NHT C3 Review (3-way speaker)

[bennybbbx]

Yes but what has the sampling rate of CD to do with that?

that people see how precise humans can process ITD. I think nobody hear 20 khz. this is period time of 0.05 ms (50 microseconds) . but it is possible to hear for humans in midrange a delay of 0.02 ms between the ears. this also show that it is maybe not need to have 58 khz tweeters or electrostatic tweeters. because over 3 khz ITD humans do not use. maybe better is have a mid range speaker that is faster, maybe elektrostatic midrange or such a midrange speaker as NHT C3

 

[amirm]

the reason wy it is usefull to have in all speaker tests a CSD waterfall. for example this test have a CSD. https://www.audiosciencereview.com/...rk-rokit-5-gen-4-review-studio-monitor.20711/ many other have this not.

I stopped posting CSD for speakers a long time ago. It can be a very misleading graph. For active speakers, I have started to publish it again as it can show resonances. That's why you saw it in KRK speaker.

 

[MZKM]

I stopped posting CSD for speakers a long time ago. It can be a very misleading graph. For active speakers, I have started to publish it again as it can show resonances. That's why you saw it in KRK speaker.

Why does being active play a role?

 

[j_j]

Yes but what has the sampling rate of CD to do with that?

First, above 2kHz, the envelope delay of a signal is very important, and also has a very high senstivity to ITD's. Below 500Hz ITD sensitivity is related directly to the waveform. Above 2kHz it is mostly related to the waveform's ENVELOPE. Remember you have to filter the waveform into ERB's to make any sense of what the ear is going actually detect. Between 500Hz and 2kHz both mechanisms work, with some conflict, so ITD sensitivity gets a bit wonky there.

As to the time resolution of CD's, 1/(2*pi*20000*65536) is much smaller than the minimum detectable ITD. It's not the sampling rate, either, it's 2*pi*bandwidth that matters.

 

[j_j]

And as far as ITD's, etc. Two things to watch:

https://www.aes-media.org/sections/pnw/pnwrecaps/2019/apr2019/ first, for monaural kinds of things and then
https://www.aes-media.org/sections/pnw/pnwrecaps/2021/jan2021/ for beginnings of binaural discussion

 

[j_j]

because over 3 khz ITD humans do not use.

False. Above 2kHz the signal envelope onset is detected very accurately. The claim we do not use ITD is wrong.

This means that we have trouble localizing a sine wave, but if we pulse the waveform, especially if it has a sharp onset, we can easily detect the ITD if we can detect the carrier frequency.

 

[j_j]

Why does being active play a role?

If a crossover/equalizer is correcting a nasty driver peak, you may not see actual cancellation of the hangover, in fact you probably won't. Correcting non-minimum-phase things is, after all, 'interesting'. Yes, it can be done with gigantic FIR's. Most people don't bother.

 

[MZKM]

If a crossover/equalizer is correcting a nasty driver peak, you may not see actual cancellation of the hangover, in fact you probably won't. Correcting non-minimum-phase things is, after all, 'interesting'. Yes, it can be done with gigantic FIR's. Most people don't bother.

Ah, ok so for speakers with active crossover/DSP, not so much “powered speakers” that simply have passive crossovers with integrated amps.

 

[bennybbbx]

And as far as ITD's, etc. Two things to watch:

https://www.aes-media.org/sections/pnw/pnwrecaps/2019/apr2019/ first, for monaural kinds of things and then
https://www.aes-media.org/sections/pnw/pnwrecaps/2021/jan2021/ for beginnings of binaural discussion

thanks for your links, but i trust more medical science in hearing. and see my link there stand this with 890 and 3 khz. here is another medicinical exmplain of binaural hearing. https://uol.de/f/6/dept/mediphysik/ag/sigproc/download/papers/SP2018_24.pdf but the real question is, for speaker buyer, if they can hear this. people that not hear this for this people are big 2 way speakers good enough.

on this link https://www.sfu.ca/sonic-studio-webdav/handbook/Binaural_Hearing.html there is a link sound example and he write this text

Localization of a sound from left to right using only binaural time delays (heard only on headphones).

. I hear this with the MTM and Eris 3.5 and headphomne. with kali i have not test. maybe this can on slow speakers not hear. but the sound i hear walk from right to left. and on right (begin) position on MTM it sound as it comes too from behind me. it sound very wide in front and back. on the eris 3.5 on full right position it sound not so width. on headphone too not. measures show eris a little better but on MTM reverb sound fuller and warmer. same happen with the test signal full right. it sound more spacy. seem the eris 3.5 is more true speaker.

 

[j_j]

thanks for your links, but i trust more medical science in hearing.

Given that's what I'm actually teaching, I would suggest that you re-evaluate your attitude.

Furthermore, your own alleged "evidence" supports my points, and I suspect that you do not actually understand your own references.

