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Apple HomePod – The Audiophile Perspective and Measurements (reddit.com)
83 points by lqueenan 11 months ago | hide | past | web | favorite | 76 comments

>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.

This. Even with a giant subwoofer system, 20 hz is more felt than heard. The "deep 808 bass drum" usually centered between 40-60 hz. My Tr-808 was centered at ~53 hz. Keep in mind that a doubling of frequency is an octave, so 26.5 hz would be an octave down and 106hz would be an octave higher

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.

Ah yes, the subwoofer rattling sound. Dreadful indeed. Can kinda take me out of it.

I wonder if the "undertone series" for a bass hits this, since a low E on a 4-string already is at the ~40hz range. Definitely something that's felt, more than heard, as you mention.

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.

Of similar vintage to Bass Mekanik, The Crystal Method's "High Roller" has some very deep, musical bass in the first minute. This bass is lost entirely by most MP3 encodings. Makes for a good reference point for both subwoofers and music sources!

Agreed. Also a really clean recording, though somewhat over squashed dynamics. But love those drums...

I am a bit surprised, having received mine last Friday, I was very disappointed by the sound quality but even more with the actual features themselves. Of course this is highly subjective but I will keep my two Sonos Play:1 stereo and return the HomePod. I just wish Sonos Play:1 had a line-in or/and bluetooth connectivity...

It sounds to me like you're comparing the solo HomePod against a stereo setup?

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 energies of loudness to perceived loudness by the human ear. That is, the dB of sounds in the 2KHz-5KHz is decreased by several decibels, because the human ear is more sensitive to them.

>They recommend putting the HomePod on a small stand (5 in), because even the room correction processing Apple is using is unable to compensate for echoes that originate so close.

>There is apparently some agreement within this community, at least, that if Apple made a HomePod Plus with a larger subwoofer to allow reproducing sounds down to 18Hz, they would essentially beat the entire high-end audio market.

[1] - https://gfycat.com/BiodegradableNiftyKoala

[2] - https://en.wikipedia.org/wiki/Equal-loudness_contour

> 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 flat loudness curve.)

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.

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.

Oh, that's an excellent point too! Bass boost and loudness buttons on stereos are meant to give you a way to make music sound the same at a lower volume, but most people just set it and forget it.

With fully digital players, I guess there's no reason to not have dynamic EQs that adjust along with the volume. I'd think you'd see this more often, but I guess even basic EQs aren't available most of the time, so it's just not a feature that most people would care about.

>(That is, I would expect audiophile-grade equipment to best mimic the monitors on which most recordings are mixed, which presumably is a flat loudness curve.)

Not necessarily, because that assumes the audio was mixed correctly to begin with. The audio will have to be played back over digital and analog broadcasts with varying dynamic range characteristics, not to mention various output technologies, including $5 headphones. And not to mention how the shape of each persons ear affects the response curve in different ways.

There is no way for an engineer to produce a rendition that sounds great in all of those scenarios, making 'mimicking the monitor' a pointless pursuit to begin with - even IF you were an audiophile listening to 400MB DSD files.

>Does anyone know why Apple finds it needed to further apply sound shaping to recorded sound?

I'd say the vast vast majority of people want more to have the audiophile label/association than actually listen to music with a flat curve, because most music will sound like crap.

Sorry for the rant :P

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.

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.

What surprises me most are the rave reviews in the absence of stereo (coming later), which I always thought was de rigueur for audiophiles. I look forward to those future reviews.

That's part of the point: it has a 7-tweeter 360º array that is used to add directionality to the sound. Obviously won't compare to a true stereo pair, but it's not nothing either.

Personally speaking, I'd take great mono over sub-par stereo any day anyway.

This is part of what I don't understand; directionality of sound is a concept understood to be in reference to the listener (or point of measurement). So what exactly is the homepod doing? Since the listener could always be moving within the room is it dynamically tracking and adjusting? I assumed it just optimized the sound for the room in a more generalized sense (i.e eliminating weird reflections, dead spots, etc)

It uses beam forming to create a left right and center channel spread.

