AudioCircle
The Commercial Zone => Audio Shows and Events => Topic started by: mac on 14 Jan 2005, 10:42 pm
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http://www.tmcnet.com/usubmit/2005/Jan/1107763.htm
"NHT Xd is the result of the combined efforts of three companies - NHT, DEQX (Digital Equalization and Crossover), and PowerPhysics - that pooled their respective core technologies to develop a system that removes virtually all possible distortion from the audio signal path while providing a much wider soundfield that remains accurate, even when listening far off axis. The end result is a small system that offers a new level of clarity than any previously heard. The system features two small speaker cabinets; a powered bass, or woofer module; and a hybrid outboard component that houses the DEQX-calibrated DSP (digital signal processor) and PowerPhysics One-Cycle Sound (TM) amplifiers. Additional channels and bass modules can be added to create surround systems."
Overall, the best sound that I heard the at the show was coming from the DEQX room.
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These awards (http://www.cesweb.org/attendees/awards/demmy.asp) should be very interesting next year.
The 2005 DEMMY Awards will recognize recordings that reflect the highest quality of sound engineering, incorporate natural tonal balance, great clarity of detail, and have a realistic, three-dimensional soundstage.
[/list:u]
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I am not sure how prestigious this award really is for audio companies.
I client that I have done some design work for asked me about the award, so I checked into it. He had heard about it because some other speaker manufacturer that he had heard about had based their whole marketing campaign around winning this award.
First of all the award is given by a television station (G4Tech TV) for new technology products. It has nothing to do with performance, sound quality, or how the product compares to other similar products.
Secondly, it is not something being competed for by every company at the CES. In order to be considered for their awards you must register with them to win.
The category of high end audio, this year called "Ultimate Audio", has the lowest participation of all categories.
From Caroline Diaz of G4Tech TV: "Yes, we do not have as many entrants into the high-end audio category as we do in the other categories."
So the winner of each category competed only against others registered in that category.
I asked Caroline how many companies had entered each category, each year, to get a feel for how much competition there really was. I had been told unofficially that in first year only three companies had entered. Her reply was that there were, ah, less than a handful.
And year two? Well ah, not very many more...
But last year she seamed to believe that there were nearly 25 that entered, if memory serves her correct.
How many were there this year? Dera Revel, CES coordinator, G4TechTV stated that this year there were about 10 entrants in the Ultimate Audio category.
However, this years winner does seam to be an innovative standout worthy of serious recognition whether recognized by Tech TV or not.
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Did anyone from AC have a chance to hear the system? Any comments?
Thanks!
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I saw them this year for the second time. The nice young man that was in the room recognized me from last year.
Last year I sat down and really looked at what they were offering.
If I remember correctly, last year they had two pairs of speakers set up and I think they were NHT's. One pair was stock and one pair was being run with their DEQX system.
Clearly the stock units were nothing to be impressed with, but the pair of speakers running on the DEQX system sounded really good.
My guess is that using the system with higher quality drivers would be well above the norm. Maybe limited only by the quality of the DA converters and type of amps used.
Mac, is this what you are using with your Seas Excel woofer and ribbon tweeter combo? It can't be anything but excellent.
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Mac, is this what you are using with your Seas Excel woofer and ribbon tweeter combo? It can't be anything but excellent.
Hi Danny, Yes. I'm using a standard DEQX PDC-2.6 with my DIY built speakers and dipole subwoofers (http://lowfat.sytes.net/~mike/ribbon/satellite/P1010011.JPG). The system sounds really good, especially since changing over to all UcD (http://www.diyaudio.com/forums/showthread.php?s=&threadid=42146) amplifier modules.
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Mac, that setup is both tasty, and tasteful - nice job on the woodwork, and I like the overall "feel" of how that comes together!
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It's been a few years since I last attended the CES but in years past these "awards" were little more than a high school popularity contest. The winners were grouped in a room and everything assembled before the show started. This meant that it wasn't like you had judges going around listening and then picking a winner - it was all determined beforehand. Not something I would take much stock in other than a publicity shot for the CES to be promoted in the various publications.
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the CES but in years past these "awards" were little more than a high school popularity contest...
Thanks for sharing your cynical insights. I'm sure VMPS and Joseph Audio didn't deserve their past awards either (yeah, right). :bawl:
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Mac, that setup is both tasty, and tasteful - nice job on the woodwork, and I like the overall "feel" of how that comes together!
Thanks! I'm currently working on a very different project that I think is promising. Hopefully, I should have things sorted out in a couple weeks.
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nt
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Rick is right, many awards, if not most, have more to do with politics or other BS, but if you look at the totality of stuff on Xd, you'll see there is far more to it than a ditsy prom queen. There's some real science behind it and it measures better overall than just about any speaker ever created, at least in most areas - about the only place it could be challenged would be THD at high volumes, but only by a much larger speaker system. At typical listening levels, you're going to get less than .2% midran ...
Thanks for backing me up. I'm sure that the NHT system is an excellent performer. I just wanted to let everyone know that these awards are not something you would take much stock in. In the past I've seen both good and mediocre products win awards like this.
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Base on my experience with best of CES products recently, I will say that they can be good but not neccessarily better than other excellent products out there. In another word, I don't put much stock in best of CES any more (I used to).
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Be aware that Mr. Ashman is a NHT/NAD/Meridian dealer. You likely know him better as Alimentall/Joel Bernstien on AVS.
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nt
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Hehehe. I think you need a few more announcements on that forum. :)
There are plenty of systems that can compete with the Xd so you might be a busy guy. It's just a standard small box system after all and there are certain limitations that no amount of fancy DSP-processing can overcome.
You're going to fit in well here at the Audio (three-ring) Circle. :)
Cheers,
Davey.
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Anyone have a link that actually shows the thing? Isn't it a smallish 2-way speaker? You'd think DSP or no, you'd be pretty dynamically challenged. DEQX can't change the laws of physics. :roll: Then again, I guess the separate bass modules probably help out a lot.
