NHT Super Zero 2.1 Review (bookshelf speaker)

[Dennis Murphy]

The directivity difference between a 4" and 5.25 or 6.5" is not much. In other words you generally gain very little, a 4" woofer still needs to be crossed at nearly the same frequency as a 6". OR use a waveguide or a true midrange driver (anything LESS than 4 or a 4" designed for midrange specific duty)
/QUOTE]


That hasn't been my experience. My mod of the little Pioneer BS22 uses a 4" "woofer' with a 1" dome with no wave guide, and the crossover point is around 2800 Hz, which is higher than that of the NHT. Yet there is much less directivity error. Perhaps this has to do with the crossover slopes involved. They appear to be mixed order acoustically for the NHT--quite gradual for the woofer, pretty steep for the tweeter. I used 4th order acoustic for both drivers in the Pioneer mod. I don't know whether this is the same exact NHT as I had experience with a few years back, but if it is, its just bolsters my opinion that we're placing too much emphasis on controlled directivity. To me, the overall sound of the little speaker was quite decent, albeit a bit, uh, bass shy.

 

[Bruce Morgen]

For this sort of bass-deficient, low sensitivity performance in a tiny sealed box, you can spend a tiny fraction of this product's price on Dayton Audio B-452s @$35USD/pair or the AMT-equipped "AIR" variant for $46USD/pair -- and both are frequently on sale for even less.

 

[Shike]

It’s a current model, and MSRP is $300/pair. I see no qualities that would compel someone to buy this over another offering.

The only current aspect on it is that they added a real crossover. They admit that they require a subwoofer and they've always had directivity dips so not sure why people thought it would magically change for the 2.1.

I still use my SuperZero XU's - though they're nearfield, have correction added, and use a subwoofer. There's definitely better today, but in the right application are passable - then again I'd never pay anywhere near MSRP for them.

 

[ROOSKIE]

That hasn't been my experience. My mod of the little Pioneer BS22 uses a 4" "woofer' with a 1" dome with no wave guide, and the crossover point is around 2800 Hz, which is higher than that of the NHT. Yet there is much less directivity error. Perhaps this has to do with the crossover slopes involved. They appear to be mixed order acoustically for the NHT--quite gradual for the woofer, pretty steep for the tweeter. I used 4th order acoustic for both drivers in the Pioneer mod. I don't know whether this is the same exact NHT as I had experience with a few years back, but if it is, its just bolsters my opinion that we're placing too much emphasis on controlled directivity. To me, the overall sound of the little speaker was quite decent, albeit a bit, uh, bass shy.

I was trying to explain to another poster that you can't assume a 4" driver is automatically able to cross well at a lower frequency. (2k)
Obviously it varies a bit from drive unit to drive unit and whatnot but in the 4-6.5" range there is more overlap and similarity than differences. Plus xover design choices/skill.
Deff not saying a waveguide is required in all cases, only that even many smaller woofers still might need one. (At least from the point of view of the way the tests here are presented)

You have magnitudes more skill than many and deep experience so your designs deff show that. Plus that Pioneer woofer is likely very well designed, Andrew Jones's choice and all.

 

[restorer-john]

A 4.5" in a sealed cabinet of that size cannot be expected to deliver any bass of significance. But they are compact, inexpensive, look to be well finished and are just the shot for test speakers (or sacrificial speakers as I call them) on the bench just as @SIY uses them.

I've always used small sealed 2 ways for sacrificial speakers, currently I have a similarly small pair of Gale 3010S which are fabulous for the purpose and only cost me $60 the pair. They do a lot right, and do not attempt to go low either.

The last pair of 1970s SEAS two way (sacrificial speakers) finally expired after decades of abuse.

 

[pavuol]

Yes, imo speakers clearly advertised by a manufacturer to be complemented with a sub shall be judged "less strict".

Another question is whether it is ethical calling such an old design "true high-end mini-monitor" even in current amazon product page..

