SMAS Audio Quality Review

Pimax Hardware P2: 8kX
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EDIT: Thanks to all who participated. Relevant information from this topic has been merged into https://community.openmr.ai/t/review-of-8kx-production-and-comparison-to-8kx-not-final/32503 . This topic is no longer intended as an official submission to the It’s 8KX! Event’

Finally have had a chance to do proper frequency sweeps and such in a quiet environment.

To my ears, the SMAS audio quality is simply excellent. From about 280Hz to >20kHz, the frequency response is essentially flat as advertised - no sharp dips. To have done this with a small pair of lightweight directional loudspeakers mounted above (rather than in front of or to the side of) the user’s ears is impressive.

Music notes sing from one note to the next as they should, drum and rumble sounds still have a ‘boom’ sound to them.

Left/right separation is excellent, about 10x better than a set of desktop speakers. Decently loud music completely shifted entirely to the left/right channel does not remain noticeably audible at all in the other ear, at least not without plugging that ear for comparison.

That said, I can perceive the limitations of these types of speakers, which some users are complaining about.

‘Loudness equalization’ needs to be enabled. This does not seem to change volume dynamically - it is not obviously a compressor (this is good). However, after one reboot and/or change back to 5k+ headset, I found it necessary to re-enable this again, so the MSW OS can ‘forget’ this setting.

Bass boost may also help, but do not overdo it - the MSW OS will attenuate higher frequencies to compensate if this is set to more than 3-6dB .

Equalizer experiments show that while bass response does drop off below 280Hz, >>10dB improvements can be set in software before the audio output starts ‘clipping’. It is a matter of time before suitable software is made available to drastically improve the base response without the high-frequency attenuation imposed by the MSW OS.

Minor distortion does seem to occur with the SMAS, but not as a sharp resonance at any particular frequency. Listening by ear, there seem to be a tiny bit of mostly even harmonics added, and this only becomes significant in ‘side-by-side’ comparisons. The distortion could easily be a software problem due to MSW OS ‘loudness equalization’.

Thus, after software fixes, the SMAS speakers are mostly as loud as typical headphones or earbuds, but with a (very nice) much flatter frequency response.

Personally, I care much more about high frequency response than extra bass or a little even-harmonic distortion. I want to hear the sharpness of a jackhammer impact, as much as I want to hear piano notes smoothly transition across the entire keyboard, or violins sing across high/low strings. Most headphones even today will completely drop entire notes, and this does NOT approximate any claimed ‘natural resonance in the outer ear’.

While I can see what some people are complaining about, I think the SMAS is far better than it is given credit for - an underappreciated gem.

To me, the biggest selling point of the SMAS is convenience. Just to have fewer obstructions while taking the headset off and putting it back on is nice. Particularly when diagnosing finicky flight sim applications, or doing professional CAD/game development, as these use cases can unfortunately force users to frequently return to the 2D ‘graphical desktop’ on their ‘legacy’ 2D flat screens.

So, don’t expect the SMAS to be a subwoofer, or rock concert speaker. But do expect its performance as an ‘above-ear’/‘off-ear’ speaker to be much better than what you get from most headphones.

Besides, if you ordered the DMAS, which has a similar high-frequency response, you should be able to get a stronger bass response right from that.

All of which is to say, the SMAS lives up to the advertised frequency response graphs, and personally, I am very happy with that.

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(Pimax NOW - The VISION 8KX Is Shipping! - YouTube)

EDIT: An explanation for poor SMAS audio quality reported by some users has been found - another effect of the incorrectly chosen dimensions of the stock MAS hinges. For reference, the correct distance between the SMAS speaker ports and the top of the outer ear is approximately 1cm. Not 3cm, 6cm, or 9cm, distances that all cause progressively worse loss of audio quality.

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Yeah I am going to get a set of these to compare to.

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The SMAS audio is really bad. Clearly you’ve never tried Index speakers or Vive DAS headphones.

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What I read he is saying okay for very specific applications. Not for average use scenarios.

I would just go with the neck speaker.

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I have tried Index speakers, I use the Vive DAS on my 5k+ (mostly for roomscale now), I have lots of experience calibrating headsets to perceptibly flat frequency response using fully parametric equalizers.

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You read wrong. I am saying the SMAS is ok for ‘average use scenarios’, as long as you are aware of the limitations, and correctly enable ‘loudness equalization’ in the MSW OS.

The weakest point of the SMAS is the bass response, mostly because there is no software correction for this.

There is of course also the possibility of some defective units. However, mine was one of the first shipped, so that should rule out audio quality design defects…

I don’t really care what anyone else thinks on this, least of all those who are not renowned audio frequency response professionals. I have worked with such persons, I basically know how to do what they do, and I did that here.

I stand by my opinion of the SMAS - if you value the convenience of built-in ‘above-ear’/‘off-ear’ speakers built-into a VR headset, it works rather well for that.

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So just like Quest Audio. Average use where your not looking for good immersion. Not a quality solution for high end vr. This would be good as a default included SMAS on the Artisan.

The Neck speaker has much better use by it’s reviews compared to the SMAS and only costs $29 Canadian.

This is why it is great pimax is honoring the KS specs with on ear headphones.

And yes there are some Audiophile folks that have already examined the SMAS. It is simply not good for a high end headset & not as originally advertised; though the later claim suggests downgraded the SMAS. :wink:

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At the inconvenience of putting on another headset. As it is, I have a set of my favorite earbuds mounted on a heavy gauge wire with a Bluetooth audio receiver for that.

