I will have my new DFR-8 drivers installed into the NFX cabinets along with the required foam spheres necessary for proper cabinet dampening by tomorrow evening as they are scheduled for delivery in the afternoon.

Finally, I will begin the burn in process for these speakers and prepare them for evaluation over the next two weeks. As these trail off rapidly below 50 Hz, these will be evaluated in conjunction with my WO32 subwoofer.

These will be tested with three different amplifier types including the TORII MK2, Taboo (original model),and the SV83M- DC monoblocks.

I expect to have a full analysis completed on these in about a month. These have been staring at me without drivers for the last month and finally they are about to be complete.

You will be reading about these and the performance characteristics for which these are capable in a few weeks. This will be posted in the review section if anyone is interested to read my results at that time.

Paul

Steve,

Understood. The front portions of the side vent area are indeed canted to a degree of roughly five percent inward toward the opening while the rear portion seems to be parrallel to the cabinets. I will evaluate these only as experimental versions and treat them accordingly. If any reference is stated towards this particular pair, this factor will be clearly defined as being different in the regard which you have made clear. Because of this design variation, there will be no review on this pair in respect to the actual production versions or relating to them as such.

Any comments about these will be clearly stated in regard to the offset variation to prevent any confusion. They will make for an interesting test bed just to find how they actually perform. If these do in fact turn out to be substandard, any further evaluation will be abandoned without mention. It would be interesting to compare this set directly with a production set as per blueprints. We then would know just exactly how much deviation has occurred from this alteration.

I will however, get in touch with you privately to relate my experience with this prototype set.

Thanks for clearing that up.

Paul

Quote:

The sides appear to be canted inwards which may change the triangulation of high frequencies inside the cabinet, preventing them from exiting the ducts properly.  This would create the same congested sound as most any other cabinet.

I can assure you that this does not apply here! Truth by discovery has proven just the opposite in a clear and decisive manner.


Quote:

If the cabinets sound good, it won't matter because A) we won't know if the originals sound better and B)We will be selling the original design

Bob Z. has compared these to actual production models, noting no discernable trace of deflection in character between the two.



Quote:

I didn't realize by the picture that the canted sides were the result of adding another board to the outside of the cabinet.  The insides of the cabinets are still the same shape.  So it is likely that your pair are going to be very close after all.

And this is perceived as so. From my perspective, if there was any change applied to the end result, it would be regarded in a very positive manner.



Bob Z's response;  “Your NFX should be as close to the drawing as one could want. Steve didn't realize the angled pieces he was referring to in his post that it wasn't a deviation from the plans or Paul’s original but was esthetics added to the outside of the cabinet and done by his suggestion. I noticed no difference between the two“.



I have had the new DFR-8 (modified Fostex) drivers installed within the NFX prototype cabinets since last Monday evening. Since then, I have been  playing these consistently throughout the week , accumulating a vast amount of critical listening time.

Involving the cabinet set-up, the following recommendation is highly suggested as the optimal way to prepare these internally. I found that THREE each  of the foam “poof” balls are ideal for the proper amount of cabinet dampening. IMPORTANT: Place one ball in the upper chamber of each cabinet directly above the driver with approximately 1 inch of the ball visible while looking directly down through the driver mounting area. Place ONLY two more balls within the lower section of the cabinets so that they are tightly butted against each other and roughly centered within the lower section so that there is open space at the bottom of the chambers. You want to apply the same technique as when the upper chamber was stuffed. While looking down through the driver hole, you should see about 1 inch of the ball extended visibly when looking straight down. By placing these in this manner, you will find that not only are they acoustically optimal in that position as I have discovered, but this will also prevent the balls from slipping down into the bottoms of the cabinets where they would be loose within the chambers and much less effective.  You will find that if the lower ball has exceeded past a certain point, the grip is lost along the rear center rail and the ball will simply fall to the bottom. Make sure that you have properly lined the internal rear wall sections with absorptive material to control internal deflections as well. Once these have the optimal degree of dampening inside the cabinet chambers, they allow the drivers to perform at peak potential and these drivers will tell ALL very clearly.

