Erin's review for the March Audio Sointuva

[sigbergaudio]

Some individual design with familiar drivers and concept does not necessarily need listening. I've done it few times also with commercial products, but then someone else has accepted or selected the best model and drivers by listening. XO tuning could be needed if data was not accurate enough, but not necessarily otherwise. Importance of listening tests increase exponentially with new - especially experimental concepts and drivers designer has not used before. Of course designer needs quite much (earlier) listening experience and knowledge in order to make proper conclusions, set targets and compromises with combination of measurement data and acoustical design.

I can't imagine designing and selling speakers without listening to them quite extensively, but I respect your opinion (respectfully disagreeing).

But I understand that you may not need as much listening if as you say both the drivers and concept are familiar to the designer.

 

[MaxBuck]

These appear to be nearly as good as the BMR Philharmonitors, at only twice the price.

Seriously, I'd love to be able to audition both speakers and compare and contrast; obviously both are great performers. Measurements are great, but they can't substitute for actual listening.

 

[Chromatischism]

These appear to be nearly as good as the BMR Philharmonitors, at only twice the price.

Seriously, I'd love to be able to audition both speakers and compare and contrast; obviously both are great performers. Measurements are great, but they can't substitute for actual listening.

I bet they sound quite different due to the massive difference in dispersion.

 

[restorer-john]

For instance, the usual 50 db range of the scale on a simple frequency response plot leads many think a response is flatter that it really is.

Amplifiers and recievers were traditionally reviewed and the FR plots presented with a 50dB scale in the 1970s. Of course everything looked deceptively flat. Imagine presenting that as an accurate representation today.

 

[Larry B. Larabee]

Good old “Floyd and Toole”, great to know you have thoroughly looked into their work…

Note to self: Newman and DDF. On my list.

 

[Holmz]

Good old “Floyd and Toole”, great to know you have thoroughly looked into their work…

I have a couple of thoughts:

• Was he beside himself
• perhaps it was an early reflection?

 

[bigjacko]

Same with Usher

From what I have know, the original owner could not pay his employees, so the busniess was transfered to other people. Don't know if that is the reason they can't be bought in retail.

 

[sweetchaos]

Erin just posted his updated measurements on:

March Audio Sointuva Bookshelf Speaker Review

March Audio Sointuva Review

www.erinsaudiocorner.com

Erin said:

Note: I reviewed a previous version of this speaker with some slight differences from what the manufacturer intended, based on his measurements. The manufacturer used my data as feedback and adjusted a few things in the design to arrive at this version. Given the two “versions” are a month apart and all versions now sold - and sold before - will be using the same build and crossover methods, I have replaced the previous review with this review.

Note: the original review link and the updated one are the same, which means the previous data is no longer available.
I pulled it from @pierre website, so you can see the previous spinorama:

And here's the latest (from Erin's website):

I suspect the other graphs to be similar to last time:

Erin's conclusion:

• The enclosure is built like a tank. Tons of fill material and what appears to be a very thick layer of (some sort of) constrained layer damping.
• These sound awesome.
• While the sensitivity measured at a low 82.4dB, the implementation of some of the best drivers out there make this a speaker with super output capability. And with an F3 = 43Hz, you might not need a subwoofer if you don’t necessarily need a lot of output below 40Hz. The compression and distortion data show this speaker maintains its composure very well even at high(er) volume.
• The on-axis response shows a treble lift. However, this combined with a narrowing radiation in the treble result in a more linear estimated in-room response (EIR) with what I would consider a mild treble lift overall. I sometimes find a treble lift in the EIR to equate to a “bright” sound but this is more subdued and even throughout which (I believe) is what caused it to not stand out to me in a negative way.
• Interestingly, it looks like the best vertical positioning for this speaker might actually be above the tweeter axis by about 5°. This would also bring the treble boost in the EIR down a tad.
• Objectively speaking, I believe (recalling from memory) this is the best passive speaker I have measured to date. It rivals linearity and directivity on par with some of the best speakers I have seen.

Discuss!

 

[tuga]

Could that discontinuity at around 700Hz in the horizontal contour plot be the result of baffle step?

 

[Juhazi]

It's most likely because resonances leaking thru passive resonators 400-600Hz, then cleaning above, which makes on-axis response higher. Look at polars and distortion.

Ps. I hate resonators!

 

[ctrl]

Could that discontinuity at around 700Hz in the horizontal contour plot be the result of baffle step?

It depends a bit on how you define "baffle step". If you consider "baffle step" only as a transition region where radiation goes from omni-directional to directional, then this is not sufficient to describe the on and off-axis FR.

If you consider the baffle step as part of the edge and cabinet diffraction of a loudspeaker, then you can explain the effects on the frequency response and the radiation of the speaker.

What is often forgotten, the cabinet depth also plays a role and represents a parameter with which also influence the radiation pattern of a loudspeaker - depending on the cabinet shape and size, the influence can be very significant (therefore, a 2D baffle simulation is not sufficient to simulate the effects).

I had already simulated the "old" version of the speaker in the other Sointuva thread. If you look at the simulations for an "ideal" woofer (in a closed cabinet, with dimensions like Sointuva), you can see the influences of the cabinet on the radiation very nicely.

