Re: Re: Re: Re: bamboo cabinet-worlds smallest Feastrex cabinet project
I'd rather drink the wine than look at it.
Strange -as GM says, there shouldn't be enough grunt from a small unit to start exciting things -especially in a small box. If it worries you, mass loading the top with granite or marble chopping block should sort that out.
I think it was one of his road trips, but don't hold me to that. Dave?
I'd rather drink the wine than look at it.
Strange -as GM says, there shouldn't be enough grunt from a small unit to start exciting things -especially in a small box. If it worries you, mass loading the top with granite or marble chopping block should sort that out.
GM said:
I think it was one of his road trips, but don't hold me to that. Dave?
GM, Scott,
Yes, I was also somewhat surprised that the wine had any rippling.... and I'm only using a 2-watt 45 amp (okay, so it puts out a solid 2.25 watts). Not sure if it was a massive glass... just normal for a good red... and besides, I didn't leave it there, a temporary parking place while swapping media. Still, the BVR is a nice sounding enclosure for the D5nf. I'm tempted to build the updated version (has the driver at the top of the baffle board) but living in Germany for the rest of the year sorta prevents me from doing much audio work until 2009.... sigh.
Regards, KM
Yes, I was also somewhat surprised that the wine had any rippling.... and I'm only using a 2-watt 45 amp (okay, so it puts out a solid 2.25 watts). Not sure if it was a massive glass... just normal for a good red... and besides, I didn't leave it there, a temporary parking place while swapping media. Still, the BVR is a nice sounding enclosure for the D5nf. I'm tempted to build the updated version (has the driver at the top of the baffle board) but living in Germany for the rest of the year sorta prevents me from doing much audio work until 2009.... sigh.
Regards, KM
Yes, I'm going to try and work on a couple audio projects when I'm back in the US end of September (mainly building my 2A3 amps) but will also try some mods to the BVRs as well. Here's a pic of the upper chamber showing the bracing:
It's pretty stout in general, but I'm going to try adding some vertical braces from the rear brace of the driver to the top and bottom of the chamber. I'm starting to worry about loosing too much cubic space however.
Regards, KM
An externally hosted image should be here but it was not working when we last tested it.
It's pretty stout in general, but I'm going to try adding some vertical braces from the rear brace of the driver to the top and bottom of the chamber. I'm starting to worry about loosing too much cubic space however.
Regards, KM
This message just in from a happy builder of the new standard Feastrex box for his D5nf drivers:
"I don't know what 'method' Feastrex used to come up with their new standard enclosure but they have managed to create a true 'full range' enclosure (i.e., flat to 50Hz) with no need for baffle step compensation, which in my mind is no small feat. For me, it makes the difference between being able to use a 2W SET amplifier or having to forego that for a more powerful amp. (I would do the correction at line level.) Of course -- assuming all other things are equal -- the overall SQ is going to be better if you can avoid BSC in the first place, although obviously there are situations where the trade-offs are worth it. Now I'm wondering what might happen if I experimented with a similar enclosure for my Lowther drivers too . . . "
My comment: I think a lot of it may have to do with the driver. I suspect the rising frequency response curves of many fullrange drivers tends to exacerbate the need for BSC, so the relatively flatter response curve of the Feastrex drivers gives them an advantage in that regard. (That's just my guess, of course. Maybe the enclosures are doing something special too, but I'm inclined to think most of it owes to the drivers themselves. In any case, I'm glad we've been able to add another happy camper to the list of Feastrex enclosure builders.)
-- Chris
"I don't know what 'method' Feastrex used to come up with their new standard enclosure but they have managed to create a true 'full range' enclosure (i.e., flat to 50Hz) with no need for baffle step compensation, which in my mind is no small feat. For me, it makes the difference between being able to use a 2W SET amplifier or having to forego that for a more powerful amp. (I would do the correction at line level.) Of course -- assuming all other things are equal -- the overall SQ is going to be better if you can avoid BSC in the first place, although obviously there are situations where the trade-offs are worth it. Now I'm wondering what might happen if I experimented with a similar enclosure for my Lowther drivers too . . . "
My comment: I think a lot of it may have to do with the driver. I suspect the rising frequency response curves of many fullrange drivers tends to exacerbate the need for BSC, so the relatively flatter response curve of the Feastrex drivers gives them an advantage in that regard. (That's just my guess, of course. Maybe the enclosures are doing something special too, but I'm inclined to think most of it owes to the drivers themselves. In any case, I'm glad we've been able to add another happy camper to the list of Feastrex enclosure builders.)
