Hi Gordon,

I really enjoyed reading your August 2020 article on your top-ten products. I noticed that you included the DALI Rubicon 6 C and B&W Formation Duo.

I’m considering buying either the Callisto 6 C or the Formation Duo. I’m wondering if you have heard the Callisto. If so, how do you think it would compare with the B&W? Any advice would be greatly appreciated.

Kind regards,

Hi Laurens,

Thanks for your note. I have reviewed DALI’s Callisto 2 C and Rubicon 6 C, but never the Callisto 6 C, so I can’t really say how it would compare sonically with the Formation Duo. I haven’t heard any of these speakers for a few years now, so in terms of sonics, the best I can do is refer you to my original reviews. But I don’t think you can go wrong with either speaker you are considering. I loved listening to the Formation Duo, Callisto 2 C, and Rubicon 6 C, and I have no doubt that I’d also enjoy the Callisto 6 C.

Other factors may guide your decision. An obvious one is form factor—the Callisto 6 C is a floorstander, the Formation Duo a standmount speaker.

If you go with the DALI, do you plan to use it with the DALI Sound Hub and optional BluOS NPM-1 module? Do you have any conventional components, such as a disc player or HDTV, that you want to play through the speakers? The DALI Sound Hub has line-level analog inputs (3.5mm and RCA) and S/PDIF digital inputs (coaxial and TosLink), but the Formation Duo has no inputs for connecting external components; you’ll have to buy a Formation Audio streaming preamp if you want to play audio from a disc player or TV with the B&W. On the other hand, if you’re not using external components, the Formation Duo has the advantage of being a complete, self-contained system.

Given the nature of these products, I assume that you will be streaming music to your speakers via Wi-Fi. Assuming that’s the case, there are some very important differences between the B&W Music app used for the Formation Duo and the DALI Callisto 6 C / Sound Hub / BluOS NPM-1 module combo’s BluOS app. BluOS has integrated support for more than 20 different streaming services—many more than the B&W app. Both systems support Tidal, but B&W’s does not have MQA capability yet, so you don’t get hi-rez streaming from Tidal. (You can of course get uncompressed CD-resolution audio from Tidal with the Formation Duo.) The Formation Duo supports Apple AirPlay 2; the Sound Hub / BluOS NPM-1 combo does not, so you can stream directly to the B&W system from an Apple device via Wi-Fi, but not to the DALI setup. Both products support Spotify Connect, but the DALI system also supports Tidal Connect. So with both products, you can cue up music in the Spotify app, then transfer playback to the Formation Duo or DALI system, but with the DALI setup, you can also do this with Tidal.

Do you want to play locally stored music files? With the DALI Callisto 6 C / Sound Hub / BluOS NPM-1 setup, you can load up a USB drive with music, plug it into a USB port on the NPM-1, and play these files via the BluOS app. This isn’t possible with the Formation Duo.

Are you a Roon subscriber? If so, some of these considerations will be moot; both the DALI system and Formation Duo are Roon Ready, so you can stream to either system via Roon.

One last note. Bowers & Wilkins uses proprietary wireless technology to stream music to the two speakers. The company claims that latency (the lag between the left and right speaker) is less than a microsecond—which is hugely impressive. DALI specifies a latency of less than 25 milliseconds for its system, but I can’t speculate how much this affects elements like imaging and soundstaging. The two DALI systems I reviewed performed very well in these areas, and the Formation Duo was superb. With the DALI active speakers, I occasionally experienced momentary dropouts in the connection between the Sound Hub and the speakers—I never had any dropouts with the Formation Duo. Granted, I only had these systems for a couple of weeks each, so my experience may not be representative.

I hope this is helpful, and once again, thanks for writing.

Best regards,

Hi Gordon,

Thanks for your reply. After listening to both speaker systems, I decided on the DALI Callisto 6 C. I found that the DALI expressed more detail than the B&W Formation Duo, with an immersive soundstage that seemed to float (the instruments seemed to hang in space, with great separation). I did find that the Duo speakers had a big bottom end for their size, but sometimes I felt that it was a little too forceful relative to the rest of the music. These differences became even clearer when playing Tidal Masters (MQA) recordings.

