Exciting new line of fullrange drivers from Feastrex - Page 132 - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > Feastrex

Feastrex Hand crafted speakers

Reply
 
Thread Tools Search this Thread
Old 20th October 2008, 11:18 PM   #1311
Aengus is offline Aengus  Canada
diyAudio Member
 
Aengus's Avatar
 
Join Date: Apr 2004
Location: Victoria, BC
Quote:
I'll endeavor to post more responsibly in the future, so as to avoid committing any more faux pas.
Well, OK, if you want to be absolutely unique on the forum.
  Reply With Quote
Old 21st October 2008, 08:22 PM   #1312
diyAudio Member
 
Phil Townsend's Avatar
 
Join Date: Jun 2004
Location: Santa Fe, New Mexico
Default Da Boys

Da Boys at RMAF
Attached Images
File Type: jpg l1000568.jpg (50.0 KB, 684 views)
__________________
Phil
Santa Fe
  Reply With Quote
Old 23rd October 2008, 04:33 AM   #1313
diyAudio Member
 
Join Date: Apr 2005
Location: Seattle
Default Hi all,

I was going to go ahead and announce a few things. Soon, in response to popular demand, I will upload to Feastrex.com a Feastrex Recommended cabinet design for the 5 inch enclosure after Mr. Laurence Platt's build. It is nice, detailed, and conveniently marked in inches for all of us thick headed imperial types. if you want metric, then multiply by 28/11.

Also, I have now updated my personal website Blumenstein-Ultra-Fi.com to reflect some recent developments in what I am offering. Of course, I will always offer advice as much as I can to the DIY community, I have learned so much here, come so far with you guys!

I am now building everything for Blumenstein-Ultra-Fi.com out of Jason Flanary's shop at Lovecraftdesigns.com. Jason bought Terry Cain's business, shop and tools two years ago (thankfully!) and Jason has continued and refined upon all of Terry's current models and is even releasing some new ones of his own.

Something that alot of people did not know at the time that Terry died was that Jason had prettymuch single-handedly build every pair of Cain and Cains that had been made during the two years previous to Terry's death. So when Terry died, alot of people wondered what of the fate of Cain and Cain. Therefore, THANKFULLY, there was a qualified successor to Terry... Jason, noticing that the CNC machine was heavily underused, is the type of guy who finds himself now taking advantage of his extensive tooling and expertise and working in collaborations to build OEM speakers for people of all sorts, including one offs for the DIY community, even worldwide.

In either case, we have alot of fun at the shop now. My latest project was negotiating with Terry's ghost (seriously) in order to soup up the B20UF20 corner horns, which serve as the shop stereo and rocking out loud enough to keep everything intelligible through our hearing protection. These things are so fun.

And of course, the final purpose of this post, and the reason that it is in the Feastrex forum is to announce the Annabelle, a Feastrex based loudspeaker. The specific dims, construction, and photos are not public yet but anyone wishing to try their hand on Mr. Teramoto's 60 liter 5 inch box Ill see what sort of advice I can impart... The Annabelle is roughly based on the 60 liter box, so I have gone through a fair amount of cut and try with my own evolution of it. It is a really fun box to play with lego style. lots of rewards here.

Photos of the enclosure are on the way soon.

Ok, later,

-Clark
__________________
www.blumensteinaudio.com
Blumenstein Audio - Handmade High Efficiency Full Range Single Driver Speakers from Seattle, USA Since 2006
  Reply With Quote
Old 25th October 2008, 10:58 AM   #1314
diyAudio Member
 
cdwitmer's Avatar
 
Join Date: Apr 2003
Location: Tokyo
Some interesting video links on urushi:

Of the ones included hee, only this video clip is in English:
http://jp.youtube.com/watch?v=MLiiR6...eature=related

Here is a different way of using urushi . . . this is probably closer to what Mr. Tanaka does, as it uses clear urushi that reveals the wood underneath:
http://jp.youtube.com/watch?v=Up4brcAnO_s
(I assume the lacquer being applied in this case is uncolored (i.e., it has the natural, nearly clear color of unpigmented urushi, and that what we are seeing is mostly the color of the wood, which seems to be ebony or some similar dark, heavy, resinous wood.)

