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

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 don't think you will see new anechoic chambers being built due to Klippel...Klippel is full range and it's just better...more practical, faster, incredibly accurate. Even the best anechoic chambers are like that little bookshelf speaker that is rolled off at 80hz 😃 

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.

8th-note; I really like your response here. And Mapman you make some great points also.  I think when we see speaker auditions we all take it with a grain of salt when it comes to a reviewer stating their listening experience.  But even the best review magazines put their products on the pedestal under some type of measurement.  As all these posts have proven people come into this subject with their own predispositions -- like MOST of these posts. I can't afford the high end gear and when I wanted a new DAC I did a ton of research -- and Amir's analysis of a Gustard X16 sealed the deal for me and I loved the product. I have upgraded the interconnects as money permits and the sound gets better all the time. As we all know once you start buying components from multiple companies the only way to ensure a major mismatch is to shoot for neutrality. But in the same vein I've had a neutral system that sounded degraded on 89% of commercial music.  So adding our own colorations to suit our tate has a place here. Like tubes and SS there will always be 2 camps.

 

@amir_asr   I see you've been a member here for a couple years.  I would be very interested in seeing your home system.  Please take some time to post pictures and a list of equipment in the virtual system section of the site.  I have asked all members to post their system in the past.  I think we all enjoy seeing and learning from how other members have set up a system.  IMHO.  Cheers.

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.

Nope.  There is no "estimation" going on.  Klippel NFS makes dual scans separated by fixed distance.  This allows it to then detect the direct sound vs reflected sound due to phase differential.  The reflections are then filtered computationally.  This is what makes it superior to anechoic chambers which lose that characteristics at lower frequencies.  There is nothing "pseudo" about that.

Gated measurements are called "pseudo" because they lack low frequency resolution.  That makes them an estimate that is good at mid to high frequencies but not bass.  Klippel NFS solves this problem (and with higher SNR to boot).

"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. :-)"

Ground plane measurements have sources of error.  And require stitching to the gated measurements which again, can introduce errors. 

To be sure, you can get really good results with ground plane+gated measurements but it is very tedious.  See this post from our resident expert in that field: