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 tell me how you measure dynamics in a speaker?

I don't know how you are defining "dynamics." I define it as how loud it can play cleanly.  Distortion tests help with this but ultimately I like to listen with specific music clips that show the ability of the speaker to do so with sub-bass content.

How fast the speaker is?

There is no such thing. Every sound has its frequency and speaker driver needs to only be "fast" enough to play that.  The perception of slow bass likely comes from non-flat bass response of the speaker combined with the room it is in.  Both of these are measured using frequency response. 

Mid bass punch under actual program material?

Same answer as above.

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… 

Both of your statements are invalidated in stereophile review.  This is the frequency response:

 

This is not remotely an example of a speaker "measuring well."  Treble is exaggerated and there are serious signs of tweeter resonances.  JA's measurements have an error in them which shows a peak in bass but this is shows even more energy as he explains:

"The lower midrange and upper bass do feature a rise in level; while some of this will be due to the nearfield measurement technique, some is indeed real, and possibly contributes to the speaker's occasionally "puddingy" low frequencies. "

 In other words, there is too much (upper) bass, than not.  Of course in room and without EQ, you would have a lot of room modes to content with so even if your impressions are right, you would have to untangle them before blaming the speaker.  I have a room mode at 105Hz which I dial out in my speaker reviews for this reason.

 

 

@knock1 - I did know that! I’m so sorry if my post came across pedantically - it was merely my intention to explain and put a known psychological term to the condition of cognitive dissonance. There are many audiophiles in two minds about these issues who would find it easier to give in to the security that measurements provide - my post was to caution that those following asr do so with balance and moderation, in finding trust for the half of amir who cunningly says listening is more vital than measurements, and then get misled when the other half of amir only falls back on measurements in all other situations. A person who is inconsistent in his or her stand should never be trusted completely.

I knew I saw this somewhere and believe it applies:

Why is reductive reasoning bad?

In doing so, ideological reductionism manifests a cascade of errors in method and logic: reification, arbitrary agglomeration, improper quantification, confusion of statistical artefact with biological reality, spurious localization and misplaced causality.

What is the weakness of reductionist theory?

The reductionist approach is also more scientific than other approaches as cause and effect relationships can more easily be tested through the scientific method. A disadvantage of the reductionist approach is that these experiments can be too simplistic. They are narrow and can ignore other influences.

In other words, too much kool-aid. We are not at the apex of measuring. Not by a long shot.

@kevn Very well said. Nice insight. 

All the best,
Nonoise

Now read this by a top physicist in fluid mechanic who is also a top audio designer of world wide fame who also design his own amplifier and speakers:

 

 

An innovative approach to suppress the distortion of electronics
Dr. Hans R.E. van Maanen (Temporal Coherence)

«Every amplifier, no matter how well made, distorts. Don’t be fooled: the distortion-free amplifier still needs to be invented. The distortion, introduced by electronics, is even at low levels, annoying, which is why all designers strive for an as low as possible distortion level of their brain child. And in order to be able to compare results, the distortion is measured and is expressed in a number, usually a percentage. Sadly enough, in reality this so-called “distortion figure” shows to be indicative at best, but it certainly is not an absolute measure for how we experience the quality of the sound reproduction. This can easily be
demonstrated by a couple of simple examples from daily practice: a loudspeaker commonly distorts at least 0.5%, which is significantly more than the 0.01% of a good semiconductor amplifier. Yet, the misery, introduced by the amplifier, is clearly audible using such loudspeakers. Although valve (tube) amplifiers have distortion figures which are significantly higher than those of semiconductor amplifiers, still a lot of music lovers prefer the sound of valve amplifiers.
Also, there is no guarantee that a semiconductor amplifier with 0.001% distortion “sounds” better than one with 0.01% distortion. Unfortunately, we will not be able to dig deeper into the backgrounds of this paradox, but it is important to remember that a
distortion figure is barely informative on the experienced, sonic, quality of an amplifier.»

https://www.temporalcoherence.nl/images/docs/Distortion.pdf

Only this short quote by a scientist as well known as Toole in acoustics destruct all Amir pretense about tube amplifier being bad and S.S. being good ...

Now about the way high frequency signals way over 20KHZ affect sound perception of human :

«In-
audible high-frequency sounds affect brain activity: hypersonic effect.
J Neurophysiol 83: 3548 –3558, 2000. Although it is generally ac-
cepted that humans cannot perceive sounds in the frequency range
above 20 kHz, the question of whether the existence of such “inau-
dible” high-frequency components may affect the acoustic perception
of audible sounds remains unanswered. In this study, we used nonin-
vasive physiological measurements of brain responses to provide
evidence that sounds containing high-frequency components (HFCs)
above the audible range significantly affect the brain activity of
listeners. »

https://linearaudio.net/sites/linearaudio.net/files/high%20freq%20inpact%20on%20brain.pdf

 

I think Amir need to study acoustics more and digital signals less...

 

 

Thanks @nonoise 

@erik_squires - I’m sorry for not acknowledging your original post earlier - it was a terrific read for me and pointed out clear and understandable facts regarding the measurement of speakers that go beyond a single viewpoint or method, and engage relationships, acoustic and electromagnetic. Thanks for your insights.

 

in friendship - kevin