NHT Super Zero 2.1 Review (bookshelf speaker)

[restorer-john]

"Imaging" has become a huge buzzwords in audiophile circles. It has been elevated to heights that it doesn't belong to. Go to a live concert and tell me where the imaging is. All you hear is a diffused field. No way should imaging have a large space in our vocabulary.

Stereo recording was invented by Blumlein to present actors voices anchored to, and moving across the screeen and for the instruments of an orchestra both across the stage and from front to back in their correct space. When you go to a concert in a good hall, the instruments of the orchestra are not buried in a diffuse field, they are clearly identifiable and positioned just as they are on excellent quality recordings, when played back on equipment of a high standard.

Many speakers are incapable of providing a good image, letalone a 3 dimensional stage. Some are exceptionally good at it. Others present vague or imprecise images.

I'm 100% sure in your audiophile journey, you've heard rock solid, stable and precise imaging in speakers and also the complete opposite. What specific part of the testing can you point to that shows that?

 

[restorer-john]

Right now, the best science we have says that even when taking into account spatial differences, mono is still better than stereo for evaluating speakers.

There's a big difference between mono when discussing evaluating speakers and a single speaker evaluation. Mono does not necessarily mean one speaker. In the subjective musical single speaker evaluation Amir performs, we have stereo recordings with varying and unknown amounts of out of phase spatial effects and ambience, as well as left-right panning effects etc. When he hits the mono (summing the left and right) button (I hope he does) on those favourite recordings and listens to one speaker, it is hardly a comparative test when compared to the correct stereo reproduction of the same track. The track itself is no longer the same. If he listens to just one channel of a stereo recording, that's also flawed IMO.

But it is what it is.

For all of us who buy and listen to speakers, we buy a pair, listen in stereo and determine the characteristics of the system as a whole. Nobody would suggest auditioning one channel of a stereo amplifier on a single speaker because we all know the two channels when running together can, and do influence the performance and ultimate sound of the system as a whole. It is the same with speakers in a room. If you buy one speaker and listen to ancient classical vinyl recordings with a mono cartridge, and a mono amplifier, fair enough. But I don't know of anyone who does that- do you?

 

[richard12511]

There's a big difference between mono when discussing evaluating speakers and a single speaker evaluation. Mono does not necessarily mean one speaker. In the subjective musical single speaker evaluation Amir performs, we have stereo recordings with varying and unknown amounts of out of phase spatial effects and ambience, as well as left-right panning effects etc. When he hits the mono (summing the left and right) button (I hope he does) on those favourite recordings and listens to one speaker, it is hardly a comparative test when compared to the correct stereo reproduction of the same track. The track itself is no longer the same. If he listens to just one channel of a stereo recording, that's also flawed IMO.

But it is what it is.

For all of us who buy and listen to speakers, we buy a pair, listen in stereo and determine the characteristics of the system as a whole. Nobody would suggest auditioning one channel of a stereo amplifier on a single speaker because we all know the two channels when running together can, and do influence the performance and ultimate sound of the system as a whole. It is the same with speakers in a room. If you buy one speaker and listen to ancient classical vinyl recordings with a mono cartridge, and a mono amplifier, fair enough. But I don't know of anyone who does that- do you?

I realize that mono doesn't have to mean one speaker, but that's what Floyd Toole was talking about.

I can rephrase to make it more explicit.

Right now, the best science we have says that even when taking into account spatial differences, a single speaker is still better than a pair of speakers for evaluating speakers.

I agree that almost all of us rarely listen to just a single speaker, but that's just because it's more enjoyable that way, not because it's better for evaluation purposes.

Don't really get the amplifier analogy tbh. They will sound exactly the same as long as they're not broken, so I don't see any real need to evaluate them that way in the first place.

 

[whazzup]

There's a big difference between mono when discussing evaluating speakers and a single speaker evaluation. Mono does not necessarily mean one speaker. In the subjective musical single speaker evaluation Amir performs, we have stereo recordings with varying and unknown amounts of out of phase spatial effects and ambience, as well as left-right panning effects etc. When he hits the mono (summing the left and right) button (I hope he does) on those favourite recordings and listens to one speaker, it is hardly a comparative test when compared to the correct stereo reproduction of the same track. The track itself is no longer the same. If he listens to just one channel of a stereo recording, that's also flawed IMO.

