Search Wireless Audio Blog

Navigation

Entries in Bluetooth (19)

Monday
Apr122010

Bluetooth A2DP on iPhone 3GS and iPad better than on 3G

Noting that I railed against Apple's implementation of A2DP when iPhone OS 3.0 was released last year, I was doing so from my experience with the iPhone 3G, the most prevalent model at the time.  Just to confirm and keep me on record, it's still terrible.

However, it seems that dark little example of an Apple-crafted failing user experience may well be fading into the past.

Because fast forward a product cycle and it's apparent that the users of the iPhone 3GS (now arguably the most prevalent model) have never had to suffer like the 3G users.  I played around with the 3GS last week and the Bluetooth stereo audio protocol is significantly better than the 3G.  I mean, clearly, no argument.  Perhaps also equally noteworthy is that the iPad's Bluetooth stereo audio seems to be the same quality as the 3GS.  So that's something.

Now granted, if you consider an imaginary bar, let's call it the "sounds-like-shit bar", the 3G would reside below that bar, and the 3GS and iPad would reside above it.  Whether that bar is high enough for users to actually listen to the audio that resides above it and enjoy it at length, I'll withhold my opinion, for it lies in the realm of the subjective.  Living below the sounds-like-shit bar however, I am telling you, leaves very little room for subjectivity.
Tuesday
Jul282009

Bose SoundLink has Bluetooth inside

So another little thing I like to do from time to time is troll the FCC database to see what's happening in the field.  My curiosity was peaked by the Bose SoundLink enough to go fish.  I wrote about the new Bose product a couple weeks ago, and pointed out some viable, more affordable alternatives.

Unfortunately the full documentation is still restricted under confidentiality request submitted by Bose, so you won't get the dirty nude shots... But what you can find out from the test report that is posted to the public is that the new Bose employs a Bluetooth radio.  While it isn't marketed this way, it would not surprise me if this thing did support A2DP (another feature I've written about in the context of the iPhone).  I am sure Bose has done some sweetening if this is the case, otherwise, the sound quality would suck big time... and (to all those Bose haters) I don't mean just in a Bose way.

From report number EMC.404096A.09.192.1, page 4:

The SoundLink™ wireless music system is a system enabling the user to enjoy music from a computer in any room you choose, with a wireless connection.


It features





  • Simple wireless connection using the SoundLink USB key – no software to install

  • Long-range wireless link lets you listen in and around your home

  • Rechargeable lithium-ion battery provides hours of Bose® performance

  • Handy remote included. The remote utilizes infra-red communications.



The USB key is a separate product, which is not covered in this test report.


The SoundLink™ wireless music system is classified as a Bluetooth® data “sink” with a duty cycle that does not exceed 5% in normal operation. For the purposes of the tests described in this report, where an artificial test mode is indicated or necessary for the purposes of the test, the SoundLink™ wireless music system  is operated with a 10% duty cycle which is considered a worst-worst case for the purposes of these tests.

Thursday
Jul162009

It's the centers of gravity, stupid.

I wanted to write a little about interface standards in consumer electronics.  My purpose here isn't to write an exhaustive history of standards and formats – far from it, in fact – rather I want to present some background as a lead-in to some product-specific discussions that will be coming here on wab in the next 6-12 months.

This first article is only to give a little background on this notion of connection standards in consumer electronics, i.e. how devices from different vendors end up settling on means to send content to and from each other.

In the world of consumer electronics and their device interfaces, the most widely adopted interface formats are what we refer to as "standards."  Like what? To name a few that might sound familiar: USB, Firewire, Ethernet, WiFi, Bluetooth, RCA, VGA, DVI, HDMI, Component Video...

What differentiates interfaces from one another?

  • Some are application specific, some are non-specific

  • Some of these interfaces are digital, some analog in nature.

  • Some are wired, some wireless

  • Some communicate information isochronously, some asychronously

  • Some are secure, others are insecure


...the list goes on an on.  In many ways, the interfaces define the product, but depending on your technical depth or experience with gadgets, your lists of what set them apart will vary.

Common across these example interfaces, and the main point of this article, is that they've been adopted as standards, meaning lots of things on the back-end... but most importantly, at the consumer level, there is a general acceptance and expectation of functionality via each interface.  In addition, consumers can (should) be assured that two devices carrying an interface will be able to interconnect to another device with the same (or complementary format of the same) interface regardless of make or model - i.e. they support interoperability across brands.

