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Emotiva Airmotiv B1+ Review (Bookshelf Speaker)

sarumbear

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They care - for their profit...
I disagree that it is to do with profit.

Why we keep seeing very large companies listening to @amirm and making alterations to improve their products? Besides, re-positioning a port for a few centimetres will make zilch difference to their profits. When you sell a million units even a larger mechanical change will not alter the bottom line.

Greed is certainly a big motive but when it comes to speaker manufacturers lack of care or lack of knowledge are more often the reasons.
 
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ROOSKIE

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This is even more interesting, considering that probably every major manufacturer today uses advanced software for their designs and manufacturing. It's IMHO reasonable to expect that such software would warn of basic mistakes, and the design must pass an internal audit as well as prototyping before going into production. So It must be on purpose, especially from manufacturers who "knew earlier how to do it better". The question is, why, because a flawed design isn't necessarily much cheaper to manufacture than a good one (at least in aspects as port form and placement). The only reasonable answer I can think of: the "pennies" which it will make it cheaper are of more value for them than good design = plain old greed, oh sorry, today it's called "profit maximization". :rolleyes:

A similar question, why, in this day and age, there are relatively few non-ported designs combined with a matching sub. There were some in the 80s, and strangely died out... Maybe because 2.1 seemed more expensive to the customer than 2.0 and marketing told him 2.0 is as good?
The speaker is $229 a pair.
 

PeteL

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I disagree that it is to do with profit.

Why we keep seeing very large companies listening to @amirm and making alterations to improve their products? Besides, re-positioning a port for a few centimetres will not make a zilch difference to their profits. When you sell a million units even a larger mechanical change will not alter the bottom line.

Greed is certainly a big motive but when it comes to speaker manufacturers lack of care or lack of knowledge are more often the reasons.
Nobody sells a million units in HiFi. Nobody.
 

Bear123

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Yes because the high pass is only cutting frequency responce around and below the HP frequency.
The driver is still playing 1000hz notes just as loudly.
The resonance is similar to a room mode. The speaker box is a tiny room and accentuates/reinforces certains frequency content.
3/4/5 way speakers or subwoofers where the resonance of the box is above the low pass cutt off for the ported bass unit will not have the same issues. This is a good reason for 3 ways. Although one can still have issues if the port resonances are low like 300/400hz and the woofer is still playing there. Especially as box stuffing/lining will not help with 300hz notes.
Thanks, I thought perhaps the resonance at 900 Hz, if being caused by the port, was due to harmonics created from output at port tune or something of that nature. In which case, I wondered if reducing port output would reduce this resonance. So, are we saying that even if this speaker has zero output at the port around tune with a steep filter, the 900 Hz resonance caused by the port would be unchanged, as it is caused by the 900 Hz frequencies being produced?
 

sarumbear

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Nobody sells a million units in HiFi. Nobody.
Maybe you need to read more. B&W sold more than a million units of the 600 series. Different models.
 

Bear123

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They care - for their profit... Only a DIYer or small newcomer may not know IMHO.
They are making billions, perhaps trillions at $249/pair. No reason to keep cost down anywhere in the design when selling for such a ludicrously high price. No holds barred, cost no object design should be included at this price point.

Just kidding obviously, but the resonance at 900 Hz seems relatively minor, although certainly not perfect.

I'm not a speaker designer so don't know the answer, but someone mentioned that this resonance could have been avoided at essentially no cost. Since it is apparent that a lot of good engineering went into this design, especially at this very low price point, I wonder if the solution is truly that simple, or if it was an acceptable minor flaw in order to save a few $.
 

