Category Archives: Electronics

Introduction to Wireless Portable Speakers


We live in a generation where the mobile devices are a central part of our life.  The importance of the mobile has brought an explosion in portable companion devices such as the portable chargers, Bluetooth headsets, speakers, etc.  Portable speakers are not a new concept for folks who would have been used to boom boxes and battery equipped radios in the 1970s.  These speakers were part of a major cultural change when it came to street music.

The popularity of the IPOD brought a new wave of portable audio devices in the likes of sound docks.  However for Android which joined the party a bit later found only limited options for sound docks  due to the change in the connector (mini USB to Micro USB), and the variety of device types.  The emergence of Bluetooth as a medium for playback, and combined with music apps on smart devices truly made universal portable audio devices to come into the market.

The portable wireless audio market since then has been growing fast, and these devices are offering continue to improve on the quality audio in a smaller foot print.  In order to achieve these portable wireless speaker manufacturers have designed in extensive concepts that allow maximum use of the small space of the speaker cabinet.

For anyone who has used audio equipment will know that size of the speakers, no of speakers, type of speakers, power of the amplifier, etc are not pure indicators for good quality sound.  The speaker designers have to tune the speakers to ensure it can handle a full range of frequencies, and the circuitry and software must also be designed to ensure compressed audio is processed, amplified to make use of the speaker hardware.

Unlike home theater systems or mini hi-fi systems, which feature dedicated sub woofers or speaker units for bass, the portable speakers with the size limitation are challenged in handling playback of the full spectrum of frequencies.   Hence if your expectation is that the portable wireless speakers are going to give the same quality and loudness of GOOD home theater systems or mini hi-fi systems, you will have to tone your expectations 🙂 , but things keep improving so some of these portable speakers can provide far better output than the largish computer speakers we used in the past.

So here is a few useful notes on the basics of a portable wireless speaker that can help you buy like a pro!

SPEAKER DRIVERS

Since we refer to the complete unit as the “SPEAKER”, i will refer to the individual speakers in this unit as “DRIVERS”

Modern good quality portable wireless speakers will feature some of the following drivers.

internals-of-a-bluetooth-speaker

  1. Full range drivers – These are all purpose speakers, which will TRY to handle all frequencies with on speaker.
  2. Mid Range drivers – These speakers will usually handle most of the vocals in the music (300-5Khz)
  3. Woofers – These are used to handle low frequencies (40 – 1kHz)
  4. Tweeters – These are used to produce high frequencies (2kHz – 20Khz)
  5. Passive Radiators (also called drone cones) – The air forced by the main woofers and speakers are “re-used” and pushed through the radiators (a piece of audio equipment that specially useful for bass frequency), which add to improved bass response. Most radiators are passive in nature, as in they do no use any electrical power (they are not connected to the amplifier), but are entirely powered by the pass through airflow.
  6. Bass Reflex port – This is more common approach to improve bass responses on speakers. Many small PC computers feature this technology, which allowed superior bass outputs from standard speakers. Here again there are variation, but seemingly with smaller footprints the passive radiators seem to offer better bass responses than a reflex port, as bass reflex ports are harder to design (but cheaper to implement)

A good read for passive radiators – http://www.centerpointaudio.com/passiveradiators.aspx

If you buy a speaker and it only has two same size drivers, then its mostly likely having full range speakers, where both drivers will try to play all frequencies.  The quality of the full range driver will decide how well the total speaker system plays different genres of music, but most often such speaker will be bass limited (bass will be muffled and lacking the thump), or if the manufacturer tunes it it may lack the mids (which will effect the vocals).

Many knock offs (copies/fakes) of branded products or cheap speakers will usually feature full range speakers, and possibly a simple bass port.

Some higher quality speakers may bring in a more balanced set of drivers that combine the different types (mid range drivers, woofers, radiators, tweeters) to provide good quality audio which can also handle different music genre’s.

SPEAKER AMPLIFIER and AUDIO PROCESSOR

The drivers/woofers/tweeters/radiators are one part of the speaker, but another essential part is the sound processing hardware and amplifiers.  The speakers also consist of the DSP (Digital Signal Processor), the DAC (Digital Audio Converter), and codecs.  The quality of the hardware and software used here, along with the tuning of these to match with the drivers/woofers will be key for the overall performance of the speaker.

This is why you will find that some speakers touting very powerful speakers may not sound so great for different music genre’s, as lack of software optimization and poor sound processing can completely cause the speaker drivers to be useless. Some vendors may add buttons for controlling treble, bass but you may find  when playing wireless you will hardly use these buttons and also need to change them from song to song making them useless.

A speaker that is optimized to handle different types of audio without such perks, and not distorting will be a happier purchase !

Another important aspect is how the manufacturer has designed the speaker to perform under battery mode.   Some speaker amps throttle the output of the speaker if its running on battery to reduce the drain on the battery, hence the speaker may not sound as great on battery compared to when its connected to the power and is charging.