What's the thing cost?
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http://www.adnm.com/cesclarity.htm
Joe M.
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Some more info from PCworld (about half way down page):
http://www.pcworld.com/news/article/0,aid,119225,00.asp
Joe M.
This info was originally posted on AVSForum
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John,
At what frequency does the subwoofer cross over to the sattelites?
TIA
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I don't believe NHT offers the preamp version with their control box, but I'm wondering if you can verify that. Not a huge deal if not, but it does need to be factored when comparing costs to the DEQX system. Also, do you know if this has enough gain to use a passive preamp?
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nt
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I don't believe NHT offers the preamp version with their control box, but I'm wondering if you can verify that. Not a huge deal if not, but it does need to be factored when comparing costs to the DEQX system. Also, do you know if this has enough gain to use a passive preamp?
As I mentioned in another thread, DEQX will be releasing two new versions of their PDC, which will include 4-channel digital amplification. One of the two versions will also include a preamplifier. They demo'd them at the CES.
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nt
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As I mentioned in another thread, DEQX will be releasing two new versions of their PDC, which will include 4-channel digital amplification. One of the two versions will also include a preamplifier. They demo'd them at the CES.
I think you also told me you expect it to cost in the same ballpark as the entire NHT system. I'm guessing they cut some functionality on the Xd to not only keep the price down but to also differentiate the DEQX units??
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OBF,
I've heard from a speaker maker that they(DEQX) will sell him OEM DEQX's that he can (must) lock in the speaker XO parameters and just have the room correction for the end user to adjust. He can get that at a pretty good discount, he mentioned, but he never elaborated what the disount was.
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DEQX can't change the laws of physics.
No, but it gives you a complete tool kit for dealing with physics that really hasn't existed before. Still, the driver/cabinet design is even more critical than ever because now that is more the limiting factor than ever.
Good answer, even if it is pure sophistry. :wink: I was talking only about dynamics, which should have been obvious. The steep X-over may improve power handling to a good degree, but what in it's radical new toolkit will make it play as loud as, say, a pair of RM-40's or GR Alpha's?
I'm sure it sounds nice, though.:lol:
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Good answer, even if it is pure sophistry. :wink: I was talking only about dynamics, which should have been obvious. The steep X-over may improve power handling to a good degree, but what in it's radical new toolkit will make it play as loud as, say, a pair of RM-40's or GR Alpha's?
I'm sure it sounds nice, though.:lol:
Let's agree on a piece of music to play and whip out our Radio Shack SPL meters. I'll put my triamped DEQX system up against whatever you've got. :D In reality, there's a difference between maximum SPL and what a lot of us relate to as "dynamic range" or "wallop". In most cases I believe the multi-amped system will excel. As always, YMMV. :)
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nt
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I have slender two-way towers (and a pair of subs), so I don't doubt you'll have more wallup, Mac. I also am not in a space where I can afford the rig you have. Hell, I can't afford the tax on the NHT/DEQX rig. :oops: No need to whip it out on my account, Mac- I know you can piss farther.:lol: So consider my questions as fact finding for the day when I can. It would be great to be able to hear that rig, but I likely won't ever have the chance. My wish is to get away from the small-speakers-with-sub rig and move towards a big-speakers-with-subs deal!:P I would be interested if someone could post some stats on measured max SPL output from the NHT/DEQX.
One aspect of a line array that you guys don't take into account is the perceived increase of loudness that you get from multiple drivers. Let's say you measure two systems and they both are pumping out 100 dB/A at 15 feet. Speaker A is a 6.5" two way, while Speaker B is a 16 driver line array. Which one is louder? Neither, but a lot of research shows that Speaker B will sound louder. Why? Physical S/N ratio. More drivers gives more direct vs reflected sound for an apparent increase in volume. I'm sure Danny, Rich or BC could explain it in much more detail than I.
At any rate, there's no reason not to apply the same DEQX techiques to a line array, getting the best of both. No offense to the nice man from NHT, but many of us will always prefer to go with a "value for money" company like most of our vendors here. Most people here feel those direct market companies offer more performance for the dollar than the majors.
This have been pretty friendly, so don't take this wrong, but I'm glad to see NHT is getting wise to what many have been doing for years. A quick perusal of the forums (not just AC) will show that people have been using DEQX, and before that TACT, and some homebrew solutions for a long time. That's not meant to minimize what NHT has done- I'm sure they'll do more to bring it to the mainstream than Selah, VMPS or GR Research could ever hope to. They're simply a bigger, more mainstream company.
I've been a digital junkie for years, and the "Messiah of Multichannel." Hell, I was digital when digital wasn't cool! :lol: I'd love to have a MC DEQX'd rig with all digital amps and 5 line arrays. No analog here. I'm certainly not opposed to things new & digital, so don't go thinking that! :wink:
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OBF,
I've heard from a speaker maker that they(DEQX) will sell him OEM DEQX's that he can (must) lock in the speaker XO parameters and just have the room correction for the end user to adjust. He can get that at a pretty good discount, he mentioned, but he never elaborated what the disount was.
Would the owner be able to defeat those settings or know what they are from the software / hardware interface?
Rick
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Would the owner be able to defeat those settings or know what they are from the software / hardware interface?
Rick
From the DEQX website (http://www.deqx.com/product.html):
Pre-Corrected Loudspeakers (OEM Modules)
Loudspeaker manufacturers can implement DEQX Calibrated™certification into existing designs using DEQX's OEM DSP / digital amplifier modules which can be customized to specific physical and I/O requirements. Since the unique pseudo-anechoic measurements are made at time of production, there are no set up requirements for the user. Register your interest in DEQX OEM modules.
You probably only need to order 500 at a time. :lol:
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Who the heck is Joel Bernstien?
I'm sorry I misspelled your new name on AVS. It should have been Joel Bernstein. :oops:
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Who the heck is Joel Bernstien?
