Accuracy in Loudspeakers---Define

[ginetto61]

So, an accurate loudspeaker is one that can faithfully reproduce clipping distortion from an amplifier, or capture all of the nuance from a brickwall limiter?

le's put it this way .... if it can reproduce a SW it can reproduce accurately almost anything
Of course there will be limitations for bandwidth and SPL ... but again i would like to see this kind of test perfomed on some excellent drivers like JBL 375 and similar
I am quite sure they would perform impeccably
I guess that also the influence of the horns on the drivers performance can be evaluated in the same way with some horns more accurate than others
I do not know why SW is seen like the evil ... it is just a test signal

 

[tarior]

The DC portion of a square wave wouldn't make any sound. No loudspeaker can reproduce DC.

 

[bowtie427ss]

http://www.excelsior-audio.com/Publications/Square_Waves_&_DC_Content.pdf

 

[brian222]

I read about 25 pages here and I'm thinking a lot of you posters must have been good at math and physics. I wasn't and with me it's do I have sound coming out of both sides. I have mastered that part.

 

[tarior]

http://www.excelsior-audio.com/Publications/Square_Waves_&_DC_Content.pdf

A bunch of superposed harmonics does not a square wave make. A loudspeaker that can stay coherent with complex waveforms and/or multiple layers, especially at high volumes, is definitely a good thing.

 

[DMLBES]

Accurate to me are sounds that don't come from a recording but from a actual instrument like in a live band. The closer your gear is to duplicating this live sound the more accurate.

 

[tarior]

Holy Carp! I didn't realize that this was a 10 year old zombie thread.

 

[ginetto61]

Accurate to me are sounds that don't come from a recording but from a actual instrument like in a live band. The closer your gear is to duplicating this live sound the more accurate.
.....

Hi i agree completely of course. I wonder what the audience opinions were about the realism of the recorded sound.
On the same line another interesting video with very telling comments at the end
Actually someone preferred the recorded sound to the live one

i would like to add just that the system used for playing the recording back is fine ... but not ultimate for sure
some upgrading in the playback rig elements could have improved the sound quality even further and enhance the realism of the reproduced sound quite a bit

Maybe up to the point that a blindfolded listener could be fooled to be hearing the real event ? a virtual reality experience

I had the opportunity at an audio fair to listen to an MBL system with those strange omnidirectional metal speakers ... i was shocked by the realism of the singer's voice
Unfortunately i hate deeply omnidirectional speakers ... very very deeply
I do not like at all the way they soundstage ... it is like to be in a cave with the sound coming at me from all around ... confusing and disorienting

 

[sKiZo]

Some of those zombies knew what they was talkin' about, eh ... ;-}

No amount of attention paid to the quality of a recording can bring it home if the equipment it's played on isn't up to par. Recent example here was swapping out my fully restored Sansui QRX 9001 receiver for some maintenance, replacing it with my trusty old backup, a QRX-6001. Was a time I had thought they sounded pretty much the same, but it was immediately apparent that the untouched 40 year old 6001 had a good bit of mud and blah in comparison. Definitely needs some bench time, and it'll be interesting to hear the before and after results of even a basic re-cap of the power rail and supply.

 

[ginetto61]

... Maybe up to the point where a blindfolded listener could be fooled to be hearing the real event ? ...

Hi ! this was intended to be a provocation ... could this be possible one day ? That would be 100% accuracy
i tend to think so
By the way i find that listening blindfolded can be a more "immersive" and intimate experience

 

[Mike Stehr]

No loudspeaker can reproduce DC

300 volts B+ DC will make a loudspeaker reproduce, even though it's real fast...but very loud...

 

[tarior]

300 volts B+ DC will make a loudspeaker reproduce, even though it's real fast...but very loud...

You'll hear the rise time at any rate!

 

[Mystic]

Accurate for me is a speaker that can reproduce reasonably well a square wave ... for instance the Quad esl63 are an accurate speaker even if restricted in bandwidth and max SPL available ...

https://www.stereophile.com/images/archivesart/QUADFIG6.jpg

Fig.6 Quad ESL-63, 1kHz squarewave response on listening axis at 1m

i know the SW is not a signal present in nature ... and then ?

Another one from Rehdeko

clearly to be accurate from 20 to 20kHz and at high SPL is a challenge ...
I have the feeling that many compression drivers + horns are much more accurate than conventional drivers ... especially at higher spl
i think it can be related to very low values of Qts ...

Y'all dug deep to pull this gem outta the AK mothballed threads trunk!

 

[Mystic]

I read about 25 pages here and I'm thinking a lot of you posters must have been good at math and physics. I wasn't and with me it's do I have sound coming out of both sides. I have mastered that part.

