie soundtracks also commonly have <40Hz content for sound effects.

Pipe organ music can commonly reach down to 16 hz or so, but for those looking for (slightly) more current music containing truly deep bass here are a few options:

Pink Floyd- Dark Side of the moon. The Heartbeat in the introduction contains significant energy in the 20-40hz range

Bass Mekanik- Each of his releases includes some music but also features a test section which will play frequencies with labels as to their frequency. Even if this sort of music isnt your thing it is helpful if you are curious as to what the frequency response of your stereo.

Tchaikovsky 1812 overture- Cannon Blasts go sub sonic.