I'm sorry I misspelled your new name on AVS. It should have been Joel Bernstein. :oops:
Be aware that there could be someone else parading as "Joel Bernstein".
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From the DEQX website (http://www.deqx.com/product.html):
Pre-Corrected Loudspeakers (OEM Modules)
Loudspeaker manufacturers can implement DEQX Calibrated™certification into existing designs using DEQX's OEM DSP / digital amplifier modules which can be customized to specific physical and I/O requirements. Since the unique pseudo-anechoic measurements are made at time of production, there are no set up requirements for the user. Register your interest in DEQX OEM modules.
You probably only need to order 500 at a time. :lol:
Thanks Mike but you still didn't answer the question. Ever think about politics as a vocation ? :lol:
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From the DEQX website:
Pre-Corrected Loudspeakers (OEM Modules)
Loudspeaker manufacturers can implement DEQX Calibrated™certification into existing designs using DEQX's OEM DSP / digital amplifier modules which can be customized to specific physical and I/O requirements. Since the unique pseudo-anechoic measurements are made at time of production, there are no set up requirements for the user. Register your interest in DEQX OEM modules.
You probably only need to order 500 at a time. :lol:
Thanks Mike but you still didn't answer the question. Ever think about politics as a vocation ? :lol:
I'll carve out just the part you need: "Since the unique pseudo-anechoic measurements are made at time of production, there are no set up requirements for the user." :)
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nt
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I'm sorry I misspelled your new name on AVS. It should have been Joel Bernstein. :oops:
Pass the bong.
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Who the heck is Joel Bernstien?
I'm sorry I misspelled your new name on AVS. It should have been Joel Bernstein. :oops:
Actually I went back and looked at the various AVS posts and I don't think Mr. Ashman is the same as Joel Bernstein. I'm sure you have your reasons but Mr. Bernstein looks legit to me.
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Hi all,
Can SOMEONE here explain to me how this thread is anything OTHER than a slick attempt to market these speakers, using this forum to advertise? :o
FYI: I was at CES myself and didn't hear "boo" from ANYONE I was in contact with regarding the supposed "superiority" of this particular sound system. (In fact, this is the first "over the top" accolade I've heard of regarding this system.) Please also understand that I was in contact with more than a dozen separate audiophiles which I continuously asked "what are some of the more impressive standouts that you have heard?" (each and every day mind you too :wink: ). Many of my hard core audiophile buddies were VERY FOCUSED (perhaps even obsessed) with finding "new" audio standouts, advancements and genuine breakthroughs.
Again, this thread sure looks to me like a slick marketing attempt to impress and susbsequently sell to Audiocircle members. Any insights about the people involved in touting this system (and it's supposed greatness) will be greatly appreciated!
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nt
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Hi John,
Thanks for the clarification. It looks like this speaker may be something special, for home theater applications at least. In my humble opinion, it's one thing all together to reduce or eliminate distortions and increase the dynamic range but there are many other things to consider in creating a true world class two channel audiophile speaker system.
Here is some perspective that I am aware of regarding the history of NHT: A few years ago Ken Kantor bragged how his metal dome tweeter was made for a mere six bucks :roll: . I absolutely agree that he'd probably found the best six dollar tweeter on the entire planet. :nono: But that was also the problem. IMHO "Over the top" two channel audiophile sound reproduction takes allot more than the best six dollar tweeter to be at the same level with speakers that have decent silk dome or ribbon tweeters comparatively (at $30 to $250 for the pair of tweeters mind you, great audiophile level tweeters cost "real" money.). That has always been the downfall of NHT's engineering decisions in my humble opinion. They were so focused on the cost of their drivers that their speakers just wouldn't be truly capable of portraying the subtle nuances that can only be had with very precise drivers i.e. silk dome or ribbons for instance.
For me the bottom line regarding NHT's potential "breakthroughs" (such as reducing distortion or increasing dynamic range through DSP, DSD or other silicon based digital integrated systems along with integrated digital amplification) become fairly "moot". Overall sonic excellence requires very precise drivers made with care (and cost) that cannot be corrected with DSP and such. This is what separates the very best world class high end two channel audiophile speakers from the rest of the crowd. (Again were talking about portraying nuances that only world class drivers can convey, and which DSP, DSD cannot solve).
Of course when you are focusing on home theater requirement it's a whole different ball game. That I'll give NHT the benefit of the doubt for now. Low distortion and high SPLs are pretty damn imperative goals for home theater sound reproduction. If that is the crowd that NHT made this system for then they may have hit the ball out of the park.
Perhaps now that NHT may have figured how to drastically reduce distortion and such they may consider engineering a speaker with world class drivers too (for us "two channel guys"). One can only hope it's more than just the home theater crowd that they care about. :wink:
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I wonder how much of the improvement in this system is due to the NHT speakers? How would the new ACI Sapphire XL speakers with a maestro sub compare if calibrated with DEQX and using the same amps? I believe there has been too much positive press about the NHT system for them to be anything but awesome. I also love the look and form factor. There are simply too many variables in the system to really say why they're so good. We'll see what people say after they become available to the public.
Joe M.
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John,
My DIY dipole system will kill speakers in the $15K-$50K range and easily compete with the NHT Xd setup, and it only costs $650.00 to build. That's a steal, not the Xd system. :)
Davey.
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Eric,
I for one am glad John A is here sharing with us his knowledge. I have read most all of this thread and I don't see his 'slick marketing' of NHT speakers. It seems to me that he is tauting the virtues of the DEQX system, which I think are probably very real, albeit I haven't heard it in action myself, although I know a number of people who have.
We do have a precedent here about not schelking your wares in a general forum when your weren't directly asked. I think in this case, John A is new so he isn't going to know all the history, although there is the FAQs for manufacturers and such. Secondly, he is being addressed with regard to the NHT Xd system as he has a part in it. Therefore, I don't see anything underhanded in this thread.
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Welcome Davey!
