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New DFR-8 Drivers for NFX cabinets (Read 8373 times)
RFZ_Quest
Ex Member



New DFR-8 Drivers for NFX cabinets
08/14/06 at 02:06:41
 
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
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Steve Deckert
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If the 1st watt
sucks why continue?

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Re: New DFR-8 Drivers for NFX cabinets
Reply #1 - 08/14/06 at 14:54:13
 
Paul & Everyone else,

Bear in mind that unfortunately that pair of NFX were prototypes that were not built to original spec.  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 could be wrong, but without having ever seen the cabinet I have no way to know for sure.

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.

If the cabinets sound bad, it won't matter because A) we won't know why and B)We will be selling the original design.

Perhaps the DFR-8 drivers could be best evaluated by also installing them in a pair of HDT's.
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RFZ_Quest
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Re: New DFR-8 Drivers for NFX cabinets
Reply #2 - 08/14/06 at 22:42:17
 
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

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Steve Deckert
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Re: New DFR-8 Drivers for NFX cabinets
Reply #3 - 08/14/06 at 23:31:15
 
Okay, I talked to Bob, and turns out I was the one that told him to do that, however 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.  Sorry for all the confusion.

Steve
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RFZ_Quest
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Re: New DFR-8 Drivers for NFX cabinets
Reply #4 - 08/20/06 at 23:33:51
 
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.
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musgofasa
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Re: New DFR-8 Drivers for NFX cabinets
Reply #5 - 08/21/06 at 23:09:19
 
Paul!
That is exciting! I love the science behind this design and I would love to hear your full description on these. If all is well in Decworld with the comparisons, it gives me good vibes about tackling a pair of these with the DFR-8s as soon as I can muster the cash.
Let us know of any further comments you might have!

Thanks,
Robert
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Lon
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Re: New DFR-8 Drivers for NFX cabinets
Reply #6 - 08/22/06 at 10:32:42
 
I'm also voting for your impressions; the design and look of these speakers intrigue me.
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rmt
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Re: New DFR-8 Drivers for NFX cabinets
Reply #7 - 08/23/06 at 15:03:27
 
RFZ,

Thanks for the report on your speakers performance and the tips on interior treatment.  My NFX project is coming along ok. My kids are expecting to inherit my Klipsch RF-7s so they are bugging me aboout finishing the job. I am glad to hear that you are impressed with the speaker.  I think this design will get some serious interest from now on.
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RFZ_Quest
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Re: New DFR-8 Drivers for NFX cabinets
Reply #8 - 08/24/06 at 03:15:06
 
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
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RFZ_Quest
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Re: New DFR-8 Drivers for NFX cabinets
Reply #9 - 09/09/06 at 23:46:41
 
Here are some updated photo's of the completed NFX cabinets with the ultimate DFR-8 drivers installed.




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« Last Edit: 11/27/06 at 02:07:33 by RFZ_Quest »  
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rmt
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NIbbelin NFX

Posts: 231
Re: New DFR-8 Drivers for NFX cabinets
Reply #10 - 03/06/07 at 03:34:43
 
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.
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Select, CSP2 upgrade, Dec 685, DSRii, home built Nibbelin NFX w/DFR-8s, Klipsch RF-7, SE34.I, Zbox
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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: New DFR-8 Drivers for NFX cabinets
Reply #11 - 03/07/07 at 01:11:55
 
Thanks rmt,

These are one-of-a-kind original prototypes built by Bob Z. himself. All I did was to add the foam balls and DFR-8 drivers. These have a very exotic and quite expensive imported wood finish that Bob had left over from a special contract job outside of his venture here. If you could see his expertise in woodworking beyond the cabinets he builds here, it would amaze you. The project for which this wood came from was a very large scale, high priced job that he did in the past. Maybe he can post some pictures of that job site so that everyone can identify with the level of his expertise in woodworking. Very immpressive!

