The Dayton iMM-6 Calibrated Microphone

When designing and building speakers I use OmniMic. It's perfect for that but when it comes to basic Blu-ray or Home Theater setup I rely on a much less expensive and much more convenient device, the $30 Dayton iMM-6 calibrated microphone. 

Dayton provides calibration files via their website which make this almost a laboratory piece of equipment. It works in your cellphone or tablet. I personally use it on an Android along with Audio Tool which will read the calibration file and adjust the levels accordingly.

One of the main benefits of this device is how deep and flat it goes and is therefore more accurate than the old SPL meter method. It's much easier to set your speaker levels, including your subwoofer using it and your tablet than any other way I know.  It also has outputs for a mini-jack so you can use test signals from your iPhone/Android device simultaneously. You can use a cable like this one to connect it to your stereo inputs.

If you are a DIY hobbyist and want to build your own speakers or want to do detailed acoustical analysis of your listening environment this is also the perfect front end for Room EQ Wizard but you will need an adapter cable from it to your PC or laptop.

The only real downside of this is that it's tiny and I'm constantly misplacing it after I use it.

Ubuntu Mytek Brooklyn DSD Setup Guide

Update August, 2018:

These instructions are still valid, but I've gotten direct DSD working as well.  Please visit my updated post here:

http://pqltd.blogspot.com/2018/08/mytek-brooklyn-and-manhattan-dsd-with.html

I'm happy to report that the Mytek Brooklyn DAC is not only great sounding but it's a real treat to set up with Ubuntu. Why would you care if you are an OSX or Windows person? Because it's really inexpensive to set up a music server with Ubuntu.  From under $100 Raspberri Pi 3 to my own mini box which was under $500. In all cases, an Ubuntu server competes very well with $2,000 or more dedicated streamers. 

One major feature that is missing from a lot of "audiophile" solutions is Android app support.  This is something we will overcome quite easily.

Also, since this is really a driverless installation, these instructions will probably work for any other modern USB 2.0 DAC that claims to be "driverless" for OSX and Linux. The catch will be in setting the right device (SL_SOUNDCARD, below) but that part is easy.

There is a known limitation. Currently Squeezelite only supports DoP, which is horribly bandwidth inefficient. DoP is DSD over PCM. It is not the same thing as direct or native DSD play.

It's not my code, but I'm working on it.

Introducton to the Logitech Media Server

There are a lot of Lunix music players out there, I'm going to go with the easiest one that gives me bit-perfect playback: Logitech Media Server 7.9 and Squeezelite.  You need at least 7.9 to get DSD player support as it's a fairly recent feature. I think it was introduced in 7.8, but I never tried it.

Originally developed for the highly regarded streamers created by Squeezebox and bought by Logitech, LMS has pretty much transcended Logitech AND Squeezebox and now has a robust and active Open Source development community. It's easy to use, convenient and free, and has Android and iPhone apps available. On Android I use Squeezer but on iPhone you can try the original controller app or SlimLibrary.

The one thing that is missing from LMS is a music management feature. It doesn't tag, organize, or do much else but play music. On the other hand, it does this VERY well and without complications. For this you'll have to find another application of which there are legion.

Also, LMS has fantastic and simple Internet radio discovery and playback. It's a real marvel in this manner for which on Linux I have no better alternative, nor do I want one.

Preparation

First, you must have Xubuntu/Ubuntu 14 or greater set up. I am on 16.04 LTS, but 14.04 LTS was identical.  If you have another Linux distro, see the link to the details, below. I will say in the past I used to run Fedora and LMS was one of the main reasons I quit it, so if that's your distro and this is difficult, you have my sympathies. May the gods have mercy on your heathen soul.

Decide where your music and playlists are going to be. I prefer to put public media in /opt, so:

cd /opt
sudo mkdir Music Playlist log
sudo chown bob:bob *

Replace "bob" with your user account name.  Notice we are creating a log directory as well.  This is where any messages from the player (squeezelite) will be put.

Server Installation

First, install LMS from the public repo.  There are only nightly builds but seem pretty stable. You'll find detailed instructions here.

I used this script:

url="http://www.mysqueezebox.com/update/?version=7.9.0&revision=1&geturl=1&os=deb"
latest_lms=$(wget -q -O - "$url")
mkdir -p ~/sources
cd ~/sources
wget $latest_lms
lms_deb=${latest_lms##*/}
sudo dpkg -i $lms_deb

Mine is just a little different because I don't like cluttering up the root directory. This will look for the latest build, download to ~/source and install it.