(for those who don't know, Davey is reg on diyaudio.com and the apogee forums)
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Hey, all the Dunlavy/Duntech speakers use $10 tweeters, so I disagree that real audiophile speakers cost real money, they just take up space.
But in the case of the NHT Xd, I heard them on a trade show floor and found them exceptionally unique. I don't doubt anyone being extremely enthusiastic about them, they would probably be my ideal speakers for my jazz system at least.
steve
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It's been suggested, both here within the topic and to me on PM, that this topic has veered into self-promotion and Audio Central may not be the circle for it. I just re-read the topic and think it comes close, but still offers up good insight into an exciting new idea that reportedly reduces errors in (arguably, of course :wink: ) the one component in the audio chain that has had the least advances in the past, oh, 30 years.
So, I think it still merits a place in Audio Central, but let's not let this get outta' hand and have this end up in either Market Square, or fer' cryin' out loud, Fight Club.
Thx,
John aka TheChairGuy
Facilitator / Audio Central
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nt
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Thanks Josh. Not much on the Apogee forum anymore....lost interest. I will lurk here if you folks don't mind. :)
Davey.
Welcome Davey!
(for those who don't know, Davey is reg on diyaudio.com and the apogee forums)
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My DIY dipole system will kill speakers in the $15K-$50K range and easily compete with the NHT Xd setup, and it only costs $650.00 to build. That's a steal, not the Xd system. :)
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Dave, is the Linkwitz Orion among the speakers that your $650 dipoles "kill"? :) Seriously, as someone who has owned the Orions and now the DEQX, I can tell you it's really not a very fair comparison. Cheers, mac.
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Mac,
I hope you noticed that I used John's own words in my comment for a (hopefully) humorous effect. Maybe not. :)
Generally, if a person says speaker X "kills" speaker A, B, etc, I immediately think it's a biased subjective comment and lose interest in reading further.
The Orion and Davey systems are another subject and I'd be happy to discuss those in a different thread if someone would like to. I didn't mean to take this thread off topic with my comment. Sorry.
Cheers,
Davey.
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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.
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nt
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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
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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. :lol: 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.
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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.
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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.
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nt
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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.
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nt
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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.
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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
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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.
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Does this NHT/DEQX system presently provide any 'room correction' (modes, nodes) for those frequencies covered by the shared bass bin?
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The low frequency (<300Hz) room correction option will not be available until late this year.
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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!
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John,
I'm not sure who you're quoting, but I didn't say "this driver plays 3.6db louder, we must use it." I said "it has the advantage of approximately 3.6db more output capability (assuming the same excursion,)" and I thought I clearly outlined a couple of the trade-offs.
Anyway, it wasn't me that mentioned the larger driver, it was Val in a previous post. (I happen to think they DID make the correct choice with the 5.25" driver.)
Cheers,
Davey.
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nt
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The actual XdA hardware has a microphone input and USB port to allow use of the room correction software. The XdA currently ships without any software of any kind. There are four preset filters programmed into it for the XdS satellite. Each filter is designed to compensate for the XdS placed in a different environment. The four settings are 4pi (free field), 2pi (against a wall), 1pi (in a corner) and on top of a large television as a center channel.
When the room correction software is available, it will be licensed to trained installers and dealers on a per installation basis. It will not be sold with the Xd product to the consumer.
The consumer will be able to download different filter sets for the XdA from our website. We will provide optional filter sets for particular applications. For example, if you want higher output from the system, you can use two of the XdW bass modules placed very close to the XdS speakers and install a filter set that raises the crossover frequency to 180Hz. This will allow the XdS speakers to play quite a bit louder.
Currently the DEQX software only does linear corrections to the frequency and phase response. We are working on some new techniques that will allow it to do nonlinear correction. This will allow us to reduce the actual THD that the driver is producing.
The following link has some more information about the product. Go to the link and scroll down until you see 2004_NHT_Xd_WhitePaper.pdf. You can right click on this and save it or left click and open it in your browser.
http://www.nhthifi.com/scripts/nhttech.cfg/php.exe/enduser/std_adp.php?p_faqid=171&p_created=1088456399
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I didn't say that you did say that. ...
Yes, I misunderstood your quoted quote, and then you replied so quickly I couldn't fix it in time.
Sorry about that.
Davey.
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nt
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...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....
sorry, this sounds extremely patronizing to me. imo, most, if not all audiophiles prefer accurate musical reproduction, and can easily identify it when they hear it. i *do* know that some folks are hung up on cost (not yust audiophiles, btw!), & they *will* get bent outta shape if their multi-kilobucks baby is outperformed by something relatively cheap. but this doesn't mean they don't like better, more accurate reproduced sound! :)
ymmv,
doug s.
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Anyway, it wasn't me that mentioned the larger driver, it was Val in a previous post. (I happen to think they DID make the correct choice with the 5.25" driver.)
Of course NHT/DEQX weren't thinking about me, they have chosen what they thought will be best for them and they are probably right from their point of view; I am open minded and can't wait for the Xd to dazzle me.
Anyway, John is preaching to the choir as far as I am concerned. I have followed DEQX for years and I'm convinced they are opening doors to the future. Contrary to some posters here, to me the DEQZ is a preamp and DAC that allows me to place a CD transport close to the listening seat and the rest of the equipment behind the speakers, a bargain at $3,500 compared with what is out there; the other goodies it offers are just icing on the cake!
Val
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sorry, this sounds extremely patronizing to me. imo, most, if not all audiophiles prefer accurate musical reproduction, and can easily identify it when they hear it. i *do* know that some folks are hung up on cost (not yust audiophiles, btw!), & they *will* get bent outta shape if their multi-kilobucks baby is outperformed by something relatively cheap. but this doesn't mean they don't like better, more accurate reproduced sound! :)
ymmv,
doug s.
