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What makes speakers "disappear " and can it be measured?

That pulse response in the link, is stunning.
Tack!/Tak!

I know that it is “frequency response uber alles” here.
At some point the time domain behaviour matters. These seem to have it.
To add, the designer does not really say that this is a crucial property. In the frequency range of 200-2000 Hz there may be, during certain circumstances, audible difference. And he adds that other aspects of the speaker out such as frequency response and distortion is much more important.

(I reread his documents and the first pi60 speaker came 1978. The designer, Ingvar Öhman, was at that time 16 years old.)
 
My simpleton theory, they definitely don’t need to be a source point design. Very low enclosure resonance is important. The quality of design as in matching the drivers correctly with well thought out crossover and driver selection and attention to phase coherence. A narrow enclosure with rounded edges helps. And a decent frequency response.

Also, the room and speaker setup is extremely important.
 
That pulse response in the link, is stunning.
Tack!/Tak!

I know that it is “frequency response uber alles” here.
At some point the time domain behaviour matters. These seem to have it.
These graphs are from the original Dunlavy SC-IV, released 30 years ago. The impulse and step response are nearly perfect. A year after production started John Dunlavy changed tweeters, woofers, tweaked the crossovers, improved cabinet bracing and binding posts, because he didn't think this was good enough, and he could improve them. Stereophile also reviewed the SC-I, SC-IV/A and SC-VI, which all had similar impressive measurements. Unfortunately Stereophile never reviewed the SC-V, which John claimed was his favorite speaker. and the most accurate speaker he'd ever built, so the measurements should have been even better. The SC-III, IV, IV/A, V, and VI were all spec'd ± 1.5 db across the frequency range, and speakers never left the factory unless they met or exceeded reference specs.

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Is part of the esoteric realm with a relation to the cost of the speaker and the personality of the owner.
 
Is part of the esoteric realm with a relation to the cost of the speaker and the personality of the owner.

No - probably more that most people do not care that the speaker is putting the sound out into the room in the way that the microphone picked it.
They do not care whether the speaker is going backwards or forwards, as long the FR looks ok.
 
I’ve listened to some pretty humble speakers that successfully disappeared, so I really don’t think this is significantly a property of the speaker.

A good room with speakers and seating placed well in the room seems to me all that is required as long as the speakers don’t have extreme faults.
 
I’ve listened to some pretty humble speakers that successfully disappeared, so I really don’t think this is significantly a property of the speaker.

A good room with speakers and seating placed well in the room seems to me all that is required as long as the speakers don’t have extreme faults.
I have a sneaking suspicion that this whole thread is just people throwing up 'sensible-seeming ideas'...
 
I’ve listened to some pretty humble speakers that successfully disappeared, so I really don’t think this is significantly a property of the speaker.

A good room with speakers and seating placed well in the room seems to me all that is required as long as the speakers don’t have extreme faults.

I certainly see something to that. it doesn’t seem to take much for a pair of stereo speakers to produce a stereo presentation, and naturally that’s going to mean a lot happening in between the speakers.

But then, and I think it’s clear many of us have had this experience, there just seems to be speakers that take it to a whole new level.
Even when you were used to regular stereo imaging, some speakers seem to “ disappear” just that much more so you kind of go “Whoah.” That sense that you can look right at the speaker and not get any sense whatsoever that they are creating the sound is pretty neat.

As I mentioned before in my experience a number of audio physics speakers seem to do that really well, as did my MBL omnis, some Waveform speakers that I had (egg shaped mid range tweeter enclosure).
My current floorstander speakers do that very well too.

I also had the Thiel flagship 3.7 speakers and the slightly smaller 2.7 version of those speakers in my home at the same time for quite a while, going back-and-forth between them. Although the 3.7s were the bigger wider speaker, they actually seemed to
“ disappear” a bit better, in the sense that even hard panned instruments seem to float more free of the speaker. I’m not sure why, if perhaps there is some little resonance or something calling attention to the smaller 2.7.

I know the 3.7 was a bit more of an ambitious design, with the front baffle holding the drivers being made of solid aluminum, and a solid aluminum cap. Versus the cheaper MDF front baffle of the 2.7. so perhaps there’s a little little bit more resonance going on with the 2.7? I don’t know.
 
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the sound was coming from the big black room dividers against the wall
My speakers (average 2-way, SEOS24+15", in corners, 45º toed in) look like pointless, unnecessary, superfluous objects. The sounds look like they're coming from wall-mounted subwoofers.
 
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