NHT Xd wins 2005 'Best of CES' award

mac · « **Reply #60 on:** 20 Jan 2005, 04:22 am »

Quote from: Davey

Mac,

I hope you noticed that I used John's own words in my comment for a (hopefully) humorous effect. Maybe not. ...

Sorry, I missed the context. I thought that statement was rather bold and uncharacteristic coming from you! We'll have to set some time aside to hear the latest versions of one another's systems. Cheers, mac.

John Ashman · « **Reply #61 on:** 20 Jan 2005, 04:23 am »

Val · « **Reply #62 on:** 20 Jan 2005, 01:30 pm »

I am waiting for my local dealer to email me for a Xd demo as soon as he gets them and will be posting my comments here.

One thing I don't like about the design is the very small Seas woofer NHT chose, like they wanted to make a point and/or compromise on system size. I would have preferred the W18 but perhaps they were thinking on non-audiophiles and future HT sales.

Val

mac · « **Reply #63 on:** 20 Jan 2005, 02:59 pm »

Quote from: Val

One thing I don't like about the design is the very small Seas woofer NHT chose, like they wanted to make a point and/or compromise on system size. I would have preferred the W18 but perhaps they were thinking on non-audiophiles and future HT sales.

Val

Same woofer I chose to use and I do consider myself an audiophile.

It's not a performance limiting factor in their design due to the use of a high order crossover. I think you'll also find that within its operating range it's a better sounding driver than the W18.

John Ashman · « **Reply #64 on:** 20 Jan 2005, 03:15 pm »

Occam · « **Reply #65 on:** 21 Jan 2005, 01:18 am »

Quote from: Val

One thing I don't like about the design is the very small Seas woofer NHT chose, like they wanted to make a point and/or compromise on system size. I would have preferred the W18 but perhaps they were thinking on non-audiophiles and future HT sales.

Val,

Thats an excellent question that deserves an empirical, non anectdotal answer. The explanation is that the 'woofer' on the satellites are not really woofers at all, rather an upper bass/ midrange transducer covering 120hz to 2kHz.
Using the characteristics of the Seas W14/15 and the calculations developed by R.H. Small "Vented box loudspeaker systems, Part II: Large signal analysis" AES journal, Vol 21, No 6 (Jul/Aug 1973), we find that the satellites are capable of producing in Small's 'average room" a SPL of 106db+- @>= 130hz.. In other words, their choice of satellite woofer, with regards to cone area and linear displacement, is adequate.

[Those interested in some high school algebra can glean those calculations for a closed box driver here -
http://sound.westhost.com/qb5align.htm
Linkwitz's site also contains an Excel worksheet]

Is NHT's choice of a W14/15 over a W18 (or their OEM equivalaents) a compromise? Certainly..... , the whole implementation is a compromise. To do otherwise is simply to show that you've more money than common sense. Everything involves tradeoffs and NHT has skillfully implemented, to a price point and market, a rather charming system.

John Ashman · « **Reply #66 on:** 21 Jan 2005, 02:14 am »

Val · « **Reply #67 on:** 21 Jan 2005, 01:04 pm »

I accept both explanations and I am on record as a fan of minimonitors and subwoofers, but again with the caveat that I haven't heard the system my audiophile doubt had less to do with SPL capability and more with a characteristic of very small speakers, some of which can create huge soundstages but also small images within that soundstage, like that of midget performers. The famous LS3/5a comes to mind. I have read a couple of casual reviews saying this about the Xd and I hope it isn't true.

John Ashman · « **Reply #68 on:** 21 Jan 2005, 02:48 pm »

John Hidley · « **Reply #69 on:** 27 Jan 2005, 12:30 am »

The Xd system is designed to appeal to the average person who likes and wants to hear high quality music. It is definitely not targeted at the tweaker. Setting up a high quality audio system has become very difficult for a number of reasons. The Xd system is designed to be as simple as possible to setup without sacrificing performance.

The decision to use a 5.25" woofer in the XdS over a 6.5" woofer was driven by a couple of factors. One of the biggest goals in the design of Xd was having flat frequency response over a very wide listening area. We could not have achieved that with a 6.5" woofer. They are just too directional.

