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

Also, Mahgister, thank you for the link you posted earlier to that study regarding human hearing and the Fourier uncertainty principle - https://phys.org/news/2013-02-human-fourier-uncertainty-principle.html

It helps explain a lot about what many of us have suspected/felt for as long as we have been in the hobby, in noticing both subtle and more obvious differences with each change of our systems. The way the article has been written is both simple to understand in form, and profound in critical content. ; )

 

Thanks for your kind words...

Now try to read this one , i even bought the book of this writer :

The Body-Image Theory of Sound: An Ecological Approach to Speech and Music

https://www.researchgate.net/publication/267327268_The_Body-Image_Theory_of_Sound_An_Ecological_Approach_to_Speech_and_Music

Then relate this article to this one which confirmed that the acoustician above is right :

Pythagoras was wrong: There are no universal musical harmonies, study finds

https://phys.org/news/2024-02-pythagoras-wrong-universal-musical-harmonies.html

This second article synthetize the research in this one :

Timbral effects on consonance disentangle psychoacoustic mechanisms and suggest perceptual origins for musical scales

https://www.nature.com/articles/s41467-024-45812-z

 

This last one is very important too and confirm alll the others:

Bodily maps of musical sensations across cultures

 

https://www.pnas.org/doi/10.1073/pnas.2308859121

 

Also, Mahgister, thank you for the link you posted earlier to that study regarding human hearing and the Fourier uncertainty principle - https://phys.org/news/2013-02-human-fourier-uncertainty-principle.html

It helps explain a lot about what many of us have suspected/felt for as long as we have been in the hobby, in noticing both subtle and more obvious differences with each change of our systems. The way the article has been written is both simple to understand in form, and profound in critical content. ; )

 

It is clear that acoustics rules audio experience which is not mere room acoustic...

If we dont understand psychoacoustics we can anyway tune our system/room for sure without reading these articles above...😊

But if we want to really understand why Amir posit an ideology about a few tools as THE audio truth we must read these articles which explain what we hear and how this affect us, in a way no tools used as a set of toys to promote audio S.Q. truth could because it is only gear marketing in a new form.

There would be nothing wrong with Amir measurements if he did not disparage hearing and acoustics and users preferences parameters as basis and key, instead of the gear specs, so much important electrical synergy could be and is for sure to start a system /room journey... Acoustic synergy matter no less...

Gear dont matter at last anyway it is only a starting point ( it is budget dependant) acoustics matter at last if we want to do the best and the optimum with what we can afford ...

 

For sure you cannot replace a lesser quality component with acoustics knowledge nor compensate for it. Design quality matter too. Then in this sense specs matter.

But once said the impact of acoustics on a system/room exceed any upgrade in S.Q. improvement %... By far...

it is not well  known because marketers sell gear pieces as acoustic solution  to S.Q. problem...It is not even wrong because as i said design quality matter...

But no marketer sell their gear piece asking  the consumers to study acoustics to reach the optimum with their new piece of gear... They instead said that their piece of gear is "perfect" as it is for them... Unwrap and plug and be on top of the world...

Sorry it is false no system whatever his price can beat acoustics...

 

I love classicrock's explanation on how to not get banned on ASR forums. You can disagree but not really.

Cult seems to be an appropriate way to describe ASR followers. Amir offers simple explanations to complex problems, one central figure who has all the answers, shunning or banning if you question the guru, safe spot that doesnt encourage actual complex thought, aggressive defense of the master and an ability to find members who are searching for answers but suffer from problems of confidence.

I think a deprogramming is in order. This may be nothing more than forcing these people to sit down and listen with an open mind. However such listening might force an existential crises so get ready for some therapy. 

What on earth are talking about? Spectrum analyzer shows the spectrum, not time domain amplitude.

We are measuring output impedance. The spectrum analyzer measures the voltage amplitude for each frequency. Why do you need to introduce "time domain" here? If it is just DC voltage then you just need a Fluke voltage meter. But the output here comprises of multiple frequency that’s why you need a spectrum analyzer. Also I assume the load is mostly "real" and not "complex". If it is "complex" then it can be complicate as you need the phase as well. That is why I said this is not an easy test to do and you’re may not be prepared to perform it.

Looks like you have forgotten about ohm’s law. P12 generates 120 volt RMS AC. At 2 ohm, you would be asking it to spit out whopping 60 amps! The could cause it to be damaged at worst, or shut down at best.

Then use a higher impedance load to reduce the current load. I was only using it as an example.

Maximum Continuous Load 1000VA 1200VA
     

This is what the spec for the P12. You can use it to calculate how much current is appropriate. If the output is 120V then the max current is 1000VA/120V = 8.3A.

That is on top of needing a high voltage dummy load that could dissipate over 7 kilowatts of power!

That is why I said it’s not simple test to measure and I don’t think you have a setup for it. You can reduce the wattage by using a square wave instead of a continuous output.

You seem to be confusing how you measure the output impedance of audio amplifier rather than a high voltage AC generator.

They all have to obey Ohm’s law. They all should have output impedance that can be measured. There is nothing special here except you’re dealing with very high voltage and current. That is why the test is not easy. You took the short cut.

None of this is necessary anyway as output impedance of AC source only has a loose relationship to what comes out of your audio device as the latter has its own power supply and capacitor bank to provide power for transients.

That is just your conjecture. I don’t have data to back it up.

Square wave testing can generate highly misleading information as the signal itself may never be representable with music signals.

I am not saying you should use square wave to test for everything, but in this special case of testing a AC power regenerative, the square wave can tell you if the P12 does what is is supposed to do - that is delivering the current from a very low impedance source.

To wit, digital audio at 44.1 kHz won’t have any components above 22.05 kHz. Feed it a 10 kHz square wave and what comes out is a pure sine wave!

Then use a lower frequency for example 1KHz. Use just need to mimic a step response to see how the amp can produce a demand current. If you don’t like square wave, just use step response.