But it is what it is.

For all of us who buy and listen to speakers, we buy a pair, listen in stereo and determine the characteristics of the system as a whole. Nobody would suggest auditioning one channel of a stereo amplifier on a single speaker because we all know the two channels when running together can, and do influence the performance and ultimate sound of the system as a whole. It is the same with speakers in a room. If you buy one speaker and listen to ancient classical vinyl recordings with a mono cartridge, and a mono amplifier, fair enough. But I don't know of anyone who does that- do you?

Not quite sure what you would like Amir to do. Sure, your sentences sound sensible enough. But say Amir hooks up 2 speakers to listen. Are you asking him to start 'describing' the stereo imaging? How does he measure this 'stereo imaging' objectively?

If you do not know how (to measure objectively), and he does not know how, then sorry what's the argument about again?

 

[restorer-john]

Don't really get the amplifier analogy tbh. They will sound exactly the same as long as they're not broken, so I don't see any real need to evaluate them that way in the first place.

Sorry, that's just wrong. A typical stereo amplifier will perform quite differently with two channels driven as opposed to one. It is absolutely essential to test single channel and both channels with a stereo amplifier. The measurable and often audible differences, in no way make the amplifier "broken".

 

[EJ3]

I mean, I could imagine an experiment being designed along the lines of such:

1. Have 5 (arbitrary number) speakers within a chamber placed different distances away from a listening position.
2. Make frequency tones (a different frequency for each speaker) and record that from the LP.
3. Now play back the recorded audio from different sets of stereo speakers, some that measured well and some that measured poorly. And record that from LP.
4. Then compare with the original recording.
5. Alternatively, have humans blind test between the stereo speakers and the 'real' 5 speakers. Note: I'm not sure what questions (to ask) will best help 'grade' the stereo imaging between speakers though.
6. Finally, see if the results relate to the measurements of the singular speakers.

Will be cool to see such experiments in action. But it seems like something to be done by researchers with a research grant, as well as go through the subsequent peer review process. Not reviewers with expensive measuring equipment in their garage. Will be cool if someone is willing to throw research money at Amir to do so.

Ummm? Perhaps one of these Audiophile clubs that have popped up again in some areas could do that. That would take a team of people, therefore: (much) research money. We worry about Amir' back already. Also this is highly subjective, which I am pretty sure is not within the bailiwick of this forum.

 

[ace_xp2]

Is there any actual investigation into phase variance in a pair of identical speakers leading to changes in imaging? This initially seems like a good idea as phase can certainly have an effect on spatial impression, but then we're talking about two identical speakers presenting a different phasing image across the two speakers? And therein, where phase becomes an issue within a speaker (vertical directivity shows this well) does it not display quite clearly in the resultant frequency response issues?

I suppose the final musing here is, if a given speaker has a phase issue, it should represent itself in the resultant response, and wherein there is a phase issue represented across two speakers, is there any way it could truly not be of the room or else present in the recording? Ultimately this seems like an appeal that only has surface sense, as any phase issue is going to be equal across the pair and thus where the phase of a frequency is ✗degrees it shall be the same phase from the other speaker. Thus cancellations or the like are very possible but not likely the result of the two speakers playing and more likely the result of the recording or that old familiar nemesis, the room.

 

[ROOSKIE]

All of my speakers that measure well based on the parameters used on this site image extremely well, ALL OF THEM. I have dozens of speakers.
Imaging is important to me and while there are some difference between my speakers in exactly how they image, those differences pale in comparison to the over-all theme of generally imaging well and sounding excellent.

So much of the mind blowing imaging is part of the recording and especially due to that. Any well designed speaker should convey that well.

That said since there are some differences as mentioned and if imaging is of prime importance to someone they are just going to have to listen to a number of speakers set up in their own home. The testing here can get you close but it is not going to reveal if a speaker does have very unusual imaging properties for some reason.

 

[boselover61]

All of my speakers that measure well based on the parameters used on this site image extremely well, ALL OF THEM. I have dozens of speakers.
Imaging is important to me and while there are some difference between my speakers in exactly how they image, those differences pale in comparison to the over-all theme of generally imaging well and sounding excellent.

So much of the mind blowing imaging is part of the recording and especially due to that. Any well designed speaker should convey that well.