The second big reason was system size. We wanted the XdS to be as small as possible given our performance requirements. The 6.5" woofer would have required the system to be considerably larger.

The resulting system will play amazingly loudly while maintaining low distortion. From a demo standpoint that is one of the coolest features! People assume that they are looking at a standard 5.25" two way speaker.

John Ashman · « **Reply #70 on:** 27 Jan 2005, 01:17 am »

Davey · « **Reply #71 on:** 27 Jan 2005, 05:23 am »

Yeah, that's some good hyperboling John.

Stereophile will have to create a new "Class-X" category for these speakers. That will be just about as useless as the rest of their "classes."

I think probably size was the major consideration in selecting the smaller midrange driver. Better WAF and more "wow" factor because of the smaller boxes.
A 6.5-7 inch driver starts to get directional only about 150Hz lower than a 5.25 inch, but it has the advantage of approximately 3.6db more output capability (assuming the same excursion) or a lower crossover frequency to the woofers. In either case, the power-response of a system like this wouldn't be as linear as some other designs, but that may or may not be a good thing depending upon other factors.
The resonant peak of the Seas 7" magnesium driver is also a bit lower than the 5.25" driver so that probably factored into the decision as well. Although with the steep slopes of the DEQX that shouldn't be much of an issue.

Cheers,

Davey.

_scotty_ · « **Reply #72 on:** 27 Jan 2005, 05:37 am »

I think you are trying to say that the speakers do not exhibit lobing errors
because they do not have two drivers overlaping and operating in the same frequency range.
Instead they behave as a single wide band phase coherent transducer with a very even dispersion pattern at all frequencies up to the point where the radiated wavelength equals the diameter of the tweeter. They should also
be transient perfect and reproduce a very good squarewave if tested in an anechoic chamber. The only reason that they might not succeed in the marketplace is the absence of a number of familiar distortion charcteristics that
audiophiles are used to hearing and have come to expect from reproduced music via conventional speakers. Lip service is frequently given to desiring
accurate music reproduction that is faithful to the source. Many people
don't want it when they hear it for the first time because it does not sound
like what they are used to. Any real advance in accuracy will sound different from
what we have heard before and may require a learning curve before it is understood or appreciated. Scotty

John Ashman · « **Reply #73 on:** 27 Jan 2005, 07:26 am »

John Ashman · « **Reply #74 on:** 27 Jan 2005, 07:40 am »

Davey · « **Reply #75 on:** 27 Jan 2005, 03:44 pm »

Maybe not "lobing errors" but a simplified "lobing pattern" would be more descriptive. The drivers are non-coincident so some type of lobing direction or pattern is a given, and of course the woofers are completely separate so integration with the small boxes with high crossover slopes is not a trivial matter. In my comment I was thinking more along the lines of truly even power-response systems like omni-polar or directional speakers like dipoles. The listening environment would probably dictate which would sound more realistic.

Some "familiar" distortion characteristics are no doubt improved with the steep crossover slopes, but non-linear distortions of the drivers themselves can't be "fixed" by the DEQX and if the system is played louder then these distortions would increase as well. There's no free lunch.

The system may indeed exhibit "transient perfect" behaviour in an anechoic environment, however I don't see any claims for this in the sales literature. It matters little anyway, because we human-beings are not really sensitive to waveform or time-domain distortions. There have been a number of practical examples that seem to prove this. However, a system that's "linear-phase" or "transient-perfect" sure sounds good to the marketing types.

I think I "caught on" a long time ago John, but thanks anyway.

Cheers,

Davey.

Occam · « **Reply #76 on:** 27 Jan 2005, 05:05 pm »

Does this NHT/DEQX system presently provide any 'room correction' (modes, nodes) for those frequencies covered by the shared bass bin?

John Hidley · « **Reply #77 on:** 27 Jan 2005, 06:34 pm »

The low frequency (<300Hz) room correction option will not be available until late this year.

brj · « **Reply #78 on:** 27 Jan 2005, 06:39 pm »

Quote from: John Hidley

The low frequency (<300Hz) room correction option will not be available until late this year.

Can the existing products be upgraded to include this feature when available? Will you be charging for software upgrades in general?

Thanks!

John Ashman · « **Reply #79 on:** 27 Jan 2005, 06:48 pm »