Apple HomePod Measurement

[STUDIO51]

This post is a partial transfer from a previous article I wrote at UNDERkg.
You can check the original here

All measurements were made with the AudioPrecision APX555 and the AP's 1 / 2-inch microphone.




HomePod 4 direction frequency response measurement

This is the result of measurement in an environment without walls. In all directions the frequency response is flat. In no-wall environments, it works as a omnidirectional speaker. HomePods show wide bandwidth even with a 4-inch woofer.




HomePod depending volume level frequency response measurement

HomePod adjusts bass at high sound levels for woofer protection. At normal listening levels, you can see bandwidth extending to nearly 20 Hz.

Remember the room gain (+ 6~18dB) and stereo gain (+ 6dB @ low frequency). The bass in your HomePod is enough for real listening.




HomePod THD measurement

The distortion is also quite low. Smart speakers with voice recognition should have a THD of less than 5% above 150 Hz. The reason is because of bargin.


The Bargin function must be enabled for the speaker to respond to human voices while the music is playing. However, if the speaker's distortion exceeds 3%, Bargin will not work well.

HomePod manages less than 3% THD even at full power. This makes my HomePod recognize my voice even when the HomePod is playing loud music.



Homepod vertical directivity pattern

Vertical directivity is also well controlled.



HomePod horizontal directivity pattern

Blue : Front / Orange : Wall / Green : 45 degrees / Yellow : 90 degrees / Purple : 135 degrees

The first four-way measurement we saw was without a wall. This time, the directivity was measured when one side is a wall.

Without any setup or reset, HomePod recognizes the location and distance of the walls and adjusts the directivity. Compared to the front, the wall side response is 15 to 20 dB lower.

The response from 0 degrees to 45 degrees is no difference, and has a directional pattern that gradually decays from 90 degrees.

This is comparable to a well-made hi-fi speaker with well-controlled directivity.




In this article, I've only covered the audio performance of HomePod. But My full review covered everything on HomePods. In summary, HomePods are really advanced speakers. In the true sense this is THE REAL SMART SPEAKER.

I gave a comprehensive score of 9.6 / 10 to HomePod.
I think HomePod is a speaker worth buying. Even without Siri.

I don't live in an English-speaking country, so there may be phrases that are difficult to understand.
Give me feedback at any time.

 

[Soniclife]

How does it respond to the surface it is placed on? Does it adapt to being on a table with a flat surface in front of it vs being on some form of stand? Many studio monitors have settings for being placed on a desk, the results are not as good as getting them off a desk.

 

[restorer-john]

This is one speaker in isolation and your measurements are very comprehensive.

How does a Homepod perform in a typical stereo (2 channel) ~8ft wide implementation measured from a typical listening position?

 

[riker1384]

Is the adjustable directionality the only form of room correction it does?

When I heard that it adjusts to adapt to room acoustics, I assumed they were talking about room EQ in the bass. Has anyone checked to see if it does this as well? Is it possible to do bass EQ when the mic is in the same location as the speaker?

 

[Soniclife]

At what distance are those SPL levels taken at? 1M?

 

[sfdoddsy]

Interesting. But those measurements don't seem to reflect what I heard when I owned Homepods, notably the excessive bass.

Spinorama measurements previously posted here do:

https://www.audiosciencereview.com/...orama-measurements-of-the-apple-homepod.7417/

 

[STUDIO51]

How does it respond to the surface it is placed on? Does it adapt to being on a table with a flat surface in front of it vs being on some form of stand? Many studio monitors have settings for being placed on a desk, the results are not as good as getting them off a desk.

HomePod automatically detects walls and surface and adjusts bass levels.


Nevertheless, home pots have a lot of bass sounds, so it's a good idea to place them on a stand to prevent surface effects.


In my personal experience, putting HomePod on the stand sounds better.

 

[Soniclife]

HomePod automatically detects walls and surface and adjusts bass levels.

How close to a wall or surface does it need to be before it detects it? Is it a progressive change or and on/off thing?

 

[STUDIO51]

This is one speaker in isolation and your measurements are very comprehensive.

How does a Homepod perform in a typical stereo (2 channel) ~8ft wide implementation measured from a typical listening position?

My recommendation is to set your Home Pod stereo . In my experience, the wide and narrow directivity of speakers has advantages and disadvantages.

Speakers with wide dispersion have a good wide sound image but blurry sound image
speaker with narrow dispersion have a small sound image but clean

HomePod was a bit unusual. HomePods are clean with a wide sound image

HomePod, on the other hand, have great bass bandwidth for their size. But it's hard to expect the bass of a hi-fi speaker. Instead, the settings are easy because they are not significantly affected by the room mode.

