Tag Archives: audio

Review: Orbitsound Dock E30 one-box audio system with wireless charging aims to fix the problems of stereo

image

It is simple but appealing: one small box instead of all the clutter of a conventional hi-fi system. Orbtisound’s Dock E30 is also designed for today’s audio ecosystem. It supports wireless playback with Apple AirPlay, Spotify Connect, Android audio streaming over Wi-Fi, and also Bluetooth aptX and wired input via analogue or optical digital signals. There is an app for iOS and Android, and you can even dock your phone either by sitting it in the groove provided, handy for seeing cover art. You can also charge a phone using the built-in Qi wireless charging (as used by Apple), or by connecting a cable (not supplied) to a USB-C charging support. For wireless charging though you should lay the phone flat on the charging plate rather than standing it up.

image

Wireless charging aside, this is all what you expect from a modern audio system; but the Dock E30 has something distinctive. This is the technology called Airsound. Orbitsound says that the problem with conventional stereo is that you have to sit in a sweet spot dead centre between and in front of the speakers to get a true audio image. “We have managed to overcome this inherent limitation in stereo by doing away with the idea of left and right channels,” says Orbitsound. What they have come up with, explained to some extent here and here, is a three-speaker system, where the sound of the main front speaker is modified by two “spatial” side speakers to give, it is claimed, a stereo experience wherever you sit. There is said to be a particular advantage when you have more than one speaker connected.

Orbitsound’s explanation of Airsound is sketchy, to say the least, but it helped me to understand the results of my listening tests. I set up the Dock E30 in my living room and tried it using various types of connection from both iOS and Android. For the main listening test though I settled on wired input for maximum consistency. I compared the E30 with several other speaker systems, including the slightly more expensive Sony SRS-X9 (now replaced by the similar SRS-X99).

First impressions are good, with a powerful bass reinforced by the passive bass radiators on the back of the unit. The power output is not specified, but I got plenty enough volume for my smallish living room. I tried walking round the room and found a good consistency of sound, though frankly the SRS-X9 which uses conventional stereo speakers was also pretty good in this respect.

How does the sound compare to that from the Sony? I found my notes contradictory at first. I felt the sound, while decent, was smoother and better defined on the Sony than on the Dock E30. At the same time, I could sometimes hear details on the Dock E30 more clearly than on the Sony. One example was the delicate guitar in the background during the intro to Steely Dan’s song Peg (which is beautifully recorded). It was more prominent on the Dock E30, even though overall I felt that the Sony had more clarity.

Pondering Orbitsound’s claim of a true stereo image wherever you sit, I pulled out a handy test track, Paul Simon’s Cars. In the middle of the track there is a little stereo effect. “You can drive them on the left” comes out of the left speaker, then “you can drive them on the right” from the right. Then Simon resumes singing in a central position.

I have to say, the Dock E30 made a complete mess of this effect. Bizarrely, the “on the right” vocal projected to the left of the image. On the Sony, everything was as it should be, so no, I had not got the channels reversed anywhere. Bear in mind that the Dock E30 only has one front-facing speaker; the other drive front-facing driver is a passive bass radiator.

image

Audio processing: pros and cons

In the end this is all about processing. Orbitsound is trying to get a sense of room-filling stereo from a small box. It does this by munging the stereo signal into a mono part on the main speaker, supplemented by two spatial effects speakers that fire outwards from the left and right ends of the Dock E30, using some kind of algorithm that is not really designed to give you a true stereo image, but rather to create an illusion of depth.

This I believe explains why I found the sound perplexing at times. Some details might be brought out more prominently, others not.

You can adjust the Airsound effect by holding down mute for three seconds on the remote, then spinning the volume dial. If you adjust it for minimum Airsound, you get something close to mono. This is not a bad thing; I love my mono Squeezebox Radio. If you adjust for maximum Airsound, the sound become echoey and phasey, something which is not to my taste but might be an effect you enjoy.

Setting Airsound to minimum is close, but I would like to see an option to disable it completely and simply have mono, though that would be rather a waste of three speakers.

Don’t worry, just listen?

Listening to the stereo effects in Cars is an edge case. I found the Dock E30 enjoyable to listen to with music from classical to jazz to pop and rock. It has good bass extension, which can be excessive at times, but is easily controlled using the tone controls on the remote. Most people are not going to worry about the processing and can just listen.

Personally though I am more purist. I favour a less processed sound and prefer the clean, honest clarity of a system like the Sony XRS X9.

image

A good buy?

Leaving aside the Airsound debate, the Dock E30 offers good sound quality with exceptional bass for its size.

The design is subjective of course, but while it is not objectionable, there are better-looking speaker systems in my opinion. The groove on top may trap dust, and the controls on the front are not beautiful.

On the other hand, I am very happy with the flexibility of the unit. It has a generous range of inputs, both wired and wireless. The remote with its tone controls and mute button is excellent.

The ability to charge your phone is a nice bonus.

Unfortunately I am not convinced by Airsound or that this is the best use of three speaker drivers; but at the same time it is good to see some innovative thinking. I recommend that you audition before purchase.

