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Is the NHT Xd going to get a "Class A" rating? In what category will it be rated?

It is not appropriate to give out that information prior to the publication of the next "Recommended Components" listing, in April 2006. However, I am working on a followup to Kal Rubinson's enthusiastic review, specifically to investigate some alternative crossover filters that NHT recently emailed me. These move the subwoofer crossover frequency to 150Hz, to increase overall dynamic range, and incorporate some slight EQ changes in the top octaves.

My followup will appear in the January 2006 issue, which will hit newsstands in mid-December.

John Atkinson
Editor, Stereophile

I have a few questions for Kal on a few of his comments if he'd be willing to clarify a few things. Obviously the review was great for a $6K speaker that includes all the necessary elements and the positive comparisons to $10K and $12K unpowered speakers were great, but a few things left me wondering -

1. It was said that the Xd can't match the bass (aside from quality) of the Revel Studio or B&W 802D, which I took to mean depth. But the Xd measures deeper than the Studio for sure and, I believe, should have an F3 that is 5-15Hz lower than the 802D as well. I can't imagine that the bass level would be a problem as that is adjustable. So, did you mean more of that "thump" sound or perhaps that elusive "bass presence"? In my experience, the bass of the Xd is transparent enough to be essentially "invisible", as in transparent to the source - massively powerful on call, essentially non-existent when it's not supposed to be there. Just curious what you meant by your comment there. Does it have anything to do with ported vs acoustic suspension?

2. I noticed your mild midrange critique was with "voice" not, seemingly, the entire midrange, compared to the other two speakers. But with these two criticisms, the Xd could go "toe to toe", I recall, with these bigger speakers. In my listenings, I notice substantially more [real] resolution than certainly compared to B&Ws such as the Nautilus series or the 803D, something you appeared to imply with your comments on a few SACDs that opened up. In any case, I was curious because it seems like, in order for Xd to go toe-to-toe, there must have been things you preferred to the other systems. IOW, to whom were you being a little extra kind - the NHTs or the more expensive Revel/B&W speakers?

John-

I do not want to set a precedent by restating my own statements or doing an ad hoc update. However, since this is such an unusual product (and because you are such an unusual person!), I will comment a bit.

1. Measurements aside, there's a fullness and warmth, when appropriate, to what I hear from the N802Ds/Studios that the Xd lacks. Now, you may argue that the latter is more accurate (and that's possible) but it is less satisfying. It is not extension or level, per se, and tweaking the XdW control can only raise/lower the level at the expense of balance with the main boxes. I tried to keep it flat.

2. Both the N802Ds/Studios have midranges of unusual construction and materials and both are cut off at the bottom a bit higher than Xd mids. Those issues may or may not be relevant but there's a subtle clarity, noted particularly on voices, that they have and share with some other high-end speakers. The Xd's missing frisson is not much noticeable except on A/B comparison and at those rare moments when the others create a surprising and uncanny illusion.

I was not trying to be 'kind,' but fair, and I stand by the statement that the Xd can go toe-to-toe with almost anything. That doesn't mean they will win all the time.

Kal

Thanks Kal,

I guess, as an acoustic suspension fan, even the best ported speakers simply sound overly warm and blurred in the bass and lacking in detail and texture down low. I hear the same when comparing Xd to higher end ported speakers.

I'll have to, for the moment, assume that the 802D is substantially more resolving than the 803D if it can meet or beat Xd in that area. Of course, the 803D measures notably "warm" in HTMag and I am sure that added to my perceptions.

Unusual?!?

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2. Both the N802Ds/Studios have midranges of unusual construction and materials

Speaking of which, I'd hardly categorize the SEAS Excel as a "usual" or run of the mill driver, being made of magnesium and having exceptionally advanced motor structure. The FST design is certainly unusual, but I wouldn't say that makes it better. Otherwise, it would/could be everywhere. I think it is the primary culprit in the rather tiny sweetspot that these speakers have. The SEAS Excel is far more like the Revel design, at least in terms of the pistonic driver concept. Sorry, I know what you meant, but it's not like they just tossed a poly Vifa in there or anything!

However, some of your comments and those of others have been used to push hard for a "Super Xd". Don't know that it'll happen, but one can certainly dream!

>>> (and because you are such an unusual person!)...

LOL!

I wonder how different the NHT system would sound if it used conventional crossovers and was voiced per the room like typical speakers w/o the digital components?

The frequency charts might suggest the NHT balance thin or bright. Can one tune the bass for additional warmth?

Godzilla

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>>> (and because you are such an unusual person!)...

LOL!

We've exchanged messages before.

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I wonder how different the NHT system would sound if it used conventional crossovers and was voiced per the room like typical speakers w/o the digital components?

Probably a poor compromise. The strength of this system is the synergy. It uses drivers that are optimized in their performance in this arrangement. Without the DSP, it is almost certain that NHT would pick other components. Just look at their other models.