-- Chris
A while back I translated and posted the basic approach to enclosure design that one Japanese fellow had been using -- apparently sort of a modification of the approach taken by the late Tetsuo Nagaoka.
Well, for better or worse, his first attempt was a big disappointment.
He went back to the drawing board and came up with these:
Those were "close but no cigar." The bass was quite impressive.
Now I hear he has made some changes to the above design and is really thrilled with the results that he is getting. So it seems we are close to getting another design done.
He's working with the D5e-I, so it may be of limited usefulness to D5nf owners. Anyway, I'll keep you posted . . .
-- Chris
Well, for better or worse, his first attempt was a big disappointment.
He went back to the drawing board and came up with these:
An externally hosted image should be here but it was not working when we last tested it.
Those were "close but no cigar." The bass was quite impressive.
Now I hear he has made some changes to the above design and is really thrilled with the results that he is getting. So it seems we are close to getting another design done.
He's working with the D5e-I, so it may be of limited usefulness to D5nf owners. Anyway, I'll keep you posted . . .
-- Chris
Finally, for all you folks who have been on a hunger strike until you get your numbers, a little bird tells me that Clark Blumenstein has been quite pleasantly surprised by what his preliminary measurements are telling him about the D9e-I fitted with the new spiders. I think it would be prudent to check to make sure everything is kosher in the way that equipment is being used, but there are some very interesting implications for all drivers that use the new spiders . . .
Sorry if this only makes y'all hungrier than ever. Maybe you can pound the table harder and chant louder . . .
-- Chris
Sorry if this only makes y'all hungrier than ever. Maybe you can pound the table harder and chant louder . . .
-- Chris
cdwitmer said:
Hi Chris,
Thanks for the feedback on this one... as the D5nf is the most accessible driver for the DIY crowd (and the one I have), having a factory supported enclosure is a nice touch. I know I've asked before... so I'll ask again. Exactly what are the physical dimensions for this enclosure? What I was pointed to in the past was a single page drawing for the D5e, not the D5nf. So... is it possible to get the exact plans that were used above for this seemingly magical enclosure?
Regards, KM
Hi everyone,
I just wanted to write quickly to respond to folks who have been commenting about the lack of T/S parameters for their 9-inch drivers with the new spiders, etc. Sorry for the delay; I have been quite busy with various tasks and am still trying to adjust to a very different world. I have been limiting my activity on the forums lately due to my busy-ness in other realms.
Just in case anyone got wildly mislead by our currently vacuous state of T/S information on the new spiders, please don't think that Feastrex has been deliberately dragging its feet with regard to measuring and releasing specs because of a belief that users don't really need them, or that T/S parameters are somehow irrelevant due to Feastrex's "magic" or "uniqueness."
Some people would beg the question: Can you taste a fine dish with a mass spectrometer? To me, however, this is a completely improper analogy. A good tool in good hands is what designing and making is all about. Different people use different tools. To me, everything is secondary to this fact --- we all love music.
It's true that the principals of Feastrex (and many other Japanese speaker builders, for that matter) don't rely on T/S parameters in designing their enclosures, but that doesn't mean other people can't put T/.S parameters to good use, as long as there is also a willingness to do a lot of tweaking and experimentation with any design rather than expecting that one will be able to automagically produce a winning design as easily as popping a TV dinner into the microwave. (But as has been pointed out many times, most of the serious DIYers who would consider Feastrex drivers have enough sense to recognize that anyway.)