Specifications

Frequency response: 70Hz-17.5kHz +/- 3dB

Tone controls: Bass and treble, +/- 8dB

Drivers: 3 x 48mm neodymium drivers, 3 x 90x60mm passive bass radiators

Optional subwoofer

Removable magnetic grille

Remote

Dimensions: 291x150z114mm

Weight: 4kg

Colour: Black, Bamboo or White

The Scalford Hi-Fi show is dead – long live the Kegworth “Europe’s biggest Hi-Fi enthusiasts show”?

It was March 2009 when I took part in an unusual Hi-Fi show, variously known as the Scalford, Wigwam, Wam or Pie Show (Pie show because Scalford is near Melton Mowbray, home of the Pork Pie, and Pie rhymes with Hi-Fi). Wigwam was and is a Hi-Fi enthusiasts forum and the idea was to put on a show where the kit on show was not the latest stuff from big brands, but rather actual systems in use by enthusiasts. Without the normal income from commercial exhibitors, the cost of the hotel booking was met by the entrance fee (£10 as I recall). Exhibitor rooms were free other than a small contribution to public liability insurance. The early shows were run by audio show specialists Chester who did it, they said, as a community building exercise.

Scalford Hall is an English country hotel which must once have been a grand country residence. it is beautiful, rambling and impractical, but full of atmosphere.

The show was an extraordinary success. There was a vastly greater variety of gear on show than at commercial shows, ranging from conventional and modern to old and home-made. The exhibitors were enthusiasts who loved to talk about their systems, and the sound achieved was in general rather better than most. A few pictures, not from the first show:

image

image

Personally I had a great time at Scalford and exhibited 8 years in succession (starting with the first). Hmm let me see:

2009: plain Squeezebox, Naim 32.5/Hicap/250 and Kans 

image

2010: Ergo speakers designed by James at another HiFi forum, Pink Fish Media,  loaned to me for the event. Same source and amplification.

2011: Active Speakers AVI ADM 9 with BK subwoofer

2012: Linn Kaber loudspeakers with Naim amplification; my least successful room I feel. I thought the Naim amplifier would get the Kabers sounding at their best but the sound was average and I was not sure how to fix it. 

2013: Active Speakers Behringer B3031A. The theme here was how to get a great sound on a small budget, and the Behringer active speakers offer a lot for the price.

2014: Amplifier comparison Naim as above vs Yamaha AS500

This was fascinating; a modern budget amplifier compared to a classic pre-power combination loved by many but also considered coloured. Most thought both sounded great and were not sure which was which.

2015: DSD vs PCM comparison using Teac DSD DAC 

2016: Raspberry Pi system no separate amplifier

Some of these events have separate write-ups on this blog.

My goal was not to have the best sounding system but to do something interesting and enjoyable.

Enjoyable it was, but also hard work – at first I didn’t bother booking a room for the night as I lived within 45 minute drive, but I gradually realised that staying over worked better both for access to the room and for hearing other rooms the night before.

Heaving equipment around is no fun even though I didn’t have the heaviest stuff, even so amplifiers, subs and speaker stands are hefty enough. Some of my stuff got a bit bashed about too, though scratches rather than real damage.

The earliest events were run supposedly at break-even or thereabouts by Chester. The only commercial presence in the early shows was a record shop in the lobby.

I was personally fine with everything as we were doing something a bit different that would not otherwise be possible.

Gradually more commercial rooms appeared and it became harder and harder to secure good rooms. My room in year 1 was brilliant and sounded great as a result. Many of the rooms though were small hotel bedrooms in an extension rather than the older part of the building, with poor sound insulation. It was hard to get a good sound in these rooms.

I also began (speaking personally) to feel a bit unappreciated as it was the exhibitors who made the event worth going to, but we paid for the privilege and if someone managed to make some money (as I believe the organisers did in some years) none of it came to us not even a free beer or two. After the first couple of shows the organisation passed to the owners of the WigWam forum, which itself changed hands a few times. In 2017 my heart was no longer in it and I did not exhibit.

The trend towards greater commercialism continues and the WigWam’s current owners now promote the event as "Europe’s Biggest HiFi Enthusiasts Show". The cost for exhibitors has increased and now starts at £85. I have fond recollections of the show and hope it goes from strength to strength, but last year felt it was no longer for me.

Scalford was a wonderful venue, quirky and romantic, visitors could still be surprised to open a door or ascend a stairway and find a corridor of rooms they had somehow missed. Of course it was also a bit impractical and the catering rather ho-hum but it wasn’t a big deal for me.

The show is now moving to Kegworth, just off the M1 near Nottingham. The move to a hotel handy for the motorway and airport is another step away from the atmosphere and culture of the initial concept.

That said, I have no doubt that it will remain a remarkable and unusual event and hope it continues to be a great success.

More on MQA and Tidal: a few observations

I have signed up for a trial of the Tidal subscription service and have been listening to a few of the MQA-encoded albums that are available. You can find a list here. Most of the albums are from Warner, which is in the process of MQA-encoding all of its catalogue.

From my point of view, having familiar material available to test is a huge advantage. Previous MQA samples have all sounded good, but with no point of reference it is hard to draw conclusions about the value of the technology.

