Erin's review for the March Audio Sointuva

[f1shb0n3]

It's a rare post that makes me wish for a unlike emotion. It's a pity March Audio can't post here. Surely he's served his sentence. He's not novac dickarich is he??

I want Alan back on ASR too - he did contribute a lot to the discussion and is obviously a top engineering talent given the track record of building SOTA amps and speakers. Hope Amir eventually reconsiders and Alan actually wants to come back to re-engage with the community.

 

[617]

I numbered them to make it a bit easier.

1) IME, the ones that tend to stand out as "bright" but are flat or rising on-axis are the ones with wide radiation. This is anecdotal, though. As with every sighted test there are surely biases that we don't even intend to have. (just as there are ones we intend to have; like someone's praise or disdain for a particular brand)

2) I think(?) I answered that above.

3) Good point. Poor writing. In my defense, ya'll are supposed to care about the data and the subjective is really just there for myself to remember later. But, yes, good point. I wouldn't say it got worse. I toed them out about 10-20° and the only difference I noticed is that the soundstage seemed to widen up. But this is exactly the case for wanting/needing blind testing. Something I can't do.

4) Big. I don't have the exact dimensions but I'd say about 20x25 feet in my living room with an open floor plan extending into the kitchen, hallway, dining room and entrance area. Typical furnishings. In my home theater room the dimensions are about 16x27 feet. I listen between 80-95dB in the MLP with my reviews. I forgot to include the levels and I didn't measure the "limits" at the time but it was sufficiently loud for my needs.

Just catching up on this review, looks like an unusual offering and a great, viable purifi based speaker.

Don't let keyboard warriors bother you too much, you've contributed more to this hobby than any mere commentator.

 

[jhaider]

Pig's ass.

When it is done in the public domain where people have already plunked down their money and got completely different cofigurations, sure, that's very unfortunate. Unwilling Beta testers.

Do you know your assumptions are accurate?

The tested speaker is a prototype. The website doesn’t even show the current drive units. Everything screams “work in progress” to me.

Toole (1986) wrote:

• "Listeners, it seems, like the sound of loudspeakers with a flat, smooth wide band on-axis amplitude response that is maintained
  at substantial angles off axis. If this is achieved, the loudspeakers will exhibit smooth (but not flat) sound power responses and directivity indices."
• "The on-axis response is very important, though not only for the obvious reason that it describes the first sound arrival at the listener's ears. In loudspeakers of domestic size, with low directivity indices, the axial response also conveys much of the basic pattern that is revealed in all other measurements of amplitude response."

The issue here may be that having an "atypical dispersion pattern" is not necessarily, in and of itself, of any particular benefit to the listener. It may just be adding to Olive's "circle of confusion", rather than reducing it.

I think there’s an assumption in the above that the design axis is on axis. IMO there’s little penalty for this kind of on axis rise when the speakers are designed to point straight ahead and the on axis rise only covers a small area. The extreme HF doesn’t really affect reflections (air absorption etc.) and the direct sound has the intended tonal balance. Bryston’s Mini A (my review with measurements here) has similar treble.

 

[Ilkless]

SB beryllium + WG is a very accomplished tweeter but doesn't capture the imagination like the previous Bliesma though the directivity match is better with the WG. Personal soft spot for inventive driver design by maverick designers manufacturing at small scale, particularly when they measure well enough to be competitive/provide a unique combination of attributes. Like the Bliesma: XO capability of a very beefy 1-incher or an average 1.5-inch tweeter, but wide directivity closer to a 0.75-inch tweeter. Can't help but think at those price levels a Bliesma + wideband smooth 3 or 4-inch midrange + Purifi on the low end would yield wide and smooth directivity. Even if the mid can't beat Purifi with HD, the IMD, headroom and directivity benefits should still be worth it.

 

[Newman]

I think there’s an assumption in the above that the design axis is on axis.

No, the assumption is that on-axis means the direct line from the speaker to the ear. This even applies to a true omni.

 

[jhaider]

No, the assumption is that on-axis means the direct line from the speaker to the ear. This even applies to a true omni.

The common meaning of “on axis” is normal to the baffle. Hence, toe-in means to rotate the speaker in such that the on axis sound is aimed at the ear, straight ahead means the listening axis is “off axis,” etc.

IMO of various imperfections a rising UHF over a narrowish angle, such that the speaker is flattish at the listening position when pointed straight ahead, is innocuous. One may even argue it supports image stability, because the reflected the axis sound will be dulled by pathlength and the near wall reflections are even more likely to mirror the direct sound (assuming vertical symmetry in the loudspeaker) than in a typical speaker with conventional drivers (ie not a heroic driver/phase plug/waveguide combination a la JBL 7-series or Sausalito).

 

[Holmz]

Dude, you've always been a positive person and I appreciate that.

I don’t suffer fool(s) too gracefully.
You only think I am positive because you past passed the test.

I know I keep going on and on about, but you are really doing great work. And it is very much appreciated.
Amir and others are also doing good work, but it is a pretty small group that you are in.

It reminds me of the ol Dragnet TV show line, “Just the facts ma’am.”