That said since there are some differences as mentioned and if imaging is of prime importance to someone they are just going to have to listen to a number of speakers set up in their own home. The testing here can get you close but it is not going to reveal if a speaker does have very unusual imaging properties for some reason.

Wouldnt imaging has a lot to do with the record itself rather than the speakers?

 

[thewas]

Loudspeaker imaging qualities seem to be more correlated with their radiation pattern and thus also phase response in 3D.
https://heissmann-acoustics.de/en/kantendiffraktion-sekundaerschallquellen-treiberanordnun/

For example in "good old" times before wave guides where there were usually diffraction effects at the baffle this was a reason that compact loudspeakers usually tended to image better than larger ones.

Many problems that deteriorate imaging can be seen in measurements but as not everything is fully researched and understood yet some listening under realistic conditions (stereo or multichannel) is for sure a welcome bonus. I am not say mono listening should not be used as its more revealing for tonal flaws, but also stereo or multichannel listening has its eligibility due to other reasons like different placement (angle and distances to the side walls) and relation to the human hearing-

 

[andreasmaaan]

If the question is specifically which speaker provides the most realistic experience of being present where the performance took place, tonal quality is one component. A poorly built speaker that has bad phase behavior over frequency spectrum (hypothetically speaking) can sound just fine with one speaker but when you put two of them in stereo configuration, the sound could be really bad as @restorer-john mentioned earlier with frequency dependent summing of the two. Obviously, if my goal was to measure the sound quality (as in tonal balance, timbre, etc), this would come in the way of judging but that is only half the picture and a necessary one.

Would you mind linking to @restorer-john's post that you're talking about here? I searched the thread but couldn't find it.

Just hypothesizing, it could be one of multiple things that is a characteristic of each speaker. For example:

(a) If the phase behavior varies in some non-linear fashion across frequencies as well as signal level, then the effect of the two sound waves reaching the ear when split differentially (towards one or the other) between the two could have a changing phase difference between the two as the instrument plays softer or louder. Or when the frequencies it is producing changes. So the resulting sum could change the perceived imaging between the two (even if small enough to just not make it precise). So the measurement of the phase behavior across frequencies and/or volume levels (if it exists) could be a good predictor of image stability.

I think this is related, but I'm not sure I fully understand you.

When you say "phase behaviour varies in some non-linear fashion", are you talking about all non-linear phase speakers, or are you talking about only specific kinds of non-linear phase speakers?

And are you suggesting that two non-linear phase speakers which nevertheless have the same relative phase response could produce this effect? Or are you talking only about cases in which there are relative phase differences between the speakers.

If the former, could you explain again how? I'm not sure I grasped what you meant in particular with this phrase (least understood terms in bold): "...the effect of the two sound waves reaching the ear when split differentially (towards one or the other) between the two could have a changing phase difference between the two as the instrument plays softer or louder."

 

[restorer-john]

Perhaps the imaging/spacial postioning/stability is less important for some people than others.

Perhaps the "preferences" of most audiophiles doesn't encompass what I and some others perceive as one of the most vital parts of stereo reproduction. That is, the stability and laser-like focus across the audible spectrum. Surely some involved in the production/mastering arena can chime in?

I find it hard to believe that audiophiles here on ASR have not heard a wandering image presentation on a pair of speakers caused by poor tolerances of X/over parts or driver matching. It's very common. I remember sending back speakers to suppliers with those issues when auditioning them for, or in, clients' homes.

I have speakers which, apart from that flaw, are lovely speakers. But they will make you scratch your head on certain pieces of music simply because each speaker behaves slightly differently at certain frequencies. Many times I have reached for the headphones to confirm that Mark Knopfler* didn't suddenly jump 2ft left, when he hit a different note.

*just used as an example, not an actual issue with MK.

 

[whazzup]

With all due respect to everyone, but I feel stereo imaging seems to be a very discrete topic that will benefit from its own thread. Then the speculations, hypothesis and even testing methodology can be refined there.

In the meantime, let Amir continue to use 'current science' to churn out the reviews with singular speakers without dispute, at least from the long time asr members. Doesn't seem to make sense to having people constantly barking at him, yet have no real alternatives proposed.

