https://standards.iteh.ai/catalog/s...-415b-46ce-bfd2-16f390c03fc4/iec-60268-5-2003
20 Sound pressure under free-field and half-space free-field conditions .............................. 21
20.1 Sound pressure in a stated frequency band ........................................................... 21
20.2 Sound pressure level in a stated frequency band – characteristic to be specified ....................................................................................................... 22
20.3 Characteristic sensitivity in a stated frequency band ............................................. 22
20.4 Characteristic sensitivity level in a stated frequency band – characteristic to be specified ....................................................................................................... 22
20.5 Mean sound pressure in a stated frequency band .................................................. 22
20.6 Mean sound pressure level in a stated frequency band – characteristic to be specified.......... 23
21 Response under free-field and half-space free-field conditions ....................................... 23
21.1 Frequency response .............................................................................................. 23
21.2 Effective frequency range ...................................................................................... 24
21.3 Transfer function ................................................................................................... 24
22 Output power (acoustic power) ....................................................................................... 25
22.1 Acoustic power in a frequency band ...................................................................... 25
22.2 Mean acoustic power in a frequency band ............................................................. 26
22.3 Efficiency in a frequency band ............................................................................... 27
22.4 Mean efficiency in a frequency band...................................................................... 27
20 Sound pressure under free-field and half-space free-field conditions .............................. 21
20.1 Sound pressure in a stated frequency band ........................................................... 21
20.2 Sound pressure level in a stated frequency band – characteristic to be specified ....................................................................................................... 22
20.3 Characteristic sensitivity in a stated frequency band ............................................. 22
20.4 Characteristic sensitivity level in a stated frequency band – characteristic to be specified ....................................................................................................... 22
20.5 Mean sound pressure in a stated frequency band .................................................. 22
20.6 Mean sound pressure level in a stated frequency band – characteristic to be specified.......... 23
21 Response under free-field and half-space free-field conditions ....................................... 23
21.1 Frequency response .............................................................................................. 23
21.2 Effective frequency range ...................................................................................... 24
21.3 Transfer function ................................................................................................... 24
22 Output power (acoustic power) ....................................................................................... 25
22.1 Acoustic power in a frequency band ...................................................................... 25
22.2 Mean acoustic power in a frequency band ............................................................. 26
22.3 Efficiency in a frequency band ............................................................................... 27
22.4 Mean efficiency in a frequency band...................................................................... 27
Behind this seemingly self-evident remark hides a world of physical phenomena spread across different domains.
Listened to these for a short while:
Some time ago, Krivium made apt comments about ATC, based on his experience.
Let me put it this way: there are reasons why people like Mark Knopfler exclusively use ATC in their studios.
My biggest complaint is their low efficiency which (almost literally) seems to suck the 'life' out of the music.
Which is better/preferable, apart from 5 dB higher sensitivity of the 2nd?
Depends mainly on the objectives/application, I think.
Depends mainly on the objectives/application, I think.
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It has been many years since I heard a ATC speaker. There was nothing lifeless about it when I listened. It also sounded flat.
I wonder if the word lifelessness is often misapplied to speakers which have a flat frequency response.
The best speaker is one I can forget I'm listening to. Efficiency serves the sound; nothing more.
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Even if it's a somewhat apples to oranges comparison, here the effects of material/motor/design-inherent damping characteristics vs the intendend passband are visible, giving a glimpse of (true) energy storage that leads to low(er) efficiency, albeit good looking plots.
What (exactly) is lost/remains in the subsystems?
This multifaceted phenomenon cannot be fully qualified, quantified and measured, even though 90% of ASR members probably think otherwise.
At some level, subsystems will most likely start to exhibit Malkus-Lorenz waterwheel dynamics.
As Jeff Bagby's review shows, the ATC 75-150S is a different beast compared to the regular non-S version. However, I would never combine a dome mid with an ribbon tweeter, not even a RAAL 70-20XR, because of the completely different material and radiation characteristics.
The problem is that ATC's own SH25-76S dome tweeter is much less sensitive, requiring the midrange to be attenuated, which is not only a waste of efficiency but downright undesirable.
That said, there are plenty of examples of very good midrange domes used in highly rated systems.
Some useful comments in this thread.
What (exactly) is lost/remains in the subsystems?
This multifaceted phenomenon cannot be fully qualified, quantified and measured, even though 90% of ASR members probably think otherwise.
At some level, subsystems will most likely start to exhibit Malkus-Lorenz waterwheel dynamics.
As Jeff Bagby's review shows, the ATC 75-150S is a different beast compared to the regular non-S version. However, I would never combine a dome mid with an ribbon tweeter, not even a RAAL 70-20XR, because of the completely different material and radiation characteristics.
The problem is that ATC's own SH25-76S dome tweeter is much less sensitive, requiring the midrange to be attenuated, which is not only a waste of efficiency but downright undesirable.
That said, there are plenty of examples of very good midrange domes used in highly rated systems.
Some useful comments in this thread.
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"Lifeless" in the sense of limited dynamics > and highly dependent on the amplifiers used (one aspect related to efficiency).
And indeed: flat. Not necessarily anything wrong with that, ATC has a strong background in studio monitoring.
In fact, I'd recommend anyone looking for studio monitors to check out ATC's lineup.