 

[Dennis Murphy]

No you buy a subwoofer.

I was trying to explain to another poster that you can't assume a 4" driver is automatically able to cross well at a lower frequency. (2k)
Obviously it varies a bit from drive unit to drive unit and whatnot but in the 4-6.5" range there is more overlap and similarity than differences. Plus xover design choices/skill.
Deff not saying a waveguide is required in all cases, only that even many smaller woofers still might need one. (At least from the point of view of the way the tests here are presented)

You have magnitudes more skill than many and deep experience so your designs deff show that. Plus that Pioneer woofer is likely very well designed, Andrew Jones's choice and all.

I doubt there is that much difference in dispersion between the AJ woof and the NHT. Plus, as stated, I crossed higher than NHT did. I suspect that it's a matter of the crossover slopes. Anyhow, I'm glad to hear you're not suggesting that a wave guide is a necessity for a design like this.

 

[richard12511]

I don't agree with rating these poorly based on the poor bass response with no subwoofer, given that the manufacturer clearly states that these should never be used without a subwoofer. Reviewing these without a sub is like judging a KH80 as an IMAX speaker and saying it lacks output. I know you're not a fan of subwoofers, but some speakers are designed specifically for use with them(imo all speakers need them ). In situations like this where the manufacturer clearly states that a sub is required, I think it might make more sense to either ignore the bass response altogether, or test the speaker in the manner it is intended to be used(w/sub).

Going by the tiny sealed enclosure, I'm guessing these are meant mainly to be used as surrounds?

Other than the comments about the bass, I think the other criticisms are very fair. The speaker does have other issues that other measured speakers in the same price range somehow managed to avoid. At $300, you're starting to get into the range of some of the recently reviewed monitors, and most of those outclass this speaker.

Finally, and this goes against my initial point(but I think it's fair to point out), but the bass extension is so poor here that you'll likely have a hard time integrating it well with many subs. This is similar to the issue that the LRS had, and some say the LS50 has(though that speaker has much more extension).

 

[infinitesymphony]

If you added a subwoofer, where would you set the crossover point, 150 Hz?

 

[whazzup]

If you added a subwoofer, where would you set the crossover point, 150 Hz?

Good question. I checked their site and this is what they said:
https://www.nhthifi.com/products/10654-superzero-2-1-our-amazing-mini-monitor

...the SuperZero 2.1 complements the SS 10 subwoofer perfectly...

So their SS 10 sub, as well as their other 2 subs, their low pass filter top out at 140hz....

 

[Shike]

If you added a subwoofer, where would you set the crossover point, 150 Hz?

I use the XU's in my PC rig with an xover of 120hz to my sub.

 

[ROOSKIE]

If you added a subwoofer, where would you set the crossover point, 150 Hz?

Completely depends on the target output SPL and the slope. Not mention how they end up blending in a particular room.
150 sounds reasonable as a starting point.
Maybe you could do 100-120 if using LR8.

I doubt there is that much difference in dispersion between the AJ woof and the NHT. Plus, as stated, I crossed higher than NHT did. I suspect that it's a matter of the crossover slopes. Anyhow, I'm glad to hear you're not suggesting that a wave guide is a necessity for a design like this.

Playing around with the JBL A130 which is fantastic for $300. The smaller A120 uses a 4.5" and a waveguide.
Seeing more and more waveguides these days on 4-5.25" 2 ways. Certainly not the only solution but it does seem to be a solid approach for mating a cheap tweeter and woofer in a 2 way. Obvioudly you still need to implement a well though out crossover.

 

[posvibes]

If I remember correctly the original Super Zero's were designed by Ken Kantor of AR fame, sealed enclosure bass down to 75Hz and built on the premise of good design for small money. They were well reviewed and made a dent in the affordable but quality speaker market. I have never heard a pair and I am not sure what the lineage is to the tested super zero 2.1 @amirm tested.

