Tuesday, December 29, 2015

Squires Natural Reference 1 - Compression and Distortion




Comparing the 95 db and 70 db signals.  What errors you can see are probably due to me being lazy and using the Logitech Squeezebox volume control.


Distortion elements

Please note that while the shape of the distortion in these charts is accurate the scale is NOT!   You cannot read the actual distortion values off these charts due to a limitation (or feature) in OmniMic.  The distortion figures on on a scale not shown.  What I will say here is that the actual distortion figures are ridiculously low all the way to 100 db. :)


Distortion at 70 db

Distortion at 80 db

Distortion at 85 db

Distortion at 90 db

Distortion at 95 db
Energy Storage, flat EQ

Monday, December 28, 2015

Focal Sopra - More Business than Hi FI



Focal has recently introduced the Sopra line of speakers and demonstrates two things:

  • We live in a time of mid-fi $16,000 speakers
  • Focal has terribly good business acumen

From a technology stand point, the Sopra line is a continuation of the Profile and Electra lines.  Despite the hype, there is very little new here.  All of the drivers are fairly similar to the previous drivers with some inexpensive changes made.

Cabinet

The cabinet is bent pressboard. A fancy type of cardboard. I wouldn't buy a trash can made like that, let alone a speaker. I'd venture to say that the real reason for the "infinite horn loading" section is that it makes the design of the cabinet very simple. Construct two cardboard, excuse me, pressboard, tubes of identical cross sections and glue together with a wedge of particle board to hold the tweeter and you are done. Outstandingly cheap to manufacture. Now if they'd add a foot pedal at the bottom I would have an easy place to dispose of the cat lint that accumulates here daily.  That would definitely add class to this joint.



Tuned Mass Damper

Essentially new surrounds with slightly more complicated profiles than we've seen before. They may be effective, but from a price point, the surrounds are just not very expensive.

Infinite Horn Loading

The middle chamber allows Focal to mate an open back tweeter a horn to essentially absorb the rear wave.  They call it "infinite horn loading".  As mentioned, structurally the chamber serves the purpose of connecting the midrange and woofer drives in a very sexy and terribly inexpensive enclosure.

Little innovation here, and indeed, an irrelevant application of older ideas. The concept, as far as I know, was first seen in the B&W Nautilus lines, and continues in the latest B&W loudspeakers. In a nutshell the tweeter is a dipole, without anything to block the rear wave, and therefore eliminating the possibility of reflections internal to the tweeter housing from causing distortion and frequency response comb effects. Focal has been making different "grades" of the same tweeter by changing the rear chamber.

Of course, the proof is in the compression and distortion measurements.  While I haven't seen distortion figures, I can say the measured compression at 90 db is terrible for what should be class-leading dynamic performance.

Crossover Components

I've had exactly one glimpse at the crossover used in the Sopra in a video showing the making of them.  It looks like the same relatively inexpensive parts used all the way back to the Profile line. What's worse is that I discovered an impedance lowering circuit in the crossover of the Profiles, and the chart for the Sopra seems to take full advantage of this. This is a circuit that did almost nothing for the frequency or phase matching, but lowered the woofer impedance into the 2 Ohm range. Why would any reasonable person do this? Because it makes the speaker appear more discerning. A 2 ohm speaker is a snob, and can only be well driven by a hefty amplifier. That same speaker at 4 Ohms looses it's aloofness and plays well with any amplifier.

Own one? Open it up and count the number of high power resistors. If it's around 8, I win.By the way, those resistors are super cheap.

The Bottom Line

The Sopra 2s are tuned like ghetto blasters, with a nice big smile.  Measurements taken for SoundStageNetwork also show huge amounts of compression in the tweeter, no surprise there, and   very low impedance around 100 Hz. In addition, the line appears to use fairly old crossover design, due to essentially inexpensive woofer and midrange motors.  Instead of adding more powerful magnets to the low efficiency and low impedance woofers, Focal has done very little and has created a "discriminating" speaker.  Again, cheap drivers, inexpensive and inadequate cabinetry and poor crossover design say I.