(If you are interested in seeing how that piece of furniture was made: http://jp.youtube.com/watch?v=m1YMGntKY34 )

Here is another variation on the latter approach above:
http://jp.youtube.com/watch?v=jAAhbtYkg5s
The Japanese "subtitles" mention that this piece got nine coats of urushi. I notice that the level of gloss is a lot lower than with Mr. Tanaka's enclosures; however it is still very pretty.

Here is an interesting video clip with an emphasis on the creation of urushi-finished Seiko wristwatches:
http://jp.youtube.com/watch?v=ad2dwBGOMdQ
It is mentioned that it takes six months to take one wristwatch from start to finish; however I imagine that a lot of that is waiting for the urushi to cure.

-- Chris
__________________
"Avoiding deportation from Japan for over a quarter century!"
  Reply With Quote
Old 25th October 2008, 11:12 AM   #1315
Bunpei is offline Bunpei  Japan
diyAudio Member
 
Join Date: Aug 2008
Default Mr. Tanaka's comment on T/S parameters

I'd like to post Mr. Tanaka's comment on T/S parameters for Feastrex drivers.
“Before the turning off of my model exhibited at RMAF, eight pairs were built and scrapped. At last, a setting assuming Qts < 0.2 could grip bass satisfactorily. I really recognized how T/S parameters were useless in the case of such a powerful unit that we never have before.”

Oh, he had selected one favarite naming of his Nagaoka Nessie type prior to RMAF.

"Urussie-J"

He was very glad to get so many naming posted.
The selected naming was proposed by a Japanese person via his local channel.

Bunpei
  Reply With Quote
Old 25th October 2008, 11:35 AM   #1316
diyAudio Member
 
cdwitmer's Avatar
 
Join Date: Apr 2003
Location: Tokyo
It should be noted that there are multiple approaches to using T/S parameters to design enclosures and predict their performance inside and outside of Japan . . . if my understanding is correct, prior to working with Feastrex drivers, Mr. Tanaka had been working primarily with Fostex drivers, and was able to design good enclosures for them using formulas that involved the input of T/S parameters, and thus he was quite surprised when a similar approach did not give good results when Feastrex drivers were used. But how much one can profitably extrapolate from his experience to the situations of enclosure designers outside Japan -- who are using T/S parameters but not necessarily in the same way -- remains open to question. I would advise anyone working on Feastrex enclosures to at least keep Mr. Tanaka's experience in mind. By the way, I'm pretty sure he is talking about the NF5ex driver, which would typically have a Qts of around 0.45 (although that of course depends on the field coil voltage).

*********************************************

By the way, the only reason why Mr. Teramoto has not yet made available his T/S parameter measurements for the D5nf/D9nf/NF5ex drivers is that I encouraged him to take measurements of the Nf5ex drivers at a variety of field coil voltages rather than at only one voltage. Should be soon . . .

-- Chris
__________________
"Avoiding deportation from Japan for over a quarter century!"
  Reply With Quote
Old 25th October 2008, 12:02 PM   #1317
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Agreed.

That said I can't say I would regard, for e.g. a Qt of ~0.45 as indicative of an 'immensely powerful' driver. Their Qe is nothing to write home about (although Bl is reasonably high). YMMV as always of course.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 25th October 2008, 02:59 PM   #1318
diyAudio Member
 
cdwitmer's Avatar
 
Join Date: Apr 2003
Location: Tokyo
Default RMAF report from Feastrex's president Akiyama

Feastrex jet lag . . . Feastrex speakers may not be unique in this regard (indeed this phenomenon may not even be limited to loudspeakers), but it has been observed that Feastrex drivers take a few days of playing to come back into their groove after traveling and/or not having been played for a while. In fact, I know of one case where failure to appreciate this phenomenon led (regrettably, in my view) to premature abandonment of what could have been an excellent Feastrex loudspeaker project.