I have used both the software decoding available in the Tidal desktop app (running on Windows), and the external Meridian Explorer 2 DAC which is an affordable solution if you want something approaching the full MQA experience.

image

Note that on Windows you have to set Exclusive mode for MQA to work correctly. When using an MQA-capable DAC, you should also set Passthrough MQA. The Explorer 2 has a blue light which shows when MQA is on and working.

image

For these tests, I used the Talking Heads album Remain in Light, which I know well.

The Tidal master is different from any of my CDs. Here is the song Born under Punches in Adobe Audition (after analogue capture):

image

Here is my remastered CD:

image

This is pretty ugly; it’s compressed for extra loudness at the expense of dynamic range.

Here is my older CD:

image

This is nicely done in terms of dynamic range, which is why some seek out older masterings, despite perhaps using inferior source tapes or ADC.

This image shows three variants of the track streamed by Tidal and captured via ADC into a digital recorder at 24-bit/96 kHz.

image

The first is the track with full MQA enabled and decoded by the Explorer 2. The second is the “Hi-Fi” version as delivered by Tidal, essentially CD quality. The third is the “Master” version, in other words the same source as the first, but with Exclusive mode turned off in Tidal, which prevents MQA from working.

You can see at a glance that MQA is doing what it says it does and extending the frequency response. The CD quality output has a maximum frequency response of 22 kHz whereas the MQA output extends this to 48 kHz at least as captured by my 24-bit / 96 kHz (the theoretical maximum frequency response is half the sampling rate).

Do they sound different though, bearing in mind that we cannot hear much above 20 kHz at best, and less than that as we age? I have been round this hi-res loop many times and concluded that for most of us there is not much benefit to hi-res as a delivery format. See here for some tests, for example.

MQA is not just extended frequency response though; it also claims to fix timing issues. However my captured samples are not really MQA; they are the output from MQA after a further ADC step. Of course this is not optimal but the alternative is to capture the digital output, which I am not set up to do.

An interesting question is whether the captured MQA output, after a second ADC/DAC conversion, can easily be distinguished from the direct MQA output. My subjective impression is, maybe. The first 30 seconds of Born Under Punches is a sort of collage of sounds including some vocal whoops, before David Byrne starts singing. What I notice listening to the Tidal stream with MQA enabled is that the different instruments sound more distinct from each other making the music more three-dimensional and dramatic. The vocals sound more natural. It is the best I have heard this track.

That said, I have not yet been able to set up any sort of blind test between the true MQA stream and my copy, which would be interesting, since what I have captured is plain old PCM.

There is a key point to note though, which is that mastering offered by Tidal is better than any of the CD versions I have heard; the old Eighties mastering is more dynamic but sounds harsher to my ears.

With or without MQA; you might want to subscribe to Tidal just to get these superior digital transfers.

Update: it seems that the Tidal stream for Remain in Light (both MQA and Hi-Fi) is a different mix, possibly a fold-down from the 5.1 release. So it is not surprising that it sounds different from the CD. The question of whether the MQA decoded version sounds different still applies though.

The MQA enigma: audio breakthrough or another false dawn?

The big news in the audio world currently, announced at CES in Las Vegas, is that music streaming service Tidal has signed up to use MQA (Master Quality Authenticated), under the brand name Tidal Masters. MQA is a technology developed by Bob Stuart of Meridian Audio, based in Cambridge in the UK, though MQA seems to have its own identity despite sharing the same address as Meridian.

image

What is MQA? The question is easy but the answer is not. Here is the official short description:

Conventional audio formats discard parts of the sound to keep file size down, but part of this lost detail is the subtle timing information that allows us to build a realistic 3D soundscape in our minds. … With MQA, we go all the way back to the original master recording and capture the missing timing detail. We then use advanced digital processing to deliver it in a form that’s small enough to download or stream.

At first sight it looks like another format for lossless audio, and the description on MQA’s site confuses matters by making a comparison with MP3:

MP3 brings you just 10% of what was recorded in the studio. Everything else is lost to fit the music into a conveniently small file. MQA brings you the missing 90%.

There are two problems with this statement. One is that MP3 (or its successor AAC) actually sounds very close to the original, such that in tests most cannot tell the difference; and the other is that audiophiles tend not to use MP3 anyway, preferring formats like FLAC or ALAC (Apple’s version) which are lossless.

There is more to it than that though. There are three core aspects to MQA:

1. “Audio origami”: MQA achieves higher resolution than CD (16-bit/44.1MHz) by storing extra information in audio files that is otherwise wasted, as it stores audio that is below the noise floor (ie normally inaudible). There is a bit of double-think here as removing unnecessary parts of audio files is the sort of thing that MP3 and AAC do, which the MQA folk have told us is bad because we are not getting 100%.

This is also similar in concept to HDCD (High Definition Compatible Digital), a technology developed by Pacific Microsonics in the Eighties and acquired by Microsoft. Of course MQA says its technology is quite different!

Note that you need an MQA decoder to benefit from this extra resolution, and there is a nagging worry that without it the music will actually sound worse (HDCD has the same issue).

2. Authentication. MQA verifies that the digital stream is not tampered with, for example by audio features that convert or enhance the sound with digital processing. This can be an issue particularly with PCs or Macs where the built-in audio processing will do this by default, unless configured otherwise.