…

Then there is the frequency response.

At high-frequency, the SMAS is very accurate. Low frequency response can eventually be largely corrected in software.

Even without more effective bass boost software, I hardly consider the SMAS audio quality immersion breaking.

drum and rumble sounds still have a ‘boom’

Now a lower resolution headset - that is immersion breaking.

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Never found that Rumble and boom breaks immersion on a vr headset.

The neck speaker is no inconvenience at all to put on as it does not interfere with the headset at all.

Simply a matter of taste which the majority will pronounce the SMAS as it is. Very poor Audio solution for a high end vr headset and likely the same for a mid level headset.

Tin cans definitely suits as an accurate description. Sure for development work it might do until you need to fine tune the audio of the program for greater immersion.

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Too harsh. The SMAS definitely does not fail as badly as that term might suggest in terms of volume, frequency response, or distortion.

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Well unfortunately your opinion is not shared by the Masses thus far.

Quest like audio seems to fit quite well. Now it might be able to be improved somewhat with a small headphone pre amp which can be ran off internal battery or powered by usb.(this headphone pre amp would also work for original release headsets for both smas and dmas and likely benefit the kdmas)

One simmer doesn’t even use headset audio in favor of a full surround system.

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I’m one of those who has no complaints about the sound quality of the SMAS.

I own and use systems from AKG, BeyerDynamic, Bose, B&W, Sony, etc. Of course, I also own VIVEDAS, INDEX and Odyssey+.

I think everyone has their own taste in sound, but I feel they are above a certain standard when it comes to sound quality.

The shortcomings of the SMAS are not in the driver itself.
It’s just a flaw in the design of the hinge.

1.The speaker doesn’t sit squarely on the ear.
2.The speaker is too far away from the ear.

These two points reduce the localization and resolution of the sound image.

We believe that if we could set the SMAS speakers in the right position relative to our ears and play them at the right volume, our complaints would be greatly reduced.

Sorry to interrupt the conversation.

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Not at all, thank you for contributing this! You just provided a solid explanation as to why some people are having more significant problems with the SMAS audio quality.

Since I 3D printed a bunch of replacement hinges, this just did not affect me to begin with.

However, experimentally pushing the speaker position up, closer to the top of my head, I do notice a significant and substantial decrease in audio quality, as well as a slight loss of separation between left/right channels.

For reference, the correct distance between the SMAS speakers and the outer ear is approximately 1cm. Distances of 3cm, 6cm, and 9cm, each cause progressively worse loss of audio quality.

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This is exactly part of the issue. Those not into bass and prefer only mid to highs will be okay with the SMAS. As shown in this link. The SMAS has only 10hz of the bass range. If it started at 100 to 20k it would be decent for a high end vr headset.

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From an engineering standpoint, ‘bass boost’ can largely be compensated in software - this will just take time - while flat high-frequency response is a far more serious technical challenge.

Would you really rather lose entire musical instruments, entire sound effects, or have major artifacts in roomscale soundscapes, just to have the SMAS speakers built as subwoofers from day one?

I for one appreciate that Pimax made the better long term decision here - quality hardware with a minor software correctable deficiency.

Anyway, the DAS is on the way. A little more delay while those are produced, and that should take care of the users craving bass above all else…

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A 100hz is not is the Sub Bass range. It is in the bass range which is 60 to 250. You shouldn’t loose instruments supporting 100hz. Even a 150hz would be okay.

As said the SMAS is good for those who do not care for bass or for an entry headset like the Artisan. Though the p4k speakers are of course higher quality.

Now there should be a base MAS with 0 audio for those whom want to use their own solution. However some have already stated the design creates issues for using your own due to the protrusions(likely have to angle it as with the roadshows demonstrated).

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As a practical engineering matter, it may not have been feasible for Pimax to design the drivers to provide both good bass response and flat high-frequency response simultaneously, especially without further delay.

Low bass response is trivial to mostly correct in software. Ripples in the high-frequency response is non-trivial to correct in software - there are few people who can do this and the MSW OS does not seem able support it anyway.

For those who need both, they will get it, either from the DAS after a little more delay, or from more software correction.

For the truly desperate, a ~50W LM3886 ‘gainclone’ amplifier - or better yet a modern ClassD amplifier - with an extra opamp and low-pass filter (essentially a low shelf) filter, all connected to USB power, could bring the SMAS bass response up today.

Maybe I will build and sell such a device - with an integrated USB-C power-only hub, fans, etc. But really, enough complaining.

The SMAS is fairly good if you actually consider the engineering, manufacturing, cost, and development time tradeoffs that were made.

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Considering the number of parts composing the rest of the MAS, I doubt this would be significantly cheaper. Nothing stops someone from taking the SMAS speakers to the side of a bench grinder if truly necessary…

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If your not into quality sound range yes it is good. And maybe if it had used the original driver pimaxusa mentioned sampling it might be better.

Don’t mix up prefering quality sound range on a high end vr or mid end vr device. With your preferences. Phones have had great sound quality for what they are. But they are not a great if you want real quality sound; simply good for a quick fix without needing to bring extra speakers.

Simply put the masses disagree with your assessment.

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Estimated could be $20 cheaper as the likely cost of the drivers.

Though you can buy a Vive Pro strap without speakers for $40 :us: