[goskers]

I completely agree that the DEQX route is not one that should be taken by all people.  The difference between a 1k and 2k diy speaker is substantial.  Add to this that a dsp system means going all active which means more cables and amp channels and you have yourself a completely different system.  To each their own.  Simplicity vs complexity.  Single driver vs multi....

[opticpit]

Rick,

Your comment brings home the second question in my post.  Is the expected improvement I could obtain from a DEQXed  Nautilus 805 plus/ minus an appropriate sub enough to justify the endeavor, or should I start fresh with a system incorporating one of the two best ribbon tweeters commercially available at this time? More money, more time involved for how much gain?Lots of time and effort involved as well, getting the box right.  

To my eye, the 805's plus the DEQX plus a sub should sound very similar to the DEQX NHT system.

[Val]

I'm not planning on adding any subs to my 805's.

You would be losing two of DEQX's great functions, to perfectly blend a pair of subwoofers and low frequency room equalization.

Val

[John Ashman]

Goskers,

Thanks, but I think the CES 2005 DEQX was set up with B and W 704's and a pair of "cheap" subs.  The 704's are floorstanders and have a bit more in the bass department than the little 805's.  I'm not planning on adding any subs to my 805's.  

In the original Stereophile review of the 805's, the reviewer mentioned a significant improvement using a biamped set up with Mark Levinson amps.  I can't help but wonder what the DEQX might add to performance of these speakers.

Opticpit, I think most any speaker will have an obvious benefit from DEQX, even if you only use the tri-amp and room correction features.  I did 602s and it was a big difference.  You can cross the tweeter/midrange over lower/steeper which increases dispersion, cleans up the hashy midrange and generally makes them much more open and smooth.  You would want to set the EQ parameters so that it doesn't try to EQ below 100Hz, the cones and/or porting doesn't like it much, best to let them roll off naturally.

The CES show used N805s.  Mac e-mailed me the picture.  I take a *little* offense to the "cheap sub" comment - those are NHT Evolution subs which, while affordable, have a HELLUVA bass driver in them, great cabinetry and are flat +/- .5dB with NHT's own analog crossover, let alone what DEQX does.  Of course, they are small and the finish isn't all that elegant, but I wouldn't call them "cheap".  They embarrass a lot of $2K+ subs and I've never seen a sub that measures as flat at any price.  Brent Butterworth measured +/-.2dB in his test.  

Back to the B&Ws, yes, MAJOR upgrade.  Not the most ideal driver complement but it does ameliorate a lot of the issues with Kevlar, much better than B&W's implementation which has the crossover too high and too shallow for the best imaging, integration, clarity and dispersion.

[Rick Craig]

Rick,

Your comment brings home the second question in my post.  Is the expected improvement I could obtain from a DEQXed  Nautilus 805 plus/ minus an appropriate sub enough to justify the endeavor, or should I start fresh with a system incorporating one of the two best ribbon tweeters commercially available at this time? More money, more time involved for how much gain?Lots of time and effort involved as well, getting the box right.  

To my eye, the 805's plus the DEQX plus a sub should sound very similar to the DEQX NHT system.

It really depends on what you want the system to do and how acceptable the tradeoffs are. With the DIY route you can get more bang for the buck provided you choose the right drivers and properly execute the design.

Rick

[John Ashman]

One thing I've noticed missing in all of the comments I've read about DEQX. If we assume that it can improve a $1,000 set of speakers then how will it compare to a set of non-DEQX'd speakers that cost the same ($3,000 (DEQX) + $1,000 (speakers) = $4K). A jump from $1K to $4K in a set of well-designed speakers can be quite a difference in performance, especially if you're going the DIY route. Typically this means moving up to greater bass extension, better drivers (lower distortion, more refined and detailed), and greater output capability.

I think it would be debateable whether $1000 is enough budget to get the decent drivers to compete with a $4000 speaker, especially in the bass, but by the time you get to $2000-$3000 in the speaker and you make the right speaker choice, I think you can get to the point where it would beat any $5K-$6K speaker pretty handily and, done really well, be objectively, if not subjectively better than just about any conventional speakers.

[opticpit]

Gents,

I'm nearly convinced to DEQX my 805's. I had been planning to upgrade my ten year old CD player and preamp anyway, so the DEQX preamp version could fill that role nicely.  Add to that the potential benefit I could get from "activating" my 805's and it begins to make some sense.  Anyone have any suggestions regarding the second amp. I'm currently using an old Aragon 4004 MK2 full range.  I'd like to use it to run the mid/woofs. Always been fascinated by the tubes.

How about the 4004 for the lows and a SE 300 for the highs?  Can the DEQX do level matching of disimilar amps? Best of both worlds or bad idea?

[John Ashman]

The PDC would compensate for all of this stuff, but it might be wise to have amplifiers that don't change over time.  But other than that it wouldn't be a problem.

[ludavico]

Hmmmm, so diminishing return could set in pretty hard then?  

Active ATCs, for example, sound pretty awesome on their own.  Perhaps DEQX wouldn't revolutionize them...  

The trouble is ATC puts the amps inside the speaker enclosure.  (Plus the amps are Class A and run hotter than Hades)  I have got to believe this arrangement is suboptimal.  

I really wonder, though, if using the DEQX x-overs would make much of a difference in a well designed active speaker system say, in the $10K range.  

Of course, the room correction functions are something else...

John

[JoshK]

I think it would be debateable whether $1000 is enough budget to get the decent drivers to compete with a $4000 speaker, especially in the bass, but by the time you get to $2000-$3000 in the speaker and you make the right speaker choice, I think you can get to the point where it would beat any $5K-$6K speaker pretty handily and, done really well, be objectively, if not subjectively better than just about any conventional speakers.

Arvo Part DIY speaker, $960 total for all drivers for stereo pair

[John Ashman]

Hmmmm, so diminishing return could set in pretty hard then?  

Active ATCs, for example, sound pretty awesome on their own.  Perhaps DEQX wouldn't revolutionize them...  

It depends on the quality of the design and what flaws the speakers have.  They don't seem to me to be the optimum speakers to DEQX since they are already active.

[John Ashman]

Arvo Part DIY speaker, $960 total for all drivers for stereo pair

$1000 is plenty for DIY for world-beating performance, figure double or so for pre-built stuff.

[Al Garay]

The ATC drivers are regarded as some of the best drivers made. And ATC monitors are equally highly thought after in professional studios as accurate monitors that can handle highs spl without compression.

Using the car analogy, it's already a Porshe Cayenne. However, the DEQX may upgrade the sound (especially in how it corrects for room modes) to the level of the the Cayenne Turbo.

I don't understand generalizing all active speakers as not being good candidates for the DEQX. Seems like the SL Orion is an active system which the DEQX could help cure some of its failings... adding more dynamics, better soundstaging and integration with the H-frame woofers.

[ctviggen]

Comparing any speaker to an SUV instantly makes them Bose in my opinion.

[doug s.]

Comparing any speaker to an SUV instantly makes them Bose in my opinion.

thanks bob, my sediment exactly.     *all* suv's suck.  the bigger they are, the more they cost, the more they suck.  cayenne turbo is about the worst of the lot.  i wish gas cost as much in the usa as it did in europe.  then the plague of all these monstrosities mite diminish.   and, i drive ~40k miles a year, & love fun rides.  but, the cost would be worth it.  as long as it went to fund education, universal healthcare - etc - not to line the oil company's pockets.

ymmv,

doug s.

[John Ashman]

The ATC drivers are regarded as some of the best drivers made. And ATC monitors are equally highly thought after in professional studios as accurate monitors that can handle highs spl without compression.

Using the car analogy, it's already a Porshe Cayenne. However, the DEQX may upgrade the sound (especially in how it corrects for room modes) to the level of the the Cayenne Turbo.