After it's installed LMS should be running and available on port 9000. So open up firefox and click here:

http://localhost:9000

Follow instructions on the screen.  You'll need to setup your directories. Click on the lower right of the page, "Settings." and setup your music and playlist folders. The only tricky part left in LMS now is to enable the DSD player.  Click on the "Plugins" tab and enable "DSDPlayer."

Very cool part of this is that DSD files will be automatically transcoded if your player doesn't support DSD directly. I have a Squeezebox Touch that does not, so that gets transcoded to 88.2kHz PCM automatically for me.

Make sure your music and playlist folders are universally readable.

Player Installation

OK, that's it for the server.  Now we need to get your PC to talk to the DAC. This is even easier since the Ubuntu distribution includes squeezelite. Let's install it:

sudo apt-get install squeezelite

I've tried the distro version with Ubuntu 14 and 16, and both work great with the Mytek Brooklyn. DSD and HiRes PCM played without a hitch on both so don't feel put out if you don't have the latest version. It's not worth the trouble to get the nightly or the source and build.

Make sure your DAC is now plugged in and turned on.

You'll find the configuration file for Squeezelite in /etc/default/squeezelite.

Here is how I configured it:

# The name for the squeezelite player:

SL_NAME="Brooklyn_DAC"

# ALSA output device:
SL_SOUNDCARD=""hw:CARD=DAC,DEV=0"

# Squeezebox server (Logitech Media Server):
# Uncomment the next line if you want to point squeezelite at the IP address of
# your squeezebox server. This is usually unnecessary as the server is
# automatically discovered.
#SB_SERVER_IP="192.168.x.y"

# Additional options to pass to squeezelite:
SB_EXTRA_ARGS="-D -f /opt/log/squeezelite.log -d all=info"

# As above, but without the log file

# SB_EXTRA_ARGS="-D"

The key part is the SL_SOUNDCARD setting. If you aren't using the Brooklyn, I'm not sure this will be right.  I found it by using "squeezelite -l" and looking for the entry that said :

USB Audio - Direct hardware device without any conversions

There were other entries that worked, but I found they would convert whatever I played to 48/32, no matter the original.

Another important switch is -D which enables playing of DSD without transcoding to PCM.  Without this switch your DAC will always get PCM.

You'll see two versions of SB_EXTRA_ARGS. The first adds a log file, but really once you've got it all working it's not very useful. Once you are happy it's working comment it, and uncomment the last line, then restart.

One last command and you should be running:

sudo service squeezelite restart

Assuming all went well, you should see "Brooklyn_DAC" (set by SL_NAME, above) appear as an available player in LMS on the top right.  Select it and play some music! If you have music but it's not showing up you need to scan your library. Click on the bottom right "Settings" and in the "Basic" tab check the media folder is correct, then click "Rescan" and your files should get imported quickly.

If you need to free up your DAC for movies, or games use the player OFF switch in the LMS screen on the top right.

Now of course it is time to download some good sounding DSD music, for which I highly recommend Blue Coast Records.


Happy Listening!

Meridian Quality Authenticated - It's Snake Oil, until it's not

MQA 

Update: After a lot of reading, MQA is NOT lossless. What a shame.
A full treatment is available from this post at Benchmark Media

In fact, it's such a good and thorough post that I'm going to delete the rest of my original posting and let it speak for itself. 

I will also add that you can listen to MQA files and compare them to the originals via the 2L test site here. 

After listening for a while with a Mytek Brooklyn DAC I can honestly say I hear no difference between an MQA file which claims 384k to the "merely" PCM 96k/24 bit files. 

Magico S1 Mk II - The measurements

Sound Stage Network released their own measurements and had the chance to evaluate the S1 Mk II for a longer period of time than I have.

It's time for a closer look and to see where I was right, and where I was wrong. Hans Wetzel's review was overwhelmingly positive, while mine was positive with nuances.

Tonality

Honestly, I hate the word "tonality." Is it even a word? So many have heard the S1's and proclaimed them to have "spot-on tonality" to my surprise. I didn't think so, but hey, let's see what the measurements say.

First, remember I said it was bright, with excess energy around the bottom of male voices?  Well, based on my reference speaker curve from Bruel and Kjaer, I was right.

Take a look here, we compare the two.

At least from my own reference perspective, I was spot on. The treble runs a little high for me, and the peak energy is around 200 Hz, a little over an octave higher than I would like.  I was also right about the treble being very smooth and unblemished (more on that in the next chart). I was wrong about the overall balance being smile-shaped though. This is in fact pretty flat, just not necessarily going exactly where I'd like, but that can be adjusted for with reduced toe-in or DSP. When I listened to these speakers it was practically on axis.