Alternatives

Consumers could find much better values in this price range, but there is no denying that Focal is doing everything right, business wise.  Limited R&D investment, inexpensive manufacturing combined with creating the aura needed to create the perception of a speaker commanding over $10,000 dollars.


If you are looking for speakers with a similar frequency profile but worth their manufacture, and with a more natural and dynamic presentation in the same price range I would encourage you to look at the latest Magico S1 / Mk II instead.  It's not only a better performing speaker, with better components it's also more beautiful and smaller.

Saturday, December 19, 2015

Magico S1 Mk II - The First Review

Magico, of Hayward, California has officially announced the launch of the S1 Mk II in a press release and on the Magico website.  Now that the cat is out of the bag, so to speak, I can finally blog my initial impressions of this truly beautiful speaker. Thanks to a generous invitation extended to the San Francisco Audiophile Society by Magico I was able to audition these about a month before the general announcement.

The S1 is a diminutive, 43" tall 2-way floor stander starting at $16,500 a pair.  The driver compliment includes the Magico uber-high tech Beryllium/Diamond 1" tweeter along with a proprietary 7" carbon fiber and graphene driver.  Sensitivity is listed at 87db.

Magico has a really enviable listening room which, in addition to the S1/MK IIs they also hooked up Convergent Audio Technology preamp and the eye-wateringly expensive CAT JL3 amplifiers, known for having apparently endless power and current reserves. I forgot the source appliance, but it streamed through the Berkeley Reference DAC, another Bay Area manufacturer.  I find the Berkeleys a bit too cool for my tastes, but I don't think they'll affect my comments here.  This was also my first time listening to CATs in any situation, so if you are familiar with them, apply your own adjustments to my comments accordingly.

The listening room itself was heavily treated, with large, integral bass traps in each corner as can be seen in this Stereophile article. 

When we listened to the S1 MK IIs the paint had not even been applied. It actually occured to me the S1 would be just as beautiful in polished aluminum with a lacquer clear-coat instead of painted but according to Magico, the cost could easily double or more due to the expense in polishing the aluminum to the standards needed to be presentable. Still, I couldn't help but remember how sexy an Audi R8 in polished aluminum looks while we began to listen.

The Good

The S1/IIs shows tremendous energy and the ability to fill up the room we were in down to the low registers of all the music we listened to.  They also showed great horizontal dispersion, listening far off center you could still hear a good image and when recordings had it, with plenty of air and space appearing between the speakers.

In terms of music listening, they seemed to have nothing missing between the treble and bass and played loudly and convincingly without distortion. In my too-brief audition I thought the treble in particular was very smooth, extended and complete, the better of the B&W 802D's or Wilson Sasha's I have heard.

The Not so Perfect

Before you go on, keep in mind I do think these are very good speakers, but taking full advantage of them requires the right setting. What the S1/MK IIs won't be is all things to all people.  Please think seriously about how you really spend time listening to speakers before reading more. The S1/Mk IIs have some distinct characteristics a buyer should consider before purchasing.

The Room

Despite their relatively small foot print these speakers needed quite a lot of room to sound their best.  They need lots of room behind them, and to the sides.  Cramp them in any way and you'll end up with a muddled mess of sound.  They will hate corners and being backed up against a wall.

The Timbre 

To my ears, and where I was sitting, these are not neutral speakers.  I heard excess bass in the lower parts of a male voice, as well as in piano recordings. The treble also had extra sparkle, if not scintillation that, while fun and exciting, is not what I would call neutral.  My guess is they would measure closer to this other Magico Q5 speakers as reviewed in Stereophile.  These characteristics will make these fantastic background music speakers as well. Even at low levels you'll be able to hear the full range of music.

On the positive note, the extra treble also had more treble.  That is, it wasn't just a matter of being tilted upwards, but octave by octave the Magico's displayed no gaps at all, especially when compared to the latest Wilson's and the B&W 802D. Give me the same smoothness, coverage and dynamic range with a more neutral presentation and I'd have nothing to complain about at all in terms of the performance. As a heretic, I might say that these plus a digital equalizer could very well be the best small footprint speakers (but not small space) available.