That really isn't the point.  Drivers that are "some of the best made" for one application may not be the best for another.  For instance, metal cones generally benefit from DEQX more than poly or paper.  And you would have to guy the amp section which is just adding waste to the equation, unless there is a bypass system in place.  So, if the ATCs are a Porsche Cayenne, they may never be able to compete with a Porsche 911 on a track no matter what you did to it, but a highly modded, supercharged Miata might, done well enough, even surpass it.  It's not anything bad against ATC, in fact, I'd have to do some more research to get a better idea, but for instance, the Ellis 1801b might actually become a better speaker on DEQX than an ATC speaker.  Not sure, but it's possible.  It seems to be close to what NHT is doing with Xd and Xd was designed from the ground up for DEQX.  

And, guys?  If we had "universal AUDIO care" like some people want to do UHC, we'd all have Bose 901s for stereos.

[ludavico]

I am surpised at  John's comments also.  I would have thought starting with a high performance active system would put you closer to the summit.  Lesser systems just can't reach that altitude, no matter what you do.    

As great as ATCs are (to my ears at least) it is not hard to imagine how they might be improved, even with great room acoustics.

Only one way to find out for sure I guess....

In the meantime, has any regular civilian heard the DEQX'd NHTs?  

John

PS - Active ATCs = SUVs?  Wow.  

[John Ashman]

John,
     It simply comes down to the fact that a designer must design to the limitations of a conventional crossover, even if it's active.  ATC uses 24dB/octave crossovers, and I do not believe they are phase coherent.  Even ATCs are designed with compromise in mind.  The rules change, the optimum drivers change, lots of things change when you can use phase/time correct crossovers up to 300dB/octave and full driver FR correction.  I'm not saying Xd is the only way to design for DEQX, but it is a helluva an example of how to do it and most DEQX speakers, over time, will likely go in that direction.  

As for civilians hearing them, a lot of my customers and customers of my competitors got the chance to hear them and very few others up close and personal.  But they're within a few days of shipping, so that will change fast.   I can just say that everyone, especially people who regularly tell me they don't like NHT or think it is just "okay" were blown away by Xd.  This includes Meridian, B&W, Apogee, Genesis, Vandersteen owners.  Nothing but huge amounts of praise and, quite frankly, shock and disbelief as well.  I was sure that Xd was objectively good, I was worried how NHT critics would react, but these civilians were all amazed and are all very likely to buy them.  Most are just waiting for the opportunity to hear them next to their current system.  Here's what one person posted on my forum (and not a prior NHT fan either)

"John was kind enough to bring the Xd's to KNME-TV's studio for the DTV users group meeting on the 18th.

All I can say is WOW! Quickly set up in a less than ideal room the sound was simply incredible. I think I hear a set of these in my future. It looks like the black and whites will get relegated to the basement now. The Xd's deserve a place where they'll be enjoyed every day. "

[doug s.]

I am surpised at  John's comments also.  I would have thought starting with a high performance active system would put you closer to the summit.  Lesser systems just can't reach that altitude, no matter what you do.    

As great as ATCs are (to my ears at least) it is not hard to imagine how they might be improved, even with great room acoustics.

Only one way to find out for sure I guess....

In the meantime, has any regular civilian heard the DEQX'd NHTs?  

John

PS - Active ATCs = SUVs?  Wow.  

john, i think yure missing the point.  unless you can configure active atc's so that their x-overs can be disabled, & that their amplification comes *after* the deqx's x'over/eq, it's kinda defeating the purpose of what the deqx can do.  it mite be easier (and less expensive) to get a pair of passive atc's, disable their x'overs, & use your own amplification w/a deqx system.

doug s.

[Al Garay]

My point is that you cannot generalize and say that all active systems are not good candidates for DEQX. The Orions should be a very good candidate.

I don't drive a Porshe Cayenne Turbo. I would not turn one down if someone wanted to trade for my Toyota. But, it posted the 2nd or 3rd faster laptime ever recorded in the Porshe speedway during testing. It beat many of the 911s on the way. That was the target Porshe had in the first place.

Anyways, back to DEQX and NHT talk.