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andreasmaaan

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I am not against measurements per se. Just trying to make the same argument as @amirm when he says standards are too inflexble, hindering innovation etc. ;)

The difference between @amirm and me being that I used argued against conventional measurements if one faces real innovation, (which is rare!), while @amirm believes he needs the slack and absence of standards every time he makes measurements of commodity gear.

Which particular speaker measurements do you believe are given too much weight and/or tend to inhibit innovation?
 

svart-hvitt

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Which particular speaker measurements do you believe are given too much weight and/or tend to inhibit innovation?

I was thinking of the debate of Genelec 8350 vs 8351, that leaves the question: Which measurement(s) should one use to evaluate the (perceived) qualities of the two speakers?

PS: And one more thing. If a successful point source has less summation of driver problems, how should one weight this quality in conventional measurements? How important is this characteristic?
 
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andreasmaaan

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I was thinking of the debate of Genelec 8350 vs 8351. Which leaves the question: Which measurement(s) should one use to evaluate the (perceived) qualities of the two speakers?

PS: And one more thing. If a successful point source has less summation of driver problems, how should one weight this quality in conventional measurements? How important is this characteristic?

In terms of ranking the 8530 and the 8531, I don’t think it can be done in absolute terms. It depends too much on the intended purpose of the end user.

The 8531 will perform better placed on or near a desk/console in a small room, because reflections off the desk/console will be less disruptive than the 8530. But the 8530 will perform better if asked to play at higher SPLs and if downward reflections are adequately dealt with. That’s an oversimplification ofc, but you see how one might choose between the two depending on the intended purpose.

I still fail to see how the measurements are inhibiting innovation here btw ;)
 

svart-hvitt

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In terms of ranking the 8530 and the 8531, I don’t think it can be done in absolute terms. It depends too much on the intended purpose of the end user.

The 8531 will perform better placed on or near a desk/console in a small room, because reflections off the desk/console will be less disruptive than the 8530. But the 8530 will perform better if asked to play at higher SPLs and if downward reflections are adequately dealt with. That’s an oversimplification ofc, but you see how one might choose between the two depending on the intended purpose.

I still fail to see how the measurements are inhibiting innovation here btw ;)

If the mentioned measurements were decisive, one wouldn’t have gone ahead with the coaxials.

«Let’s maximize the measurements of the sail boat» was not a viable strategy, which by the way led to the ruin of many Norwegian shipowners at the time when motorized ships were entering the seas.
 

andreasmaaan

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If the mentioned measurements were decisive, one wouldn’t have gone ahead with the coaxials.

«Let’s maximize the measurements of the sail boat» was not a viable strategy, which by the way led to the ruin of many Norwegian shipowners at the time when motorized ships were entering the seas.

Yes ok, but I don't think most professional speaker designers would necessarily agree with that random forum member that those particular measurements were necessarily decisive.

Arguments could be made both ways as to whether the vertical polar response or the higher max SPL / lower distortion were of more importance. Ultimately the choice depends on the intended use of the speaker, and a good designer would use the research (or do their own if they work somewhere as well-resourced as Genelec) to determine the best design.

I see this 8531 as a speaker very much designed to be used in small studios in which it won't need to produce high SPLs and in which there is no choice but to place it close to a desk or console. That seems to be what it's optimised for, and for that purpose its design makes a lot of sense.
 

maverickronin

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I like to use «rabbit hole» in a positive light. To me rabbit hole means being explorative, adventurous, risk-seeking in a good way. For some reason or another, I have the impression that native English speaking people think of rabbit hole as something negative; waste of time and resources. That’s a sad interpretation of rabbit hole, I think.

You must have a unique interpretation of Alice in Wonderland... ;)
 

Cosmik

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I still fail to see how the measurements are inhibiting innovation here btw ;)
I think it's a bit like Economic Science.