I was immediately drawn to the midrange and higher frequency openess, clarity, and exceptional imaging properties that these drivers present within this cabinet design. I have heard about people comparing sound improvements to that of removing dirty layers of glass for better focus. With these, there are NO glass layers by comparison by that analogy. For three-dimensional imaging and extraction of the finest detail within the music, these are way ahead of anything else in a standard cabinet design. I owned very large full range dipole ribbon (open panel) speakers for many years before moving on to Decware amplifiers. These were by far my favorite speakers in all categories but useless with low powered amps associated with tube audio. High current SS amps bridged mono were absolutely required to drive these to decent sound levels which is common with ribbon drivers state of innefficiency. It is very difficult to achieve the type of sound that ribbons produce with "box" type enclosures and standard drivers. However, the NFX design with the DFR-8's have come the closest to that sound character and remind me very much of their effortless sound quality (and that done with low powered tube amps due to the extreme efficiency factor). In other words ' The way it should be'. My SET mono-blocks provide more than sufficient power without being driven hard, to drive these speakers with very clean, respectable SPL levels. These are not a low frequency type of speaker, but they are very realistic down to 50 Hz. A sub is required for levels extending below that. For classical or new-age music, these are perfect. Some of the holographic  imaging that I've experienced surrounding my listening position while listening to these have truely been a revelation with music that is very well known (or at least I thought I knew until these revealed a great deal of information previously veiled). If these cabinets had the low frequency extension and quality of the new retail radials, they would be my absolute favorite without question. To me, that would be the most realistic sounding speaker one could want. Then again, that is just my take on it. I hope that you will find these to be much the same way that I percieve them.

BTW: I am planning to audition these speakers again with the Teres TT and the new ZP3 phono stage with step up unit. The power of the TORIIMK2 is overkill for these speakers so the mono-blocks will come back out coupled to the new CSP2 for control. I had listened to these speakers before with the old phono stage and the mono-blocks. Vinyl really makes these speakers perform at their fullest potential. Digital can be a tad too much at times and is very material dependent to produce good quality results. Properly engineered digital can be quite pleasing but these speakers prefer vinyl in my perception of them. Remember, these drivers are ultra revealing of ALL detail (good or bad) to be ultimately exposed for what it truely is.

Paul.
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rmt
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NIbbelin NFX

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Re: New DFR-8 Drivers for NFX cabinets
Reply #12 - 03/07/07 at 22:33:22
 
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.  
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Select, CSP2 upgrade, Dec 685, DSRii, home built Nibbelin NFX w/DFR-8s, Klipsch RF-7, SE34.I, Zbox
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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: New DFR-8 Drivers for NFX cabinets
Reply #13 - 03/08/07 at 01:35:20
 
Well, there's nothing like the spirit of experimentation. I say try it both ways and compare. This way you can hear the differance for yourself and go with what suits you most. I used only three foam balls per cabinet but Steve is suggesting four. I am extremely pleased with my arrangement but then again, I never tried the speakers with four balls. Go ahead and order eight balls and try it first with the triple arrangement, then add the fourth and see if it makes any noticable change for the better. I would be interested to know your thoughts on this once you've tried it both ways. If they do sound any better than what I've heard, all I can say is WOW! Bob had used the type of sound deadening material like you would find as underlay for automotive use to line the rear spline. I do not know how other material would rate compared to this but I can tell you that my results are very satisfying with this working very well as an absorbant. There is good reason for why the use of these foam balls and their placement come into play as such a critical factor over simply stuffing with poly-fill or any other type of batting. I am sure that Steve already clarified this reason to you and he would not suggest it if he did not feel total neccessity for it's specific form.

There is no doubt that you will find these speakers to be very enjoyable once complete. I will leave it as a mystery for you to discover once the proper foam balls are in place. If you really want to hear these speakers without restriction and you have the room to do so, get them set up well into the space of the room (preferably a large room) with plenty of space to the sides and rear of the speakers position. Use plenty of absorbers at the first reflection points on the side walls as a minimum and go from there. If you could place a generous portion of absorption or diffusion to the rear wall directly behind your listening position, this will help with even greater focus. Of course, the more advanced your room acoustic modifications become, the more accurate and tailored the sound presentation will be.

All I can say is that if you are happy now, you are about to experience total bliss with the detail that will become audible with such clarity that these present. Yes, we need to hear your immpressions of all this once that you've gathered some quality listening time. If you think about the detail noticed which was previously undetected, just wait until you switch back to another speaker and really notice what is missing. Once aware of this speakers potential, the listener becomes  very analytical to a speakers capability overall with this as a referance. The DFR-8 drivers are at the top of their league and this speaker design proves it.

I am about to begin experimentation with advanced ambionic acoustic methods with these as the primary test speakers. When the testing is complete, I will post my findings and suggest in detail how to recreate my experiments so that you can hear the possibility of these advanced methods. I have been chasing this acoustic transformation to coincide with what I experienced over twenty years ago, strongly determined to duplicate it's premise. If you knew what kind of experience I was refering to, you'd understand why completely. Once exposed to something of this nature, I have found that I will stop at nothing to achieve it's presence again and permanently. I will not disclose any further information about this technique until I have found the process to be 100 percent successful. Once that I have, this information will be shared along with my impressions of it.

Enjoy!
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