The drivers do not require any sort of crossover! Wire them direct from the amplifier cables. I installed a custom set of dampened plates constructed from thick sheet metal designed with locking “notched” tabs to keep the binding posts in place and secure. In these cabinets, I built the plates to house heavy duty WBT sealed posts which accept banana plugs or heavy duty spade connections. As I built my heavy duty cables with WBT banana plugs on all ends, this was the perfect match. Once inserted, the plug sleeves screw down to expand the plug within the receptacle and become very tight with positive surface to surface bonding. All that is needed is a pair of jumper wires direct from the binding posts to the driver tabs where they are soldered into place. I had leftover solid core long grain OFC wire in a heavy gauge that I used along with silver conductors into a combined configuration. Why compromise the integrity of the high grade cables within the last foot is how I see it and I do not cut corners.

Proper room placement is crucial with these models as dictated by their nature if they are to be perceived as intended. The larger the room the better as I  believe their performance would suffer in a small room, especially if non-treated acoustically. You will need to have proper frequency balance within your room if you are to hear these in an optimal manner. These speakers are extremely unrestricted and stunningly revealing to every nuance present within the signals generated. The midrange and higher registers that you will experience is of a nature that will provide absolute sheer pleasure to hear!

I  have been breaking-in my new CSP2 preamplifier all week with these as well. This has been driving my SV83M-DC mono-blocks for which is more than abundant to drive these speakers into very respectable SPL figures. The purity of this combination is amazing to say the least. This has been one of the most rewarding listening sessions for me to date and words cannot do it justice. These speakers are absolutely in the high sensitivity range which means that a few mere quality watts will change your perspective on low powered S.E.T. amplifiers if you are one of those in doubt.

Since we have all agreed that my prototype versions are of no deviation from the production models in respect to internal design, I believe that it is fair to present these as the same in performance character as all parameters are uniform between both versions where it counts.

I am completely hyped up on what these speakers have to offer and there is much to be said about them!

If you want to hear about my impressions and findings with extensive tube rolling which has presented a major discovery by doing so, let me know. If Steve and Bob give the go ahead, I will tell all and you will be pleased with my findings.

Now back to my listening session. I am so pleased with these that I must get back to them!

Paul.

I'm also voting for your impressions; the design and look of these speakers intrigue me.

Thanks to all that replied. I greatly appreciate the requests and the comments!

I started to write some notes regarding the upcoming review on the NFX speakers and wouldn’t you know it, this evolved into a review in itself.  Imagine that. By the time that my notes had extended into the second page of writing, this became apparent and it was not my intension to go that far with it on this post.

In doing so, thanks to your response I have  initiated an in depth analysis concerning this chapter of equipment evaluations. Sometimes this becomes the motivation for getting the ball moving. So rather than post this data here, I will present it in the review section once finalized.

Up to this point, my listening impressions have been based upon the Dec685 digital source, the single ended triode amplifiers and the new CSP2 which is outstanding in every regard. Even standard compact discs have revealed a level of detail for which I never expected and this includes titles heard  many times over. My music selections for which my impressions are based upon include specially selected titles for their contributing content. These include artists such as  Kitaro, Vangelis, Tangerine Dream, Sarah McLachlan, Steely Dan, Bach, Vivaldi, Mannheim Steamroller and others along that line. What that I have heard from these discs on the NFX prototype speakers has become a true revelation  for what lies within their passages. It has truly been like hearing them in a new light with enhanced perspective.

With that in mind, look for the actual review to come and I will go in depth about this at that time.

Happy listening!

Paul

Nice looking speakers RFZ.   I did not see those pictures until just now.  I am liking my DFR-8s more all the time.  I hear things in the music I never did before.  I am experiencing this odd feeling that every CD ends too soon.

RFZ,
Thank you for posting all your tests and findings on the NFX.  I have not made an official review yet beause mine are still quite new and I have not yet placed the foam balls in the cabinet per the design. IPut them together with what I had available because I simply wanted to hear something.  I have not bought the foam balls yet so I filled the cabinet full length on both 45 deg and back panel with this stuff.
 With this stuffing the speakers are very clear and open but in Steve D.'s opinion still less than optimal for the design goal with the DFR-8s.  After installing the foam balls I will report with an official review following the design. However, I can already report that these speakers are amazingly detailed and efficient.  I hear more music in them than I thought were in my digital discs.  And to think they can get better with the orignal design tweaks will be astonishing.