Measurements are (hopefully) objective 'facts', but they are not the complete story. A measurement (such as CPI or GDP) can be an indicator of something going on in the economy. But a fundamental error is made when people begin to use the measurement as the driver of their economic policies.

GDP does not measure economic output, rather it measures spending. And the spending can be derived from the borrowing of money. So debt-to-GDP ratio is almost meaningless. If you use this as an indication of the health of your economy, you will eventually come a cropper. Even if you use 'the scientific method' you will still come a cropper because your understanding is faulty.

CPI is a proxy for inflation, but cannot distinguish between real economic inflation and the influence of world events that control global prices. The 'scientific method' will not help you, because observing the economy does not give you an understanding of the economy.

Similarly, measurements tell us something about speakers, but not everything. Maximising a particular measurement - one that assumes that music is composed of repeating waveforms, for example, may be a blind alley that stifles real understanding and progress. It results in the ugly, tortured speakers that many manufacturers produce.

Speakers with the same (incomplete) measurements can, and do, sound different - and would measure differently if anyone was motivated to do it thoroughly. But they don't, because
  1. They think music is composed of steady state sine waves so their measurements are complete
  2. They use measurement as a target, not an indicator. If the speaker meets the target, there is no point in measuring it further.
  3. It would be very laborious.
All of this could be bypassed by simply looking at the design and predicting what it will do in the round. But instead, a target-driven speaker designer must always use bass reflex in order to optimise a couple of specific measurements, even if it results in inevitable hidden horrors.
 

andreasmaaan

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Similarly, measurements tell us something about speakers, but not everything.

Ofc no single measurements tells us everything, but thorough measurements do tell us everything we need to know.

1. They think music is composed of steady state sine waves so their measurements are complete

What non-steady state measurements do you suggest should be taken?

But instead, a target-driven speaker designer must always use bass reflex in order to optimise a couple of specific measurements, even if it results in inevitable hidden horrors.

Gonna let this one through to the keeper ;)
 

Cosmik

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I think it is becoming clear that we have two approaches to speaker design:
  1. science & measurements-based
  2. ideas-based
Contrary to what you would expect, (1) is not cutting-edge, pushing forwards the technology, but is passive (in the normal sense of the word), retrospective, and maintaining of the status quo.

It works like this:

1. is based on existing science, and measurements or observations of existing speakers. It is all about 'mitigation'; "What can we get away with.". And science can help to inform us about what we can get away with.

The science shows that ... (NO! We will not use that phrase. "Science tends to suggest that..." is much better) ... humans can't resolve frequency response differences less than X dB, so we will use this as our target.

Science tends to suggest that humans can't resolve phase differences in many circumstances, so phase will not enter our consideration at all; we have a free hand to use whatever filters we like and will only measure frequency response magnitudes. Passive filters will be fine, here. Active crossovers do not appear to be any different in terms of these measurements.

Being hard-nosed measurements-driven people we would like to see the widest, flattest frequency response. Bass reflex extends the flatness of the bass further. In terms of the measurements (and therefore the sound) this is a free lunch. Result!

We have a science-based bonus: science tends to suggest that people like their music distorted, so we don't need to worry too much about distortion. If the tweeter is stretched over a wider frequency range, or we go two-way and subject the drivers to higher displacements than they would otherwise have in a three-way, it's no biggy. It might even sound better.

Science tends to suggest that people prefer a drooping in-room frequency response, so as long as we can show that our box gives an in-room response that gets close to a plausible target, we have achieved our objectives. If we play with the crossovers and 'voice' the speaker (a suck-out here, a phase inversion there), a fashionable narrow-fronted box can do this, so we will use that.

2. The ideas-based approach is different.

It ignores the science. It starts from the idea that the perfect speaker simply reproduces the signal accurately in all respects. There is no attempt to 'get away with' anything; there is no assumption that it will duplicate an existing speaker. Scientific literature is not consulted. It is not a passive, retrospective exercise.