Left, right, and center... of what? Like what is it oriented to?

I'm a bit surprised as well, but I've also recently realized how few songs actually benefit from having stereo mixes, given they're almost all added in post processing. It matters even less for a room-wide speaker, when the listener is not at a fixed point.

That said, stereo can matter, but only when the recording itself was done in stereo. Proper stereoscopic recording is pretty cool to listen to with headphones.

All my opinion, of course.

Personally I disagree on the stereo not really mattering due to post-production. Proper stereo imaging can really do wonders with vocals being dead center, for example.

I disagree as well. Any decent audio engineer will know that placing tracks, instruments and certain elements slightly, or widely, off-center is essential to a good recording.

Well, they are excited because the speaker performs excellently. I suspect many audiophiles will wait until they can get it to work in stereo, but when it does, the reviews should be the same since it’s just two of the same.

Also, I doubt most audiophiles would use it as their primary listening source, but it may be the perfect solution for additional listening areas.

There are 7 tweeters in each Pod. Not only does a single Pod do stereo, it will analyse the surroundings to make use of walls etc to make wider stereo than it could just do by naively choosing a side speaker.

Stereo requires two horizontally displaced time-coherent sources. There is no other meaning.

If you're bouncing audio off walls you may get ambience, but you're not going to get a clean stereo image.

Also, the KEF speakers are hardly world beaters. They have a good reputation as PC speakers, but that's not setting the bar very high.

Professional speaker manufacturers like Genelec use a similar adaptive tuning system, and you can buy a microphone and software add-on to flatten the response of any speaker.


The limitations are well known. The correction curve is level-dependent, because room resonance is a time domain phenomenon created by physical standing waves in a 3D space that includes damping elements, and you can't truly correct it with a frequency domain solution.

You can approximate a time-domain correction with convolution and some assumptions about the room geometry and acoustics, but it's never going to be perfect.

Bottom line: I'm sure the Homepod sounds very nice, and - as usual - it's innovating with technology that's been available elsewhere for a while, and made much easier to use.

But it's not magic, and it's not going to sound hugely better than a much more expensive true stereo system.

Of course that'll do just fine for a lot of buyers.

>There is no other meaning.

Apparently there is.


"Stereophonic sound or, more commonly, stereo, is a method of sound reproduction that creates an illusion of multi-directional audible perspective. This is usually achieved by using two or more independent audio channels through a configuration of two or more loudspeakers (or stereo headphones) in such a way as to create the impression of sound heard from various directions, as in natural hearing.[1]"

I'm inferring from that there are other methods to create an illusion of multi-directional audible perspective.

So, I guess it determines which direction to use for the left and which for the right channel based on closeness to the wall. If so, what does it do when in the center of a symmetrical room? Is there a weird border case where it starts oscillating between multiple states?

I love music but I don't consider myself an audiophile. After having written off the HomePod yet trying one for a weekend - I cannot wait for the stereo upgrade. It is astonishingly good as a speaker.

Same here. I love music and good sound, but I don't go down the audiophile optimization rabbit-hole – for many reasons, but mostly because one quickly gets to the point of diminishing returns.

I was surprised by the HomePod. It's much smaller than I had imagined, and sounds much better. I think I might get another one when the Airplay 2 update comes out.

I'm no audiophile, I do realize from reading speakers review in audiophile magazine that they tend to compare speakers in the same particular price range. The OP review seems to suggest that a dual HomePod stereo setup (about $700-800) could well compete with audiophile grade speakers in sub $1000 range. It is great feat by Apple if they can achieve it with their stereo release later this year. HomePod is "engineered" sound with its surrounding acoustic adjustment etc and I bet a large portion of audiophile prefers their gears to have a more faithful reproduction of source material. Anyway HomePod will not be the only gear for hardcore audiophile as they tend to have exotic source material equipment which HomePod can not accept. It is interesting to see in near future when dual HomePod can be used with AppleTV for movie viewing with simulated centre speaker and surround sound. I remembered Tim Cook said they finally cracked home TV few years back, maybe HomePod + AppleTV is the solution.