Bluetooth version and features

The key enhancement in newer Bluetooth versions is the reduction in interference from other devices and frequencies.  One has to understand that frequencies used for other devices vary from country to country, and hence the interference can differ.

In most cases Bluetooth 2.1 would be adequate in handling playback of HD audio, but Bluetooth 4.0 with LE support can be help improve the power consumption of Bluetooth equipment.

A good read : https://www.quora.com/What-is-the-difference-between-Bluetooth-4-0-3-0-and-2-0

Some Bluetooth speakers allow you combine speakers and provide you better stereo isolation.  Though the portable speakers have multiple drivers, they are located to close to each other to really differentiate left and right channels.  By adding two devices, the speakers split left and right enabling better stereo isolation (which will also depend on how you place the speakers)

WiFi features

Newer wireless speakers may support WiFi, and this will bring a heavy dependency on the quality of the mobile application provided by the vendor to harness the speaker capabilities.  The mobile app will allow you to combine many speakers and stream audio from your mobile device to the speakers that can be located across your house.  The app will also help integrate with popular audio streaming sites, the support sites would depend on the application.

Each speaker will use separate bandwidth, and hence your network quality and bandwidth become key factors for the quality of audio that the speakers can provide when playing over WiFi.

Purchasing speaker to harness the WiFi capabilities will need lengthy research as many products have very grave issues such as regularly failing to connect to a wireless hotspot, breaks in streaming, lack of support for popular audio streaming sites, etc.  WiFi in portable speakers still seem to be in maturing state and here its led by a fairly new company called Sonos who create good audio devices that also feature robust WiFi connectivity supported by a good app for key mobile platforms.

Most WiFi speakers will also have Bluetooth connectivity, but if you fallback to Bluetooth you won’t have the ability to connect all the speakers as one, a key selling point for WiFi speakers.

Environmental Protection

A popular demand these days if for speakers to be very outdoor friendly including the ability of the speaker to handle a dip in the swimming pool.  New speakers come with different IPX ratings, and one has to understand making a speaker soundproof also bring in various forms protection for the equipment within, and the use of different materials for speaker drivers.  These can result in reduced audio quality in some instances.

Note from Author 🙂

This is a shift in interested towards mobile speakers, since Mobile Phones have become boring in recent times !!  With evolutionary improvements being harder to even notice (slightly better camera, faster processor, better battery life, better display, etc), and some features that to me are downgrades such as the lack of a 3.5mm speaker Jack (= no high quality DAC for audio), i decided a slight change on interest was required.. and the area i have now picked is portable audio. If you have any such gadgets and are willing to loan it for me for a week or two for review, i would be most delighted!

Related Posts

Some tips when buying a portable wireless speaker – https://rayazmuthalif.wordpress.com/2017/01/29/tips-when-buying-a-wireless-portable-speaker/

Portable audio equipment owned or used

Bose Soundlink Color, Sony SRS X5, Sony SRS XB3, Harman Kardon Onyx Mini, Divoom Solo, Bose Soundlink III, JBL Charge, Bose Soundlink Mini

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Low down on Advanced / Pro Compact Digital Cameras


What are Advanced/Pro compact cameras actually?

Advanced/Pro compacts are cameras that are considered the top of the line point and shoot digital cameras, though in features and usage they are more akin to a DSLR than standard point and shoot cameras.  The key features that make pro compacts superior to the other point and shoot cameras are,

  1. The camera sensor is much larger than what you find with most normal point and shoot cameras
  2. The lens of the camera will be very high quality, and very fast (have a large aperture) to allow shooting in low light.  The lens also might be developed by a professional lens specialist firm, and also actually manufactured by the specialist.
  3. The camera body will have loads of buttons and controls to access functions that allow maximize the use of the camera (similar to a DSLR)
  4. The camera will have full manual controls (M) in addition to the auto modes and aperture, shutter priority and program auto modes
  5. The camera will support advanced auto focus capabilities that will allow it to focus better under testing conditions
  6. The camera will allow connecting an external flash (usually one from the DSLR range made by the same manufacturer)
  7. The camera body will be made of special materials making the camera very high in quality and

Who actually buys these camera’s

With the prices of such cameras actually being same or more than some of the lower end DSLR cameras, one may question why not buy a DSLR camera and avoid paying so much what to one’s first impression is a fancy point and shoot digital camera.

  1. DSLR cameras are still much larger than advance compact digital cameras, hence you cannot carry them when you go for a private function
  2. Not everyone likes to have a DSLR camera due to the fact that after a while you get sucked into the “I need more lenses and accessories” game
  3. DSLR kit lens are not that great quality and also have smaller apertures (slower lenses).  Hence these advanced compacts can match or exceed the performance of the low end DSLR with kit lenses in the lower ISO ranges, which is good enough for most.  In addition the faster lenses on these smaller compacts can make them perform better than the lower end DSLR’s indoor.
  4. A DSLR lens with zoom that has the same aperture as the one’s offered by the compact lenses can cost you at least 2-3 times the price of such advanced compact.
  5. The advanced compacts also has a far better wide angle (24mm in most cases) than DSLR camera kit lens which are usually 27 or 28mm.