What is needed in order to duplicate the signal? It includes:
  • linear phase crossovers with additional driver phase correction
  • Time alignment between drivers
  • Sealed drivers
  • Active amplification
  • More than two ways - to keep drivers in their 'sweet spots' and to maintain better dispersion with frequency
  • Steps to improve the dispersion characteristics with active means.
  • Steps to actively improve distortion.
Basically, make the speaker cones move in the way we want them to move.

No scientific literature is consulted. Measurements are merely confirmation, not the driver of the design. The speaker is not 'voiced'. The idea is not to see what can be got away with in the individual parameters, but simply to work logically towards the overall result of duplicating the signal. Implicitly, the speaker's in-room response is a result of what you get with such a speaker, not a target.

It could be argued that the (2) approach is wrong because most music will have been mixed for (1) speakers. Maybe people have learned the sound of (1) and so are attached to it. These are reasons why the science based on listening tests is as it is. But it is also a reason why the (2) approach is exciting: hearing music recordings as they have never been heard before, as fresh as if you were in the studio or at the venue.
 
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andreasmaaan

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1. is based on existing science, and measurements or observations of existing speakers. It is all about 'mitigation'; "What can we get away with.". And science can help to inform us about what we can get away with.

Yes, at its worst. But at its best, speaker design is not about using science to see what can "got away with", but rather, using it to make decisions about the inevitable trade-offs involved and how to optimise these in a way that will result in the most transparent and subjectively superior sound quality.

Science tends to suggest that humans can't resolve phase differences in many circumstances, so phase will not enter our consideration at all; we have a free hand to use whatever filters we like and will only measure frequency response magnitudes.

This is not true. Research has attempted to determine phase audibility thresholds, just as it has attempted to determine audibility thresholds in other areas of audio. People say these phase audibility thresholds are "high". High compared to what? As in all areas of audio, there are things humans can hear and things they can't. Audibility thresholds for phase have been studied in the same way audibility thresholds for anything else have been studied. I wouldn't bother designing a speaker that extends in frequency response to 100KHz, and I wouldn't bother designing a speaker with linear phase (unless in each case there were no additional cost or trade-off involved).

Being hard-nosed measurements-driven people we would like to see the widest, flattest frequency response. Bass reflex extends the flatness of the bass further. In terms of the measurements (and therefore the sound) this is a free lunch. Result!

Nobody who knows what they're doing thinks bass reflex is a free lunch. Rather, it is superior in many applications, especially when we are talking about value for money.

We have a science-based bonus: science tends to suggest that people like their music distorted, so we don't need to worry too much about distortion.

Your own speakers use direct-radiating dome tweeters and inexpensive A/B amplifiers, don't they? Aren't you making this very same calculation yourself?

Steps to improve the dispersion characteristics with active means.

The application of this idea to home audio came directly from studies of listener preference. This consideration falls into category 1, not category 2.

No scientific literature is consulted.

Perhaps no scientific literature is directly consulted. But the fact is that there's mountains of scientific research behind every aspect of speaker design, right down to the basic original principle that the human range of hearing is approximately 20Hz-20KHz.

Designers might be able to feel like they don't need to consult the literature because the profession has internalised so much of it to such an extent, but scientific research underpins everything, and denying that is disingenuous IMHO.
 
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Cosmik

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...especially when we are talking about value for money.
I am exclusively not talking about budget speakers. But implicit in the idea of value for money is that the more you spend, the better the result. I think there is a limit beyond which you get nothing more, and in many cases speakers built with diamond drivers etc. are attempting to mitigate against the speaker's other fundamental flaws e.g. passive crossovers, two-way etc. The Putzeys of this world just don't even think on those lines.
Your own speakers use direct-radiating dome tweeters and inexpensive A/B amplifiers, don't they? Aren't you making this very same calculation yourself?
My speakers are three-way, and I can choose whatever crossover characteristics I require. The drivers are in their 'sweet spots'. The amplifiers have a very easy job to do. It is almost like software: no advantage is accrued by running the software on a PC made of gold and diamond, and no advantage is accrued by using Krells or whatever if the demands on the amp are so benign. I don't think it even warrants the word 'calculation'.
The application of this idea to home audio came directly from studies of listener preference.
I can point to a magazine article from 1952 that talks about the desirability of uniform dispersion, and a KEF paper from the 1970s (about their 105 as it happens). It is an idea that science was used retrospectively to confirm - but why would anyone have thought differently if they had been given the task of designing speakers from the ground up?