Then these will do 😉
I'd rather turn that around (also bearing in mind a friendly load).
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@Ro808 personally I would've crossed the sm75150S over at ~2.5 kHz anyway. I day dreamed a mtm section using sm75150S in pairs...crossed to either that really dynamic dome tweeter or a compression driver in a 6" waveguide to match polar. The ATC dome can be crossed at 300hz normally so it should make it to 150hz-200hz in pairs. Cross that to an 18". 👏
Above a certain frequency my driver+horns decay, is as tight as sm75150s and the response is as smooth within parts of the midrange/treble. I think if this measurement was SPL matched at 75db instead of 110db, the decay timings would improve. It will be nice to get a nice Xo designed for 200hz with a measurement taken, outside.
What exactly about the ATC dome, don't you like? Have you tried it with your own personal voicings? I guess I should also consider that if the dome mid range does not have headroom it cannot re-create the transients at a realistic level 🤔
What exactly about the ATC dome, don't you like? Have you tried it with your own personal voicings? I guess I should also consider that if the dome mid range does not have headroom it cannot re-create the transients at a realistic level 🤔
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Allow me to rephrase "The best speaker is one I can forget I'm listening to". The best speaker is NOT a speaker that is forgettable. It's a speaker that reproduces in such a way that I can forget I'm listening to a speaker. One where I can be wholly immersed in a recording. Is this more understandable?
I can do this sometimes with some recordings, using my "compression driver / horn big pro mid ethos". I have also heard sound like this in various system approaches and different efficiencies. The sound is never forgettable. 🙂
An extreme example for me was listening to ESL-57's with a small watt tube amp. Low power and low efficiency. Large apparent dynamics and totally immersive sound field. They couldn't peel the paint off the walls, but what they did do, was like magic - transportation without moving. Now I'm going to have to watch the movie Dune again...
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While I shy away from subjective phrases and words ( "Lifeless", "luke warm beer") as adjectives in listening, my preferred subjective phrase would be a speaker that "disappears" (even after hours of listening.) That, to me, is the most worthy subjective goal.
Agreed paul the speaker should be out of awarness and let the music play unhindered. Speaker anomalies are really distracting. Listening to music should be that alone. Obviously nothing is perfect though .
And to add, that it seems to me that it would be impossible to describe in words something that isn't there.
Totally agree with this one.
In my (personal) experience, this excludes most mor 'high-end' systems, especially those with exotic materials, as they lead you to listen to individual aspects rather than the whole > Magico is an example.
Good speaker design also means balancing different aspects rather than just sticking parts together that are - separate - state-of-the-art. The worn-out cliché 'synergy' certainly applies. To lift this synergy above the average, an optimization process is necessary.
Despite all the work of Toole & co., ABX listening tests and whatnot, you'll find that loudspeakers awarded 'best of show' are often rather basic designs with basic quality parts that excel at 'doing nothing wrong'.
And there's hardly anything more statistically significant than thousands of visitors of a large show who prefer one specific system out of the hundreds that are demoed. "Nothing that gets in the way of the music experience" is an often heard comment.
The disappearing act is most easily done with small 2-way monitor speakers > closest to a point source.
So if you scale up this concept and add some features to hide/mask the size, like roundovers, you basically get a GL Summa.
Personally, I would include some tweaks by using a true midbass woofer, a slightly different wg and xo @ 900 Hz .
The aforementioned ATC monitors fall into the 'the basics done right' category, making them suitable for studio work. In my opinion, they fall short of what I (and my brother) always refer to as "ease" This collective term covers a number of aspects, of which efficiency is the most important.
So my answer to this question is self-explanatory:
^ why don't they just add the "ease" there and make a perfect speaker?
I think answer is because it would make whole another speaker design 😉 "one problem" is the end result of the whole set of compromises they have baked in to the speakers and this is where they ended up with it, they were not able (or willing) to also have "the ease" with all the other features, end of the road.
I guess 'Doing nothing wrong' is equivalent to a problem free speaker system which is something I like to mention often. Being problem free, or doing nothing wrong, means the system plays well with the room, acoustics, typical listening sound pressure level and so on, so depends on application. Problem free for one situation might not be for another. Which is probably part of what happens in the shows, who setups a system and in which room?🙂 Hopefully its the designer and not the marketing team. Hopefully they got the best room for their system and didn't forget portable acoustic treatment to garage if the system was designed to live in acoustically treated room.
Well, age old speculation and competition what's best. What's best depends on who's asking?
I think answer is because it would make whole another speaker design 😉 "one problem" is the end result of the whole set of compromises they have baked in to the speakers and this is where they ended up with it, they were not able (or willing) to also have "the ease" with all the other features, end of the road.
I guess 'Doing nothing wrong' is equivalent to a problem free speaker system which is something I like to mention often. Being problem free, or doing nothing wrong, means the system plays well with the room, acoustics, typical listening sound pressure level and so on, so depends on application. Problem free for one situation might not be for another. Which is probably part of what happens in the shows, who setups a system and in which room?🙂 Hopefully its the designer and not the marketing team. Hopefully they got the best room for their system and didn't forget portable acoustic treatment to garage if the system was designed to live in acoustically treated room.
Well, age old speculation and competition what's best. What's best depends on who's asking?