Also, the DALI Sound Hub / BluOS NPM-1 provides me with more options.

Thanks again.



Thanks so much for posting your KEF LS60 Wireless review. I have been checking SoundStage! Simplifi daily for something like this! Wonderful post!

I have a pair of KEF Q950 floorstanders paired with a Cambridge 851A integrated amp and the new Bluesound Node. I love the system but am looking for something just a little “more” (and incidentally, my wife loves the look of the LS60).

The one thing I did not see in your review was an evaluation of the LS60 system’s ability to fill a room with volume. Do you think this system can play at a loud volume for those occasional “needs” for a party atmosphere? Something like 75db at 8′? My listening space is a kitchen-living area of 18′ × 28′, with passages to other areas at each end.

Again, thanks so much for a great and informative review, and looking forward to your reply.

Ernie Slubik

Hi Ernie,

Thanks for writing, and I’m glad you enjoyed the review.

My room is smaller than yours. I evaluated the LS60 Wireless in my living room, which measures 12.5′W × 9.25′D. But it opens into an adjoining dining room through a wide archway, and to a hallway through a narrower opening. The total space measures approximately 22′W × 12′D. Despite the differences in our listening environments, I have no doubt that the LS60 can play loud enough to meet your needs.

Just to make sure, I played Bob Marley and the Wailers’ “Exodus” with the volume set quite high (as loud as I can play without disturbing the neighbors). I was getting peaks of 77–78dB (A-weighted) and 82–83dB (C-weighted) standing 8′ to 10′ from the speakers, with no evidence of distress or compression. There was a definite “party” atmosphere.

I hope this is the information you’re looking for. BTW, my wife (who has impeccable taste) loves the look of these speakers too.

All the best,

Hi Gordon,

I recently read your review of the Bluesound Vault 2i CD ripper-server-streamer. I am probably wishing on a star, but do you know if I can download a FLAC or MP3 copy of the songs to my iPhone for on-the-go playback after ripping a CD to the Vault? I am a little behind the times when it comes to buying music online, but I have about 3000 CDs. It would be a plus to be able to download them to my iPhone, especially for listening when I am camping and can’t get a cell signal.

Thanks in advance,
Thomas Sullivan
United States

Hi Thomas,

Thanks for your email. The quick answer to your question is that you can’t transfer audio files directly from the Vault 2i to your iPhone. If you want to play your ripped files on your phone offline, you have to import them to a Mac (or to the iTunes app on a Windows PC) first.

There are a couple of ways to import music from the Vault 2i to a Mac. You can navigate to the Vault 2i in the Network section of Finder, and drag the folders or files you want to import onto the Apple Music icon in the taskbar—those folders and files will automatically be imported into the app’s music library. Or you can choose Import . . . from the Music app’s File menu, navigate to the Vault 2i in the next window, choose the folders and files you want to import, and click the Open button. Those files and folders will then flow into your music library.

If you’re a Windows user, you have to install the iTunes app, which is available for free from the Microsoft Store. After launching iTunes, choose Add Folder to Library from the app’s File menu, then navigate to the Vault 2i, choose the folders you want to import, and click the Select Folder button. The folders will then appear in the iTunes library.

After you have imported the music you want into the Music app on a Mac or the iTunes app on a Windows PC, you have to sync your iPhone with the app on your computer. You can transfer all the music you’ve imported if your iPhone has enough capacity, or choose specific albums and songs.

There is one other complication. The Vault 2i lets you rip music in FLAC or MP3 format. In terms of sound quality, FLAC is the better choice, because it’s a lossless format. MP3 uses lossy compression. However, you won’t be able to play FLAC files with your iPhone’s Music app, as FLAC is not supported by iOS. MP3 is supported, so if you rip to that format, your files will play natively on your iPhone.

