The REAL Problem of March Audio's Sointuva WG (Review, Measurements and Reinforcements with Klippel device)

[Ron Texas]

Sarcasm or praise for OP?

No sarcasm. The OP conducted a thorough investigation. March Audio should pay him for his recommendations.

 

[MAB]

Excellent work, @Nuyes ! Thank you for your thoroughness, for documenting it in such detail, and for improving the speaker for its owner. This is a fascinating set of posts.

That said, with this promoted to the front page, I would urge that Nuyes' posts be edited and cleaned up prior to that happening.

I understand and appreciate that English is not Nuyes' first language. But still, as Nuyes has themselves admitted, there's a lot of strong, editorial judgments embedded in these posts, and some of them are just as lacking in empirical support as March Audio's emailed responses.

This is one of the very few things that drives me a little nuts about ASR, whose culture I generally feel is head and shoulders above that of many other online audio communities. Why make editorial comments about the issues with this speaker beyond what the facts show? Why attribute motives to Alan of March Audio that are not supported by the text of his email responses? Alan's emails are polite, include many phrases like "let's keep discussing," include an apology and partial refund about the binding-post issue, and include report-backs of his consultations with Purifi. The fact that Alan might not be aware of all the issues, and the fact that what Purifi told him might not be accurate or might not account for all of what Nuyes found, does not mean that Alan is making "totally false" claims, lying, trying to avoid responsibility, or dismissing Nuyes' findings. We have no idea about that.

Some of the issues here are clearly problems, and they should be called out as they have been, and should be rectified. Others are areas for improvement, and while they should be called out as well and pursued, they are not necessarily problems per se.

Alan and Erin were both banned, but not for anything having to do with their technical claims, ability to run measurements, or ability to design, create, or review quality products - so the fact that they were banned is completely irrelevant, except for the reason @abdo123 initially mentioned it: they will not be able to respond here.

In that respect, this kind of garbage comment is precisely what I am concerned about:


This is ridiculous, and totally misleading as to why Alan was banned. And everyone who clicked Like on it should take a step back and think twice about that.

The facts of Nuyes' investigation speak for themselves. IMHO there's no need to muddy the waters by editorializing, and it similarly adds nothing for some folks in the thread to be waving their engineer d**ks around piling on, which any honest person will admit is something that is happening as part (not all, but part) of this discussion.

This is so well stated. I totally agree.

 

[NTK]

Why are the holes behind the binding posts so large anyway? Surely they only need to be just large enough for the cables? What am I missing?

My guess it is for the nut and washer (plus tool access) to hold the binding post in place.

Binding Posts - ETI Research

The ETI Research offers a range of Binding Posts suitable for all speaker/amplifier types.

eti-research.com

 

[Tangband]

This review shows up flaws that almost every loudspeaker have. You would be shocked also about the differences between the same driveunits from stock. This is why passive loudspeakers sucks, because you really need a dsp crossover tuned individually for every speaker to have perfect response regardless of the variations from different drivers.

A typical difference between L & R loudspeaker with passive crossover will differ more than +-2 dB in the most sensible area.
This affects the spatial image.

 

[AudioSceptic]

My guess it is for the nut and washer to hold the binding post in place.

Binding Posts - ETI Research

The ETI Research offers a range of Binding Posts suitable for all speaker/amplifier types.

eti-research.com

Edit: wouldn't you bolt the posts to the plate first, solder the cables outside the speaker, then screw the plate to the speaker?

 

[Ra1zel]

This review shows up flaws that almost every loudspeaker have.

1.2% distortion at 400hz at 86dB is definitely not something any sensible speaker has.

 

[NTK]

Aren't the fixing screws/bolts for the binding post plate at the corners, nowhere near the posts and cables?

Even if that is the case, the nuts will still be there to hold the binding posts to the plate, and there need to be clearance cutouts in the rear panel to fit the nut. Don't think in this case if smaller holes with counter-bores is any better than larger straight holes.

 

[Tangband]

1.2% distortion at 400hz at 86dB is definitely not something any sensible speaker has.

To little damping material inside the box - just like many Klipsch and JBL .
This is easily modified.

 

[Matias]

I mod a lot of vintage speakers and turn them into nice looking subwoofers so I’m interested in a sealant that is more or less reversible incase I decide in the future i want them to function as full range speakers again.

I always wondered if silicone sealant used in bathrooms would work for sealing speakers. And they don't glue very strongly, so easy to remove if needed. Would it work?

