Some thoughts on ASR and the reviews


I’ve briefly taken a look at some online reviews for budget Tekton speakers from ASR and Youtube. Both are based on Klippel quasi-anechoic measurements to achieve "in-room" simulations.

As an amateur speaker designer, and lover of graphs and data I have some thoughts. I mostly hope this helps the entire A’gon community get a little more perspective into how a speaker builder would think about the data.

Of course, I’ve only skimmed the data I’ve seen, I’m no expert, and have no eyes or ears on actual Tekton speakers. Please take this as purely an academic exercise based on limited and incomplete knowledge.

1. Speaker pricing.

One ASR review spends an amazing amount of time and effort analyzing the ~$800 US Tekton M-Lore. That price compares very favorably with a full Seas A26 kit from Madisound, around $1,700. I mean, not sure these inexpensive speakers deserve quite the nit-picking done here.

2. Measuring mid-woofers is hard.

The standard practice for analyzing speakers is called "quasi-anechoic." That is, we pretend to do so in a room free of reflections or boundaries. You do this with very close measurements (within 1/2") of the components, blended together. There are a couple of ways this can be incomplete though.

a - Midwoofers measure much worse this way than in a truly anechoic room. The 7" Scanspeak Revelators are good examples of this. The close mic response is deceptively bad but the 1m in-room measurements smooth out a lot of problems. If you took the close-mic measurements (as seen in the spec sheet) as correct you’d make the wrong crossover.

b - Baffle step - As popularized and researched by the late, great Jeff Bagby, the effects of the baffle on the output need to be included in any whole speaker/room simulation, which of course also means the speaker should have this built in when it is not a near-wall speaker. I don’t know enough about the Klippel simulation, but if this is not included you’ll get a bass-lite expereinced compared to real life. The effects of baffle compensation is to have more bass, but an overall lower sensitivity rating.

For both of those reasons, an actual in-room measurement is critical to assessing actual speaker behavior. We may not all have the same room, but this is a great way to see the actual mid-woofer response as well as the effects of any baffle step compensation.

Looking at the quasi anechoic measurements done by ASR and Erin it _seems_ that these speakers are not compensated, which may be OK if close-wall placement is expected.

In either event, you really want to see the actual in-room response, not just the simulated response before passing judgement. If I had to critique based strictly on the measurements and simulations, I’d 100% wonder if a better design wouldn’t be to trade sensitivity for more bass, and the in-room response would tell me that.

3. Crossover point and dispersion

One of the most important choices a speaker designer has is picking the -3 or -6 dB point for the high and low pass filters. A lot of things have to be balanced and traded off, including cost of crossover parts.

Both of the reviews, above, seem to imply a crossover point that is too high for a smooth transition from the woofer to the tweeters. No speaker can avoid rolling off the treble as you go off-axis, but the best at this do so very evenly. This gives the best off-axis performance and offers up great imaging and wide sweet spots. You’d think this was a budget speaker problem, but it is not. Look at reviews for B&W’s D series speakers, and many Focal models as examples of expensive, well received speakers that don’t excel at this.

Speakers which DO typically excel here include Revel and Magico. This is by no means a story that you should buy Revel because B&W sucks, at all. Buy what you like. I’m just pointing out that this limited dispersion problem is not at all unique to Tekton. And in fact many other Tekton speakers don’t suffer this particular set of challenges.

In the case of the M-Lore, the tweeter has really amazingly good dynamic range. If I was the designer I’d definitely want to ask if I could lower the crossover 1 kHz, which would give up a little power handling but improve the off-axis response.  One big reason not to is crossover costs.  I may have to add more parts to flatten the tweeter response well enough to extend it's useful range.  In other words, a higher crossover point may hide tweeter deficiencies.  Again, Tekton is NOT alone if they did this calculus.

I’ve probably made a lot of omissions here, but I hope this helps readers think about speaker performance and costs in a more complete manner. The listening tests always matter more than the measurements, so finding reviewers with trustworthy ears is really more important than taste-makers who let the tools, which may not be properly used, judge the experience.

erik_squires

I borrowed a Topping D whatever it was with the balanced outs (their top model kinda from a couple of years ago). When you played dense tracks is when it started to fall apart, in comparison to my other dacs...(technics, denafrips...or even the Schiit Yggdrasil).