3. Audio “de-blurring”. According to MQA’s team:

There’s a problem with digital – it’s called blurring. Unlike analogue transmission, digital is non-degrading. So we don’t have pops and crackles, but we do have another problem – pre- and post-ringing. When a sound is processed back and forth through a digital converter the time resolution is impaired – causing ‘ringing’ before and after the event. This blurs the sound so we can’t tell exactly where it is in 3D space. MQA reduces this ringing by over 10 times compared to a 24/192 recording.

If this is an issue, it is not a well-known one, at least, not outside the niche of audiophiles and hi-fi vendors who historically have come up with all sorts of theories about improving audio which do not always stand up to scientific scrutiny.

So is MQA solving a non-problem? That’s certainly possible; but I do find it interesting that MQA has received a generally warm reception from listeners.

Here’s one audiophile’s reaction:

Have never really “done” digital before. 16/44 has always sounded ghastly to my ears right from the start and still now. MQA did indeed “fix” the various forms of distortion that I could hear present in everything where the sampling rate was taken down to just 44. … My findings – those of an improved sense of solidity in the stereo image and the lack of that horrendous crystalline glassy edge to things, especially on the fade, seem to be being mirrored in what people are hearing. It doesn’t have that thing I describe as a “choppy sense of truncation” which I suspect others mean by “transients”.
Basically, per the post above, it’s a bit like “good analogue”. Digital can finally hold its head up high against an analog from master-to vinyl performance. And not only that, hopefully, walk all over it and give us something genuinely new.

If this history of audio has shown us anything, it is that subjective judgements about what makes something sound better (and whether it is better) are desperately unreliable. Further, it is often hard to make true comparisons because to do requires so much careful preparation: identical source material, exactly matched volume, and the ability to switch between sources without knowing which is which, to avoid our clever brains from intervening and telling us we are hearing differences which our ears alone cannot detect.

We should be sceptical then; and even possibly depressed at the prospect of a proprietary format spoiling the freedom we have enjoyed since the removal of DRM from most downloadable audio files.

Still … is it possible that MQA has come up with a technology that really does make digital audio better? Of course we should allow for that possibility too.

I have signed up for Tidal’s trial and will report back shortly.

Review: Libratone Zipp Mini

I am quite taken with this Libratone wireless speaker, though I had a few setup hassles. The device comes in a distinctive cylindrical box with a nightingale image on the top. Unpack it and you get a medium-size desktop (or table or shelf) speaker, around 22cm high, with a colourful cover that looks zipped on and a carry strap. There is also a power supply with UK and European adaptors, and a very brief instruction leaflet.

image

Plug in, and the device starts charging. The leaflet says to download the app (for iOS or Android) and “set up and play”. It was not quite so easy for me, using Android. The app is over-designed, by which I mean it looks great but does not always work intuitively. It did not find the speaker automatically, insisted that a wi-fi connection was better than Bluetooth, but gave me no help connecting.

After tinkering for a bit I went to the website and followed the steps for manual wi-fi setup. Essentially you temporarily disconnect https://www.itwriting.com/blog your normal Wi-fi connection, connect your wi-fi directly to the Zipp, go to 192.168.1.1 in the browser, select your home wi-fi network, enter the password, and you are done.

Everything worked perfectly after that. I fired up Spotify, played some music, selected the Zipp under Spotify Connect, and it sounded great. For some Android apps you may need a Bluetooth connection though, or you can use DLNA. The beauty of Spotify Connect is that the connection is direct https://www.itwriting.com/blog the speaker to the internet, it does not depend on the app running, so you can switch off your phone and it still plays. It is actually a better solution than Apple Airplay for internet streaming.

image
The Nightingale button

Control is either via the app, or through the Nightingale button on the top of the speaker. The button works really well. Tap to pause or resume. Slide finger clockwise or anti-clockwise for volume. Skip forward or back by tapping the right or left edge. Then there is a neat “hush” feature: place your hand over the button and it mutes temporarily.

A bit more about the sound. Although this is the smaller Zipp Mini, you can tell that Libratone has taken trouble to make it sound good, and it is impressively rich and full considering the size of the unit. You are getting your money’s worth, despite what seems a high price.

I spent some time comparing the Zipp with Squeezebox Radio, another (but sadly discontinued) wireless audio device I rate highly. Both are mono, both sound good. I did notice that the Zipp has deeper bass and a slightly softer more recessed treble. I cannot decide for sure which sounds better, but I am slightly inclined towards the Libratone, which is actually high praise.

One lovely feature of the Zipp is internet radio, which comes via Vtuner. This is hidden in the feature called Favourites. You select favourite radio stations in the app, with the default being BBC stations and Classic FM. You can change your favourites by tapping the Nightingale icon in the app (another hidden, over-designed feature) and tapping My Radio.

image

Once set up, tap the heart button on the Nightingale button on the device to switch to radio. Tap twice to skip to the next station. Internet radio does not depend on having the app running, it works directly https://www.itwriting.com/blog the Zipp.

The Zipp has a power button, press and hold to power on or off, tap to show remaining battery. It also has an aux jack socket, for wired playback https://www.itwriting.com/blog any source, and a USB socket which you can use either for charging a phone, or for playback https://www.itwriting.com/blog music files on USB storage (I did not try this, but a wide range of formats are supported, including MP3, WAV, FLAC, Ogg Vorbis, WMA, AAC, AIFF and ALAC). You can also use USB for wired playback https://www.itwriting.com/blog iOS, but not https://www.itwriting.com/blog other devices.

