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

Showing 7 responses by erik_squires

I may need to clarify something. When I say that the Klippel results are quasi-anechoic I’m not arguing that "quasi-anechoic" is bad, but that by definition it means measurements with anything other than an anechoic space.

I made the mistake ot descrbing a specific quasi-anechoic measurement technique, and it may seem I’m saying that quasi anechoic is 1 specific process. It isn’t. It’s an adjective. It classifies measurements broadly into 2 categories: anechoic or not based on the measurement methods. Regardless of the post processing methods, Klippel or otherwise, unless the measurements were donoe in an anechoic space they must then be "quasi-anechoic." if they attempt to replicate an anechoic measurement.

The Klippel system may in fact be the best we can do today. It may be the best ever. There may never be anything better. It’s still going to be quasi-anechoic in my mind.  Always and forever.

I never said ground plane measurements were perfect, but that they could be used for an anechoic measurement below 80 Hz, so why bother to argue that they have issues as well? I don’t care. They are still anechoic while Klippel is not. If this winds you up in a knot, I’m sorry. Have a cookie. If you think "anechoic" is better than "quasi-anechoic" that’s on you, not me. You clearly have a branding problem you want to argue. If your entire web presence now hangs on the perceived value of the brand Klippel, that’s not my concern either. Klippel doesn't care what I think of it and vice-versa.

So if you want to argue that there are pros and cons of any kind of measurement, sure, go ahead, but please don’t expect me to engage in arguments I didn’t make.

Klippel is actually better than anechoic. For example, at the NRC the chamber is only good to around 80hz....it’s just too small.

I’m not arguing this at all. I’m just saying that, by definition, it’s quasi. :) The results may be better than anechoic, but the measurements are considered quasi.  We are estimating an anechoic response even though the measurements themselves were not done in an anechoic environment.

Fortunately for low frequencies we have ground plane measurements, which I believe are actually anechoic... but I’ll leave that to the scientists to debate. :-)

I’m really glad we have all the modern tools for speaker measurement and design, certainly nice to see them trickle down to being affordable for DIY enthusiasts.

totally agree with you on crossover point analysis...cost tradeoffs....however, I suggest you learn more about the Klippel...you are greatly underestimating it’s abilities. ;-)

 

@seanheis1 I look forward to having the time, energy, space and money...

Having said that, my experience is that mid-woofers are funny to work with, and I'd have to see actual far field measurements before I took the simulations at face value.  I leave the overall value and accuracy of Klippel tools up to others who really care to debate.

Also, quasi-anechoic means anything besides an anechoic measurement. Taking a thousand measurements and having advanced room simulation tools is not "fully anechoic." It’s a simulated anechoic measurement, and that’s exactly how I define quasi-anechoic.

I am happy to learn that Klippel is a much more advanced quasi-anechoic system than I thought. That’s great. Still quasi. 😀

Best,

 

Erik

@fstein  - You know, I definitely build speakers I'm proud of from an engineering perspective, but when it comes to value... humans are not nearly as picky as you'd think.

I can think of a number of VERY successful speakers which had a number of issues I'd raise.  So, who is right?  Me, the measurements, the buying public?

Definitely not Amir.  😂

I'm reminded sometimes of the Top Gear episode where they were comparing a couple of sports cars on the track.  The one with the loose rear end had the worst performance on the track but was the most fun to drive according to one driver.  Was he "wrong?"  I leave that up to the consumer.

This thread has gone far far afield from what I meant to talk about, and I'm going to let it.  You all talk amongst yourselves.

@roadcykler  While some gear is like candy, tastes great but poor long-term diet, let's be clear that the science is only worthwhile if it feeds our emotions.

Without emotions, there is really no point in music.

I have a choice, I can either argue about what the definition of "nit picking" is, or the definition of "quasi-anechoic."  Stepping back I'm not sure either argument is worth having.