I tested two Schiit Yggdrasils, finding design errors in them.  Company disputed that so a third person volunteered his unit.  In doing so, he told me he had bought a Topping and it did not sound as good.  He gave me the model number and precise tracks he had used for that testing, and the fact that he had used Stax headphones.  I own Stax headphones, and said Topping DAC and same music in high-res (what he had used).

First thing I had to do was match levels as out of box levels were not the same, invalidating any such listening test.  After I did that, the two DACs sounded identical in AB tests.  The Topping cost 10% of the Yggdrasils.  

I was also told that the Yggdrasils needs to warm up.  So I left it on for days, measuring it along the way. Its performance never changed.

Again, I duplicated his listening tests to the letter, except that I was careful to match levels when he had not done.  

If you all just learned how to properly test equipment so that only the fidelity is being evaluated, then these arguments would all go away.  Instead, you keep doing faulty testing, with all manner of mistakes and biases and arrive at conclusions that are not supported by any science or engineering.

 

If it is just one boring bird squealing to a single string in a simplistic manner, one may not catch stuff like that about the ASR Topping miracle. These Chifi engineers are fairly sharp though and maybe they’ve learned a thing or two (progressed over time, wouldn’t know until a newer dac is compared)..

A few years ago, Schiit decided to take measurements seriously, put aside their lousy audio measurement and buy an Audio Precision analyzer like I have.  In less than a year, they managed to produce superb performance and price as good as Chinese companies.  Here is one of many examples, the Schiit Midgard

 

As you see, it garnered the highest award from me (the golfing panther).  The product like many others was sent to me by the company.

They are not alone.  Here is JDS Labs doing the same.  Of course Benchmark Audio has been there longer than many producing excellent products.

As a consumer, you need to celebrate the fact that companies are working hard to produce the most transparent audio products they can without charging you a premium.  Not go on some racist tangent that if it is Chinese, it can't be that good or that they must have learned something from others.  Topping has been and continues to be the only company that includes in its manuals complete set of measurements.  They did this before I started reviewing anything.

But this is audio where religion and beliefs dominate more than actual facts.

I would like to see Majidimehr design/build a dac from scratch though... show us all what a genius he is with his unfathomable bachelors degree n all (instead of dumping rudimentary output from a AP kit all day...that a 12 year old could be taught to do).

I hate the audio hardware business so you are never going to see me get involved in it.  I did grew up with electronics as my hobby and put myself through college repairing all manners of electronics from audio to RF radios. 

DAC design is not hard anyway as the IC companies provide full reference designs.  What is hard is the implementation to keep noise down.  That, is hard and I tip my hat at likes of Topping, SMSL, Schiit, etc. for having that hands on knowledge (I hired experts for that when I was managing engineering at Sony and others).  Check out this review of Mytek Brooklyn Bridge II DAC and Streamer

 

It got the worst rating from me not just for performance, but for having DAC filter selections that did nothing!  

Same problem was found by stereophile months earlier in their review and they still had not bothered to fix it!  There must have been a shortage of 12 year olds where they work per your statement to run this simple test and find the bug.

I imagine, they went through changing the settings in the UI and picked the one that sounded best to them, not realizing that all the time nothing was changing in the unit!!!

We are talking about a $5000 unit there.  Now compare that to this review of Eversolo DMP-A6 Streamer and balanced DAC:

As you see it is a gorgeous looking device with proper form factor, running Android.

This is how well it performed:

 

Now compare its FFT performance on top right to that of Mytek:

 

You see all that power supply and interference noise in Mytek?  This is what happens when there is a shortage of 12 year olds that know how to run Audio Precision!

Forgot to mention that the Eversolo streamer costs $850 or about 1/5th the cost of Mytek.

@deep_333  That's correct.  I dislike nearly all other Topping DACs (I've heard 3 older ones).  This unit has been extensively praised by reviewers and owners.  This is the one two of my friends use, one is a spendthrift with limited funds and the other a very wealthy audiophile who probably has a dozen DACs he plays with. 

I especially enjoyed the D70s openness listening to complex acoustic orchestral and opera.  No problem with heavy metal that my wife listens to occasionally.  I understand you finding some other D model inferior.  It could be.  I am using a very high end audio system to evaluate it's potential.  It will probably be used in my second system for occasional use for CDs and streaming.