The main reason for the lack of T/S parameters for the new spiders is that Mr. Teramoto was so eager to get the new drivers to customers that he overlooked the opportunity to take measurements. The coming T/S parameters will be measured with the WT2 since that's what the previous drivers were measured with and it will provide the best comparison between "before" and "after." While the closed box method could provide some valuable insight, I will use the weighted cone method for Vas, as that is the most easily replicable test in the field (by you).
Frankly, Feastrex only has the time, money, and expertise to be honest about what we are measuring and measuring with. It ain't gonna be flashy, and therefore it will be useful.
Importantly to Mr. Teramoto, he notes that we are taking these measurements under a particular set of conditions. The temperature and humidity changes, for instance, and so does the driver response. Therefore, we are hardly trying to provide values which could be considered as absolutes. And furthermore, we will provide the additional data points of temperature, humidity, approximate driver age, etc. for the sake of those repeating these tests in the field.
Also, as a message from Mr. Teramoto, we'll be sure to email all purchasers of the drivers with the new spiders our T/S parameter measurements by request, and we will also gladly send them to anyone who inquires. (Email is fine.)
Although consistency among drivers built with the same components and techniques is very high, there is a bit of change in sound as the drivers age. Also, other measurement methods might come up with slightly different results. In any case the parameters we provide will hopefully still be useful for enclosure design amongst the skilled individuals who are designing enclosures for these drivers.
Eventually I hope to be able to do more extensive measurements of the drivers and document the pattern of how the drivers typically change in their behavior as they get run in over time, and the paper, glues, varnishes, surround, spider, etc. all reach their final state, and eventually become perfectly happy together. There are varying theories as to exactly how long it takes Feastrex drivers (and drivers from any company, for that matter) to reach their final sound. In the nature of this case, ascertaining that will take time . . .
Feastrex drivers in particular use parts, adhesives, and processes which are not in the slightest to be considered "quick and dirty." It is a time consuming, deliberate, and patient hand making process that sounds the best. This is a notion that I slowly learned on my own before I came here, and am now having confirmed in spades. For the best sound, considering almost any audio product, is all about avoiding internal stress in the first place. How do you eliminate internal stress from an engineering standpoint? Can you hear the sound of a third hand clapping?
When freshly plugged in, (except for the first 10 minutes, (Mr. Teramoto's analogy is to a baby crying...)), I have been surprised that the drivers actually sound quite good. As reported from customers, they only get better with time, and the very most final character is "clicked" into within about a year or two, with some aspects changing during this year or two irregardless of playing time (owing to the eventual "curing process" of the glues, etc.).
From what I have personally noticed so far, there are fluctuations in SQ along the way, (seemingly up and down in a slight manner (SQ changes on a few different planes, actually, considering all the different parts which change in different ways and rates)). But fitting those data points to a logarithmic curve, the trend is that they gently become stronger and more pleasingly forthright in sound with time passing.
Katajikenai,
Curaku-san
http://img393.imageshack.us/img393/3954/clarknr2.jpg
I just wanted to write quickly to respond to folks who have been commenting about the lack of T/S parameters for their 9-inch drivers with the new spiders, etc. Sorry for the delay; I have been quite busy with various tasks and am still trying to adjust to a very different world. I have been limiting my activity on the forums lately due to my busy-ness in other realms.
Just in case anyone got wildly mislead by our currently vacuous state of T/S information on the new spiders, please don't think that Feastrex has been deliberately dragging its feet with regard to measuring and releasing specs because of a belief that users don't really need them, or that T/S parameters are somehow irrelevant due to Feastrex's "magic" or "uniqueness."
Some people would beg the question: Can you taste a fine dish with a mass spectrometer? To me, however, this is a completely improper analogy. A good tool in good hands is what designing and making is all about. Different people use different tools. To me, everything is secondary to this fact --- we all love music.
It's true that the principals of Feastrex (and many other Japanese speaker builders, for that matter) don't rely on T/S parameters in designing their enclosures, but that doesn't mean other people can't put T/.S parameters to good use, as long as there is also a willingness to do a lot of tweaking and experimentation with any design rather than expecting that one will be able to automagically produce a winning design as easily as popping a TV dinner into the microwave. (But as has been pointed out many times, most of the serious DIYers who would consider Feastrex drivers have enough sense to recognize that anyway.)