 

[Colonel7]

So you're saying that it is possible that something like the Adam T5V or Genelecs where despite their good measurements, may have a weaker stereo imaging than some other speaker that measured worse? Not saying you're wrong, but what's the basis for such a hypothesis? Phase differences?

Agree with you on this. These are not hypotheses, it's spitballing. What will be tested? And the onus is on the spitballer.

Also, this is a silly rabbit hole that's been gone down before. Ignore Amir's subjective part of the review and people are still saying measurements are not capturing...well what? Imaging, soundstage, microdetails, love, or magic? And, if there were 2 speakers in stereo, there's be all kinds of arguments over listening distance and toe-in. We've seen how lots of manufacturers are vague and others where owners just know what's best is not in the manual.

Keep going Amir!

 

[Sgt. Ear Ache]

Any decent set of speakers once set up well in a given room will image just fine (from the sweet spot that is.) It's largely dependent on the recording. I get fantastic imaging from the DBR62s I'm using right now. I also got fantastic imaging from the "crummy" Micca RB42s I was using before. It isn't magic. Primarily positioning and room EQ (and of course the recording.)

 

[beagleman]

I guess my main "issue" of the subjective part if this review, would be, not understanding why similar priced smallish speakers with similar or worse overall response, are almost semi-praised or seen as pretty good for what they are, and THIS speaker the subjective portion seems like there is an attempt to be comical or almost some Dislike of the speaker, for simply being what it is. .....................A small low priced speaker.

Having heard an earlier version, yes it had no bass, but the rest, when paired with a sub, was quite listenable.

I do not believe I could (nor should) compare it to multi-thousand dollar speakers, but for a cheap, small bookshelf it was clear, clean and not very bad overall.

I guess I see it as being closer to ideal than a total disaster, as how the subjective portion "Seemed" to read to me.

Apologies to Amir, if I come off as gruff or unhappy, but just feel you were a bit too tough for what it is.

 

[sarumbear]

I would have been curious to see it reviewed with a sub because I never was able to get the original to work well, as intended, with a sub.

It would have been interesting to see if that issue has been improved over the decades.

Unless an active crossover with inbuilt parametric equaliser or a DSP is used, the distortion and the frequency response irregularities will stay the same.

 

[sarumbear]

Having heard an earlier version, yes it had no bass, but the rest, when paired with a sub, was quite listenable.

Some like the sound of distortion. That is why the "valve sound" survives.

 

[beagleman]

It's not like the manufacturer was trying to advertise better extension. You know that if the manufacturer isn't claiming amazing extension that your testing isn't going to make it any better. It was reasonable to believe that it rolls off at that point if not earlier. As such "bass limited" is a reasonable expectation right out the door.



It has the makings of a speaker that has specific compromises. The goal is to be as small as possible, affordable, and better sounding than most entry package systems/soundbars when used as intended.



People that would purchase a HTiB or Soundbars would be perfectly served by these in a small to medium room in the event size becomes a deciding factor. I've had an installer flat out tell me that spouses would come in and one of them, typically the wife, would be dead set on Bose cubes due to aesthetics. Usually they were able to bump them up to these (actually the SZ XU when I spoke with them, but same market) because the pricing was often cheaper, size was "close enough", and the sound was significantly better. I'm guessing the battle has shifted to in-walls or in-ceiling though . . .

Clearly if you have the room for larger speakers there's better out there. The point is that this isn't aimed at that segment at all. It's like being angry that a bookshelf doesn't compete with a Revel Salon in extension or a pro speaker in loudness.

People aren't telling you that you don't have valid gripes, but that using a demographic requirement as a drawback doesn't seem reasonable.

tl;dr:

You view this as a bookshelf, but it's not. It's a satellite speaker and as such is bass limited by design necessity. Anyone purchasing should already know this and want to know how it performs within its segment.

I see this small speaker, as almost just a bit of a step up for a minimus 7 in actual use with MOST owners. Not quite as small obviously, but for the same intended purposes mostly. Small, decent enough sound, that with a sub it seems a lot better, but can be used on a desk, in the kitchen, or any small space where "real" speakers are simply too large.

 

[sarumbear]

I would not thump one study as the bible without allowing for the possibility of it studying what it tried to study but not the whole picture. Studies can be improperly interpreted. That would not be science.

How very true... as you keep demonstrating...