Feastrex Fun

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The one and only
Joined 2001
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My Feastrex D9nf's arrived just in time for the weekend.

:cool:
 

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I really want a set of those, I'd sell one of the cars and buy a set tomorrow if they were half the price. These are the sort of driver where you fly to the dealer with a pelican case, then hand-carry them home with the case handcuffed to your wrist.
I'll be watching closely what you do with them Nelson. It will be very interesting.
Run them in on an OB then measure theile small specs I presume?
 
Nelson Pass said:
I'll be back in a couple days with some data.

If taking measurements is easy for you, it might be interesting to repeat measurements occasionally over time, as it seems almost everyone reports the drivers sounding better with the passage of time. (Sounding better with run-in is common, but Mr. Teramoto has been struck by how much better his drivers sound after -- for example -- they have spent a year in service.) It would be interesting to see how, if at all, changes in driver behavior over several weeks and months might show up in measurements. Mr. Teramoto does have his own personal pair of Feastrex drivers, but only of one model, and most of the time he only gets to listen to his drivers while they are very new. He puts 'em through boot camp and then they're out the door.

-- Chris

(P.S. Can't begin to tell you how excited I am that Pass-sensei, who is an icon in his own right in Japan, is going to use these drivers.)
 
According to Mr. Teramoto, one reason for the rejoicing in Feastrexville tonight that Nelson Pass is using a pair of these drivers stems from the fact that in much the same way that the drivers reflect the personality of their builder, the drivers also seem to come to reflect the personality of their user. That opinion is based on his follow-up observation of different units and they way they have been used by their respective users. Mr. Teramoto told me on the phone a few minutes ago that one incident in particular comes to mind. Of all the D5nf units that have been shipped so far, there was exactly one pair that Mr. Teramoto felt like he wanted to recall for a "service" reconing: the very first pair of commercial units that were delivered to a paying customer. He had some second thoughts after shipping the first pair of D5nf and made a change from pair No. 2 onward, a decision which he felt improved the sound significantly. He had been maintaining regular contact with that customer over the span of a year and was mightily impressed with how that customer was using his units, and finally suggested to the customer that those units be shipped back for a recone that would bring them up to the same standards as all the other D5nf units. When that very first pair of D5nf units came back, Mr. Teramoto was amazed by how good they sounded -- he almost felt it was a shame to recone them since it might them take another year of aging for them to sound as good as the older drivers! But he did make the change because he felt that in the long run the drivers would benefit and the customer did report that he could detect the overall improved character of the reconed drivers, in spite of their newness, upon their return. (At the opposite extreme there was a case of a pair of drivers that were badly abused by their owner and had to be repaired out of warranty; Mr. Teramoto was aghast that someone would spend so much for a pair of drivers only to treat them so badly.) So if the user of the drivers plays a role in "finishing" their sound and in drawing out their full potential, the pair of D9nf drivers now in Nelson Pass's hands should be counting their blessings, for he will probably have them singing very sweetly indeed.

-- Chris
 
The one and only
Joined 2001
Paid Member
Here's the first particle of data, a free air impedance curve of both
drivers. The top curve (@60 Hz) is one driver out of the box, the middle
one is the second driver, and the bottom is that same driver after
a short workout, showing lower Q from slightly broken-in suspension.

Nice consistency between the two.
 

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Joe,

FWIW, simple measurements of T/S parameters taken with the Woofer Tester 2 are available here:

http://puremusicgroup.com/yabb/YaBB.pl?num=1191708899

There are several ways of arriving at T/S parameters, and the results may vary slightly depending on the method, how the measuring devices are calibrated, etc., but I expect they should be in the general ballpark of those figures.

-- Chris
 
Thanks, Chris, I'd forgotten about that post. We just did some testing of the D5nf and the D5e TypeII. I'm a little reluctant to publish the results as I think, at least in regard to the D5nf, that they were somewhat anomolous. We came up with a much higher Qts than any other previous tests. We used the weighted cone method with MLSSA software.
 
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