The main reason for the lack of T/S parameters for the new spiders is that Mr. Teramoto was so eager to get the new drivers to customers that he overlooked the opportunity to take measurements. The coming T/S parameters will be measured with the WT2 since that's what the previous drivers were measured with and it will provide the best comparison between "before" and "after." While the closed box method could provide some valuable insight, I will use the weighted cone method for Vas, as that is the most easily replicable test in the field (by you).
Frankly, Feastrex only has the time, money, and expertise to be honest about what we are measuring and measuring with. It ain't gonna be flashy, and therefore it will be useful.
Importantly to Mr. Teramoto, he notes that we are taking these measurements under a particular set of conditions. The temperature and humidity changes, for instance, and so does the driver response. Therefore, we are hardly trying to provide values which could be considered as absolutes. And furthermore, we will provide the additional data points of temperature, humidity, approximate driver age, etc. for the sake of those repeating these tests in the field.
Also, as a message from Mr. Teramoto, we'll be sure to email all purchasers of the drivers with the new spiders our T/S parameter measurements by request, and we will also gladly send them to anyone who inquires. (Email is fine.)
Although consistency among drivers built with the same components and techniques is very high, there is a bit of change in sound as the drivers age. Also, other measurement methods might come up with slightly different results. In any case the parameters we provide will hopefully still be useful for enclosure design amongst the skilled individuals who are designing enclosures for these drivers.
Eventually I hope to be able to do more extensive measurements of the drivers and document the pattern of how the drivers typically change in their behavior as they get run in over time, and the paper, glues, varnishes, surround, spider, etc. all reach their final state, and eventually become perfectly happy together. There are varying theories as to exactly how long it takes Feastrex drivers (and drivers from any company, for that matter) to reach their final sound. In the nature of this case, ascertaining that will take time . . .
Feastrex drivers in particular use parts, adhesives, and processes which are not in the slightest to be considered "quick and dirty." It is a time consuming, deliberate, and patient hand making process that sounds the best. This is a notion that I slowly learned on my own before I came here, and am now having confirmed in spades. For the best sound, considering almost any audio product, is all about avoiding internal stress in the first place. How do you eliminate internal stress from an engineering standpoint? Can you hear the sound of a third hand clapping?
When freshly plugged in, (except for the first 10 minutes, (Mr. Teramoto's analogy is to a baby crying...)), I have been surprised that the drivers actually sound quite good. As reported from customers, they only get better with time, and the very most final character is "clicked" into within about a year or two, with some aspects changing during this year or two irregardless of playing time (owing to the eventual "curing process" of the glues, etc.).
From what I have personally noticed so far, there are fluctuations in SQ along the way, (seemingly up and down in a slight manner (SQ changes on a few different planes, actually, considering all the different parts which change in different ways and rates)). But fitting those data points to a logarithmic curve, the trend is that they gently become stronger and more pleasingly forthright in sound with time passing.
Katajikenai,
Curaku-san
http://img393.imageshack.us/img393/3954/clarknr2.jpg
KM, here is the PDF file of the newest version of the Feastrex enclosure in question. If you do decide to try building this at some point, I recommend corresponding with people who have built it, and also checking with Feastrex to ask if there are any new ideas, etc. I heard one person in Japan (not one of the principals of Feastrex) saying that when he built this enclosure, he got best results by having the distance from the center of the driver and the top of the enclosure be the same as the distance between the center of the port and the bottom of the enclosure . . . and he also used an OVAL port of the same area as the rectangular port shown in the attached PDF file. FWIW. "Your mireage may belly . . . "
Anyway, the consensus does seem to be that this is a good enclosure.
-- Chris
Anyway, the consensus does seem to be that this is a good enclosure.
-- Chris
An externally hosted image should be here but it was not working when we last tested it.
Ha ha, "Ku-Raku," bitterness and pleasure, suffering and the happiness that music brings -- yes, that pretty well sums up the life of anyone who builds musical instruments, be they the ones that make the music going in, or the ones that make the music coming out.