For any company that owns the critical intellectual property defining a standard, if you can manage to connect dots for a consumer, positive network externalities await you.

Problems with interfaces and standards


In general, inter-device connections tend to confuse and scare the non-geek consumers, and for good reason... They come in strange shapes, sizes, colors, require wires, passwords, control panels, etc... and they are complex and they come into the market in many ways... with a splash, like a mouse, or like a tornado.

I admit that above, I cheated a little.  Some of the examples I gave for standards don't always fulfill their marketed expectations. HDMI had and still has issues with interoperability, and Bluetooth is often and rightfully criticized for its profile madness.  There are always market truths, and marketing messages.  As always, caveat emptor.

To me, the best interface standard is the one you never notice!  It just works.  This is the holy grail phenomenon.  Not noticing frequently entails not seeing the wires... so of course wireless interfaces are particularly interesting to me.  However, I am the first to admit that my work-life is very much consumed with some very important wired interfaces... (USB, Apple's 30-pin, HDMI... etc).

As an example, I wish most consumers appreciated how much "stuff" is happening over the iPod dock connector.  Just getting audio out of the iPod is a unique engineering, business relationship, and component economics challenge.  Apple has made its own proprietary standard, and while it's a challenging standard to work with, they've earned it to a degree by delivering an incredible consumer experience in the iPod/iPhone, the ecosystem's host gadget.  The accessory world pays to play as a result.  What's incredible to me is that pretty much every modern interface standard has some sort of obstacle course that must be navigated in order to implement... system integrators spend most of their time with this stuff.

This is the other problem-set when it come to interface standards – working with a given standard can be easy or challenging.  Highly planned and rationalized standards tend to be easier for device makers to employ, as the technology vendors (connector makers, protocol baseband chip suppliers, etc) have competition and thus have to earn their customer the old fashioned way, through affordability, quality of support, and solution convenience.  The more proprietary and closed a standard is, the harder (and more expensive) it typically is to access and implement, and unfortunately this slows the growth and decreases the standard's overall potential.

The pursuit of the next big thing standard


Much of the electronics industry is driven by the pursuit of creating a technology that can become a standard. Duh. Silicon companies, algorithm IP creators, etc... can retire once they land a standard.  It's the home-run everyone wants.

There is no one way to be successful in achieving this.  It can and has happened by many recipes and business models.

Standard creation involves tradeoffs:
- Trying to be all things to all people versus risking not doing enough and thus missing a critical application and losing to a competitive standard.
- Doing it alone, doing it with partners
- Opening it up, or keeping it proprietary

The standards creators can be anything from a single engineer, to a startup, to an R&D lab of an industry giant (how Bluetooth began at Ericsson), to a committee of all of the above...  There are also practical, technical, and economic implications, which is why silicon companies are often right in the middle of these discussion.  Most of the standards above require chip-based solutions for implementing, and thus chipmakers become vital part of any go-to-market strategy for a standards format, particularly wireless ones.

Go-to-market strategies also run the gamut of business models.  There are companies like Apple who create new standards and just take them to market – the "why wait for everyone else... I need this" approach.  They like to create proprietary standards and if they're lucky... down the road force partners in the industry to pay to use their connectors, protocols, etc...  Microsoft too.  Nintendo too.  Think game controller plugs.  Microsoft used a custom variant of USB for Xbox controller accessories and a custom variant of 802.11 for their wireless Xbox 360 controllers and headsets.  Nintendo uses a custom profile over Bluetooth for the Wii.

There are also marketing SIGs.  Joint bodies chaired often by the inventor entity(or entities). These participants may have been part of the design phase of the standard as well, or the tail end of it to get their 2 cents in so they feel ownership.  Look at Bluetooth SIG, WiMedia Alliance, Wireless USB, WirelessHD, WHDI, WiGig Alliance to see works in process at various levels of success/maturity.  Interface standards are really no different than format wars in media (Blu-ray, HD-DVD, VHS, Betamax).  Just that in format wars you also involve the media owners which opens up another can of worms...

What any of these approaches reveal is that the one thing you need to create a successful standard is: a center of gravity.

Be one.  Make one.  Find one.


My feeling on marketing standards about 4 years ago was: find a center of gravity in the industry, and you will find a potential sponsor of a standard.

Apple is a center of gravity because of their leadership in design and software.  Their almost flawless execution in the portable/mobile world has solidified this for years to come.  So there you go - great example.  Build one of the coolest product ever designed, put tons of clever marketing behind it, build in your own core technology, publish a programming guide and API to access your IP, and create a license program, and... ok... this is not for everyone.