Anyway, on this issue of "driver jet lag," forewarned is forearmed . . . here is my translation of a description that Feastrex's president Akiyama gave at his blog about their experience at RMAF this year -- Chris


********************************

(Part 1: D5e-III Units)
Speaker units and enclosures change slightly during transport due to various factors that we don't completely understand, but I expect that the vibrations that take place during shipping have something to do with it. It definitely takes time for the sound to settle back down into what one would normally expect the drivers to produce. In the case of the 5-inch drivers we took to RMAF, there was a related issue in that the drivers had just been completed a few days before -- on October 2, to be precise -- and they had not undergone sufficient aging. Therefore it was doubly to be expected that their sound would change during the course of RMAF. We had to implement numerous countermeasures in our preparations and during the course of the show to ensure that they gave, as much as possible, the sort of stable performance and excellent sound that they ought to be normally capable of producing.

RMAF Day 0 (pre-show)
In the case of Mr. Tanaka's urushi enclosures, the first sounds that they produced in the RMAF hotel were really disappointing. None of that surprised us, but normally we would expect the drivers to settle down and start coming into their own after about an hour of play. This time, no way! Standing waves in the room were not helping things either. We were exhausted from our own travel from Japan the day before the show, and after setting up the D5e-III and the D9e-III in the two rooms, with two different amplifiers and enclosures we decided to call it quits after confirming that the systems were producing sound. We finally got to bed around 2:00 A.M.

RMAF Day 1
The Tanaka enclosures have never been used in a room with such thick carpeting, and the standing waves in the room are making it hard for the Tanaka enclosures to sound their best. We used a cheap trick to spruce up the sound -- we change the tubes in the first stage of the amplifier to more energetic, powerful USA-made tubes. That was a slight improvement but not a complete solution. We went out and bought some maple planks to place underneath the enclosures, and we repositioned the enclosures to minimize the effects of standing waves in the room. The result was better bass and overall tuning. We were not entirely satisfied but we considered it acceptable.

RMAF Day 2
The drivers finally started to come into their own. In fact, now they were playing too powerfully so we returned the amplifier's first stage tubes to the original European tubes we had been using, and got a smoother, more refined sound. We also changed over to connectors that we have found useful for fine-tuning of the sound and were satisfied with the full, rounded sound that we achieved.

RMAF Day 3
The drivers continued to sound even better than on the previous day, so we removed the connectors that we had installed on day two. We were finally back to what we would consider to be normal for this system and the sound was finally where we really wanted it to be.

I left out various details, but when you have such young units playing 12 hours a day, the sound keeps changing so you have to keep an eye -- no, make that an ear -- on them. Actually, this process continues for the better part of a year, but the change in the first three months will be the most pronounced, probably because of the time it takes for all the glues used in the driver to fully cure, so we expect that they will have the potential to sound better (assuming all other things are equal) at CES (T.H.E. Show) in early January. Give them a full year and they will have really matured into wonderful-sounding creatures. A lot of people had a very high estimation of these drivers at RMAF but if the same drivers would be played one year from now the reaction would be even better, I'm sure.

We had an even harder time with the D9e-III drivers.

(Part 2: D9e-III Units)
The enclosures that we used for the D9e-III drivers at RMAF this year were originally developed last year for the D9e-II. It turned out that this decision on our part was a mistake, and we really had a hard time getting the D9e-III drivers to sound their best.

RMAF Day 0 (pre-show)
We removed the D9e-II drivers from the enclosures and inserted the young D9e-III drivers. Initially, the sound seemed to be very promising indeed, despite the thick carpet in the room. Hearing that initial sound, we thought the show would be a great success for these drivers.

RMAF Day 1
During the morning, the bass sounded pretty good. Things got off to a good start. But as more and more visitors came to the room in the afternoon, these drivers started to wake up out of their slumber. It turned out that their initial sounds had been produced in their sleep! The midrange and treble started to become too powerful, and we had no choice but to use our secret weapon "magic connectors" to control the overly powerful midrange and treble, and somehow we were able to get through the first day.