i dunno if this continues today, but before digital became prevalent there was something of a holy war in the audiophile community between mono and stereo. i know a lot of people still prefer the mono mix of sgt pepper, but that might be because the stereo mix of that particular album is actually inferior.

today practically all new systems marketed to audiophiles are stereo, but my guess is that most would consider faithful reproduction of the signal to be more important than the number of channels if they had to pick.

Does anyone really expect proper stereo from a single speaker?

For those looking to add some deep bass to their home listening, there are really good options available these days. The availability of high power class D amplification means that you can (relatively) cheaply provide room shaking bass to a level that was prohibitively expensive even a decade ago. parts-express.com(and others as well Ive no interest in plugging their site) offers a large range of high quality subwoofer drivers in the 1-300 dollar range, they offer pre-made cabinets, but you can really save if you build your own MDF cabinet. The subwoofer plate amplifiers run ~250 bucks for 3-500 watts rms. It definitely can make movie night at home more fun.

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 listen after measurement, tweak, measure again, listen, ... you get the point.

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

Hmm. I disagree with that video on several points, mostly because I think it's a bit disingenuous and unfair. If you're going to make comparisons, you have to make them equal (or as close to equal as possible) for them to have any validity.

For one, he makes the point that, for the price, you can get that amp, an Echo Dot, and build the speakers he put together... except that's the entire point. You'd have to build the speakers yourself (including soldering!), have 3 (technically, 4) distinct pieces of equipment to maintain, and you have to have that unsightly hardware and wires everywhere. The setup he shows in the video looks like complete crap to me and there's no way that I would put it out for display like that in my house. The HomePod isn't meant to be an alternative for that. It's meant to compete with other wireless speakers and, when compared against those, it's a significantly better product at a slightly higher price. It's like the "I can build a PC myself that's way better than an iMac for cheaper". Sure you can...but don't pretend like it's the same quality, form factor, ease of setup, or any multitude of reasons why the price differs from a DIY solution. That's not the point here.

The other thing that bothered me is that he tested it in a studio with sound insulation on the walls and then complains about the audio and balance, saying that it's very bass heavy. Again, this isn't what the HomePod was designed for. The mics and the processor are specifically meant to listen for acoustics and reflections and use those to set up the soundstage for the speaker. He's taken all that away and then complains that it's too bass-heavy. Of course it's too bass-heavy! He removed the entire mechanism by which the HomePod determines its output!

Now, I'm sure everyone will be quick to point out that he moved it into his bedroom as if that's a good example of his objectivity. I would agree except that he then doesn't objectively assess the HomePod. He, again, compares it (which he says he set up on his nightstand or table) to his custom-built speakers that are mounted to provide directionality to his sweet spot. He's starting from a non-neutral reference point, comparing to something that the HomePod is not even attempting to be a comparison to, and then pretending to make the objective assessment that it's lacking. Of course it's lacking! It's also lacking when compared to my home theatre setup. That's not really a fair assessment. If he had put an actual Echo on the same nightstand/table and then compared them, I'd find that fair.

Again... I think the HomePod is really just a wireless speaker that is significantly higher quality than what you'd normally get from a wireless speaker at a slightly higher price. As an audiophile, I like it much better than my Echo, my Sonos, or the little Bluetooth speaker that my wife has for obvious reasons. Of course I can build something that sounds better for that amount of money. That's not the point. I'm not going to be able to put together what they did in the package they did for that money without a ton of hassle. That's where the HomePod is worth it to me. YMMV.

Is it better to test audio products with a meter or with double blind humans?