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The frequency charts might suggest the NHT balance thin or bright. Can one tune the bass for additional warmth?

Sure. NHT has already demonstrated alternative filter configurations. I guess you'll have to see JA's follow-up.

Kal

I see that "eerie recognition" from the 802D requires a 4dB dropping slope in upper midrange response, a 3dB 4000Hz peak and a 4dB peak at 10kHz and a very unusual off axis dispersion.

I also see that the "lightweight" bass on the Xd is *not* having a ~6dB bell shaped curve at 60Hz.

I think I can live without "eerie recognition" and "full bass" from my speakers.

Time and history will be far more kind to Xd than the current reviewing circle. It's unfortunate that most simply don't understand the revolution these will trigger (or that they will be able to be colored to taste). Or maybe they're simply trying to prevent it. Who knows.

I'm constantly amazed by the inability of reviewers to detect speaker/driver coloration and/or their ability to somehow turn it into a positive attribute. Sorry Kal. But it's true. God, I miss Corey Greenberg. Probably the best ears the industry has ever had, but way to honest to keep a job in the industry.

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God, I miss Corey Greenberg. Probably the best ears the industry has ever had, but way to honest to keep a job in the industry.

Excuse me, but are you refering to THIS Corey Greenberg?

http://www.washingtonpost.com/wp-dyn/articles/A3110-2005Apr19.html

RG

OUCH. LOL.

Crap. I guess "honest reviewer" and "honest politician" are both about the same on the oxymoron scale. I'm more than disappointed in Corey. I just lost all my respect for him. It's one thing to be inept or biased, but that it just crap.

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Crap. I guess "honest reviewer" and "honest politician" are both about the same on the oxymoron scale.

Excuse me?

"...We view this as a breach of journalistic ethics," said Sue Geramian, a vice president at parent company Gruner + Jahr USA Publishing..."

"...Oppenheim, who did not respond to an e-mailed request for comment, told the Journal that corporate payments do not influence his judgment..."

Hmmm... interesting. Ties in with the thread I started regarding objective reviews. I hadn't heard about this article when I started that thread.

Perhaps I should say "unbiased reviewer". I'm sure most reviewers attempt to be honest, within the limits of not saying anything bad enough to piss off an advertiser, at least.

I did notice that Kal omitted some of the many things that Xd does better than the B&Ws in his article (backed up by the measurements). I think that's like Rule #3 or something - "Always let the more expensive piece 'win' any comparison". Of course, he also engaged Rule #2 in the Xd review - "Always compare to products that are not the same price, and always make sure the lesser product is pronounced not quite as good as a more expensive one."

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Perhaps I should say "unbiased reviewer". I'm sure most reviewers attempt to be honest, within the limits of not saying anything bad enough to piss off an advertiser, at least.

John, I suspect that most reviewers do not pay attention to the ads and have no real knowledge of who advertises and who does not.

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I did notice that Kal omitted some of the many things that Xd does better than the B&Ws in his article (backed up by the measurements). I think that's like Rule #3 or something - "Always let the more expensive piece 'win' any comparison". Of course, he also engaged Rule #2 in the Xd review - "Always compare to products that are not the same price, and always make sure the lesser product is pronounced not quite as good as a more expensive one."

First, I left out nothing significant, constrained only by the number of pages. Second, comparisons were made to the other speakers in house at the time. Anything else would be speculative.

Finally, since I am familiar with your position and your style from many posts on other forums, let me point out to others that you are (1) a long-time critic of B&W speakers, particularly, the Kevlar midrange, (2) convinced that the Xd design is superior to all conventional designs, in concept and performance, and (3) an NHT dealer.

Let him who is without bias cast the first stone.

Kal

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I did notice that Kal omitted some of the many things that Xd does better than the B&Ws in his article (backed up by the measurements).

Kal didn't omit anything from his NHT review. However, as NHT subsequently made available different filters for the Xd, to improve both its HF response and the less-than-optimal integration between the woofer and satellites that Kal noted, I have written a followup for publication in the January issue.

John Atkinson
Editor, Stereophile

No, my point was, sure, in Kal's subjective experience, the 802Ds do some things better than the Xds. That is "legal" because they are more expensive and is therefore put in the Xd article. But what I thought was missing is that it is *also* true that the Xds do some things better than the 802Ds. This is apparently not "legal" and so it is not put in the 802D article. It's fine, it's normal, just a shame.

And, sure, I used to work for a B&W dealer, that's how I learned to not like them so much. And, yes, Kevlar cones have always been problematic because they have unusual properties. The other reviews I've seen have actually, finally mentioned that the kevlar midrange is now the weak spot of the speakers. Quite frankly, it always was. The B&W Matrix 3, with its poly midrange, was probably the finest B&W speaker, adjusted for time, they ever made. I don't dislike B&W, I dislike Kevlar and am constantly surprised that reviewers don't notice the colorations that is causes.