Let me disagre. Most of the audiophiles learned to listen and enjoy a pschychoacustically completely wrong setup, a very specific kind of distortion, namely the stereo reproduction. The idea of 2 loudspeaker, communicating with both ear, trying to produce virtual sound sources between them is completely unnatural, but most audiophile learned this kind of distortion so well, that wen they hear the real thing, the unamplified live music from the proper distance, they complain about the lack of this kind of distortion ( the soundstage flat, not well defined image, not enoug layering and all kind of other nonsense).
Listening to this mess ( the stereo) the brain always complaining that the different sonic clues are crontroversial, the created soundfield is not real. There are moments when the failures in the recording, reproduction chain, room acoustic can mask momentarily these faults, then the proud owner can claim, that he found the perfect record/gear/room treatment etc., but these moments are rare, non reproducible and non transferable to other environments, which is the base of the never ending audiophile nervosa and flame wars.
OTOH these pschychoacoustic inconsistencies make the audiophile reproduction less appealing for the masses. High-end systems while having less distortion, better FR, but they are still annoyingly not real or not different from a boombox for an "uneducated" ear.
Csero
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Contrary to some posters here, to me the DEQZ is a preamp and DAC that allows me to place a CD transport close to the listening seat and the re ...
Are you thinking with a very long digital cable, or something wireless like a Squeezebox?
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Are you thinking with a very long digital cable, ...
Yes, a long digital cable to the DEQX.
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nt
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Let me disagre. Most of the audiophiles learned to listen and enjoy a pschychoacustically completely wrong setup, a very specific kind of distortion, namely the stereo reproduction. The idea of 2 loudspeaker, communicating with both ear, trying to produce virtual sound sources between them is completely unnatural, but most audiophile learned this kind of distortion so well, that wen they hear the real thing, the unamplified live music from the proper distance, they complain about the lack of this kind of distortion ( the soundstage flat, not well defined image, not enoug layering and all kind of other nonsense).
Listening to this mess ( the stereo) the brain always complaining that the different sonic clues are crontroversial, the created soundfield is not real. There are moments when the failures in the recording, reproduction chain, room acoustic can mask momentarily these faults, then the proud owner can claim, that he found the perfect record/gear/room treatment etc., but these moments are rare, non reproducible and non transferable to other environments, which is the base of the never ending audiophile nervosa and flame wars.
OTOH these pschychoacoustic inconsistencies make the audiophile reproduction less appealing for the masses. High-end systems while having less distortion, better FR, but they are still annoyingly not real or not different from a boombox for an "uneducated" ear.
csero, no - i REFUSE to let you disagree! :lol:
seriously, i do not disagree w/much of what you say re: the lack of ability of2-channel stereo to approach a real sonic ewent. but, most audiphiles i know *do* prefer anything that helps get them closer to this.
as far as soundstaging/imaging/layering, etc - for music that's recorded & mixed in a studio (which accounts for the vast majority of what is recorded), there IS no right or wrong, yust one's personal tastes. as an example: in another thread, someone asked me if i had compared the magnepan 3.6's to the newform research 645r's. i told him that i was not a good person to ask, for this kind of comparison, as i do not enjoy the soundstage presented by dipolar speakers such as magnepans. some folk like this sonic signature, others do not. it doesn't mean either is right or wrong.
as far as your statement re: hi-end systems being not different from a boombox to an uneducated ear, this is yust completely 100% different to what i have observed, in my experience. EVERYONE who i have EVER observed listen to a hi-end system for the first time, has UNIVERSALLY been flabbergasted about how amazing a good audio system can sound. and, not, i am not only referring to uneducated ears listening to *my* system, but other people's systems, & well-set-up systems in commercial establishments.
regards,
doug s.
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I completely agree with you here, but that is a different thing than accuracy in a speaker. Even Xd will still not be as ideal having three or five front speakers, but the good news here is that even hardcore audiophiles that are used to what I consider to be a high degree of speaker distortion and coloration felt Xd was amazing and wanted another crack at listening in their own homes. So, I'm not counting out the audiophile crowd on this one, though many may feel that it is somehow necessary to wait for the "right" digital speaker with the "right" name brand and the "right" component parts.
your comment speaks to some "audiophiles", who aren't concerned about sonics, but are concerned only about status, as i mentioned earlier. these aren't real audiophiles, imo...
regards,
doug s.
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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 ...
I went back and looked over your posts at the AVS Forum and I appreciate your solid scientific approach to engineering speakers. I think your objectives for this design are very good for both sound quality and form / function.
Rick
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csero, no - i REFUSE to let you disagree! :lol:
seriously, i do not disagree w/much of what you say re: the lack of ability of2-channel stereo to approach a real sonic ewent. but, most audiphiles i know *do* prefer anything that helps get them closer to this.
Would they still prefer that if the solution is completely oppose to what they ever learned, claimed, believed, got used to in hi-fi reproduction?
as far as soundstaging/imaging/layering, etc - for music that's recorded & mixed in a studio (which accounts for the vast majority of what is recorded), there IS no right or wrong, yust one's personal tastes.
If I'd believe that sound recording is an art and the recording engineer/producer is the artist, than i'd be in an easy situation, I just have to get similar gear/room they use to get as close to their art as I can.
But I believe the purpose of the hi-fi is to believable reproducton of a sonic event, or for for music that's recorded & mixed in a studio, to create a presentation, where your brain does not complain much about the artificial nature of the reproduction, and let's you concentrate to the musical happening - and I'm not speaking about adding pleasant colorations here. The biggest problem with the present sound reproduction, that somewhere in the back of your brain, you allways know that the sound is artifical, and this does not let you fully enjoy the performance, but always force you to evaluate, appreciate the gear. From this point the whole high-end/home theater bandwagon is on the wrong track for me.
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nt
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But I believe the purpose of the hi-fi is to believable reproducton of a sonic event, or for for music that's recorded & mixed in a studio, to create a presentation, where your brain does not complain much about the artificial nature of the reproduction, and let's you concentrate to the musical happening - and I'm not speaking about adding pleasant colorations here
csero, Do you feel that this belief is in conflict with the goal of accurate reproduction
of the recorded waveform. Shouldn't the burden of "believability" be on the listener rather than on the hifi equipement. Assuming of course that the equipement is reproducing the information as accurately as possible.