 

[txbdan]

Thanks for taking the time to measure this speaker not once, but twice. I like this speaker (have them on my desk) and like them quite a bit. In the near field I think their good dispersion plays a role. I also like that they're sealed being that they'r quite close to my rear wall. And the fact they don't like to play loud is also fine in this instance.

It was also interesting to have measurements of two samples of the same speaker. There is the anomaly in the high freq, but otherwise the two speakers were extremely similar. That speaks to the measurement equipment and process as well as the speaker manufacturing.

 

[cursive]

Thanks for taking the time to measure this speaker not once, but twice. I like this speaker (have them on my desk) and like them quite a bit. In the near field I think their good dispersion plays a role. I also like that they're sealed being that they'r quite close to my rear wall. And the fact they don't like to play loud is also fine in this instance.

It was also interesting to have measurements of two samples of the same speaker. There is the anomaly in the high freq, but otherwise the two speakers were extremely similar. That speaks to the measurement equipment and process as well as the speaker manufacturing.

I also have these in a desk setup, may I ask how close to the rear wall you run them? Now I'm just debating between in room correction, or just correction based on the Klippel measurements paired wit more room treatment.

 

[bennybbbx]

Given that's what I'm actually teaching, I would suggest that you re-evaluate your attitude.

Furthermore, your own alleged "evidence" supports my points, and I suspect that you do not actually understand your own references.

at 14:49 sec stand as text in this video (from your link)

The ear is a frequency sensitive organ
The filter structure is unique to the ear, and unlike what most people expect.
The detectors come after the filter structure.
Yes, the filter mechanism on the basilar membrane is well supportet

The detectors work differently at diffrent frequencies. At low frequencies(under 500 hz) they fire at the start of the waveform itself as filtered on the cochlea.

At high frequencies (over 2000 hz or so), they fire at the waveform envelope.

then at 30:54 stand as text

We can compare time relationships between the two ears, to the level allowed by what the detector capture, which is to say, waveform under 500 hz, a mix of waveform and envelope between 500 hz and 2 khz.

I understand from 30:54 that the time relationship detect work from 500 hz- 2 khz but in diffrent ways. he use the word envelope. maybe he mean with that the ears set the start point of the phase compare between left and right ear to transient envelope highest point on frequency over 500 hz. a envelope is this

https://www.teachmeaudio.com/recording/sound-reproduction/sound-envelopes

and for frequency upto 500 hz there is the level of the wave cycle use. but i guess it use highest level of the wave cycle. because the beginning of the wave cycle have very few level it is not easy to detect.

EDIT: Also should notice even when level relationship work at this frequency too, that because of less level diffrence on low volumes there need hear louder. this also show my experience. the sound of mtm and eris i think good on 10 db less level as the sound from Kali. so fast midrangve protect also ears. in the video he tell at 19:30 sec that the detectors are uniform from erb and then he speak about hearing damage.that many young people have damage ears because they hear often loud. this stand not in the text but you hear when you hear what he say.

 

[txbdan]

I also have these in a desk setup, may I ask how close to the rear wall you run them? Now I'm just debating between in room correction, or just correction based on the Klippel measurements paired wit more room treatment.

The backs of the speakers are prob 4" from the wall. It's a deep desk so I'm prob 3' from the speakers. I also have a 10" sealed sub in the 12x14'x8' room. I use Dirac Live correction as the small room has some pretty ugly modes.

 

[bennybbbx]

this seem same speaker, but with grill. specs look same. there is a waterfall diagram and step response in this test
https://www.stereophile.com/content/nht-classic-three-loudspeaker-measurements

that crossover is 800 hz i think is not so optimal. normaly 3 way speakers have crossover around 450 hz.

 

[Robbo99999]

Given that's what I'm actually teaching, I would suggest that you re-evaluate your attitude.

Furthermore, your own alleged "evidence" supports my points, and I suspect that you do not actually understand your own references.

at 14:49 sec stand as text in this video (from your link)



then at 30:54 stand as text


I understand from 30:54 that the time relationship detect work from 500 hz- 2 khz but in diffrent ways. he use the word envelope. maybe he mean with that the ears set the start point of the phase compare between left and right ear to transient envelope highest point on frequency over 500 hz. a envelope is this

https://www.teachmeaudio.com/recording/sound-reproduction/sound-envelopes

and for frequency upto 500 hz there is the level of the wave cycle use. but i guess it use highest level of the wave cycle. because the beginning of the wave cycle have very few level it is not easy to detect.

EDIT: Also should notice even when level relationship work at this frequency too, that because of less level diffrence on low volumes there need hear louder. this also show my experience. the sound of mtm and eris i think good on 10 db less level as the sound from Kali. so fast midrangve protect also ears. in the video he tell at 19:30 sec that the detectors are uniform from erb and then he speak about hearing damage.that many young people have damage ears because they hear often loud. this stand not in the text but you hear when you hear what he say.