Apple Airplay is supported and worked great when I tried it with an iPad. One thing to note: there is currently no iPad app, so you have to search for the iPhone app, which does also work on the iPad.

This very flexible device also supports Bluetooth 4.1 and you can use it as a speaker phone, just tap the Nightingale button to answer a call, so yes it has a microphone too. It also supports DLNA which means you can “play to” the device on some applications, such as Windows Media Player.

If you have more than one Zipp you can connect them for multi-speaker playback. You can select Stereo if you have two speakers or more, but Libratone recommend something they call FullRoom, which means leave it to their digital signal processing (DSP).

Sadly I only have one Zipp, but there are a few options in the app to set DSP optimization for things like Outdoor, Shelf and Floor. I did not notice a huge difference.

You can get different colour covers, and I tried removing mine. It is a bit fiddly, and the current Zipp Mini does not quite match the explanation on the Libratone site. The handle on this Zipp does not come off; you unzip the cover, twist to disconnect the zip, then feed the handle through the hole. Not something you are likely to do often.

image
The device naked

Finally, if you are curious like me, here are some specifications:

  • Class D amplifier
  • 1 x 3” woofer, 1 x 1” tweeter 2 x 3.5” low frequency radiators
  • Frequency response 60-20,000 Hz (no dB range specified)
  • Maximum volume 96 dB SPL/1m
  • 2400 mAhs battery
  • Bluetooth 4.1
  • 10 hours of playback approx.

Conclusion? I really like the Zipp Mini. It sounds great, supports a wide range of standards, and works well for Internet radio. I like the appearance, the Nightingale button is elegant, and you can expand it with more speakers if needed. This or the larger Zipp model might be all the hi-fi you need.

Caveats: many of the features are a bit hidden, initial setup I found fiddly, the supplied instructions are hopelessly inadequate, and with all those choices it can get confusing.

No matter, it is a lovely device.

More information on the vendor’s site here.

Raspberry Pi does Audio at the Wigwam HiFi Show 2016

The Wigwam Hifi Show is an unusual event, in that most of the exhibitors are not vendors with their latest and shiniest, but enthusiasts showing off their own systems. It is a lot of fun, with plenty of exotic and/or old equipment that you will not see or hear elsewhere.

image

I have exhibited at the show in the past, and try to do something a little different each time. This year I thought it would be interesting to contrast the many multi-box and expensive systems with something at the other end of the scale. I was impressed when I reviewed the IQAudio Pi-DigiAMP+ for issue 36 of the MagPi magazine, so I took it along.

This unit is a board that plugs in on top of the main Raspberry Pi board.

image

It is very simple, the only external connectors being power in, and left and right speaker terminals. It includes a DAC and a class D amplifier, based on the Texas Instruments (TI) TAS5756m chipset. The DAC is based on a Burr-Brown design.

I assembled my unit using a Raspberry Pi 2, the above board, and the matching case and power supply from IQ Audio. The power supply is the XP Power VEF50US15 which means I get up to 2x20w; if you use a VEF65US19 you can get 2x35w (both available from the IQAudio site).

Here it is in the room at Scalford Hall, home of the Wigwam event.

image

The speakers shown are the Cambridge Audio Aero 6, though we also had a pair of Quad 11L and tried them both.

The way things work at this event is that you sleep in your room the night before, and the next morning the bed is removed and it becomes your exhibition room. Having tried the system with the bed in place, I was distressed to find it sounding markedly worse (bloated bass) once the bed was removed. With no time for proper experimentation we dragged the mattress back out of the cupboard and leant it against the wall, which improved matters; we also used foam bungs in the speaker ports to tame the bass. Not ideal, but shows the difficulty of getting good sound at short notice in small hotel rooms.

The Cambridge Audio Aero 6 speakers I would describe as a good budget choice; they sell for around £350. Philosophically (as with the Quads) they are designed to be clean, detailed and uncoloured. The choice of floorstanders rather than small standmounts was deliberate, as I wanted to demonstrate that using a tiny amplifier does not necessarily mean a small sound.

Having said that, we also put the Quads on from time to time, which are small standmounts. The sound was not radically different, though bass extension is less and to my ears the 11Ls are a little less precise than the Aeros, with a warmer sound. I preferred the Aeros but as ever with loudspeakers, tastes vary.

The complete parts list as shown:

  • Raspberry Pi 2 £26.00
  • IQAudio Pi-DigiAMP+ £57.99
  • IQAudio Pi-CASE+ £15.60
  • 15v Power Brick XP Power VEF50US15 £25.50

If I were buying today, I would recommend the new Raspberry Pi 3 and the more powerful 19v power supply which increases the cost by about £10.00.

So that is between £125 and £135 for the complete device, and then whatever you choose for the speakers.

For the demonstration I brought along a router with wi-fi, to which I attached a hard drive with lots of FLAC files ripped from CD, along with a few high-res files. The router lets you attach a USB drive and share it over the network, so I configured Volumio on the Pi to use that as its source. In a typical home setup, you would probably store your music on a NAS device and use your existing home network.

Where’s the amplifier?