The primary buyers are the users who don’t want to own the DSLR, and want a camera that can take good to very good photos for family, home, adventure use opt for these advanced compacts.

The secondary buyers are the DSLR camera owners who usually have an advanced compact that they carry with them.  It also provides them the ability to take a quick shot without having to miss the opportunity while the try to change the lens that suits the shot!

What about the entry of the mirror-less compact system cameras

The introduction of the mirror-less compact system camera’s by Panasonic and Olympus, initialy laughed away by the giants Canon and Nikon, has surprisingly caused a large stir.  So much so these camera’s outsold DSLR camera’s in 2011 in Japan, a market that is more open to new innovations than the western markets.  Even the sales in US has increased to almost 20%, and has cause Canon and Nikon to also start developing mirror-less solutions.

Panasonic and Olympus are now challenged by products from Sony and Samsung, which feature the larger sensor found in DSLRs in the same mirror-less configuration.

This year saw two more entries, one from Pentax, a rather odd mirror-less since it features a body hosting a point and shoot type sensor (a sensor smaller than what you find inside an advanced compact!) yet with removable lens, baffling.

The latest entrant has been Nikon with the J1 and V1 models, which have been just released, and these have smaller sensor than the Panasonic and Olympus camera’s  though larger than an advanced compact camera.

The key selling point of these camera’s is that with the omission of the mirror shutter, resulting in these cameras shrinking in size so much that some of them have bodies smaller than the advanced compacts. However the term smaller is only valid when they are usually fixed with a fixed aperture lens, and when a zoom lens is added these are again larger and bulky compared to an advanced compact.  Olympus offers a folding type lens to make the zoom lens configuration also even more leaner, but this is also still larger than the largest advanced compact.

These mirror-less compact systems, with their larger sensor, smaller yet better quality kit lens (most of the kit lenses from these systems are much higher quality than the kit lenses that come with DSLR) offer very good picture quality though they are significantly smaller than DSLRs.  These cameras definitely out perform advanced compacts, but still have some limitations as the DSLRs such as the need to change lens, buy multiple lenses (and the need to be swapping lenses), high quality lenses being very expensive and being bulky than an advanced compact when fixed with a zoom lens.

Hence the need and market for these flagship high quality advanced compacts is not going to vanish very soon, as seen by the increase in the number of competitors in the market.

What models are current and recent Advance Compacts

In recent times the Nikon, Canon and Samsung cameras all use the same sensor supposedly manufactured by Sony, hence it’s the lens, software, features, and size of the cameras that make the difference.   The perennial challenge is from the Panasonic LX, that uses a different sensor but competes and matches the trio.  The newcomer from Olympus also seems to use the same sensor as the Panasonic.  Fuji was the newcomer with a new Fuji EXR sensor that is a bit larger than the other two sensors used by all other cameras.

Canon seems to be doing gentle upgrades mostly to fix the complaints of older models every year, so there are very little notable improvements, with the newer models doing better video and having faster auto focus being key improvement.  While the zoom levels are increased in some, you will notice the lens are also slower at the telephoto end, so be vary of that.

 Model Size (in) Size (mm) Megapixels aperture Zoom Lens
2011 Nikon P7100 1/1.7″ 7.49 x 5.52 10.1 F2.8 – F5.6 7.1 Nikon
2011 Canon S100 1/1.7″ 7.49 x 5.52 12.1 F2.0 – F5.9 5 Canon
2011 Fuji X10 2/3″ 8.8 x 6.6 mm 12.0 F2.0 – F2.8 4 Fujinon
2011 Olympus XZ-1 1/1.63″ 7.89 x 5.81 10.0 F1.8 – F2.5 4 Olympus Zuiko
2010 Canon G12 1/1.7″ 7.49 x 5.52 10.0 F2.8 – F4.5 5 Canon
Nikon P7000 1/1.7″ 7.49 x 5.52 10.1 F2.8 – F5.6 7.1 Nikon
Samsung EX1/TL500 1/1.7″ 7.49 x 5.52 10.1 F1.8 – F2.4 3 Schneider kreuznach
Canon S95 1/1.7″ 7.49 x 5.52 10.0 F2.0 – F4.9 3.8 Canon
Panasonic LX5 1/1.63″ 7.89 x 5.81 10.0 F2.0 – F3.3 3.8 Leica Vario-Summicron
2009 Panasonic LX3 1/1.63″ 7.89 x 5.81 10.0 F2.0 – F2.8 2.5 Leica Vario-Summicron
Canon G11 1/1.7″ 7.49 x 5.52 10.0 F2.8 – F4.5 5 Canon
Canon S90 1/1.7″ 7.49 x 5.52 10.0 F2.0 – F4.9 3.8 Canon
Post 2009 milestone models Canon G-Series (G10, G9, G7, G6, etc)Panasonic LXNikon P5000/5100