I've been convinced by a knowledgeable person[1] that measurements are the only useful way to measure performance. To paraphrase poorly: subjective reviews are useless since they are limited by the reviewers subjective perception, their ability to turn that perception into words, and your ability to turn those words into a concrete idea about how something sounds. Since there is no part of a speaker's performance that cannot be precisely measured, the best course of action is to learn how each measurement affects your perception and what qualities you like in a speaker. Then you can fairly accurately evaluate if you would like a speaker with just a few graphs.

(Of course this is completely impractical for almost everyone, but I'm talking about some platonic ideal of audiophile)

1: http://zaphaudio.com/

Have a look at this: http://www.nutshellhifi.com/library/FindingCG.html It applies mainly to amps, but when you learn about amps you start to realise that loud-speakers are really all part of the same big circuit.

With amps, specs only take you so far, once you get above the absolutely dirt cheap crap it doesn't really help. Using THD as one example, above 1% might indicate something wrong with the amp design... bellow doesn't really make any difference because these are just tested with sine waves (do you listen to pure sine waves? no), very low might even indicate that the design has been compromised just to get good paper specs.

Headphones and speakers can be similar, frequency range doesn't really tell you anything unless they are severely limited and thus it only really helps sift though crap.

You are correct about reviews though, it really depends on who is reviewing it, and 99.99% of the people out there have hardly anthing worth comparing what they are reviewing it to. If i've never had a pencil before, and I get a pencil and it's all crumbly I will be like "It's frickin amazin, it makes marks on paper", but that doesn't really help anyone else trying to make an informed decision. Additionally, even if you start going through audiophile forums and vet authors for their background knowledge, _even then_ you have the aspect of personal taste, musicality etc.

So yeah... if you want good audio, your fucked :) the only way is to try. And try not to go crazy. But not buying stuff with any integrated digital nonsense is a good starting point.

I know from experience that different headphones with similar frequency response can sound radically different. Most reviewers don't measure anything else, so that doesn't really help.

Depends on if you want factual technical measurements or subjective human opinions

If it's double blind isn't it objective?

It's as objective as a subjective measurement can get.

It's not repeatable, and I don't know what units of measure could be used either.

Only if all humans have the same opinion about what good audio sounds like.

So basically all this intangible nonsense makes it sound like the second coming of the Bose WaveRadio. Er, no pun intended.

Great marketing to let an obvious fan (check his history) who loves writing get an early look at your product.

He was very open & clear I thought:

"I also paid full price for this HomePod, with my own money. I paid for all the equipment to measure it with, and I own every speaker in featured in this review."

This is very clear too:

"Neither KEF, nor Apple is paying me to write this review, nor have they ever paid me in the past."

This wasn't necessary, in my opinion, but again is very open:

"At the same time, I’m a huge apple fan. Basically, all the technology I own is apple-related. I don't mind being in their ecosystem, and it’s my responsibility to tell you this."

Not to mention, you can still be a fan and objective in your review of a product. The two are not mutually exclusive.

"He was very open & clear I thought:"

It could be just to make the review feel more authentic, and also both advertisers and audience are getting smarter.

This is not a statement about this particular reviewer, just my thoughts.

Why stop there, though? Maybe he’s lying about having paid his own money for it. Maybe he’s lying about the measurements. Maybe his entire user account is a fake persona. Where do you draw the line?

The reviewer seemed to be very frank about listing their biases in fairness (see the big section titled 'Bias' in the review). And they shared their original data, so it's up to you what you want to make of it.

Now if only more tech reviewers gave out raw data or even actually measured. Too many just read off the specs and go yep sounds good!

Where does it say they got it early? It's plausible this was done over the weekend.

Looks like he got to play with it for an hour. TFA is his measurements from multiple hours of use at his house.

He was given an intro listen before the device came out. Meanwhile he ordered one for himself, promising to post measurements after he received it.

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.

The HomePod is wired, not battery-powered. I don't think you've looked at it very closely.

Having purchased the HomePod, it's noticeably better than the bookshelf speakers I own (AudioEngine A2+ and Odyssey LES).