If you want to use a Vault to rip CDs in FLAC format and then play those files on your iPhone, there are some workarounds, but they’re cludgy. You can play FLAC files from the iOS Files app using a third-party music player app like Vox Music Player, Plex, or Onkyo HF Player. Or you can convert FLAC files to ALAC (Apple Lossless) format, which is supported by iOS and iTunes, using a FLAC-to-ALAC converter app; these are readily available for both macOS and Windows.

However, if your only wish is to rip your CD collection so you can play your music on your iPhone, there’s an easier, less expensive solution than buying the Vault 2i. If your computer does not have an optical drive (most modern computers do not), you’ll have to buy one. They’re cheap—you can pick up an external USB CD/DVD drive for $50 or $60. The macOS Music app and iTunes for Windows both have ripping functions.

Before ripping CDs, you should choose the codec you want to use for ripped files. You do this by selecting Preferences in the File menu, and then tapping the Files icon in the pop-up window. You’ll see a button at the bottom called Import Settings. For maximum storage, use AAC or MP3. These are lossy codecs; but you can also choose Apple Lossless, which is what I use. After that, you can insert a CD into your optical drive, and the iTunes or Music app will automatically rip the CD. It will also pull metadata like song, artist, and album names from the internet and fill in that information automatically. The only time this doesn’t happen is if you’re ripping a really old or obscure CD.

However, if you also want to stream your ripped CDs to BluOS-enabled components for home listening, the Vault 2i offers real benefits. You’ll be able to use the BluOS app to play music stored on the Vault to BluOS-enabled components on your home network. You can also use the BluOS app to play music stored on a PC or Mac, but that involves setting up network shares, which can be a very fiddly process.

Good luck to you with whichever approach you choose.

All the best,

Hi Gordon,

Thanks for the timely and detailed response. I am sure I will have to be patient as I explore the Vault and finally get my CD collection in order. I will take your advice into account.

Take care,

To Doug Schneider,

Hi there—I live on the west coast of Canada. As your website is Canadian-based, I am writing to ascertain the availability of Apple Music’s lossless and HD content in Canada. I have been trying to access it for most of the month of June, and so far have come up with nothing. So, do you folks know if Apple Music lossless is available in Canada? If not, why not, and when will it be launched?


Hello Thom,

Doug Schneider has forwarded your email asking about the availability of Apple Music’s lossless and high-resolution service in Canada. It has in fact been available in Canada since June 7. SoundStage! Simplifi will publish a feature on this subject, as well as Apple Music’s spatial audio offering, on July 1.

To get lossless and high-resolution audio from Apple Music, you have to update to the latest version of iOS, iPadOS, or macOS. On an iPhone or iPad, you also have to enable lossless and hi-rez playback in the Music menu of the Settings app. On a Mac, you have to enable lossless and hi-rez playback in the Preferences menu for macOS’s Music app. This is spelled out in an Apple support page on the subject.

As I outline in my upcoming feature, there are some serious limitations that affect the ability to play hi-rez music from Apple Music through external components. If you want to write back and describe your system, and how you hope to play lossless and hi-rez content from Apple Music, I’d be happy to give whatever guidance I can.

Best regards,
Gordon Brockhouse

Thank you, Gordon.

My intent is to connect my iPad Pro to my audio system: a McIntosh Laboratory C2500 preamplifier (with USB DAC), a PS Audio BHK Signature 250 amplifier, and Wilson Audio Specialties Sophia Series 3 speakers. I understand I will need a Lightning-to-USB dongle, and a USB cable between that and my preamp.

My confusion comes from the fact that when I go to the Music settings on my iPhone or iPad, I do not see the Audio Quality option. Would this be because I’m not currently an Apple Music subscriber?

Note: I also subscribe to Tidal HiFi, which I access through a dCS Network Bridge. I like the potential to access hi-rez files from Apple Music at a good price.

I look forward to reading your upcoming piece on this subject.


Hi Thom,

I strongly suspect you’re right about iOS not displaying the lossless and hi-rez options in Settings until you subscribe to Apple Music. But the setup you describe—a USB connection between your iPad Pro and McIntosh C2500 (via a Lightning-to-USB adapter)—should work.

You mention price as a factor, and the fact that Apple Music costs half as much as Tidal HiFi is certainly compelling. But I think there are other things to consider. For instance, Tidal’s Masters content uses MQA decoding, while Apple Music uses ALAC, a true lossless format. I haven’t poked around in Apple Music enough to get an idea of how much hi-rez content they have, compared to Tidal HiFi, but for me, the biggest issue is the user interface (UI). So far, I like Tidal’s UI a little better, Spotify’s even more, and Qobuz’s a whole lot better. (Too bad Qobuz isn’t available in Canada yet.) Of course, UI is an area where personal preferences vary a lot.

All the best,
Gordon Brockhouse

Hi Gordon,

I hope this email finds you both well and staying healthy. I read your “tweaks” article today (which was great, by the way, as it reveals some opportunities to fine-tune an integrated system), and it reminded me that I’ve been meaning to ask you something.

After our e-mail exchange last year, I came across an exceptional buy for an open-box set of Elac Navis ARF-51s (in the Gloss Ebony Emara finish). I hadn’t been able to consider them before, given my budget, but they are now in my house! Your review, which is one of just two I’ve found out there on the web, and your comments on these speakers are much appreciated. I subsequently purchased NAD’s C 658 BluOS streaming DAC.

Now that I’ve had the Elacs and the C 658 for several months, I’ve noticed the treble performance seems to be a bit “soft” in terms of detail. Has this been your experience? I remember you mentioning some sibilance in your original review and a follow-up reader letter, which leads me to believe you have not. Perhaps my experience is attributable to the Elacs’ soft-dome tweeters vs. the aluminum domes on my previous speakers (bookshelf Totem Acoustics)—I think the Totems are known for being lively. Your thoughts are appreciated when you have a spare moment to respond. Keep those Simplifi! articles coming!

United States

Hi Jack,

I wouldn’t call the ARF-51s “soft,” though they’re definitely not as lively as any Totem speaker I’ve heard. Only on a few recordings do I hear that sibilance I referred to in my original review. I just looked at the Dirac curves for my NAD C 658 and the Elacs, and the response starts falling off modestly at about 5kHz. I continue to enjoy this system a lot, and have felt no need to change anything (other than adding the tweaks I discussed in the article you mentioned).

I have a couple of suggestions and a couple of questions.

Have you tried boosting the highs and/or mids with the rear-panel EQ controls on your Elacs? A +1dB lift to the highs, and maybe the mids as well, may deliver the liveliness you’re missing.

Are you using Dirac Live room correction on your C 658? (I hope you are.) If so, are you using the standard limited-spectrum version (correction to 500Hz) provided with the C 658, or have you upgraded to the full version? I’m using the full version, and find it worthwhile. With NAD’s standard target curve in the full version, HF response tilts slightly downward. You may find it worthwhile experimenting with the target curve. You can perform one set of measurements (or use measurements you’ve already performed and saved), and then drag points in the target curve (bold yellow line) in the Dirac app to produce flat HF response (or any other target curve you want to try) and then save the results into a different Dirac slot on your C 658, and compare the results in the Player section of the BluOS app’s Audio menu.

Dennis Burger recently wrote an interesting article on SoundStage! Access about room correction, which you may find useful. Dennis prefers not to do full-spectrum correction. On the other hand, other SoundStage! writers (Diego Estan, Wes Marshall) favor full-spectrum correction. I’ve experimented with both approaches. I use full-spectrum correction most of the time, but after reading Dennis’s article, I tried setting the target curve in Dirac to limit correction to frequencies of 800Hz and below. The sound was livelier with that setting, but smoother and more inviting with full-spectrum correction. I personally prefer full-spectrum correction, but I certainly see Dennis’s reasoning, and understand why many listeners would like his approach.