But Kantor was to me a practical down to earth designer that would often go to the mattresses against the purveyors of audiophile snake oil, so I am a little surprised if this speaker is a late iteration of the original?

 

[YSC]

Actually to my eyes it didn’t look too bad considering the price? I think it should be a good candidate for a 2.1-5.1 system as surround and a subwoofer? The power factor I think could be solved by using 2 or more of them in an apartment, wall mounted. Asking a small speaker at mid to far field playing alone seems harsh for the job. The lack of port design maybe for flatter response in wall mounting situation?

 

[boselover61]

Actually to my eyes it didn’t look too bad considering the price? I think it should be a good candidate for a 2.1-5.1 system as surround and a subwoofer? The power factor I think could be solved by using 2 or more of them in an apartment, wall mounted. Asking a small speaker at mid to far field playing alone seems harsh for the job. The lack of port design maybe for flatter response in wall mounting situation?

I mean there are better options at this price point. Unless you are fixated on only NHT products. JBL stage a120 is most likely a lot better than this and comes with wall mounting kits.

 

[Silly Valley]

As a frequent visitor who appreciates Amir's work I have to say that I don't know if I am more disappointed in the speaker or Amir's review.

How on earth can anyone who has even a modest amount of experience in this hobby even consider doing a listening evaluation of this speaker without a sub? It simply is not designed to be listened to without a sub. "There is no bass" Are you kidding?

Amir, you condescendingly state that this is a tiny sealed enclosure with no obvious port. SINCE WHEN is a speaker REQUIRED to have a port? Some speakers are purposely designed without a port due to the fact that the sealed enclosure and its natural roll off can be a positive attribute for speakers intended to be integrated with subs....like this one. In fact there are some manufactures of fairly expensive speakers that do not add a port to their speaker precisely for this reason. And, some of these speakers are highly acclaimed. Yes it's true. Do your homework.

When I am looking for smaller speakers to use in a 2.1 system, I actually consider sealed boxes a positive attribute. Ports are often used as band aids and can have negative consequences. Everyone knows a port can be useful to improve bass extension especially in smaller boxes if one wants the option to not use a sub. It is a very common choice to port these days but not a hard and fast rule.

After reading this opening section I could barely bring myself to read the rest of the spin data. It seems all the spin was in the opening comments. Perhaps you would better serve your readership by sticking to testing DACs and amps or at least avoid the commentary on design choices for speakers. BTW, as one reader said, these speakers which in one iteration or another have been around for years have received many decent reviews. Your $70 dollar purchase price does make me wonder if you got e real NHT. There are some fakes out there.

But for myself, the foul here is the opening statement about ports, sealed boxes and lack of bass. I award your review the headless panther.

 

[Robbo99999]

Quick question @amirm or others in the know. Are waveguides on tweeters there to essentially make the tweeter bigger than it really is? Is part of the problem with blending a tweeter & woofer is that they are hugely different diameters, and therefore you need a waveguide to expand/widen the the frequency response to almost mimic if the tweeter was the same physical diameter of the woofer? Was just imagining this now, but no idea if that's the crux of the issue.

EDIT: and I guess waveguides act a bit like the horn on a gramophone or megaphone....but to lesser extents?

 

[YSC]

Yes, imo speakers clearly advertised by a manufacturer to be complemented with a sub shall be judged "less strict".

Another question is whether it is ethical calling such an old design "true high-end mini-monitor" even in current amazon product page..

I agree with that and beside the waveguide-less choice it seems amazing for the price and size to me, obviously when u decide to use it alone without a sub it’s another story but then it’s against what the design is about

 

[MDINNO]

What a hack this reviewer is. I don't know how anybody takes any of these reviews seriously. Another great speaker shot down again. No credibility whatsoever.

 

[SIY]

What a hack this reviewer is. I don't know how anybody takes any of these reviews seriously. Another great speaker shot down again. No credibility whatsoever.

Serious question: what makes these "great" speakers?