 

[phoenixdogfan]

That HF rise is minimal. This think is linear to ca. 8 khz.Than it goes very slow up. Whit that some dB peak at 15khz,Thats more a littel air raising. And imo very hard to hear.

For most audiophiles, impossible to hear (given we're all over 50).

 

[phoenixdogfan]

Some ASR members really don’t know how to read measurements without Armir’s commentary. Or they’re not paying attention and don’t really know what else is out there.

This 1/2 cu foot speaker IS state of the art.
It plays louder and cleaner and is smaller than others 1/2 cu foot speaker.

Is this audio science review or 7moons beauty contest?

Besides It comes in any colour you want.

Did you notice how Erin is comparing the dynamic levels to the JBL M2- with its 15”
Woofer, and is about the size of a small refrigerator ?

And the Kii Three with its FOUR 6.5” midwoofers and FOUR 400W amplifiers can’t keep up with a single Purifi?
(Clue: Look and compare distortion and dynamic range (instantaneous compression tests))

The Purifi 6.5TT-X is a !super! midwoofer.
And the Satori beryllium tweeter in waveguide is one of the best. Good old fashioned cabinetry and crossover work.

Show me any Genelec as small they can play as cleanly and as loudly.

In fact, Genelec need to get their orders in with Purifi for their next superspeaker. I’ll give it 24 months…

They're $3500 a pair, and I think they are indeed SOTA for a smaller speaker. And the ability to play that loudly, that cleanly, that deeply with that small an enclosure is indeed groundbreaking. Good to see someone has figured out how to design something worthy of that superb 6.5 inch Purifi midwoofer.

The obvious comparable is the ASR Directiva which also employs the Purifi driver but doesn't use a Beryllium tweeter, and costs around $1200-1400 to build DIY. It has a 6.6 preference score which goes up to 8.2 with perfect sub, and 8.5 with Pierre's EQ.

I really like the way this speaker measures. If it's being used in a music only system, I don't even think a subwoofer would be required.

Another great review by EAC.

 

[phoenixdogfan]

Also interesting how directivity width is the polar opposite of another high end bookshelf using a Beryllium tweeter--the Revel F126be. Would be interesting for someone to bring both in house and do a subjective listening comparison.

 

[Newman]

If it's being used in a music only system, I don't even think a subwoofer would be required.

No.

Too many people have some idea that music can be reproduced reference-quality without high quality, equalised bass to 20 Hz and 100+ dB.

It can't.

 

[kimmosto]

IMO of various imperfections a rising UHF over a narrowish angle, such that the speaker is flattish at the listening position when pointed straight ahead, is innocuous.

Yes. For example some compression drivers and ribbons/ATMs have extreme directivity and hump/rise at top octave, but it's not visible in LW and 15 deg off-axis anymore. Slope of sound power is clearly negative. In that case default/initial "design axis" is LW or ca. 15 deg off-axis and slope of LW is adjusted slightly negative up to 20k and user manual should instruct how much toe in/out is recommended.
This and many other requirements related to directivity have been known for 40+ years (at least in my neighborhood), but still people on forums refer Toole like the only God on earth who knows, and are lost if he has not specified/recommended something very clearly.

Anyway, also in this case on-axis can have small lift at UHF, but LW is better to be more linear at the end. Some dome tweeters have small diffuser for smoothing directivity at HF.

 

[sigbergaudio]

Speaker design is a number of compromises. Floyd and Toole Toole and Olive are obviously generally right that on-axis performance important, but there are a number of reasons a less than perfect on-axis performance is the right trade-off.

As mentioned by me and others, speakers may be specifically designed to NOT have toe-in. That means the actual listening axis is not on-axis, but typically 10-15 degrees off-axis. Then that is what should have a flat even response not on-axis. You may also have artifacts on-axis that evens out significantly (into an actual flat response) off-axis, that will end up being uneven off-axis if you correct the on-axis too much. So the combined response of 0-15-30 (at least) should be considered, and it's not necessarily a good thing if one axis is made perfect at the expense of others.

While the on-axis response is a strong indicator of a good speaker, you can't look at on-axis response in isolation and assume you know everything about the speaker.

Speaker design also can't be done by measurements alone. Overcorrected drivers doesn't necessarily sound right, so sometimes leaving good enough alone actually sounds better than paper perfect response.

With regards to "sounding bright", most speakers that sound bright has significant rise from 2-4khz. This speaker has hardly any rise before 8khz. The sound of moderately added level at 8khz and beyond sounds very different that the typical brightness or harshness, and is rarely offensive given a good driver with low distortion.

The measurement focus of ASR is great, but when suddenly the entire forum is a speaker design expert and can determine the quality of any speaker just by reading graphs they hardly understand, we're headed in the wrong direction (in my humble opinion).

 

[Newman]

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

 

[ernestcarl]

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

Probably he was just thinking of Toole and Olive....

 

[sigbergaudio]

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

Sorry, I was thinking of Toole and Olive.