The decisions made in the recording studio are a seperate issue from accurately reproducing the results of their efforts. Most of the recent studio recordings I have listened to have not been been an attempt to capture a live performance but were rather a completely artificial sounding creation that while entertaining could not in any way be interpeted as a realistic grouping of musicians playing in front of me.
With a few exceptions producing a realistic sounding recording documenting the performance of the musicians has not been goal of recording in a studio for decades.
Scotty
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Just thought I'd mention for the record, Csero's system, hand's down by no small margin is the most believeable system I have ever heard, ever. His system is not filled with audiophile approved components, in fact totals less than a grand for the whole system. However, not my system, nor systems I have heard that were in the six figures could touch the believeability and you-are-there experience that Frank's system produces.
It changed everything for me and helped me realize that no amount of money spent on audiophile equipment is going to get me to where the end goal is, I have to think outside the box and leave the crowd to learn where stereo REPRODUCTION goes fatally wrong. There is a lot of good work on the subject that audiophiles have refused to realize or read over the last couple of decades. The problem isn't the stereo recording, hell even mono recordings were wonderfully believeable on Frank's system. The problem is stereo reproduction was a first attempt at using more speakers to match the spacial cues our ears hear and it stopped there. However this is utterly wrong, and MCH music ala DVD-A and SACD are going further in the wrong direction.
If this piques your interest at all, browse to ambiophonics.org and start a little bit of reading. This isn't just another audiophile tweak, it is the real deal and once you hear it as I've had there is no going back if real reproduction of the even is the goal, not just audiophile hi-fi sound.
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i believe the purpose of hi-fi is to enjoy music. to reproduce the musical ewent is a misnomer, in most cases. sure, some music is live & unamplified. but, unless yure listening only to classical music, this is not the majority of what yure gonna be hearing. even if you go to a live music concert. the "musical ewent" is usually amplified electronically, if live, or recorded from highly-proccessed multi-layered tracks from individuals in small soundproof rooms. and, in many cases, the sound i hear from a hi-fi system is more enjoyable than what i've heard at a live concert. does it "reproduce the musical ewent"? not a relevant question, in most cases.
re: definition of an audiophile, i use it as a music lover. of course, i know there are "audiophiles" who are more interested in equipment than music, and some of these are only interested in how *expensive* the equipment is. which is why i put the term in quotes. these people aren't audiophiles or music lovers. they're egocentric snobs.
these types of people exist in all hobbies, btw, not yust music reproduction. ever been to an enthusiast car event? :wink:
ymmv,
doug s.
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nt
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But how can one even know what the event is supposed to sound like? My CDs don't sound anything like the concerts I attend. For instance, I don't think I could ever place the bass player on stage just by using my ears (I'm talking amplified rock concerts here, with extra speakers). Most times, I can't even hear the words as everything is turned up so loud.
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...If this piques your interest at all, browse to ambiophonics.org and start a little bit of reading. This isn't just another audiophile tweak, it is the real deal and once you hear it as I've had there is no going back if real reproduction of the even is the goal, not just audiophile hi-fi sound....
funny you should mention this site. a few years back, i purchased three jvc xpa-1010's direct from jvc - they were sitting unused/unsold in one of their warehouses. they gave me a good deal, to get rid of 'em; i sold two to ralph glascal to help subsidize the purchase of the one i kept. a great li'l dewice, imo, for imparting that *live* sound to conwentional 2-channel audio. unfortunately it was the wictim of a personal family dispute, & ended up in a pile of little pieces. :( oh well. at least i am still here to tell about it! :wink:
this is the only way i am presently interested in doing surround sound - from properly processed signal derived from conwentional 2-channel audio. perhaps i may run across another xpa1010, or something else similar & relatively inexpensive will be deweloped in the marketplace, in the future.
regards,
doug s.
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Yeah I've been looking for one of those too, but shhhh don't want that much competition. Actually the JVC is only part of the solution, the other part isn't as easy because there is no off the shelf solution.
Bob, I understand where you are coming from but when you hear Frank's system I think it answers questions that I could never explain to you satifactorily. Basically though, Frank's system allows you to choice the approximate venue size, say Jazz club for a rock recording (not live), or concert hall for an orchestral piece and then the acoustics choosen actually matches what is on the recording so you really think you are in that venue. It isn't like the cheesy DSP stuff inside most mass market receivers, JVC actually went around and measured a lot of popular venues and got really info, this meshes well with the ambiophonic processing of the stereo to give a really realistic reproduction. If you close your eyes you can't tell that you aren't there from the spatial cues alone.
There are many other benefits to this system as well that I have never experienced in my hi-fi or any other hi-fi system. One is that when Frank played an old LP that had some surface noise, the surface noise was completely non-irritating. It was on a totally different realm, not part of the recording. This is what Frank analogized to like a baby crying in a concert. You hear it but if you are into the music it isn't part of your focus and all background noise in this system was like that. This is a lot different than background noise in my system, which gets confused with the spacial information and becomes fatiguing. Another is that imaging is real, not hyper real like stereo and doesn't shift or change when you move to the side a few feet, instead only the direction of the image towards the center changes, which is like what you would hear if you were there.
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i believe the purpose of hi-fi is to enjoy music. to reproduce the musical ewent is a misnomer, in most cases. sure, some music is live & unamplified. but, unless yure listening only to classical music, this is not the majority of what yure gonna be hearing. even if you go to a live music concert. the "musical ewent" is usually amplified electronically, if live, or recorded from highly-proccessed multi-layered tracks from individuals in small soundproof rooms. and, in many cases, the sound i hear from ...
