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NHT C3 Review (3-way speaker)

Kinda surprised you gave it such a good rating given that it's a 6.5" woofer with very little bass, along with a quite a funky frequency response. When you say "the benefits of a sealed enclosure was there with its ability to play sub-bass without getting distorted", I'm quite surprised by that because sub-bass is below 60Hz and judging from the spinorama with the bass starting to roll off quite steeply at 90Hz I'm surprised there'd be any sub-bass to be heard at all? I would think this speaker would need to have a Low Shelf Bass boost via EQ of at least 5dB to even start noticing the sub-bass, but then you'd be pushing the speaker towards it's 94dB measured level which would put it into unhappy distortion territory? Given that this is a 6.5" woofer it should be able to play lower, and I don't think it really deserves it's awarded status.

EDIT: even on their spec page for the speaker they list the Frequency Response as 55Hz-20kHz, so that's not really covering the sub-bass below 60Hz
https://www.nhthifi.com/products/16546-c-3-bookshelf-loudspeaker#specs
I think for sealed boxes you would get much less bass impact than same driver size ported speakers so it makes sense, for sub bass comment I have no clue also
Roll off is slower in closed boxes, so whilst the -3dB point is higher for a given box size the bass extends well in room because the wall and floor gain have "something to work with", ie some output to augment, whereas with a reflex the level below port tuning is so low it isn't augmented and around port tuning it can be excessive particularly if the room has a principle mode near that frequency.
A slow roll off in the bass, starting even at 100-200 Hz often gives good in room results and needs less/no room correction.
Actually, you might be onto something re Room Gain (@Frank Dernie), I had been looking through reviews of 8" models to disprove you in saying well how come these well received speakers didn't sound boomy with their deep bass reach combined with the Room Gain that you're supposing. Well actually what I found in the following three 8" speaker review examples (see pics & links at end of post), during the listening tests Amir either put in a High Pass Filter to cut off the bass in the 308p review citing distortion issues, but potentially could have been confusion with Room Gain boominess. The 708p Amir chose to listen in farfield rather than on his desk, so perhaps speakers not so close to the wall in that one......so no adjustment to bass required. Adam T8V review he had on his desk & noted he had some boominess from the room due to low-playing speaker activating room modes. So it looks like you're onto something re Amir's listening situation and the room gain.....and it could be possible he confused boominess of the 308p on his desk with distortion but that latter point is just a coincidental theory. Going back to the review of the speaker in this review (the NHT C3), I think your Room Gain point does carry weight to explain adequate sub-bass.....however this speaker would still be underpowered in the bass if you didn't have Room Gain, so I don't particularly like it.
https://www.audiosciencereview.com/forum/index.php?threads/adam-t8v-studio-monitor-review.17118/
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https://www.audiosciencereview.com/...ds/jbl-308p-mkii-studio-monitor-review.17338/
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https://www.audiosciencereview.com/...s/jbl-708p-review-professional-monitor.20006/
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Actually, you might be onto something re Room Gain,
I have been "on to it" for over 50 years!
Nothing new just neglected nowadays because people feel free to use room compensation rather than account directly for room acoustics like we all had to do for the huge majority of my time getting good sound in a room.
 
I have been "on to it" for over 50 years!
Nothing new just neglected nowadays because people feel free to use room compensation rather than account directly for room acoustics like we all had to do for the huge majority of my time getting good sound in a room.
Awesome sausome
 
I bought a pair of these to try out and my ears seem to be validated a little bit here which is nice. Playing my favorite acoustic and singer/songwriter material, the male vocals were a little thin and the guitars just a bit too bright. The coverage was nice though with the 3-way design and presented a nice image but it definitely needs EQ like Amir suggests.
 
I initiated the exchange and the replacement speaker is on the way. Curious to see how it compares.