Example:

https://www.amazon.com/Loctite-Silicone-Waterproof-2-7-Ounce-908570/dp/B0002BBX3U/

 

[Tangband]

I always wondered if silicone used in bathrooms would work for sealing speakers. And they don't glue very strongly, so easy to remove if needed. Would it work?

Technical yes - But I would say its a very bad idea if you some day need a way to open up the boxes.
There is good sealing material to buy for loudspeakers.

 

[AudioSceptic]

Even if that is the case, the nuts will still be there to hold the binding posts to the plate, and there need to be clearance cutouts in the rear panel to fit the nut. Don't think in this case if smaller holes with counter-bores is any better than larger straight holes.

Edit: I've got out of sync. .

Yes, looks ugly though and requires extra work afterwards to fill the holes.

 

[ex audiophile]

[So far i remember,] there was no criticism of Erin's work.

Yes you're right, I think it was more a question of why he had left out (or had not done the testing) at a lower db level. I would still like to hear his comments.

 

[changer]

Alan’s response was measured, polite and customer friendly. I find his replies where professional and it to be concerning that some anonymous enthusiast generate general allegations from this.

What is clear however is that this comparatively cheap (!) high-end design has issues which I would attest to missing previous experience with such problems, their identification and solution.


This can happen in cases, even after a formal education, if a business or a product category is started for the first time. Others have pointed out this sort of flaws are frequent with many industry leading producers and many manufacturers accept them.

In this case however, small leakages can cause very loud noise when the air velocity is just too high and this must be solved where it occurs, and damping is essential.

This will help to improve a very good CEA 2034-A performing speaker.

 

[Laserjock]

Erin tested a different pair, correct?

The speaker here, looks like it was put together by someone that doesn’t understand audio..

 

[AudioSceptic]

Alan’s response was measured, polite and customer friendly. I find his replies where professional and it to be concerning that some anonymous enthusiast generate general allegations from this.

What is clear however is that this comparatively cheap (!) high-end design has issues which I would attest to missing previous experience with such problems, their identification and solution.


This can happen in cases, even after a formal education, if a business or a product category is started for the first time. Others have pointed out this sort of flaws are frequent with many industry leading producers and many manufacturers accept them.

In this case however, small leakages can cause very loud noise when the air velocity is just too high and this must be solved where it occurs, and damping is essential.

This will help to improve a very good CEA 2034-A performing speaker.

The price seems to be around $4k/pair. I'd expect excellent build and QC for that.

 

[FrantzM]

Hi

I believe this is an opportunity for March Audio to work on their QC issues. This kind of analysis takes time and objectivity. It may difficult to conduct such thorough forensics in-house. Resources are scarce, time always being shared between being a designer, an owner, a marketer, a PR person and family or friends or spouse or partners .. or life ... Or the fact that you have worked over it a thousands time and would not notice what is , literally, staring at you...
Same for Erin, albeit on a different plane. I would have preferred that he not be banished, rather an off-forum honest discussion about whatever issues he and Amir may have and clean them out. I would suppose their goals to have several points of agreements...
I have no horse in that race... This said Congratulations to @Nuyes : 원본 포스터 축하합니다
Superb methodology and well documented.

 

[chris719]

Don't be sad. Answer the question of what OP asked: why Erin's measurements didn't include 86 dBSPL where problems were seen.

Fair, but that's not really related to the question I answered, though. I also prefer not to prematurely jump to conclusions of a conspiracy.

 

[TOR]

Yes you're right, I think it was more a question of why he had left out (or had not done the testing) at a lower db level. I would still like to hear his comments.

Just speculation. Would it be he got so many orders that he start sub-contract some of these out to be made??

I've seen these happened in our industries. Not audio related obviously.

For us, we put in penalty clause to prevent mistakes from happening and recuperate losses due to non-conformances issues.

 

[AudioSceptic]

Erin tested a different pair, correct?

The speaker here, looks like it was put together by someone that doesn’t understand audio..

Or basic ideas of build quality.

 

[Cars-N-Cans]

Looks like something, a liberal application of hot glue, would fix during construction... That is if disassembly was a something one wanted to give up. Perhaps theres a "rubber cement" type application of hot glue?

Ideally it really needs to be solved at the design level. They need to come up with foam gaskets to install around the drivers (as other speakers do) and make the binding posts one sealed assembly that can be installed into a routered hole with a gasket as well. The tweeter probably should also be positively located and sealed or cemented into the waveguide to make it one assembly as well before installation. Even midrange speakers from Best Buy tend to have these features as a matter of course. I’m surprised they did not include these here.