There was a steady stream of visitors from around 10.00am to the close of the show at around 17.00. The goal was not to be the best sound at the show, but rather to be the smallest and still deliver decent sound quality, and for many visitors I think we succeeded. We stuck the equipment list on the wall and lots of people photographed it with the intention of looking into it further.

image
A demo under way: spot the mattress leaning against the wall and the smaller Quad speakers alongside the Cambridge Audios.

A number of visitors knew of, or were even using, a Pi for streaming, but the idea of having the amplifier included on a small board was less familiar; it was fun when people asked where the amplifier was, or whether the speakers were active (they are not). Some were really astonished that you can get respectable sound quality from such a small box.

Volume was more than sufficient for a room this size and frankly plenty for most home situations though of course not for huge rooms or loud parties.

Note that despite playing loud throughout the day the amp board did not get warm at all; this is because a Class D design delivers almost all the power supplied as output to the loudspeakers.

A few early comments from the forums:

“The super small Raspberry Pi based system by onlyconnect was a brilliant demo of what can be achieved by something tiny and low cost.”

“I wouldn’t have thought it possible if I hadn’t have heard it… To boot, completely taking price out of the equation, it was one of the better sounding systems at the show to my ears, I enjoyed that more than some far, far more expensive rigs.”

“Highlights. Onlyconnect’s raspi based system, honestly why pay more for music around the house?”

“Onlyconnect’s Raspberry system was impressive and wins the GVFM award.”

“Onlyconnect’s mini/budget system – just amazing how good a £125 raspberry pi setup containing streamer, dac, preamp and 35w per channel amp could sound. I can’t forget how flabbergasted another listener was to discover the total system cost  -” I’ve obviously doing it all wrong all these years”

“I spent a while looking for the amplifier, following the cables etc like everybody else. I was impressed by the sound coming out of the Cambridge Audio speakers, I would certainly put this in the top 40% of rooms based on the sound quality, maybe higher.”

Devialet’s Phantom audio system on show in Barcelona

I was glad to see and hear the French Devialet Phantom system at the Mobile Focus event in Barcelona, just before Mobile World Congress, having missed the company’s recent presentation in London.

image

The Phantom is a device that looks like a giant eyeball, and is essentially an active mono wireless DAC and speaker. There are two models, the Phantom which delivers up to 99dB at 1 metre and costs €1690, and the Silver Phantom which delivers up to 105 dB at 1 metre and costs €1990. There is an optional Dialog unit at €299 which is a wi-fi router that creates a private network for the Phantom as well as supporting a guest network designed for music sharing. A Dialog can also control up to 24 Phantoms and is necessary for multi-channel; obviously for stereo you need at least two. An app called Spark runs on iOS, Android or Windows (not Windows Phone) and handles playlists as well as visualising music.

Each Phantom has a midrange unit, a treble unit, and two woofers. It measures 253 x 255 x 343mm and weighs 11 kg.

My encounter with Phantom did not get off to a good start. I am allergic to misleading jargon, and the pitch the Davialet representative made to me was confusing to say the least. “Digital chops up the sound,” he told me; but with hybrid technology Devialet was able to reproduce the purity of analogue sound. I observed that every DAC in the world is able to decode digital formats to analogue sound, and we had some difficulty progressing to what exactly is different about Devialet’s approach.

The case for the Phantom is not helped by the over-the-top language in the brochure, which modestly claims “the best sound in the world” and under a heading “IN TECHNICAL TERMS” promises Zero distortion, Zero background noise and Zero  impedance.

The system was playing Hotel California by the Eagles when I was there. I know the sound of this album well and it sounded boomy and unpleasant, though it is difficult to get good sound on a stand in a busy exhibition so I make generous allowance for that.

I did get a copy of a white paper which offers a bit more information. There are several technologies involved.

The first is what Devialet called ADH (Analog/Digital Hybrid). This combines class A amplification with the efficiency of class D. The way Devialet puts it is that several class D amplifiers act as slaves to the class A amplifier, so that the class D amplifiers provide the power while the class A amplifer the control.

A Texas Instruments PCM179x DAC is positioned next to the amplifier to minimise any loss between the two.

Next comes SAM (Speaker Active Matching) which processes the audio to compensate for the characteristics of the drive units. This “takes place ahead of the DAC and power amplifier section” according to the paper, so you could think of it as a kind of digital pre-amplifier. SAM has “a mathematical model of the complete drive unit, accounting for the electrical, mechanical and acoustical behaviour.”

image

A third feature has the name HBI (Heart Bass Implosion). This tackles the tricky problem of reproducing deep bass with a small enclosure. The idea is to use a sealed box design for high efficiency at the lowest frequencies, a driver with long 26mm excursion (the difference between the foremost and backmost position of the driver) in order to move more air, and to use two symmetric drivers to cancel mechanical vibrations.

This does result in high maximum air pressure inside the enclosure, up to 174dB SPL according to Devialet’s paper. Most drivers collapsed in this environment, so Devialiet designed its own woofer.

Finally Devialet’s engineers figured that a sphere is the ideal shape for producing sound without “diffraction loss”.

The result, according to the specs, is 16Hz to 25kHz +- 2dB, and 20Hz to 20kHz +- 0.5dB which is impressive for a speaker system.