Horizontal normalized sonogram (+-180°) and normalized FR (+-90°) Sointuva woofer:

The simulation shows a radiation pattern for the woofer that is comparable to Erin's measurements of the Sointuva up to near the crossover frequency.
One can nicely see that there are several times of widening and narrowing of the radiation, which is due to the interference of the woofer with the various "pseudo-sound sources" of the edges.

Vertical normalized sonogram (+-180°) and normalized FR (+-90°) up and down Sointuva woofer:

In the vertical direction, the woofer is arranged asymmetrically on the baffle, which results in a radiation pattern that is significantly different from the horizontal one.

Edge and cabinet diffraction shows of course every speaker, by appropriate design you can control the radiation pattern and must decide what compromises you take.

 

[hardisj]

FWIW, the olive score I came up with for this is 6.9 w/o sub. I don't know if it's the highest in the passive speaker category but I believe it is.

And if the score alone isn't enough (which, I never believe should be), then the distortion and compression data are also quite great as well.

So, let's understand that you're nitpicking to the nth degree what - by all accounts - appears to be an incredible speaker.

 

[YSC]

FWIW, the olive score I came up with for this is 6.9 w/o sub. I don't know if it's the highest in the passive speaker category but I believe it is.

And if the score alone isn't enough (which, I never believe should be), then the distortion and compression data are also quite great as well.

So, let's understand that you're nitpicking to the nth degree what - by all accounts - appears to be an incredible speaker.


View attachment 190589

I would say it looked very impressive to me, adding a sub would be epic. but then it's price means it's always only a source of admire to me

 

[sarumbear]

FWIW, the olive score I came up with for this is 6.9 w/o sub. I don't know if it's the highest in the passive speaker category but I believe it is.

And if the score alone isn't enough (which, I never believe should be), then the distortion and compression data are also quite great as well.

So, let's understand that you're nitpicking to the nth degree what - by all accounts - appears to be an incredible speaker.


View attachment 190589

It is indeed a great speaker and indeed it is at the top of the Harman Scoring list. KEF R3 is currently the leader with a score of 6.5. I'm sure when the list is updated this speaker will dethrone the R3.

KEF R3 now sells for around US$1720 per pair, whereas this is advertised at US$3995. FWIW, a 132% mark-up for 0.4 score points.

KEF R3 scores 8.2 with a subwoofer. One can buy a very good subwoofer with price difference of US$2275 and beat this speaker out of the race!

 

[tktran303]

People like to nitpick.

I would like to give credit where credit is due.

This beats a speaker that Erin has measured that has 2 mid-woofers AND a midrange. And twice as big and twice the twice the price. (Revel F226Be)

Bravo Alan.
Bravo Purifi.

 

[hardisj]

I'm sure when the list is updated this speaker will dethrone the R3.

FWIW, they don't include my results here on this site past sometime early last year. It was brought up last summer and never remedied. Not that I'm flummoxed by it. Just saying that many of the speakers I have reviewed have been the best or among the best in terms of preference score. In fact, the Kii Three has the highest score of all and it's not included. Whoever is in charge of the list just stopped updating it with my reviews at some point. So, just keep that in mind when looking at the master list on this site.

 

[sarumbear]

FWIW, they don't include my results here on this site.

I hope a solution will be found as I cannot see any reason why a master list cannot be maintained. It is not difficult to add a column to show who tested the speaker. Then we can make our own minds to trust the tester or not.

 

[Rick Sykora]

Yes, but while definitely improved, still pricey...

When you can get a number of nicely made speakers for a comparable spend, the Olive score is not likely to be the deciding factor on a purchase.
Pretty difficult to choose anymore when there is nowhere to go to hear them and shipping speakers around is expensive. Rough market to be in.

Good luck Alan!

 

[hardisj]

Yes, but while definitely improved, still pricey...

Someone commented there's not a whole lot of profit on this speaker.

That's true. I just totaled up the costs here in the USA. And even *at dealer price* from Madisound for the drivers alone, I don't see how Alan is making much profit off these. The PR, woofer and tweeter alone are about $2200 MSRP. And dealer pricing isn't a huge discount, either. .

So, yes, not cheap. But Alan isn't printing money off these, either. Especially after you account for the other stuff like crossover components and enclosure/materials. And as I mentioned, the enclosure is the most damn inert enclosure I've ever seen. The amount of things inside to treat resonances is far beyond anything else I have tested.

 

[pierre]

FWIW, they don't include my results here on this site past sometime early last year. It was brought up last summer and never remedied. Not that I'm flummoxed by it. Just saying that many of the speakers I have reviewed have been the best or among the best in terms of preference score. In fact, the Kii Three has the highest score of all and it's not included. Whoever is in charge of the list just stopped updating it with my reviews at some point. So, just keep that in mind when looking at the master list on this site.

I maintain a list with all known spinoramas (all of ASR and EAC plus others), click in https://pierreaubert.github.io/spinorama/scores.html
Filter on passive and sort by score. Also filter on high quality measurements if you only want klippel like measurements.

The March is at the top as good as the KEF R3 but with more bass. Remember that the score is meaningful +/-0.5 and doesn't take into account distorsion and SPL.