In the end there's really no cheating physics and there is only so much you can do with a small driver but I am really surprised the energy falls off that soon, it does sound better than that, but this early bass peak does explain why I though the mid bass was a little too much.  At the same time, that early drop off is going to give a sense of exaggerated bass clarity, since you won't activate troublesome room modes below 100Hz as much as with a true full-range speaker. 

Compression

One measurement I was surprised by was the amount of compression between 70 dB and 90 dB.  That is, at higher volume levels the top treble will stand out more due to compression in the mid-treble.  It is going to be really important to evaluate these speakers at the right volumes for you.  If you listen at low volumes, listen to them that way, and vice-versa.  This undoubtedly contributed to my impression the speaker was smile-shaped.  At 90 dB, it starts to go that way.

Based on the early bass drop off I would try to keep the speakers within 2 feet of the rear wall, but far far from the sides to get a little bit more bass without compromising the imaging and clarity of those wide dispersion tweeters.

Comparing the S1 to the B&W 802 D3

Let's do another graphing trick.  Let's compare Stereophile's measurements of the B&W 802 D3 to the S1 measurements from the NRC of Canada. There are many reasons to be critical of this chart, as the measurement methods are undoubtedly different and I never had access to the raw data.  Still, I think it's worth using as a rough guide to what we could expect, and at least one dimension of how these two speakers could be alike, or different:

Notice the Stereophile Curve is in play with the B&W. See the dip at 2.4 kHz and the peaks at 4kHz and 10 kHz? Not a neutral speaker at all.  The Magico S1 is in fact much closer to neutral, without any gimmicks applied. Of course, the B&W has more bass, and about 7 dB more sensitivity, among many other differences. This technique is fun to play with and as long as lives are not at stake, worth showing.

The Impedance Curve

What about the minimum impedance? I was wrong to worry too much about it going too low. In fact, the impedance measured by Sound Stage is very good, reaching a minimum of around 3.6 to 3.8 Ohms at 150 Hz with a near 0 phase angle.  Quite benign for most modern amplifiers.  Further, that same impedance chart is evidence of a simple, no-nonsense crossover based on well meshing drivers. Fabulous!

The Amplifier

That being said, I was not wrong about these speakers needing a beefy amp. Take a look at the 1 kHz sensitivity. 82 dB?? Wow, that really is pretty low.  In fact I can't remember the last time I saw a 2-way design with such a low sensitivity rating.  The S1 Mk II's will in fact need a big amp to sound loud.

So is this worth $16,000? I think it's a pretty nice speaker, with my objections noted. Listen for yourself. With proper toe-in (as in none) and a subwoofer to support them, and space, lots of space, the S1's are pretty nice.  Whether you find the compression or limited bass objectionable or delightful however is going to be entirely up to you.

Last, unlike some other mid-price speakers introduced this year, they are unlikely to melt in the rain.  Bam! Hahahaha.

Poor Music Lover's Alternative

If $16,000 for a two-way, limited bass speaker pair is never going to be realistic let me suggest three very good sounding kits you can build from $500 to $3,000 on my other blog, here.

Bang & Olufsen Releases Ugliest Speakers Ever

Bang & Olufsen, the 90 year old Danish electronics manufacturer has released speakers to prove that the 0.5% of buyers who could afford them have no taste whatsoever.

While using good but not extravagant speaker drivers in their $80,000 BeoLab 90 speaker system they have certainly achieved what are probably the most electronically complicated home speakers ever produced.

Borrowing technology professional makers such as Meyers Sound, JBL and others have been using for several years now, B&O has produced a loudspeaker with a user selectable radiation pattern or beam steering. Beem stearing technology  can only be achieved with Digital Signal Processing (DSP) and an amplifier per loudspeaker driver.  Those of you with expensive tube or solid state amplifiers will find yourselves scratching your heads and wondering where the speaker cables go.

The real issue with this technology is that it's completely out of place in a home. If you were doing a travelling show, ending up in a different room each week, then this type of very high tech approach to sound steering makes sense, but in a fixed listening room, where you can adjust the location of the speakers and room treatments I'm still trying to find a reason for these being considered consumer devides.


The speakers are technically interesting and the array of high quality drivers and amplifiers alone would justify the cost but the styling is unforgivable. All I can think of is they remind me of a cross between a body bag and a Dalek from Dr. Who. B&O would have to pay ME rent if they wanted to keep a pair of these plywood refugees from a House of Horrors in my living room.

Honestly, don't they give you nightmares?