For kicks, here's a close-mic comparison of the C1 (5.25") vs C3 (6.5") woofer. They both have relatively high -3dB points, but you can see the relatively smooth drop off of the sealed enclosures. You can see in the in-room measurement of the C3s I posted on Page 1 that I got good in-room response down to 50Hz.
c1c3bass.jpg

Here are a couple other speaker's woofers thrown into the mix, Q150 and Atom SE. You can see how they drop off more quickly until the ports take over. They offer the extension of the C3 with a smaller woofer at the expense of port resonance and the gap in the 50-100Hz where the C3 has 'em beat. This is why sealed enclosures are friendlier with rooms and subwoofer integration.
woofercompare.jpg
 
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Distortion was two completely different stories depending on level

a quick question to understand the practical implication of distortion graphs at 86 vs 96 dB: when I set the volume on my 140W-rated Denon 6500 AVR to 73 (out of 100 max), my bookshelf speakers similar to these (Revel m106) start playing really loud. But is this volume closer to 86 or 96 dB? when I measure only 1 speaker playing various content with my sound meter @ 1m distance, it shows from 70 to 98 dB. Thanks!
 
Not all that bad for another little speaker and, unless there is some underlying damage, the little mid dent is unlikely to have affected the results all that much (if at all). ;)
 
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I think for sealed boxes you would get much less bass impact than same driver size ported speakers so it makes sense, for sub bass comment I have no clue also
It doesn't extend as low, but in my experience there's some level of immediacy to sealed boxes that you don't get with ports. But yeah, tradeoffs exist for sure (bass efficiency and lower THD in the low end vs lack of port resonances and "quicker" delivery... I know I'll get shit for that one, but it's directly related to what you see around the port tuning frequency on a CSD waterfall - or don't, in the case of a well designed sealed box).
Roll off is slower in closed boxes, so whilst the -3dB point is higher for a given box size the bass extends well in room because the wall and floor gain have "something to work with", ie some output to augment, whereas with a reflex the level below port tuning is so low it isn't augmented and around port tuning it can be excessive particularly if the room has a principle mode near that frequency.
A slow roll off in the bass, starting even at 100-200 Hz often gives good in room results and needs less/no room correction.
Yep. And it's not even like you can't design a sealed box that has a low F3, it just might need more driver surface area and/or some DSP help to get there. It's something I'd like to see more in budget studio monitors that for some inexplicable reason isn't there.
 
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And it's not even like you can't design a sealed box that has a low F3, it just might need more driver surface area and/or some DSP help to get there. It's something I'd like to see more in budget studio monitors that for some inexplicable reason isn't there.

"Budget" and "more driver area" cannot co-exist. That is why you will not see a budget sealed box speaker that has a low F3.
 
"Budget" and "more driver area" cannot co-exist. That is why you will not see a budget sealed box speaker that has a low F3.
The point is you don't see any. The cheapest monitors that purport to be full range (that is, excepting NS10 style and Auratone 5C style grotboxes) on Sweetwater are $1850 a pair - and they're passive ATCs.

There's no reason they couldn't exist. I see no reason there couldn't be something like a Kali IN-8 - or LP-8, for that matter - but sealed. Could still get to a reasonably low F3 with an 8" woofer. You don't need anything crazy like dual opposing subs to get decent low end extension out of a sealed box, just some clever DSP and an 8" low driver.
 
The point is you don't see any. The cheapest monitors that purport to be full range (that is, excepting NS10 style and Auratone 5C style grotboxes) on Sweetwater are $1850 a pair - and they're passive ATCs.

There's no reason they couldn't exist. I see no reason there couldn't be something like a Kali IN-8 - or LP-8, for that matter - but sealed. Could still get to a reasonably low F3 with an 8" woofer. You don't need anything crazy like dual opposing subs to get decent low end extension out of a sealed box, just some clever DSP and an 8" low driver.

There is at least one/two examples of a sealed powered monitor, the Fluance Ai40 and 60 monitors.
napilopez reviewed them

https://www.audiosciencereview.com/...si-anechoic-measurements-and-spinorama.12027/

His biggest problem with them was that they had a non switchable dynamic Eq for the bass. This might be ameliorated by using the sub out to control the bass output. They have been replaced with the Ai41 and 61 which are ported. Apparently small sealed speakers just are not successful in the marketplace notwithstanding their distortion advantage in the midrange and better matching with a subwoofer.
 