 

[Rick Sykora]

Speaker design is a number of compromises. Floyd and Toole Toole and Olive are obviously generally right that on-axis performance important, but there are a number of reasons a less than perfect on-axis performance is the right trade-off.

As mentioned by me and others, speakers may be specifically designed to NOT have toe-in. That means the actual listening axis is not on-axis, but typically 10-15 degrees off-axis. Then that is what should have a flat even response not on-axis. You may also have artifacts on-axis that evens out significantly (into an actual flat response) off-axis, that will end up being uneven off-axis if you correct the on-axis too much. So the combined response of 0-15-30 (at least) should be considered, and it's not necessarily a good thing if one axis is made perfect at the expense of others.

While the on-axis response is a strong indicator of a good speaker, you can't look at on-axis response in isolation and assume you know everything about the speaker.

Speaker design also can't be done by measurements alone. Overcorrected drivers doesn't necessarily sound right, so sometimes leaving good enough alone actually sounds better than paper perfect response.

With regards to "sounding bright", most speakers that sound bright has significant rise from 2-4khz. This speaker has hardly any rise before 8khz. The sound of moderately added level at 8khz and beyond sounds very different that the typical brightness or harshness, and is rarely offensive given a good driver with low distortion.

The measurement focus of ASR is great, but when suddenly the entire forum is a speaker design expert and can determine the quality of any speaker just by reading graphs they hardly understand, we're headed in the wrong direction (in my humble opinion).

I agree, but it is not only folks thinking they can interpret the graphs (and am going a bit off topic here)...

Some of the problem starts with how the data is presented IMO. For instance, the usual 50 db range of the scale on a simple frequency response plot leads many to think the response is flatter than it really is. Here is on-axis Klippel data from a highly regarded active monitor (is quite flat shown using the standard range), shown at a 4 db range:

Does not look very flat now, does it? Harder to eyeball a trend line too. I can tell you if you fit a trend line to this data, it is neither flat or zero slope.

Some might argue that is raw data and too harsh a presentation. So, here is the same data with 1/3 smoothing:

Wonder how many would flock to buy this speaker now?

Not so pleasing to the eye any longer, but is a much more revealing presentation than the usual scaling. If we start by presenting the data with more of the true nature of its complexity, the technical consumer is forced to think more critically (or may realize that judging the speaker is not as simple as it was made to appear).

Maybe more useful scaling would be a simple start towards more objective analysis of speakers. There are certainly others, but suggest it deserves a thread of its own. So, I started one here: https://www.audiosciencereview.com/...r-more-meaningful-speaker-measurements.29768/

 

[BenB]

I agree, but it is not only folks thinking they can interpret the graphs (and am going a bit off topic here)...

Some of the problem starts with how the data is presented IMO. 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. Here is on-axis Klippel data from a highly regarded active monitor (is quite flat shown using the standard range), shown at a 4 db range:
View attachment 177749

Does not look very flat now, does it? Harder to eyeball a trend line too. I can tell you if you fit a trend line to this data, it is neither flat or zero slope.

Some might argue that is raw data and too harsh a presentation. So, here is the same data with 1/3 smoothing:

View attachment 177751

Wonder how many would flock to buy this speaker now?

Not so pleasing to the eye any longer, but is a much more revealing presentation than the usual scaling. If we start by presenting the data with more of the true nature of its complexity, the technical consumer is forced to think more critically (or may realize that judging the speaker is not as simple as it was made to appear).

Maybe more useful scaling would be a simple start towards more objective analysis of speakers. There are certainly others, but suggest it deserves a thread of its own. So, I started one here: https://www.audiosciencereview.com/...r-more-meaningful-speaker-measurements.29768/

I think we need to be realistic about the sensitivity of the human hearing system, as well as its ability to normalize out (and thus forgive / hide) some types of errors from us.

Here's an interesting and related listening test, that I hope Rick and others will consider participating in:

A Listening Challenge

Challenge: Listen to the linked mp3 from the beginning (no skipping around, and no visualizers) and post how long it took you to pick up on what was changing. Warning: it's full scale (loud) so start softly. Please put any discussion about the actual change in spoiler tags. I can't...

www.audiosciencereview.com

 

[kimmosto]

Speaker design also can't be done by measurements alone.

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.

The measurement focus of ASR is great, but when suddenly the entire forum is a speaker design expert and can determine the quality of any speaker just by reading graphs they hardly understand, we're headed in the wrong direction (in my humble opinion).

Focus seems to be widening - thanks to Erin, but it's still quite weighted to off-axis frequency responses. This is okay as long as people don't think that it's all what is adequate for others than true spinorama and preference rating -believers.
Acting as an expert and "previewing" products some other has designed and invested work time and money is modern/popular, fast, less risky and probably easier way to get noticed before the end. Designing, manufacturing and selling own products from scratch might be decades more challenging.

Sorry about off-topic.

 

[ahofer]

I want Alan back on ASR too - he did contribute a lot to the discussion and is obviously a top engineering talent given the track record of building SOTA amps and speakers. Hope Amir eventually reconsiders and Alan actually wants to come back to re-engage with the community.

You can add my strong endorsement to this (@amirm ). FWIW.