 

[STUDIO51]

Is the adjustable directionality the only form of room correction it does?

When I heard that it adjusts to adapt to room acoustics, I assumed they were talking about room EQ in the bass. Has anyone checked to see if it does this as well? Is it possible to do bass EQ when the mic is in the same location as the speaker?

Six microphones surround the surface of the HomePod.


I'm not a HpomPod engeneer so I don't know very well.

But my guess is that instead of the omnidirectional bass, the directional treble may will determine the location and distance of the walls.


Based on this information, it is assumed that the HomePods are calibrated after specifying the room size and their location.

 

[STUDIO51]

Interesting. But those measurements don't seem to reflect what I heard when I owned Homepods, notably the excessive bass.

Spinorama measurements previously posted here do:

https://www.audiosciencereview.com/...orama-measurements-of-the-apple-homepod.7417/

This measurement was made in free space. In a real room, there may be more bass because the room gain and the stereo gain are reflected.

And because HomePod is a smart speaker, accurate measurements will be impossible except for Apple engineers.

 

[tmtomh]

Interesting. But those measurements don't seem to reflect what I heard when I owned Homepods, notably the excessive bass.

Spinorama measurements previously posted here do:

https://www.audiosciencereview.com/...orama-measurements-of-the-apple-homepod.7417/

I could be mistaken, but the very extended bass response of HomePod (at normal listening levels at least), combined with the high THD at bass levels (up to about 20% it appears) would suggest to me that it might sound bassy because the bass is both EQ-boosted internally in the unit and also somewhat distorted - it could perhaps sound boomy or overbearing because of harmonic distortion products.

Just a guess - I could be completely wrong!

Regardless, and even taking @restorer-john 's caveat into account, I am a bit surprised at how well this unit measures.

 

[SIY]

And because HomePod is a smart speaker, accurate measurements will be impossible except for Apple engineers.

Have you tried the new AP Transfer Function measurement? It was designed specifically to do this and I have verified that it works.

 

[STUDIO51]

How close to a wall or surface does it need to be before it detects it? Is it a progressive change or and on/off thing?

It's gradual, but it doesn't seem like a lot of steps.

Maybe it's 2-3 steps including off.

 

[Soniclife]

It's gradual, but it doesn't seem like a lot of steps.

Maybe it's 2-3 steps including off.

And what sort of distance is does off start at?

 

[STUDIO51]

I could be mistaken, but the very extended bass response of HomePod (at normal listening levels at least), combined with the high THD at bass levels (up to about 20% it appears) would suggest to me that I might sound bassy because the bass is both EQ-boosted internally in the unit and also somewhat distorted - it could perhaps sound boomy or overbearing because of harmonic distortion products.

Just a guess - I could be completely wrong!

Regardless, and even taking @restorer-john 's caveat into account, I am a bit surprised at how well this unit measures.

As I answered john, the bass on the home pod is not high quality.

It just means that the extended bass is impressive despite the small size of the HomePod.

The bass and directivity of the HomePod is amazing, but it shouldn't be compared to hi-fi speakers

 

[STUDIO51]

Have you tried the new AP Transfer Function measurement? It was designed specifically to do this and I have verified that it works.

Yes. I am doing a lot of measurements using TRF.

However, when I measured HomePods, the AP did not support TRF. Therefore, measurements were taken with openloop stepped sine measurements.

 

[JJB70]

Excellent information, it is very good to see measurements like this of the mainstream wireless speakers which dominate the audio market now. There was some discussion of these speakers in the thread on evidence based speakers, as there is a lot of clever engineering and science being invested in these speakers. Nobody is trying to claim that the Apple Homepod or speakers from Sonos, Bluesound, JBL's consumer wireless range, Bose etc are better than good hifi speakers, but they are benefitting from serious research and development and within their limits the good ones do sound pretty good nowadays. The Apple Homepod displays a real depth of engineering.

 

[watchnerd]

Excellent information, it is very good to see measurements like this of the mainstream wireless speakers which dominate the audio market now. There was some discussion of these speakers in the thread on evidence based speakers, as there is a lot of clever engineering and science being invested in these speakers. Nobody is trying to claim that the Apple Homepod or speakers from Sonos, Bluesound, JBL's consumer wireless range, Bose etc are better than good hifi speakers, but they are benefitting from serious research and development and within their limits the good ones do sound pretty good nowadays. The Apple Homepod displays a real depth of engineering.

I need to get a Bluetooth / WiFi turntable to go with these new speaker advancements.

 

[restorer-john]

I need to get a Bluetooth / WiFi turntable to go with these new speaker advancements.

Here you go:

https://au.yamaha.com/en/products/audio_visual/hifi/musiccast_vinyl_500/index.html