This one was sort of a greatest hits of Tom, Zilch, Ray, w/ occasional & classic pesterings of Justen. I've enjoyed (re)reading it today.

 

[ginetto61]

taken from the review of the
Rockport Technologies Antares loudspeaker on Stereophile page3
https://www.stereophile.com/content/rockport-technologies-antares-loudspeaker-page-3

... When I listened to my own voice, as recorded on The Ultimate Test CD (out of print), I was taken by surprise at how the Antares put me—not just my voice—in my own room, nasal twang and all, without added colorations.
It was an out-of-body experience...

i would call that playback chain quite accurate speakers included of course.

Then i was watching to this interview of Alan Shaw, chief designer at Harbeth speakers company ... listen from 4:28 on

if i understand rightly his point is that high quality voice recordings are a very powerful and convenient tool to assess speakers accuracy ... and almost nobody in the industry use them.
Quite weird isn't it ? not him of course.
I trust his judgement completely. Great designer indeed. I love Harbeth speakers deeply. But my funds do not allow ...for now

 

[rothwellaudio]

The DC portion of a square wave wouldn't make any sound. No loudspeaker can reproduce DC.

I'm not quite sure what this comment is getting at. Yes, in theory a loudspeaker can reproduce DC. DC across the voice coil will produce a displacement of the cone by a certain amount and the cone will stay at that displacement, and if the enclosure is a sealed box the air pressure in the room will be changed - which is effectively DC. However, ears don't perceive a change in atmospheric pressure as sound unless the change is occurring at about 20Hz or more.

A bunch of superposed harmonics does not a square wave make.

Don't they? Tell that to Joseph Fourier.

 

[tarior]

I'm not quite sure what this comment is getting at. Yes, in theory a loudspeaker can reproduce DC. DC across the voice coil will produce a displacement of the cone by a certain amount and the cone will stay at that displacement, and if the enclosure is a sealed box the air pressure in the room will be changed - which is effectively DC. However, ears don't perceive a change in atmospheric pressure as sound unless the change is occurring at about 20Hz or more.

You'll hear the change in voltage as it goes from more negative to more positive and back again, yes. But you're not hearing DC. You're hearing the change in displacement of air as the voltage on the coil (or the current flowing through the coil) changes. Pulsing DC is effectively, as far as cone (or whatever the diaphragm configuration happens to be) motion is concerned, little different from AC.

Don't they? Tell that to Joseph Fourier.

It's generally useless to argue with someone who is selling something.

 

[JoeESP9]

Hi ! this was intended to be a provocation ... could this be possible one day ? That would be 100% accuracy
i tend to think so
By the way i find that listening blindfolded can be a more "immersive" and intimate experience

I just turn out the lights and close my eyes.

 

[fill35u]

Accurate for me is a speaker that can reproduce reasonably well a square wave ...

How well is "reasonably well"? What's your metric?

Over which frequency range? If you want a 20kHz perfect square wave to arrive at the listener, you're going to need an amp and tweeter that can play hard enough to make harmonics high enough to get you "square" enough. If you need the 9th harmonic to achieve your standard of "reasonably well", you're talking a tweeter good up to 180kHz. Everything in that 20-180kHz range is going to be drastically attenuated by the mere air it passes through on the way to the listener. And it's going to beam like a pencil, you'd literally need your head in a vice to reap the benefits. You better be listening nearfield!

At what volume level? The amplifier will need to have sufficiently high slew to power that 180kHz component of the square signal at whatever voltage you specify. The output inductor and the Zobel network are going to frustrate you before the signal even leaves the amp. Distortion is typically climbing from 1kHz on up, and it just gets worse beyond 20kHz as you continue to run out of feedback. A tweeter with a coil is going to have steeply rising inductance at high frequencies. The increasing driver reactance, decreasing feedback, and decreasing phase margin at ultrasonic frequencies could push the amp into oscillation.

Outside of test tones or some electronica, got any examples of music with significant square wave content?

Clean audio reproduction of square waves has as much to do with tweaking microphone placement as anything else.

 

[rothwellaudio]

You'll hear the change in voltage as it goes from more negative to more positive and back again, yes. But you're not hearing DC. You're hearing the change in displacement of air as the voltage on the coil (or the current flowing through the coil) changes. Pulsing DC is effectively, as far as cone (or whatever the diaphragm configuration happens to be) motion is concerned, little different from AC.

Yes, all is which is pretty obvious - hence why I said I didn't know what you were getting at. Why state the obvious?

It's generally useless to argue with someone who is selling something.