The problem with such measurements is that they typically taken in an anechoic chamber whereas actual listening rooms have all sorts of resonances that result in a much less accurate sound.

Does Devialet’s Phantom system sound as good as a more traditional system at its price level? That is the question which interests me; if I get an opportunity to try it out I will be sure to report back.

Playing native DSD with Raspberry Pi 2 and Volumio

There are many intriguing debates within the world of audio, and one which has long interested me concerns DSD (Direct Stream Digital). This is an alternative technology for converting and recovering sound from digital storage. The more common PCM (Pulse Code Modulation) works by sampling sound at very short intervals and recording its volume. By contrast DSD records the difference between one sample and the next, sampling at an even greater frequency to compensate for the fact that it only captures a single bit of data in each sample (ie on or off). For example the standard used by CD is:

16-bit precision, 44.1 kHz sampling rate

and by SACD (a DSD format):

1-bit precision, 2.8224 MHz sampling rate

The SACD was introduced by Philips and Sony in 1999 as an upgrade to CD, since it is a higher resolution format cable of a dynamic range of 120 dB and frequency response up to 100 kHz. It was an effort, like the PCM-based DVD Audio, to convince the public that the CD is not good enough for the best quality sound.

SACD was largely unsuccessful, mainly because there was not really any dissatisfaction with CD quality among the general public, and even some experts argue that CD quality already exceeds what is required to be good enough for human hearing.

That said, SACD was popular in the niche audiophile community , more so than DVD Audio. Some listeners feel that SACD and DSD results in a more natural sound, and believe that PCM has some inherent harshness, even at higher-than-CD resolution. Enthusiasts say that DSD stands for “Doesn’t sound digital”. For this reason, there is a regular stream of new SACD releases even today, and DSD downloads are also available from sites like Native DSD Music and Blue Coast Records. Some DSD downloads are at higher resolution than SACD – Double-rate or Quad-Rate.

The resurgence of DSD has been accompanied by increasing availability of DSD DACs (Digital to Analogue Converters). While these tend to be more expensive than PCM-only DACs, prices have come down and a quick eBay search will find one from under £100.

There are several complications in the DSD vs PCM debate. While DSD is a reasonable format for storing digital audio, it is poor for processing audio, so many SACDs or DSD downloads have been converted to and from PCM at some point in their production history. If PCM really introduces harshness, it is presumably too late by the time it gets to DSD. That said, it is possible to find some examples that are captured straight to DSD; this can work well for live recording.

Another complication is that some consumer audio equipment converts DSD to PCM internally, to enable features like bass management.

Is there any value in pure DSD? I wanted to try it, preferably with DSD files rather than simply with SACD, since this is much easier for experimenting with different formats and conversions as well as enabling Double DSD and higher. Unfortunately SACD is rather hard to rip, though there is a way if you have the right early model of Sony PlayStation 3.

The first step was to get a DSD-capable DAC. I picked the Teac 301 which is a high quality design at a reasonable price. But how to get DSD to the DAC? Most DSD DACs support a feature called DSD over PCM (DoP), which conveys the DSD signal in a PCM-format wrapper. DoP is not a conversion to and from PCM, it merely looks like PCM for better compatibility with existing playback software.

Next, I used a Raspberry Pi 2 supplied by Element14 (cost around £25.00) and installed Volumio, a pre-built version of Linux which includes an audio streamer and web-based user interface. You download Volumio as a single file which you burn onto a micro SD card using a utility such as Win32DiskImager. Then you plug the card into the Pi, connect to a home network via Ethernet and to a DAC via USB, and power on.

After a minute or two I could connect to Volumio using a web browser.

image

My music is stored mostly in FLAC format but with a few DSD files in Sony’s DSF (Digital Storage Facility) format, and located on a Synology NAS (Network Attached Storage). In Volumio’s menu I went to Library and mounted the network share containing the media. Next, I tried to play some music. PCM worked, but not DSD. I changed the playback settings to enable DoP:

image

Success: My DSD files play perfectly:

image

If you squint at this image you will see that the 5.6 MHz light is illuminated, indicating that the DAC is processing Double DSD.

It sounds lovely, but is it any better than the more convenient PCM format? I am sceptical, but intend to try some experiments, using a forthcoming audio show to find some willing listeners.

That aside, I am impressed with the capability of the Raspberry Pi for enabling a simple and cost-effective means of playing DSD over the network, although with the assistance of an external DAC. It plays PCM formats too of course, and with Volumio is easily controlled using a mobile device, thanks to the touch-friendly web UI.

A nearly perfect boombox: take your audio on the road with TDK’s Trek Max

I first heard the Trek Max at a busy press exhibition; audio rarely sounds good in big noisy rooms but I was struck by the fact that this TDK device was not dreadful but made a valiant attempt to deliver the music: there was at least a little bass, there was volume, there was clarity, and this from a small box, 24 x 5 x 10cm to be precise.

image

I asked for one on loan to review and it has not disappointed. There is not much in the box, just the Bluetooth speaker, a power supply/charger, and some mostly useless bits of paper.

image

The hardest task was getting that sticker off the front without leaving a gooey mark. Having done that to the best of my ability, I charged the unit, and paired with a phone. My attempt to use NFC (one-touch Bluetooth connect) failed with a Windows Phone, but worked with an Android tablet. It is no big deal; pairing is straightforward with or without NFC.