PeteL

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Maybe you need to read more. B&W sold more than a million units of the 600 series. Different models.
OK, that's exceptional, over different models, over 5 decades, that's not really what we where discussing...
edit, 3 decades of 600
 
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respice finem

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...Greed is certainly a big motive but when it comes to speaker manufacturers lack of care or lack of knowledge are more often the reasons.
Then, looking at the "big players", this is even more sad. Certainly, you can't expect perfection on the cheap, but due diligence, yes. Maybe (again, the "big players", which Emotiva isn't) want to keep their more expensive offerings more exclusive, by deliberately "limiting" the cheaper ones? IDK...
Anyway, it's more than strange for me that knowledge from 30 and more years ago isn't "available" now.
 

ROOSKIE

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Thanks, I thought perhaps the resonance at 900 Hz, if being caused by the port, was due to harmonics created from output at port tune or something of that nature. In which case, I wondered if reducing port output would reduce this resonance. So, are we saying that even if this speaker has zero output at the port around tune with a steep filter, the 900 Hz resonance caused by the port would be unchanged, as it is caused by the 900 Hz frequencies being produced?
Yes, it will still have the same responce at 900hz. The driver is still playing 900hz at the same level.

Think about it this way.The 9th harmonic of 100hz is 900hz. You would need massive 9th order HA distortion at 100hz to genetate that level of gain/influence at 900hz.

Or think about it this way. The frequency is measured for a typical frequency responce using a sweep. So at 900hz only 900hz is playing when measured.

Anyway this very common issue in ported design that is not appropriately dealt with in many speakers in many price points, may be part of the reason some prefer a rear ported unit to pulled well away from the wall and why they will say "it cleared things up a bit" ... pulled away, the reflections from the rear port off the wall are more delayed (brain may subtract them "better")and likely slightly more diffused.
 

sarumbear

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I'm not a speaker designer so don't know the answer, but someone mentioned that this resonance could have been avoided at essentially no cost. Since it is apparent that a lot of good engineering went into this design, especially at this very low price point, I wonder if the solution is truly that simple, or if it was an acceptable minor flaw in order to save a few $.

The port resonance issue exists across a broad range of speakers with equally broad price range. It defines an industry failing to care.

An analogy would be the lack of any aerodynamic consideration on the cars manufactured during the last decades of the 20th century. Since the 1973 petrol crisis car manufacturers knew fuel efficiency is a selling point. As a car moves through the air, the friction of the air reduces fuel efficiency. Any engineer can see that the aerodynamics of the car's body shape will make a difference. Why have the car manufacturers had not altered their car's shape to make them more aerodynamic for decades? Even a small rear wing would have increased the fuel consumption of a car up to 15%. As they do regularly manufacture millions of cars the benefits to the nation would be immense. They didn't because they are crap engineers!

Like car manufacturers, speaker manufacturers generally are not good engineers.

If you are not a speaker designer what was it "apparent" to you "that a lot of good engineering went into this design"? I am a retired electro-acoustics engineer. I see bad engineering and @amirm confirms this with his measurements?
 

Bear123

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If you are not a speaker designer what was it "apparent" to you "that a lot of good engineering went into this design"? I am a retired electro-acoustics engineer. I see bad engineering and @amirm confirms this with his measurements?
I'm basing this on the fact that, for $229/pair, Emotiva has offered a speaker with excellent measured performance in terms of on axis, off axis, directivity, and even distortion performance. No way this happens by accident. To me, it is apparent that Emotiva very obviously set out to create an objectively very good speaker at minimal cost. Just seems like a pretty safe and logical assumption. Do you disagree?

Hopefully, a well informed buyer can recognize well designed speakers based on measured performance without actually being a professional speaker designer! :):):)

As far as the port resonance, perhaps they are aware of the issue, but the software and engineering expertise, along with tooling cost etc for a custom designed port would not have fit into the budget price point of this speaker, vs using an existing low cost port option? They aren't selling tens of thousands of these so maybe an expertly designed port and all the cost associated with it was not feasible?
 
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sarumbear

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Maybe (again, the "big players", which Emotiva isn't) want to keep their more expensive offerings more exclusive, by deliberately "limiting" the cheaper ones?