RMAF Day 2
By Day 2 the D9e-III drivers were fully awake and their bass was overpowering the enclosures designed for the D9e-II drivers. The mismatching of these drivers with the enclosures was starting to become a problem. We tried tuning with various enclosure insulators and boards on the floor beneath the enclosures and we managed to get the sound to where we could live with it. One factor that made the sound even worse for part of Day 2 was the fact that our 811A SE amplifier, which has a switch to allow three different NFB settings, had a less than ideal NFB setting for some music. We actually intended that one setting would be used for drawing out the excitement of drums, another setting for jazz, and another setting for classical and vocal music. However, one of the assistants that we had helping out accidentally played vocal music with the amplifier NFB switched to the worst setting for that type of music. People who heard the D9e-III speakers at that time probably got an unpleasant earful. But aside from that temporary screw-up, by the evening of Day 2 the drivers were simply overpowering the enclosures so much that there was nothing we could do to keep them in control, and we ended up removing them and replacing them the more properly matched D9e-II drivers. People who heard the larger drivers on Day 2 had a high likelihood of encountering problematic sound.

RMAF Day 3
On Day 3, the D9e-II drivers were a much better match to the enclosure and sounded much better. On the other hand, in the room next door the smaller D5e-III drivers were doing really well, and anyone who assumed both rooms simply had different sizes of comparable drivers would have to be forgiven if that came away with the belief that the D5e-III is a superior driver to the D9e-III.

The D9e-III is like an F-1 racer: it is capable of tremendous performance but is very sensitive to how it is set up. We really regret that we did not bring an enclosure designed especially for these drivers. The D9e-III drivers are capable of performance in no way inferior to that of the D5e-III drivers, and we are committed to demonstrating that next year. (Whether we can prepare the requisite enclosures in time for CES [T.H.E. Show] in early January is doubtful.) All in all, it was a wonderful learning experience for us and we are sure that all of our products will be better in the future as a result.

********************************

-- Chris Witmer
__________________
"Avoiding deportation from Japan for over a quarter century!"
  Reply With Quote
Old 25th October 2008, 06:10 PM   #1319
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
Quote:
Originally posted by cdwitmer
It should be noted that there are multiple approaches to using T/S parameters to design enclosures and predict their performance inside and outside of Japan . . . if my understanding is correct, prior to working with Feastrex drivers, Mr. Tanaka had been working primarily with Fostex drivers, and was able to design good enclosures for them using formulas that involved the input of T/S parameters, and thus he was quite surprised when a similar approach did not give good results when Feastrex drivers were used. But how much one can profitably extrapolate from his experience to the situations of enclosure designers outside Japan -- who are using T/S parameters but not necessarily in the same way -- remains open to question. I would advise anyone working on Feastrex enclosures to at least keep Mr. Tanaka's experience in mind. By the way, I'm pretty sure he is talking about the NF5ex driver, which would typically have a Qts of around 0.45 (although that of course depends on the field coil voltage).

*********************************************

By the way, the only reason why Mr. Teramoto has not yet made available his T/S parameter measurements for the D5nf/D9nf/NF5ex drivers is that I encouraged him to take measurements of the Nf5ex drivers at a variety of field coil voltages rather than at only one voltage. Should be soon . . .

-- Chris
I quite agree that one should not just plug in the numbers and out pop the design. But basic parameters gives one a ball park idea which is better than nothing.
__________________
Hear the real thing!
  Reply With Quote
Old 25th October 2008, 08:22 PM   #1320
kmaier is offline kmaier  United States
diyAudio Member
 
kmaier's Avatar
 
Join Date: Jul 2007
Hi Chris,

An interesting post on the drivers needing time to break back in after being shipped. I've been living in Germany since July.... went back home a few weeks ago to check on life, etc. My D5nf drivers had sat for a solid 9 weeks without any signal. Needless to say, that powering up the house again also included powering up the 45 amps and putting some music on the Feastrex drivers. I had them playing in the background while I was busy doing some other bits. I finally got around to some more serious listening the next day. I can't really say I noticed any real difference.

Could it more related to the fact the the drivers brought to RMAF were just new or possibly that air transport and the cold temperatures in the cargo section of the plane where more influential than sitting?

Regards, KM
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 11:45 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2