Hope this helps. If you try any of these suggestions, please write back and tell me how they worked for you.

All the best,
Gordon Brockhouse

Hi Gordon,

Thanks for taking time to reply so thoroughly to my question. I appreciate your insights; perhaps the one that will be most valuable is running Dirac Live—I completely forgot that I hadn’t tried it (I’ve been a little busy here evidently!). I’ll pop for the optional full-range solution to receive the optimal benefit in the upper frequency ranges. To answer one of your other questions: yes, I have the treble on the Elacs set at +1, but have kept the midrange at 0.

I played around with things the other day after reading your reply and here is the most interesting new observation: the perception of soft treble disappears when I crank the system up! I probably mischaracterized the sound as “soft in terms of detail” in my earlier message, as all of the detail is present. Elements such as hi-hat and ride cymbals are there and easy to recognize at higher volumes. They are just less prominent at lower volumes.

After I thought about it, perhaps the Totem Dreamcatchers I was using for years prior are overly lively. The Elacs are in a different league when it comes to oomph across the music scale and are likely much better balanced. I’ll know more when I run Dirac Live. Or I just need to turn it up when listening!

I enjoyed your tweaks article (and all of the Simplifi content). After setting up Dirac Live room correction, I may try iFi Audio’s AC iPurifier on my NAD C 658 to see if there is any noticeable benefit. I like to DIY on the cable side (having constructed a pair of XLR cables using some well-reviewed Mogami cable to connect the NAD with the Elacs). I may eventually try the same with the power cables for the speakers if I get motivated.

United States

Hi Gordon,

I just read your review of Elac’s Navis ARB-51 active speakers on Simplifi. Thanks for your great insights on these speakers. I am wondering if you think these speakers would be a good option for use in the nearfield at my desk, about 12″ from a wall? My usage is about 70% nearfield in the evening when I want to play at lower volumes, and then playing out into a large room from time to time.

Thanks in advance if you are able to provide any further insights!


Hi Nathan,

Thanks for your letter. I don’t have a definitive answer to your question, as I have never used the Navis ARB-51s for nearfield listening. But I have used them at close-to-nearfield distances, as documented in my reviews of the HEDD Type 07 and Focal Shape 65 analog studio monitors. For both those reviews, I did some of my listening in my basement family room. The speakers were 4′ apart and 5′ from my listening chair. And as you envision for your nearfield application, the speakers were 12″ from the wall behind them. All three speakers sounded wonderful. You can read how the Elac, Focal, and HEDD speakers compared to each other in those two reviews.

My question to you is this: how close will you be seated to the speakers? The HEDD and Focal speakers are designed specifically for nearfield listening, though as my reviews stated, they work really well for listening at regular stereo distances as well. The Elacs aren’t designed as nearfield monitors, but in my experience, they sound wonderful in close-to-nearfield conditions. If you’re going to be sitting very close to the speakers, you might want to consider a speaker specifically designed for nearfield monitoring. But if you're listening from 4′ or more, any of these speakers should work really well.

Thanks again for writing, and I hope this helps. Please write back and let me know which choice you make, and how it works out for you.

Best regards,
Gordon Brockhouse

Hi Gordon,

Thank you so much for the reply and linking those reviews. I had heard about the Focals, but not the HEDDs, so I will read through both reviews. I did decide, kinda spur-of-the-moment, to buy some used Elac Carina [bookshelf] speakers, as I got a great price on them, and I still have my amp. But I am still intrigued about active speakers.

When I am at my desk in the evening I normally sit about 3′ away and listen at quiet levels, or use headphones. If I have some time to myself in the daytime, I will play louder at the same place, but I also move around the open living area in my house where my desk is. It’s about 12′ × 30′, so I like to be able to listen loudly while working out or cooking, etc. I am playing with placement a bit, but the speakers won’t be much more than 12″ from the back wall. I previously had some MartinLogan Motion speakers and they seemed fine, but I wanted a speaker with less depth so I could play with placement a bit.