Perhaps no scientific literature is directly consulted. But the fact is that there's mountains of scientific research behind every aspect of speaker design, right down to the basic original principle that the human range of hearing is approximately 20Hz-20KHz.

Designers might be able to feel like they don't need to consult the literature because the profession has internalised so much of it to such an extent, but scientific research underpins everything, and denying that is disingenuous IMHO.
I'm not denying science per se. Just the twisted, tortured, audiophile version of it. Identifying fundamental physiological characteristics in the biological hardware is completely different from asking people how they feel about music played over a 'legacy' audio system - from which they extrapolate their 'excuses' for the building of new legacy audio systems.
 

andreasmaaan

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I think there is a limit beyond which you get nothing more

I agree :) But just one post ago you were bemoaning the "good enough" attitude.

My speakers are three-way, and I can choose whatever crossover characteristics I require. The drivers are in their 'sweet spots'. The amplifiers have a very easy job to do. It is almost like software: no advantage is accrued by running the software on a PC made of gold and diamond, and no advantage is accrued by using Krells or whatever if the demands on the amp are so benign. I don't think it even warrants the word 'calculation'.

Yes, and your speakers are extremely well-designed! But you must be aware that the tweeters are likely generating audible distortion at moderate levels, and that further steps could be taken to mitigate this.

Meanwhile, you've gone to great lengths to mitigate a "problem" which has never been shown to be audible (i.e. the small degree of phase distortion caused by conventional crossover filters).

(Please don't be offended by this. I am very impressed from an engineering perspective by what you've done on this front :) )

I can point to a magazine article from 1952 that talks about the desirability of uniform dispersion, and a KEF paper from the 1970s (about their 105 as it happens).

Would be interested to read these - do you have a link please?

I'm not denying science per se. Just the twisted, tortured, audiophile version of it. Identifying fundamental physiological characteristics in the biological hardware is completely different from asking people how they feel about music played over a 'legacy' audio system - from which they extrapolate their 'excuses' for the building of new legacy audio systems.

I agree, but if you're implying that the majority of research falls into this category, then I believe you're wrong.

EDIT: re: your linear phase design, I'm not just impressed from an engineering perspective; I also acknowledge that in your case, in which cost, low latency, and mass-manufacture are not considerations, there is very little trade-off involved.
 
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Cosmik

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Cosmik

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I agree :) But just one post ago you were bemoaning the "good enough" attitude.
But again, the implication is that more money spent = better. In the audiophile world, this does't necessarily hold. In fact, the titanium drivers, etc. may be worse in terms of having to control resonances and so on. Expensive amplifiers may actually perform worse because of their 'musicality', particularly in the application of an active crossover system. I don't see that I am compromising at all; I might even choose the hardware I have used even if I had loads of money to spend! (I'm not denying that there is some satisfaction in using cheap hardware, however, even if I don't need to. I am a Yorkshireman, after all :)).
 

andreasmaaan

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But again, the implication is that more money spent = better. In the audiophile world, this does't necessarily hold. In fact, the titanium drivers, etc. may be worse in terms of having to control resonances and so on. Expensive amplifiers may actually perform worse because of their 'musicality', particularly in the application of an active crossover system. I don't see that I am compromising at all; I might even choose the hardware I have used even if I had loads of money to spend! (I'm not denying that there is some satisfaction in using cheap hardware, however, even if I don't need to. I am a Yorkshireman, after all :)).

Haha no argument with me on this point.


Thanks :)
 
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