The business plan of most big players is to build the 'ultimate' speaker with a cost no object approach, sell a few but market lower end models using the light of that ultimate model. B&W has the perfect example; Nautilus & D800 series that cost five figures carry the 600 series that cost three figures but sold million units. 600 series certainly was not deliberately limited to sell more D800 series.
 

sarumbear

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I'm basing this on the fact that, for $229/pair, Emotiva has offered a speaker with excellent measured performance in terms of on axis, off axis, directivity, and even distortion performance. No way this happens by accident. To me, it is apparent that Emotiva very obviously set out to create an objectively very good speaker at minimal cost. Just seems like a pretty safe and logical assumption. Do you disagree?

I agree on your assumption but disagree that it is not apparent that good engineering went into this design. Internet is full of calculators that gives you the dimensions for a box to place two units and a port. Doing that is not designing. It is the start of a design. It is perfectly possible that the drive units are of good quality for the price, hence it sounds OK for the price. That is also not design, it is procuring!

Hopefully, a well informed buyer can recognize well designed speakers based on measured performance without actually being a professional speaker designer! :):):)

I hope so. They shouldn't buy this speaker though as it's measurements show a bad port resonance peak! :)
 

napilopez

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If you are not a speaker designer what was it "apparent" to you "that a lot of good engineering went into this design"? I am a retired electro-acoustics engineer. I see bad engineering and @amirm confirms this with his measurements?


I agree on your assumption but disagree that it is not apparent that good engineering went into this design. Internet is full of calculators that gives you the dimensions for a box to place two units and a port. Doing that is not designing. It is the start of a design. It is perfectly possible that the drive units are of good quality for the price, hence it sounds OK for the price. That is also not design, it is procuring!

But we've seen so many good drive units in speakers with bad directivity and bad on-axis!

I think it's just a bit of a not seeing a forest for the tree type of thing. Not saying this couldn't be improved, but in the case of this specific speaker, it is among the best we have seen for the price. We've also seen speakers that are more expensive and have a controlled port resonance that don't measure as well in other metrics.

Perhaps you're right that it could've and should've been avoided, but given Emotiva seems to consistently make good designs for the price, I wouldn't immediately assume it's such a simple fix.

Moreover, I'm also not convinced it's just the port resonance causing the broad bump around 1kHz as the resonance itself seems rather narrow, and it looks like it might take a some additional crossover tweaks to really flatten out the response. The broad 1khz bump is very common and it's not usually just because of the port.
 
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I had to laugh when I saw, 'the product is presently shown as Unavailable on the Emotiva website'. I think Emotiva is respected as a budget hifi direct seller, but their website often has multiple products shown as 'Unavailable'. They also have a habit of introducing new pieces in their product lines and cancelling items after short production cycles. This is probably a consequence of supply and demand but I've never bought an Emotiva product because I was never sure it wouldn't be replaced by something newer and better relatively quickly.
 

cursive

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When port resonance is mentioned are we talking about the port plastic itself physically resonating (vibrating) and causing additional output at 1000hz, or am I totally misunderstanding?
 

sarumbear

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I think it's just a bit of a not seeing a forest for the tree type of thing. Not saying this couldn't be improved, but in the case of this specific speaker, it is among the best we have seen for the price.
You are spot on!

However think of it this way; when a forest is infected with some disease you start investigations with the healthiest tree, the one that looks (measures) the best. Hence, I am posting this issue on this particular speaker, which "is among the best we have seen for the price".

Moreover, I'm also not convinced it's just the port resonance causing the broad bump around 1kHz as the resonance itself seems rather narrow, and it looks like it might take a some additional crossover tweaks to really flatten out the response. The broad 1khz bump is very common and it's not usually just because of the port.

The port resonance matches the peaks in the combined frequency response pretty well. The reason the bump in that range is common is because the speaker boxes are within the same size range creating the port resonance in the same frequency range.


Emotiva Airmotiv B1+ frequency response measurements.png



Emotiva Airmotiv B1+ driver frequency response measurements.png
 
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