When you hear those babies crying, you know the birth pains were all worth it . . . here's hoping you can keep food on the table and your sanity intact . . .
-- Chris
kmaier said:
Magic? well, I would say that it is simply a piece of good, patient engineering. The magic is all in your music...anyone other than the musician would have to be a fool to take credit for creating that magic. The act of communicating that magic however, is a selfless pursuit, and is much more along the lines of what a good stereo system should do. (IMO)
Also, I think that experimentation is encouraged. The Feastrex enclosures are indeed excellent, but there are so many different directions the drivers could be taken in. The trick is trying to find a better balance than the Feastrex enclosure. Of course, we would be fools to try to prevent anyone else from trying...
-Clark
mostly feeling the "raku" today...
Chris,
Thanks for the very quick reply. The dimensions are mostly similar to the earlier 5e enclosure, albeit 35mm deeper, some additional bracing pieces and a larger cross-section on the port and being located much lower. Thanks for the added details on relocating the port and shape change... perhaps a round port would be more akin to the round driver cone and a better choice still.
I'll probably build this enclosure once I return to the US. I don't plan on using oak the next time either, as it's just a pain to work with and I'm not convinced it's the best material for this use. A solid wood is still nice and easier to miter than plywood... but BB ply has some advantages no doubt.
Clark,
Yes, the magic is in the music itself.... but without a good signal chain (implying start to finish) much of it can be lost or distorted in it's reproduction. The past 2+ years for me have been spent designing a clean SE triode amplifier using the 45 and/or 2A3. Speaker work has been limited to the better Fostex drivers, my current favorite being the F120A. The Feastrex D5nf goes well past the F120A (as it should) and enclosures for both are still being tried, hence having a design endorsed by Feastrex should be a meaningful reference.
A new preamp design will follow next year (tubes only) to continue improving each link in the chain as it were. So far, Feastrex represents an excellent final link.
Regards, KM
Thanks for the very quick reply. The dimensions are mostly similar to the earlier 5e enclosure, albeit 35mm deeper, some additional bracing pieces and a larger cross-section on the port and being located much lower. Thanks for the added details on relocating the port and shape change... perhaps a round port would be more akin to the round driver cone and a better choice still.
I'll probably build this enclosure once I return to the US. I don't plan on using oak the next time either, as it's just a pain to work with and I'm not convinced it's the best material for this use. A solid wood is still nice and easier to miter than plywood... but BB ply has some advantages no doubt.
Clark,
Yes, the magic is in the music itself.... but without a good signal chain (implying start to finish) much of it can be lost or distorted in it's reproduction. The past 2+ years for me have been spent designing a clean SE triode amplifier using the 45 and/or 2A3. Speaker work has been limited to the better Fostex drivers, my current favorite being the F120A. The Feastrex D5nf goes well past the F120A (as it should) and enclosures for both are still being tried, hence having a design endorsed by Feastrex should be a meaningful reference.
A new preamp design will follow next year (tubes only) to continue improving each link in the chain as it were. So far, Feastrex represents an excellent final link.
Regards, KM
yeah,
I am definitely a (personal) fan of the 45/2A3. Back at Cain and Cain, I spent alot of time with Terry Cain's electronluv 10Y to 45 system. the 45 amp ran a few different tubes, and I don't remember the names. Just the stunning dynamics. If you throw enough transformers at a 45 tube or 2A3 tube, they transform into something of a completely different ilk. Nothing is perfect, but geez, certain approaches really have a way of getting the word "wow" to pass the lips, and to then getting you to sink in your chair and simply watch the music unfold.
-Clark
I am definitely a (personal) fan of the 45/2A3. Back at Cain and Cain, I spent alot of time with Terry Cain's electronluv 10Y to 45 system. the 45 amp ran a few different tubes, and I don't remember the names. Just the stunning dynamics. If you throw enough transformers at a 45 tube or 2A3 tube, they transform into something of a completely different ilk. Nothing is perfect, but geez, certain approaches really have a way of getting the word "wow" to pass the lips, and to then getting you to sink in your chair and simply watch the music unfold.
-Clark
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.