I mean, c'mon Kal, you like warmer bass, but as you can see in the measurements of the 802s, that's just a big, fat peak in the response. I heare "high-end" expensive speakers ALL the time from all kinds of companies and I hear TONS of colorations. When I read the reviews, I hear lots of glowing praise and either no mention of the obvious, or it's understated in a way to make it seem like it is either a plus or a very minor issue. Well, you know, when you can build an accurate speaker for $1000, you'd expect that a $100,000 speaker might also be accurate. Hell, that cheap Wharfedale speaker measured nearly as well as Xd, but everything else in the same issue measured pretty poorly.

The think I like about John's measurements is that you can see, if you can understand the basics of the measurements, how a speaker *really* performs. The only thing I think is missing is a distortion measurement. I think if one can get great performance from an inexpensive speaker, one should demand impeccable performance from flagship products. And it just hasn't been so. And the reviewers all give the big buck products a big, fat, happy hall pass and are more critical of the more affordable gear. It's not abnormal, but it's a shame. I wasn't expecting anyone to proclaim that Xd was "the best", but turnabout is fair play and you know that it does some things better than the 802D. It should have been mentioned in the B&W article.

I do look forward to seeing the additional measurements of Xd. I think it's great when a magazine and the manufacturer can collaborate to improve a product. In fact, I do believe that each review should end with a list of what the reviewer would like to see improved on the next version of every product. That forces them to remember that no product is perfect, all can be improved and it should all be in the review, not just glowing praise proportionate to the retail price.

Quote John Ashman: "...The only thing I think is missing is a distortion measurement...."

That reminded me of the Velodyne speaker from several years ago. Didn't they claim to have the lowest distortion? But as I recall, the speakers were not very well received.

I'll go look for the reviews.

Are there accurate speaker distortion measurement techniques? Seems doable. Sorry if it's a dumb question!

It would be highly cool, and maybe help put into perspective the 0.01% type numbers we see with electronics.

All those zeroes behind the decimal point during the 70's and 80's electronics ads never played out, but I haven't seen this considered for speakers.

It would sure make for interesting discussions!

Those were Velodyne DF-661s as I recall. My rep wanted me to carry those, god bless her soul, and it took me about, not kidding, about 30 seconds for ear fatigue to set in. I guess they didn't count cone resonance as "distortion". My ears sure did! Of course, that should have been picked up in the waterfall plot. But instantaneous distortion would be different. I saw some Revel M20s that had about 50% distortion in the bass at 95dB. Not kidding! Good stuff, but obviously needs to be crossed to a sub. Distortion measurements would fill in a huge missing piece of the puzzle.

Hi Folks,

I wasn't intending to post here, but the word "distortion" caught my eye. I like John Atkinson's loudspeaker measurements in general, but I agree that not quantifying distortion in a meaningful way is a big shortcoming.

But yet a very understandable shortcoming. Quantifying distortion between different speakers in a meaningful, consistent way is usually quite daunting, and especially when room acoustics simultaneously come into play.

Best,
Mark

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I like John Atkinson's loudspeaker measurements in general, but I agree that not quantifying distortion in a meaningful way is a big shortcoming.

I somewhat agree. Problem is that I don't have a good way of producing repeatable distortion measurements with loudspeakers. The MLSSA system I use can measure distortion spectra, but I am nervous about the effect of background noise when I use it outdoors (like I do for response and dispersion measurements) and on the effect of room acoustics if I use it indoors.

John Atkinson
Editor, Stereophile

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Does your system not allow quasi-anechoic (inital arrival pulse) indoor distortion measurements?

Of course. But for distortion you need to use a continuous tone, and I can never be sure that room acoustics are not affecting the measurements unless I get very close to the diaphragm. I have occasionally published some distortion measurements -- see http://www.stereophile.com/standloudspeakers/272/index9.html , for example -- but overall I am not sufficiently convinced of the repeatability of these measurements.

BTW, you can find some of my thoughts on the relevance of speaker distortion measurements at the bottom of the page at http://www.stereophile.com/features/100/index6.html.

John Atkinson

Editor, Stereophile

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How much could room effects lower the measurement?

My concern is for low-frequency measurements, which I believe are the only ones which could be significant. Let's assume I play a high-level 100Hz tone but inadvertently place the speaker and microphone at positions in the room where resonant modes both accentuate the 100Hz level at the microphone and notch the third harmonic at 300Hz. This is unlikely, I know, but not impossible. The result will be to lower the measured level of the third harmonic with respect to the fundamental, giving a false reading.

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There are some incredibly low published distortion measurements at:

http://www.ecoustics.com/secrets/volume_12_3/b&w-804s-htm3s-speakers-8-2005-part-2.html

Interesting. Thanks for including the URL. I wonder what the measurement conditions were.

John Atkinson
Editor, Stereophile