It also sounds as good as my Vizio soundbar/subwoofer combo, though I've not compared it at high volume or with movies.

It is, not unexpectedly, vastly better than my battery-powered BeoPlay P2 Bluetooth speaker.

I'm very impressed.

Battery powered or not it will be low powered... there is no class-A amp in that little thing unless it's being cooled by liquid nitrogen, it will be Class-D.

I've no doubt many people will be impressed, it's all relative. But if you actually care about audio you could have bought a lot more for you $300 or whatever it is, but then people don't buy these types of things for audio, they buy them for integration.

The fact that you are comparing it to a "soundbar" shows that you probably haven't heard much better. (i'm not trying to be nasty, it's just true of most consumers, we are not living in the HiFi age anymore).

What $349 speaker will beat the HomePod and provide the same features? Omnidirectionality and built-in AirPlay have to be considered. The HomePod is a single speaker that can fill a room with no additional amp, receiver or subwoofer.

Comparing the HomePod to a class A amplifier is nonsensical. Nobody is pretending it's competing with that segment.

> What $349 speaker will beat the HomePod and provide the same features?

None, I'm not considering those features, only audio quality.

> Comparing the HomePod to a class A amplifier is nonsensical. Nobody is pretending it's competing with that segment.

The author is implicitly:

> The HomePod is 100% an Audiophile grade Speaker

Your absolutely right, it is nonsensical, it's _physically_ in a different class all together. The author has gotten out his spectrum analyser or whatever and measured a relatively flat frequency response of a sine-wave and concludes... this is good audio: Except, "No" says every amplifier and speaker designer ever.

You are aware that "class A" and "audiophile" are not synonymous, yes?

I've got one or two respectable 2-channel audio systems around the house (although I remain solidly in the "cables matter almost not at all + the room matters a lot" camp) and am willing to consider that Apple may have produced a very nice-sounding active speaker for $350 a pop if they decided to. Consider how much more manufacturing scale and tech reach Apple has, compared to, say, Dynaudio or a boutique room correction software shop. Give it a fair shake before remounting the audiophile high horse.

> You are aware that "class A" and "audiophile" are not synonymous, yes?

Yes, it was just an argumentative counter example to the Class-D amp that will inevitably be used by this item.

It is an audiophile grade speaker. For the class of device it is, it's the highest quality, best sounding speaker for the price. If you want a wireless speaker (whatever your reasons for wanting it), the HomePod is the best one, hands down.

That's like saying a £5 pair of headphones is "audiophile grade" for the price. While it doesn't have a strict definition it definitely doesn't mean good for the price.

No it's not. You're misconstruing my statement to make a cheap semantic point. An "audiophile" grade product is the product that best reproduces sound for that class of device. If we were talking about headphones, then a $5 or £5 headphone wouldn't be audiophile grade because the components to accurately reproduce the audio can't even be found for that price, much less the whole package. In this case, we're talking about a class of product - wireless smart speakers. If there were enough of them on the market, we may be able to separate these into budget, consumer, and professional. The point is that the HomePod offers the best sound reproduction in its class.

I’m sure you’ll offer a list of the thousands of amplifier and speaker designers who feel it’s not good audio?

Why thank you mr rhetorical... If you are interested go have a look for yourself i'm not a walking audio system design book. In fact, I challenge you to find the inverse instead - empirical proof that the amp specs the author is measuring actually correlate to better sound quality.

I’m satisfied that a significant number of audiophiles have said that they feel the HomePod produces good audio. The numbers seem to back that up.

We live in an age of lo-fi hi-bling, high consumer numbers from people who consider themselves experts in audio quality because they have a soundbar and a subwoofer don't really count for much.

I don't expect you to be convinced by me, but maybe one day you will experience some nice audio on a good system and then have a personal baseline to understand why calling something this small "audiophile quality" seems silly.

To me, the key is that Apple has created something with astounding sound quality for its size. And flexibility. And price point.

If they scale it up it could very well be truly spectacular.

This device is not battery operated. FYI.

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