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Is your messurement system describe in a thread? And how you use it?

The distorsion measurements, are they made by mic in the traditional way or is it by scanning and calculation?

//
 
I would have thought 3-ways priced at $780/pair would have been able to play louder. Disappointing. At the very least, the tweeter should have been padded down some more.
 
Interesting! I sent this one in to Amir as I have a pair of these on my desktop. I did a casual $300ish bookshelf shootout where I really liked the C1, but wanted more low end. That prompted me to up-budget a bit and get the C3s. The price fluctuates quite a bit on Amazon, I paid $322 each. The two standout qualities for me is the accurate low end and (don't shoot me) transparency. They sounded so natural to my ears. Finish and build quality is very good, too, they are tanks. That said, I do currently use Dirac Live to correct them :-D

FWIW, here's my measured room response. Interestingly it looks a bit more like soundstagenetwork's measurement than Amir's. Bump at 1.5-2kHz and dip around 5-7kHz. Of course the mess below 600Hz is my room. (The light colored line is the response, the dark flat line is Dirac's predicted response after correction)
View attachment 111869
Interesting! I sent this one in to Amir as I have a pair of these on my desktop. I did a casual $300ish bookshelf shootout where I really liked the C1, but wanted more low end. That prompted me to up-budget a bit and get the C3s. The price fluctuates quite a bit on Amazon, I paid $322 each. The two standout qualities for me is the accurate low end and (don't shoot me) transparency. They sounded so natural to my ears. Finish and build quality is very good, too, they are tanks. That said, I do currently use Dirac Live to correct them :-D

FWIW, here's my measured room response. Interestingly it looks a bit more like soundstagenetwork's measurement than Amir's. Bump at 1.5-2kHz and dip around 5-7kHz. Of course the mess below 600Hz is my room. (The light colored line is the response, the dark flat line is Dirac's predicted response after correction)
View attachment 111869

This looks pretty good, even uncorrected ... especially if you overlay the Harman curve instead. Have you tried correcting only to 500Hz?
 
The point is you don't see any. [...] There's no reason they couldn't exist. [...] Could still get to a reasonably low F3 with an 8" woofer.

There is a big reason I'm afraid: physics!

If you think that there is no reason such a speaker shouldn't exist why don't you create a fictitious 8" driver that will give you the F3 you want in a budget size sealed enclosure and show us its parameters. You will be surprised...
 
Is your messurement system describe in a thread? And how you use it?
I have written an article on it for Widescreen Review Magazine. I think it is published now so I can process and post it here.
 
Speaking of the exotic and three-ways, I wonder if someday Barefoot Audio will ever make it across the meters here? I wonder how much of the industry chatter is well-deserved praise and how much is just "tripe hype." They are based in nearby Portland, Oregon which isn't too far from Amir. Maybe they would be up for sending him a loaner unit seeing that now the Footprint02 is well into production and stock is plentiful.

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Speaking of the exotic and three-ways, I wonder if someday Barefoot Audio will ever make it across the meters here? I wonder how much of the industry chatter is well-deserved praise and how much is just "tripe hype." They are based in nearby Portland, Oregon which isn't too far from Amir. Maybe they would be up for sending him a loaner unit seeing that now the Footprint02 is well into production and stock is plentiful.
As I understand it, @direstraitsfan98 is sending a FP01 to Amir. But yeah this seems like the kind of place that Thomas Barefoot would enjoy. He loves him some DSP.

Also, I own a set of Barefoots - they actually are that good.
 
As I understand it, @direstraitsfan98 is sending a FP01 to Amir. But yeah this seems like the kind of place that Thomas Barefoot would enjoy. He loves him some DSP.

Also, I own a set of Barefoots - they actually are that good.
Just saw it, while searching Google to see if I missed any old posts right, if I might add, as you replied. That's fantastic news! I have been looking forward to this for quite some time, in fact, and only looked into it again after seeing this three-way review. I am really curious to see if these take everything that an already competent monitor can do (like Genelec) to a whole other level with, among other things, added bass extension.
 
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