So you are also an audiophile who could not change to something better, because you think your sound is better than the original. You don't "prefer accurate musical reproduction", and can't "easily identify it when you hear it" because it is not as pleasant as the sound of your hi-fi. :D
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You mean like the guys that buy a hot car and then are to terrified that it will get a nick in the parking lot that they begin stalking people in the parking lot? Or are you talking about the guys that have all these nice cars that they spend more time buffing than driving? :)
YES!!! :lol:
plus, ya forgot all the folk that think their cars are the best, yust cuz they cost more than a lot of houses... :lol:
there was a recent thread about cars here. (moved to the fight club, i think. :o ) seems a lot of folks are pretty perturbed (in the automotive community also, not yust here), that the mitsu evo can spank the pants off lotsa cars up to three times (or more?) the price.
as the owner of alfa romeo daily drivers, & a weekend de tomaso pantera "fun" car, i know what this is all about. i guess i have the same outlook about cars as i do re: audio - champagne taste, beer budget; so i yust look for the best end result possible, on a shoestring budget! :wink:
regards,
doug s.
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So you are also an audiophile who could not change to something better, because you think your sound is better than the original. You don't "prefer accurate musical reproduction", and can't "easily identify it when you hear it" because it is not as pleasant as the sound of your hi-fi. :D
frank,
it is a misnomer to say the *original* is real, if it is amplified, & heard thru a pa system... what part of it is real? and, what i said is not an absolute. *many* times, i come home from a concert totally wowed. so, you cannot judge whether or not i prefer accurate musical reproduction, or whether or not i can "easily identify it when i hear it", based upon what i said.
the point i am making is that at least 95% of music software has absolutely nothing to do with "accurate musical reproduction", so this term "accurate musical reproduction" is meaningless. what i enjoy is music. sometimes it sounds "natural", sometimes not. and, i do not choose to listen only to software that has been naturally recorded. i listen to music i like.
i also find it interesting that you also enjoy the xpa1010 in your system, something i found extremely fun to listen to music with, in my system. tho, i admit, that when i switched to all-tubed gear in a 26x38 listening room, its utility was dramatically reduced, as i was getting a really nice sound from conwentional two-channel.
regards,
doug s.
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Pantera, very nice - lots of fun that is.
As for bang for the buck vehicular fun, that is why I was so passionate about building Suzuki bikes all those years.
Take one 1986 Suzuki GSXR750 (lightest one ever made). Remove all bodywork, and passenger related equipment. Remove 750 motor. Install 1107 motor from 1992 GSXR1100 (most torque ever...). Optional upgrades include suspension from the 1991 GSXR750 (inverted forks) and wheels from same (17 inch, and 5 inch wide rear to accomodate wider and stickier rubber).
Add a helmet, and complete disregard for posted speed limits.
Now hunt EVERY nice car and bike that you can find... 0-60 in around 2.7 or so, IF you are light enough, and can ride well enough - I was light enough, but did not have the lightning reflexes for those launches, so my 0-60 times at the track tended to be in and around the boring old 3 second timeframe... Not many cars will show you a tail light even at that time.
Oh, and count on spending somewhere around $4000 US for this treat.
Nobody said it was pretty, or could carry groceries, or could attract the ladies - it was just straight up performance. Period.
Somehow that does not mix with marriage and family... funny that!
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Pantera, very nice - lots of fun that is.
As for bang for the buck vehicular fun, that is why I was so passionate about building Suzuki bikes all those years.
Take one 1986 Suzuki GSXR750 (lightest one ever made). Remove all bodywork, and passenger related equipment. Remove 750 motor. Install 1107 motor from 1992 GSXR1100 (most torque ever...). Optional upgrades include suspension from the 1991 GSXR750 (inverted forks) and wheels from same (17 inch, and 5 inch wide rear to accomodate wider and sti ...
birds of a feather... :D
regards,
doug s.,
'78 ducati darmah,
'95 buell s2, hot-rodded...
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The following link has some more information about the product. Go to the link and scroll down until you see 2004_NHT_Xd_WhitePaper.pdf. .....
http://www.nhthifi.com/scripts/nhttech.cfg/php.exe/enduser/std_adp.php?p_faq ...
I found that comparison betweem your Xd and SB-3 speakers (complete with graphs!!!), as well as the non-ambiguous technical talk, particularly illuminating. Thanks.
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The other speaker used in the comparison is actually an SB1, not an SB3. For some reason the version of the white paper on the website is slightly corrupted. Some fonts don't show up. I'll try to post an updated one with some more measurements.
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SB1.... oh, even better.
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doug s wrote -
'78 ducati darmah, '95 buell s2, hot-rodded...
- "yust" gotta respect a guy with great taste in twins!
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doug s wrote - '78 ducati darmah, '95 buell s2, hot-rodded...
- "yust" gotta respect a guy with great taste in twins!
thanks, mark! :) i know these won't touch yer "gixxers" in outright performance, but they're so much fun, & they make such nice noises! and, really, 0-60 in the high 3's/low 4's is plenty fast for me. and, i don't usually wanna cruise much over 100... :wink:
regards,
doug s.
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The actual XdA hardware has a microphone input and USB port to allow use of the room correction software. The XdA currently ships without any software of any kind. There are four preset filters programmed into it for the XdS satellite. Each filter is designed to compensate for the XdS placed in a different environment. The four settings are 4pi (free field), 2pi (against a wall), 1pi (in a corner) and on top of a large television as a center channel.
When the room correction software is available, it will be licensed to trained installers and dealers on a per installation basis. It will not be sold with the Xd product to the consumer.
The consumer will be able to download different filter sets for the XdA from our website. We will provide optional filter sets for particular applications. For example, if you want higher output from the system, you can use two of the XdW bass modules placed very close to the XdS speakers and install a filter set that raises the crossover frequency to 180Hz. This will allow the XdS speakers to play quite a bit louder.
Currently the DEQX software only does linear corrections to the frequency and phase response. We are working on some new techniques that will allow it to do nonlinear correction. This will allow us to reduce the actual THD that the driver is producing.
