The Absolute Zero replaces the NHT SB1 but the street price has roughly doubled. I have a pair of the original Super Zeros, a pair of SB1s, and now a pair of Absolute Zeros. I've compared all 3 to each other in a carefully set up environment listening to a variety of material from high quality sources.
Unlike older NHT products, the Absolute Zeros are made in China which makes the new higher price even harder to swallow. I'm betting NHT's costs have actually gone down over the USA made SB1s. So it's kind of sad they saw fit to raise the price so high? This is even more true because, as I'm about to explain, one can argue the much cheaper SB1 sounds better!
Before I get to the sound, the Absolute Zero looks nicer, less obtrusive, and a bit more expensive than the previous SB1. The curved cabinet makes them look more sleek although the plastic grill frames don't fit all that well and have two cheesy visible strips of foam rubber that's tacked on flanking the tweeter. I presume the strips are there to control high frequency diffraction effects improving the sound but it's ugly if you look at the speakers from the side with the grills on.
Sound wise, the Absolute Zero is the brightest of the three speakers. Some have said it's more detailed as well, but that's very subjective. Most people consider a brighter speaker to be more detailed, but that's not always true. More high frequency distortion, for example, can make a speaker sound brighter while revealing LESS detail. I'd say the new Absolute Zero reveals about the same musical detail as its predecessors and many other good speakers in its price range.
The deeper bass performance is very similar to the SB1 which means there's honest bass down to 90hz or so. Below that, the bass rolls off more gently than in most similar sized speakers which are typically ported these days. The sealed NHT designs are also better for putting up against a wall, in a cubby hole, cabinet, etc. as there's no port to worry about. The new Zero has much more satisfying bass than the much smaller original Super Zero but most will still want a subwoofer if you like real bass.
The new Zero allows a subwoofer to be crossed over around 100hz with no big "hole" in the bass like you get with most small satellite speakers. Most satellites with 4.5 inch or smaller woofers have trouble honestly making it down to even 150hz despite their optimistic specifications. Not so the Absolute Zero or SB1.
In terms of soundstage (imaging), all 3 speakers are about the same with perhaps the SB1 being slightly weaker. NHT speakers have always done a good job of "disappearing" and the Absolute Zero is no exception.
My biggest complaint with the Absolute Zero is a somewhat nasal character in the lower midrange that's missing in the SB1 and Super Zero. It's especially obvious on certain vocals and it's the same sort of sound, just less obvious, that you often hear from those cheap plastic enclosure surround sound satellites that are so common these days. Perhaps NHT is making their drivers at a different factory in China and they're not as accurate as they used to be? Whatever the reason, it's a step backwards.
The brighter high-end can also be a mixed blessing. The old SB1 is more forgiving of MP3 material with encoding artifacts, poorly recorded/mixed content, etc. The Absolute Zero can make less than pristine recordings sound more harsh--especially at louder volumes. The tweeter looks very similar to the SB1 tweeter, but it's clearly not identical and there may be crossover changes as well. Again, it's possible the new tweeter is made by a different manufacture in China.
In terms of efficiency, NHT has been steadily increasing it. The SB1 is slightly more efficient than the old Super Zero, and the Absolute Zero is very slightly more efficient still. It will play about equally as loud as the SB1 before it starts to sound obviously strained. But again, the brighter high end makes it sound more harsh when pushed hard. I was driving them with a high-end power amp with 200 watts per channel and clipping indicators, so I'm quite certain it wasn't my amp that was straining.
Most people will think either the SB1 or Absolute Zero sound significantly better than the original Super Zero--at least unless you're using a properly set up subwoofer. The SB1, in particular, sounds notably warmer and more full than the thin sounding Super Zero. The Absolute Zero initially sounds a bit louder (which it is) and brighter (which it also is) than the SB1 perhaps giving it an edge in a quick A/B comparison.
But if you spend some time listening to a variety of material on both the SB1 and Absolute Zero, as I have done, I think most would agree NHT has taken a small step backwards even if the Absolute Zero were the same price. At roughly double the price, I think they've taken a BIG step backwards and there are better options in the Absolute Zero's now lofty price range.
Overall, I wish NHT still made the SB1 as I prefer the sound and they were half the street price. Still, if you require a non-ported small speaker under 10 inches high that can reach down below 100hz, there are not that many good choices. So for these rare applications, the Absolute Zero might still be worth considering. Or, if the street price ever drops back to where it should be, the Absolute Zero would again be competitive.
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NHT N-AZB Absolute Zero Speaker (Black).