The Amplifiers

While listed at 4 ohm speakers, Magico is no stranger to low impedance designs, and I fear that is how they are getting their output, by creating low impedance, high current drivers that demand a lot from the amplifiers.  This is what some reviewers charitably call "discriminating" speaker design.  I call it cost-saving.  Anyway, I have not seen the impedance graphs, but my gut, and only my gut, warn me these speakers may need some pretty stiff amps to sound well.  

The Bottom Line

While these speakers show an incredible amount of craftsmanship, unique designs and high tech cabinetry resulting in small speakers with really amazing output they are not for long term critical music listening.  If you truly need speakers to act as transparent windows into a recorded environment that can be listened to for hours and never tire of I think you'll find these speakers too hot and seasoned for your needs unless you have matching hearing loss in which case they may actually be perfect. This is a subtle thing though, other speakers currently in vogue are far worse. They would however lend themselves very well to a little digital EQ before your DAC, if you aren't averse to a transparent sounding tone altering.

I think these speakers are going to be great as part of an entertainment system where you host guests to watch movies, play games, or in a home where you would like to have music playing in the background without being forced to sit in the throne or use with a subwoofer.

The amplifier demands could also be challenging.  If you aren't going to use the speakers for critical listening, and are going to hide the electronics it makes no sense in my mind to go crazy with spending money here, but you will want to make sure any amp is up to the challenge.  Fortunately there are good, and good value, amplifiers that will have ample power reserves such as the Parasound Halo A21. 

Lastly, as mentioned before, the speaker's small footprint belies it's need for space. For an apartment dweller dreaming of high-end speakers to place in the corners and do critical listening with for hours-on-end these are just not going to be your speakers.  For a well-heeled executive who needs a small foot print, beautiful speaker to enjoy with friends in a medium to large den or living room and at times put out seemingly limitless amounts of clear sound, my friends and oligarchs, your ideal speakers may very well have arrived.


Measurements

Thanks to the good people at Soundstage Network we have been able to examine the test results produced by the National Research Council of Canada, and have a follow up discussions here


Your Next Steps

Of course, if you are at all interested in these speakers, go give them a listen, and get an in-room audition before committing.  Lots of things may be different between this author and your situation, so at the end of the day it's your wallet and therefore your tastes that should rule all.  I do hope however that I've given you some pointers as to what to pay attention to so that if you buy these speakers you'll end up completely satisfied with your choice. I look forward to your own comments and impressions. 

Saturday, December 12, 2015

Noes - XSin vs. Actual

A big thanks go out to Bill Waslow for his excellent and free XSim.  Together with OminMic and DATS I did in weeks what it would have taken me years if ever.

To make the long story short, here is a comparison between the simulated crossover, and XSim's expectation.  Blue is simulated.  Differences in phase are probably due to inexact placement of the microphone between early measurements and now. 

If we take that data, and overlay it on the simulation from LEAP


Saturday, December 5, 2015

I love XSim! 

Here is the test schematic


Sorry about the part numbers.  I can't reorder them.  On top is the 2nd order design, on the bottom is the first order. 

Here we have the impedance of each, seen from the amplifier's point of view:

The top, yellow curve is the 2nd order filter, the bottom green line is the first order. 

Next, let's take a look at the power dissipation in the series resistors in each. 


R1 and R6 are part of the first order , R3 and R5 part of the second order filter.  You can see in each case the power of the 2nd order filter lags (is lower) than the first order filter, except at the very end for the first resistors in the circuits.  

Here are the simulated frequency responses, but please bear in mind having a good response was not part of the experiment.   Tweaking the crossover becomes very arbitrary.  The goal of this experiment was just to examine how power and impedances changed based on 1st vs. 2nd order.  Also, the first resistor is not really needed, it's again there for the investigation.



 

Thursday, December 3, 2015

XSim - Simulated Noes Xrossover

A quick posting for the currently simulated crossover.  As soon as the real one is built we'll compare!  

And here is a weird pre-ringing issue with the tweeter.  minor, but weird.