Quite a fascinating video from JJ, probably unrelated to the discussion, but at 50:00 JJ says roughly "the ear is really good at throwing away parts that it thinks you're not listening for"........makes me think this could be one way in which we get quickly adapted to different headphones......after an hour long gaming session on my headphones, music through my headphones sounds significantly better, I think this is a brain adaption thing. A loose correlation, but I wanted to throw it out there......it's just I've noticed my headphones (regardless of which pair) sounding significantly better with music after an hour or so gaming session using them (where I'm listening acutely for enemy sound details in the spatial domain using virtual 7.1 surround processing)......it's almost like my ears have locked in on the frequency response of the headphone to normalise it......loose interpretations I'm making, but I'd figure I'd voice them.....headphones just sound so much better after an hour of fps gaming, it's a strange phenomenon. The difference was so significant that I figured it might be the drivers warming up and functioning better after an hour of wearing the headphone.....but now I'm thinking it's a brain related phenomenon. Very loose connections (perhaps) to what is being discussed, but I couldn't help typing them!

 

[j_j]

this seem same speaker, but with grill. specs look same. there is a waterfall diagram and step response in this test
https://www.stereophile.com/content/nht-classic-three-loudspeaker-measurements

that crossover is 800 hz i think is not so optimal. normaly 3 way speakers have crossover around 450 hz.

Would you prefer to put a crossover where the resulting phase shift is in an audible place, or put it, perhaps, in a different place where the ear is less sensitive to small phase changes?

 

[cursive]

this seem same speaker, but with grill. specs look same. there is a waterfall diagram and step response in this test
https://www.stereophile.com/content/nht-classic-three-loudspeaker-measurements

that crossover is 800 hz i think is not so optimal. normaly 3 way speakers have crossover around 450 hz.

Not that it's a huge difference, but the crossover and drivers are slightly different in the C3 vs the classic three. 1 in tweeter vs 3/4in tweeter, 817hz crossover vs 800hz and on the tweeter according to hometheaerhifi it's actually 4750hz vs 3200hz on the classic three, so quite different there.

https://hometheaterhifi.com/reviews/speaker/bookshelf/nht-c3-bookshelf-speaker-review/

Measured quite a bit better there, but of course he is measuring outdoors vs using klippel. Some definite improvements to the tweeter, much better listening window with the 1in tweeter over the classic three.

 

[bennybbbx]

Would you prefer to put a crossover where the resulting phase shift is in an audible place, or put it, perhaps, in a different place where the ear is less sensitive to small phase changes?

I dont know, because i have never hear a 3 way system with 800 hz crossover. I only look what the good testet high price speker have. https://www.stereophile.com/content/bowers-wilkins-802-d3-diamond-loudspeaker-specifications

Crossover frequencies: 350Hz, 4kHz.

I only do some tests with LP6 (6.5 inch too) and mtm and lowpass. when i use a lowpass 48 db /oct at 700 hz (i test it longer ago so no 800 hz result) i hear still less stereo width of kali. when lowpass is 500 hz then i hear not less stereo width. so the question is only answer with more tests. I can test it with t.racks kali and mtm what sounds more as single mtm in stereo width and transients. use kali upto 800 hz or upto 500 hz. and for rest of frequency the mtm flat on kali. but it is more work to do. It need all 4 speakers in the t.racks delay exact set

BTW: a easy way to set systems in correct phase on REW measure is use the tweeter as timing reference and enable in REQ measure "use acoustic timing reference" for 1 speaker. Now depend on the delay of the system the step response of the other speaker is before or after 0. the result before or after 0 in ms can add then direct in the DSP. I verify this after correct work good. because t racks use 48 khz sampling rate it have 0.021 ms minimum steps in delay because it delay only sample steps.

when i let play both speakers over all frequency range together and measure and do FR correct and same loud, then transients are not so good as with single speaker. maybe it is because only 0.021 ms limit or it is because area in mid range is larger and i sit 60 cm away. but i can test it because i have a 4 channel mixer and the t,reacks mini dsp have 4 inputs and 4 outputs so i can avoid the 0.021 ms limit. but shift the delay 0.021 ms is very less hearable for me, so i think not so important

 

[bennybbbx]

Quite a fascinating video from JJ, probably unrelated to the discussion, but at 50:00 JJ says roughly "the ear is really good at throwing away parts that it thinks you're not listening for"........makes me think this could be one way in which we get quickly adapted to different headphones......after an hour long gaming session on my headphones, music through my headphones sounds significantly better, I think this is a brain adaption thing.

The adaption to diffrent frequency range slopes work faster. you can hear a song 1 minute you think good. now reduce with treble over 4 khz high freq all. then hear 1 minute. then set it back to neutral. then the song sound in first moment too bright. when you notice it only after longer hear when remove headphone and all around sound more silent, and this happen more than 2 minutes, then it is possible that your ears are overload because of too loud headphone hear