The following link has some more information about the product. Go to the link and scroll down until you see 2004_NHT_Xd_WhitePaper.pdf. You can right click on this and save it or left click and open it in your browser.
http://www.nhthifi.com/scripts/nhttech.cfg/php.exe/enduser/std_adp.php?p_faq .. ...
Mr. Hidley,
A few questions -
Regarding the first graph in your WhitePaper comparing the THD (total harmonic distortion) -
1. To what extent is the the difference in THD attributable to dsp or the differences in the drivers? [Yes, we understant those benefits of the high crossover slope with regards to driver overlap. Davey has addressed this.] How significant is the choice of these very different drivers, a polypropolene cone on the $300/pr SB1, and a magnesium cone, distortion reducing Faraday ring, etc... on the Excel driver in the Xd system.
2. As you've cut off the THD at <3,000 hz and the curves appear to be converging, can we assume that the tweeter on the SB1 is quite good? The descriptions for both tweeters appear quite similar.
3. The present legend on the graph descibes it as "at 10W". Should I assume this is 10 watts drive, as 10watts of acoustical output would destroy the drivers? I am used to seeing comparisons at equal SPLs(which might call for different drive level) at the same distances and preferred axis. Would you explain the possible resulting differences?
Regarding the 2nd & 3rd graphs on that same referenced WhatePaper which compare dispersion characteristics -
4. To what extent are those characteristics, for specific frequency ranges, influenced by DSP and which is attributable to flat baffle on the SB! and and the molded baffle on the Xd?
5. The legends and descripions on all the graphs are inadvertantly obscured, and I can't discern what angles off the listening access they represent. Would you clarify?
6. Both graphs show that expected crossover off axis nulls. On the Xd I see that impressively deep null, but on the SB1 I see a shifting null. A low sloped crossover largely explains the minimal depth of the null, but the shift puzzles me. Could you clarify and describe the crossover on the SB1? Is it similar to the Xover on your SB3, with its deliberately implemented lobing via its asymmeteric? Xover specifically engineered for its reccomended positioning and listening axis?
Your R&D efforts towards the reduction of non-linear distortions is facinating. Will this be possible with the computational capabilities on your present DEQX modules or will this have to wait for the next couple of gernerations of DSP engines? I do hope that this will not delay your efforts to deliver that room correction with conflicting resource demands.
IMO, your eventual delivery of your room correction cabability will be a tremendous upgrade. I've recently been astounded by the impact of this rather modestly demanding capability, parametric equalization(s) below 200-300hz, can have. I'd never really realized how much room modes/nodes at low frequencies can obscure resolution at higher frequencies.
Thanks in advance.
Paul
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nt
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Paul,
My training of John is going better than I thought. He hit almost all of the relevant points right on:)
1) The THD difference in the first graph is entirely due to the driver choice. The Xd 5.25" motor design is responsible for about 70% of its distortion performance. The cone design is responsible for the other 30%.
2) Yes, the tweeter in the SB1 is very good. It has almost the same distortion performance that the Xd Seas tweeter has, but the Seas unit is more consistent.
3) The THD measurements are made at a drive level of 8.94V. This is 10W into an 8ohm load. I can run the same test in a regulation mode that automatically adjusts the output level at every data point to hold the SPL exactly constant. There are two problems with this. It takes a long time. It causes the voice coil to heat up during the test. This makes the results dependant on how close the driver is to the target SPL at a particular place on the curve. Since the two 5.25" woofers in question have the same nominal sensitivity, we choose to just sweep them at a constant voltage.
4) The depth and narrowness of the notch at the crossover frequency is entirely due to the DSP high slope crossover. The smoothness of the off axis curves above 3kHz is due to the baffle design of the Xd. The relative lack of smoothness in the off axis curves in the SB1 is due to diffraction from the baffle.
5) I've posted the updated white paper on the NHT site. It has all of the legends fixed so you can read them and has a few more measurements.
6) The wide area of cancellation in the SB1 speaker is typical of passive loudspeakers. When designing the crossover, the number one priority is to get flat response on the most likely listening axis. Since the drivers each have their own varying group delay with frequency and non textbook rolloffs, this can be very challenging. This wide area of cancellation is the result of having to compromise the frequency and phase response at the exact crossover frequency with the frequency and phase response adjacant to the crossover frequency. You can use higher order filters, but in the passive world this costs more money, but more importantly it requires ridiculously high tolerance components to function.
The nonlinear distortion reduction will work on the existing hardware. It uses some very simple techniques to achieve our goals. The room correction option doesn't add any processing overhead beyond what the XdA is already doing. The DEQX processing is already using long convolution FIR + IIR filters to do the impulse response correction. When the room correction is applied to the system, the necessary filters for the room correction are just convolved with the existing filters to correct for the drivers themselves. This results in only one set of filters being processed in the XdA for either situation.
Frequencies between 100 and 400Hz do a very good job of masking higher frequencies.
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Mr. Hidley,
Thank you very much for the direct answers and the update of the WhitePaper. [excuse the formality, but I don't want confusions between the Johns]
Indeed, having Mr. Ashman on your team is a tremendous plus. The danger of his priaprismatic hyperbole sending certain participants into diabetic shock is far outweighed by the effect of his salesmanship on most readers. :)
Thanks again,
Paul
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Mr. Hidley,
Thank you very much for the direct answers and the update of the WhitePaper. [excuse the formality, but I don't want confusions between the Johns]
Indeed, having Mr. Ashman on your team is a tremendous plus. The danger of his priaprismatic hyperbole sending certain participants into diabetic shock is far outweighed by the effect of his salesmanship on most readers. :)
Thanks again,
Paul
what does priaprismatic mean? Can't find it on dictionary.com and it's bugging me not knowing what it means... I figure over enthusiastic or something along those lines :?: :)
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Ryan,
Sincere apologies for my wretched spelling. The word should have been 'priapismatic', from priapism - Persistent, usually painful erection of the penis,...
As the television ads say - If your erection lasts more than 4 hours, you should seek medical help immediately. Though my tendancy would be to call everyone I know and brag....