Then I played some music. I put on Santana Abraxas; this thing boogies, and does a great job with the complex percussion and propulsive guitar. I played Adele’s 21; it sounds like Adele singing, not the squawky sound you might expect from a device this size, and the drums on Don’t You Remember have a satisfying thud. I played Beethoven’s Third Symphony; the drama and power of the opening movement came over convincingly, albeit in miniature form.

I am not going to pretend that this is the best Bluetooth speaker I have heard; it has tough competition at much higher prices. I do not judge a thing like this versus a home audio setup or a larger Bluetooth speaker that is only semi-portable. This is something to take with you, and even sports a “weatherized” case; the manual makes clear that it is “splash-resistant” rather than anything more serious, and then only if you make sure to close the rubber flap over the panel on the right-hand side, but still a handy feature.

Any clever tricks? Just a couple. One is that you can use the Trek Max as a battery charger for your mobile phone (or any device compatible with USB power). Here is that side panel in detail:

image

From right to left, there is the USB power output (it has no other function), an AUX in for a wired audio connection, power in, and a master power switch which turns the entire unit off (including the USB power output).

The other party trick is the ability to work as a speakerphone. You are grooving along to music from your mobile, and an incoming call comes in. The music stops and a call button on the top illuminates. Press to answer, take the call hands-free, and press twice to end it. Neat.

image

Note that the Trek Max is surprisingly heavy for its size, around 1.25Kg. It does not surprise me; there is a lot packed in, including a decent battery.

The speaker configuration is right, left, central woofer for the (mono-ed) lower frequencies, and passive bass radiators at the back, boosting the bass.

It is worth noting that the Trek Max goes surprisingly loud – louder than I have heard before from a device of this size. That is important if you are outside or in a noisy room – but please do not annoy others too much!

The Trek Max  A34 replaces the Trek A33. What is the difference? Primarily, NFC Bluetooth pairing, pause, resume, forward and back buttons (they work fine), and better sync with iOS devices: on these, the volume control on the Apple device directly controls the volume on the Trek, whereas on other devices the volume controls are independent.

Conclusion: a great little device, and make sure you hear it before dismissing it as too pricey for something of this size.

Specifications

Weight: 1.25 Kg
Size: 24.1 x 9.8 x 5cm
Power output: 15w total
Bluetooth: 2.1 + EDR, A2DP, HFP, HSP, AVRCP
Battery life: 8 hours

Arcam’s high-end Solo soundbar: fixing TV sound

Arcam launched its Solo soundbar and subwoofer at a press event in London last week. When this footage was playing I was not thinking about the soundbar at the foot of the video screen, nor of the subwoofer sitting in the corner. Rather, I was thinking how wonderfully the great B.B. King is playing on this concert Blu-ray; and that is how it should be when auditioning hi-fi.

image

The Cambridge-based Arcam occupies a distinctive spot among UK audio manufacturers, neither low-budget nor at the silly-expensive end of the market. MD Charlie Brennan told me that the company’s focus is audio engineering: not lifestyle, nor ultra high-end, but products that are affordable and which sound great.

The aluminium-bodied Solo bar seems at first listen to be a good example. It is a solid product in every sense, weighing a hefty 6.4kg and featuring 100w of class D (highly efficient) amplification into 6 speaker drivers, midrange (4″), woofer (4″) and tweeter (1″) for each channel.

image

This is more than just a better audio system for your TV. The Solo bar has four HDMI inputs (with 4K support) and one output, so you can connect your games consoles and video streamer sources. There are also optical and coaxial digital (S/PDIF) inputs, and an analogue input for general purpose use, and an output for a subwoofer.

image

It does not end there. The Solo bar supports aptX (which means high quality for systems that support it) Bluetooth streaming both as player (for your mobile device) and as source (for your wireless headphones).

A setup microphone is included in the box, which accounts for the mic input on the panel. Use of this is optional, but it is often worth running this type of setup routine, by placing the mic at the normal sitting position and having the unit optimise the sound for the room, taking into account the position of the subwoofer if present.

Room effects are huge and often ignored, so it is good to see this. However you cannot fine-tune the results yourself; you either disable it, or enjoy the results the bar comes up with.

There is a controller app for iOS and Android but sadly not for Windows Phone, though all the functions are also accessible through the supplied remote. You can switch between unvarnished stereo, or audio processing for Movie or Concert.

image

The Solo subwoofer has a 300w amplifier and 10″ driver. We heard the system with and without the sub. My brief observation is that while it sounded good without the sub, adding it lifted the sound substantially; it is not so much the added bass that you notice, but greater realism. The sub is also important for those all-important explosions and sound effects in movies and games.

The Solo bar is £800 and the Solo subwoofer £500. That does not seem to me expensive given the quality I heard, but neither is it a casual purchase. There are drawbacks to the soundbar approach, notably two-channel sound rather than surround, but the simplicity of the system more than compensates for many (Brennan said that the soundbar market is one of the few areas of home audio that is growing).

Personally I would recommend getting system with the sub if possible, as they are designed to work together.

You should be able to buy a Solo later this month, November 2014.

This is not a review; that will have to wait for an opportunity to try the system for myself and test it in detail.

More information on Arcam’s site here.