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

So the only difference between a $200 topping and a 2k dac with meters is meters? 

No, it could be anything.  I measured a $20,000 DAC last year that a company sent me.  Measurements clearly showed that it had the implementation bug we call "ESS IMD Hump" which every major Chinese company had already solved.  Even outside of that, performance was ordinary.  The DAC had beautiful build, and weight more than any other DAC I have tested.  But failed in delivering what matters: transparency for the input signal as a $100 DAC provides.

It is a sad fact that the more you pay for audio electronics today, the more likely it is that you get worse performance.  Take that Eversolo DAC:

 

Now compare that to Mytek Brooklyn Bridge II Streamer which costs five times more at $5,000:

Look at all that power supply noise and how dirty its spectrum is.  Poor attention was paid to circuit layout and design, causing interference from digital circuits to bleed into the sensitive DAC.  Clearly Eversolo people know how to better do this job than Mytek.

And it is not like you got something prettier:

 

This is the power of what we do at ASR.  Objective analysis that points out who cared to produce a high fidelity product and who did not.

This sentence made no sense at all.

No, I am just going by the assumption that you are hearing a different sound with tube amps than transistor. That coloration is therefore added to every piece of music, making it different than what the artist intended.

First all tube amp are different as all S.S. amp.

Then it makes no sense to generalize saying that all tube amp are in the same bag : bad coloration.( i bet he does not know Berning Tube amp )

And what the artist intented to do do not represent a single intent but result also from what his recording engineer trade-off set of choices is adding to the artist intent. There is an acoustics complex set of information ( not a simple single intent) which is recorded and must be translated in your Room ACOUSTICALLY. The amplifier type does not play the main role here save for people completely ignorant of acoustics powerful impact .

Putting this double intention of the artist and of the recording engineer in relation with your amplification type is ridiculous.😊

it is complete acoustics ignorance promoting digital gear by a bias directly resulting from his digital software engineering background.

I already discussed all that with Amir here using  the work of a designer and physicist Van Maanen one year ago. Amir did not understood anything attacking this physicist reputation in audio ad hominem .. I will not use all this a second time...😁

If me a complete dilettante playing in my dedicated room with acoustics basic can see through this narrow ideology anybody reading science articles can...

Then it is useless to argue... We understand only if we are not paid to be deaf by money, pride or hubris...

 

 

 

@ricevs I can vouch bought an $80 dongle based on a ASR review just for kicks and I can assure you the listening tests correspond to the measurements. That thing is as clear and detailed as I have heard and I’ve heard it all.  
I also have a Chord Mojo that got lesser reviews and though I enjoy the Mojo quite a bit as well the sound is much warmer and not as detailed.

Also I picked up a second Fosi amp based on ASR review that I use in a desktop system and that also lives up to the measured performance.

So like him or not Amir is doing something right I would have to say. Probably at least as much as anyone, maybe more. YMMV.

Other gear I own includes Bel Canto, Cambridge, Sonus Faber, KEF, Ohm, Linn and Electrocompaniet. It all sounds really good but different.

I’ve owned tube gear in the past as well and not missing it. The best SS and tube gear tends to sound more similar than different to me over the long term.

 

So tell me how you measure dynamics in a speaker? How fast the speaker is? Is that measurable? Mid bass punch under actual program material?

I had pioneer S1ex speakers. Heavy as hell and measured really well. Well they had 0 mid bass and no dynamics for anything other than acoustic rock… which they were amazing at! If I was just that or maybe a classical guy might have been perfect. But alas despite the amazing measurements and the bombshell cabinet it was a no go. My Focal 836w measured worse but similar.They sounded TOTALLY different real world with a multitude of amps both ss and tube.

Amir,

Where is your proof that an $80 DAC.....or any DAC for that matter, is transparent? 

There are multiple peer papers I suggest you read on this topic:

“Noise: Methods for Estimating Detectability and Threshold, ” Stuart, J. Robert, JAES Volume 42 Issue 3 pp. 124-140; March 1994
“Dynamic-Range Issues in the Modern Digital Audio Environment, ” Fielder, Louis D., JAES Volume 43 Issue 5 pp. 322-339; May 1995

If you don't have access to AES, you can read my quick write up in this article I published on audibility of small impairments. Or this video starting at 5 minute mark:

 

Once you read/watched those, take a gander at the review of the SMSL SU-1 $80 DAC. Here is its dashboard performance:

 

FFT spectrum shows distortion products way below threshold of hearing.  Even discarding simultaneous masking, those impairments are inaudible.  Dynamic range likewise covers threshold of hearing to playback level of about 115 dBSPL:

 

That is transparency for you, albeit, just at the edge with respect to dynamic range.  This $80 DAC cleans the clocks of many expensive DACs.  

Here is for example PS Audio DirectStream DAC which costs $6,000+

 

Distortion products are now at -80 dB which is a massive 50 dB worse than the $80 SMSL DAC!  It uses an output transformer which saturates and generates these harmonics.  Its noise floor is so high that it can't even clear 16 bit audio:

 

 You have no idea what transparency is since you do not listen.

Well, there are my listening tests of above PS Audio DAC:

Listening Tests
For subjective testing, I chose to use the recently reviewed and superb Monoprice Monolith THX 887 Balance Headphone Amplifier. This headphone amp has vanishingly low distortion and hence is completely transparent to DACs being tested. For the alternative DAC, I used my everyday Topping DX3 Pro 's line out RCA to Monolith. I then used the XLR input to connected the DirectStream DAC. Once there, I played a 1 kHz tone and used my Audio Precision analyzer to match levels using PS Audio's volume control. PS Audio claims perfection there ("bit perfect") so I figured they can't complain about that. :) The final matching was 0.3 dB difference between the two.

For headphone I used DROP + MRSPEAKERS ETHER CX with its XLR connection to THX 887 amp.

I started the testing with my audiophile, audio-show, test tracks. You know, the very well recorded track with lucious detail and "black backgrounds." I immediately noticed lack of detail in PerfectWave DS DAC. It was as if someone just put a barrier between you and the source. Mind you, it was subtle but it was there. I repeated this a few times and while it was not always there with all music, I could spot it on some tracks.

Next I played some of my bass heaving tracks i use for headphone testing. Here, it was easy to notice that bass impact was softened. But also, highs were exaggerated due to higher distortion. Despite loss of high frequency hearing, I found that accentuation unpleasant. With tracks that had lisping issues with female vocals for example, the DS DAC made that a lot worse."

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