Who else is out there that has muscle?  Who defines and builds platforms and owns networks?   Who else build compelling user experiences?  Who has vast marketing budgets?

Intel?  Yes.  Qualcomm?  Yes.  Heard of CDMA.  Microsoft?  Yes.  Verizon?  Well they certainly try.  Google?  Yes.  Nintendo?  Yes.  Sony?  Yes.  Once more so, but still have rabbits in hats.  Cisco?  Probably?  Dell?  Yes.  Vizio?  Maybe.

On their own, some of these require a little imagination, I'll give you that... but vision and the will to shoot the moon come at many moments, and these companies have track records and resources that those with a vision on a new standard would die to have in their quiver.

Certainly, a center of gravity can arise from groups of enough firms.  For some small firms, there-in lies a marketing strategy.  The WiGig Alliance mentioned earlier is an example of an alliance that is largely dependent on one silicon startup's success - Wilocity - who have decided to create a center of gravity around a specification, and now it is up to them to deliver the key enabling silicon.

What haven't I mentioned?


What are some other ways to find a center of gravity that can affect an interface standard's success?  Who has the power to ascertain what technologies are best for consumers?  Who has the power to shape the product design decisions at a CE device maker?

Stay tuned...
Thursday
Jun252009

Apple iPhone OS 3.0 shines fresh light (and enmity) on A2DP Stereo Bluetooth

So it's clear from my Google Analytics data that since the release of iPhone OS 3.0, there is a heightened interest in Bluetooth stereo audio. There is also concern about its quality, and whether it sounds like shit on purpose.

Well let me tell you, something funky is definitely going on with the Bluetooth stereo audio performance on the iPhone. Your suspicions are not unwarranted. The bottom line is that Bluetooth A2DP as implemented in the iPhone will sound like shit. Anyone with an ear (but not a preference) for audio distortion will corroborate there is a ton of it when listening to Bluetooth wireless audio on the iPhone running 3.0 OS. High frequency sounds such as symbal-hits sound like digital-ringy-thrash-crap. Awful. Un-listenable. Period.

After poking around a bit, it seems (I suspect) Apple may be short-changing users on the bitpool allocation. From an internet discussion regarding hacking BT performace via Windows registry, it is noted that the Bluetooth A2DP implementation guide outlines how to adjust over-the-air quality for A2DP:

Medium Quality
BitPool=35, SampleRate=44.1khz = 229kb/s
BitPool=33, SampleRate=48khz = 237kb/s
High Quality
BitPool=53, SampleRate=44.1khz = 328kb/s
BitPool=51, SampleRate=48khz = 345kb/s


The trade-off is of course weighed and excuted by Apple. It appears, and logic would backup, that the source device in the A2DP link is the "decider" for the bitpool. The setting, that is, that determines bitpool is embedded in the iPhone itself, rather than the receiving BT accessory.

All bitrates are not created equally


Do NOT be fooled. The bitrates you see above are not typical compression bitrates you are used to seeing in your desktop music libraries. BT doesn't use a fancy psychoacoustic lossy compression scheme like MP3 or AAC (optional A2DP codecs, btw, but neither employed by Apple). The standard for A2DP Bluetooth uses sub-band coding (SBC) for compression. SBC is royalty-free, low complexity, low latency, and by many measures, a crude form of compression. The bitrates that apply to it do not yield the same sound quality at comparable bitrates of MP3 or AAC. Some estimates are that you require 3x the bitrate to achieve comparable quality to MP3. To highlight just how much better MP3 and AAC are consider, AAC and MP3 are not royalty free, and in spite of that, they are employed in infinitely more places, and are thus commercially acceptable. You get what you pay for, people.

Doubling down on lossy


Also keep in mind that you are *re-compressing* an audio file that has already been uncompressed from a lossy codec (MP3 or AAC). Meaning, the original CD-quality track (1411 kbps) was compressed using some (better) codec like MP3 or AAC. Do it once and the quality is very acceptable for most consumers at 192 kbps or above, even if it is mildly, and unarguably, degraded from the original source file. Here's where A2DP gets nasty. It takes this degraded uncompressed file, and compresses it again, this time using a particularly crude compression scheme, SBC, and what you are left with after wireless transmission and local uncompression in the speaker is an audio file that is riddled with tandem artifacts from daisy chaining multiple lossy encode/decode cycles. Nasty.

WWJD


Now if Apple increased the bitpool, what would happen? Would this solve all the issues with current BT audio quality? Not really. Audio quality would improve, but likely only slightly, because you still don't conquer the tandem artifact issues. Transmission range would decrease and power consumption would increase – owing entirely to the increased use of bandwidth and its increased transmission duty cycle required to ship more data, nominally.

Practical remedy


The right answer is to support MP3 or AAC via Bluetooth – possible and feasible because as mentioned, either are supported optional codecs for A2DP. This means you would not have to decompress a file that is already in the format you are sending over the air. You send it over in its orginal compressed state, then you decompress it once at the receiver. There are some non-dealbreaking implications that must be considered:

  1. The receiver must carry the cost of a royalty in order to decode the Mp3 or AAC. That's a bummer for accessory makers. It's not big, but it also hard to get paid for by the consumer, so it eats right into margins. What ends up happening is accessory makers will choose to only support the optional codec in a premium product offering, and run the risk of embedding the low-performance SBC option in entry level products or leaving it out altogether cause it more or less sucks.

  2. It is difficult to support BOTH Mp3 and AAC, meaning Apple would likely choose to support AAC as this is the format they sell via iTunes, and so it would make sense that they would want to offer the best audio experience with the format they purvey. This is also something of a bummer for consumers who for the most part still trade and burn in mp3.


Bottom line



  • My recommendation as a product developer, but more importantly as a consumer, is that Apple supports MP3 as an optional A2DP codec for the iPhone. I'll take AAC as a second choice... but it's more evil as there is so much music I simply won't convert to AAC, and I will resent having to buy all my music I want to enjoy wirelessly from iTunes.

  • Consumers will reject the audio quality currently offered in the iPhone's A2DP standard implementation.

  • Accessories will lack efficacy in their wireless audio feature, and the brands that do this will be at risk of taking the heat for the poor performance. This will hamper implementation of the feature in the accessory space.

  • These last two bullets, unaddressed, are the two major factors why I predict Bluetooth stereo audio will fade into history, which is sad, because there are dozens of engineers who've worked very hard to get it so close to the original vision's intent. To see it still fall short is depressing.


---

Related articles from wirelessaudioblog.com: here on announcement, here on BT headphones.
Thursday
Mar262009

Bluetooth Headphones: which ones can hold an iPhone's jock?

Here's a question for you all:  what model of Bluetooth headphones do you think can honestly hang with the design sophistication and street cred of an iPhone?  When A2DP support is released for the iPhone later this year, what models will get the bump in sales?  Here are the ones (from Amazon's list of category bestsellers) that I think are the most attractive...

Kensington Bluetooth Stereo Headphones with Microphone

Plantronics Voyager 855 Plantronics Voyager 855

Motorola S805 Bluetooth D.J. Style Stereo Headset Motorola S805 Bluetooth D.J. Style Stereo Headset

Sony Ericsson HBHDS980 Stereo Bluetooth Headset Sony Ericsson HBHDS980 Stereo Bluetooth Headset

Even though each model's execution is pretty good, there are still a number of issues in the lot.

  • Bulk.  The competition are wrappable earbuds that don't need batteries.  The primary design issue for any wireless headphones is where to put the battery. For the on-the-go experience, an especially tough constraint.

  • Oddness.  Lapel clip designs (which Sony's is the highest quality example) are strange, and still have many wires.  The chief tangle issues are still present.

  • Lack of mass appeal form factors.  Circum-aural and super-aural designs are not the mainstream, so the actual design execution will need to bring the benefits that their size provide.  Comfort is one.  Audio quality is the other.  Sadly BT is the limiting factor on quality.

  • Comfort.  This is not an issue that is wireless specific.  But so many have done so poorly here in the BT space... largely because they aren't typically headphone experts (motorola's MOTOROKR and early logitech models come to mind).  Everyone is getting better, and one design does not fit all.  Still I look to Sennheiser, Shure, and Sony to be the experts here.


My gut feeling is that none of the models out right now (the above included) have the "right stuff."  They are still too dorky and the burden of keeping them charged and stowed on your person are overwhelming.  Headphones are the real fashion statement when listening to music in public.  People do take these matters rationally or casually.

The wireless headphone designer who can focus on the real benefits that having wireless headphones give a user, and nail an attractive minimalist design will address may of the existing models' shortcomings.

The product that results... that will be your best seller.