It is a good thing it was a cloudy, damp, and cool to cold day here. Otherwise I would probably not have ported the 126 mod to the 127.
Before I post the results I would like to say a few things about some ideas recently stated in this thread.
First, there is a problem with using a poor performing driver as a reference. To do so assumes that everyone hears the defects in the same way. There is considerable research to contradict this assumption. I remember an AES paper from as early as the 1970s about CBC's attempts to design a new monitor loudspeaker. They did considerable work on listening evaluations and evaluating the listeners. One interesting finding was that people rated loudspeakers differently depending upon the performance of the loudspeaker and the degree of listener's hearing loss. The poorer the performance of the loudspeaker and the greater the hearing loss the more likely to have wildly different evaluation ratings.
Two, I am not promoting the idea of driver modification for this project. I believe a better idea would be to reopen driver consideration. Despite testimonials of sound quality, I don't want to listen to loudspeakers based upon either the 126 or the 127 in stock condition; even for short periods of time.
Third, I am becoming somewhat leery of sharing the details of even the 126 modification because it ports so well to the 127 and because of the commerical project using the 127 referenced several times in this thread. Not my entent or desire to provide free design work for other's commercial endeavors. I do not know if this is the "risk" refered to earlier, but it is, then it was a valid concern.
Fourth, my modifications vary from driver to driver. Some are difficult, some are easy to implement. Each is designed for the particular driver. It depends upon the needs of the driver whether the modification is simple or difficult. While there have been two unsuccessful modifications posted to this forum, I have identified both of them as unsuccessful. For the successful modifications, the modification reduced unit to unit variability. In other words, you are likely to have more consistent results from the modified drivers than you are from randomly purchased stock drivers.
It is always possible to mess up any project, however, and the diyer would know better than anyone else what they are or are not capable of doing. Because of this, choosing a driver modification scheme for this project will eliminate some participants. That being said, I reiterate my earlier proposal to reopen driver selection. Let us see if we cannot come up with a driver that more people will hear as the same regardless of hearing loss and that does not need modification. Just a suggestion consistent with the design criteria set forth for this project.
Now, as to the FE127E modification. The cone modifications are the same as for the FE126E. The prefilter is different, much more agressive. Of particular interest is the sensitivity comparison of the 127 and the 126. As shown, the 127 is significantly less sensitive than the 126 and is comparable to a lot of other available drivers.
If you can drive the 127 to satisfactory listening levels then you can do it with other drivers generally considered too insensitive for use with low wattage amplifiers.
Good designing and good building,
Mark
Before I post the results I would like to say a few things about some ideas recently stated in this thread.
First, there is a problem with using a poor performing driver as a reference. To do so assumes that everyone hears the defects in the same way. There is considerable research to contradict this assumption. I remember an AES paper from as early as the 1970s about CBC's attempts to design a new monitor loudspeaker. They did considerable work on listening evaluations and evaluating the listeners. One interesting finding was that people rated loudspeakers differently depending upon the performance of the loudspeaker and the degree of listener's hearing loss. The poorer the performance of the loudspeaker and the greater the hearing loss the more likely to have wildly different evaluation ratings.
Two, I am not promoting the idea of driver modification for this project. I believe a better idea would be to reopen driver consideration. Despite testimonials of sound quality, I don't want to listen to loudspeakers based upon either the 126 or the 127 in stock condition; even for short periods of time.
Third, I am becoming somewhat leery of sharing the details of even the 126 modification because it ports so well to the 127 and because of the commerical project using the 127 referenced several times in this thread. Not my entent or desire to provide free design work for other's commercial endeavors. I do not know if this is the "risk" refered to earlier, but it is, then it was a valid concern.
Fourth, my modifications vary from driver to driver. Some are difficult, some are easy to implement. Each is designed for the particular driver. It depends upon the needs of the driver whether the modification is simple or difficult. While there have been two unsuccessful modifications posted to this forum, I have identified both of them as unsuccessful. For the successful modifications, the modification reduced unit to unit variability. In other words, you are likely to have more consistent results from the modified drivers than you are from randomly purchased stock drivers.
It is always possible to mess up any project, however, and the diyer would know better than anyone else what they are or are not capable of doing. Because of this, choosing a driver modification scheme for this project will eliminate some participants. That being said, I reiterate my earlier proposal to reopen driver selection. Let us see if we cannot come up with a driver that more people will hear as the same regardless of hearing loss and that does not need modification. Just a suggestion consistent with the design criteria set forth for this project.
Now, as to the FE127E modification. The cone modifications are the same as for the FE126E. The prefilter is different, much more agressive. Of particular interest is the sensitivity comparison of the 127 and the 126. As shown, the 127 is significantly less sensitive than the 126 and is comparable to a lot of other available drivers.
If you can drive the 127 to satisfactory listening levels then you can do it with other drivers generally considered too insensitive for use with low wattage amplifiers.
Good designing and good building,
Mark
Attachments
Where are we now?
Greetings everyone.
I am a little disapointed in where things have gone of late.
The choice of driver was made based on the available information, that being the Fostex published specifications. Drivers considered ranged between the FE103 to the FE206, with Fostex being the chosen brand as it had a good rep and is generally available worldwide. Trying to keep costs down, we focused on the FE126/127. While I liked the extra sensitivity of the FE126, the FE127 was better suited to the chosen enclosure, that being a TL. While the published specs showed a few less peaks for the 126, it showed rising response that the 127 did not.
Having said that, while too many people did not vote, the driver selection was done fairly. I personally voted for the 126, but have no regrets with having gone with the 127.
I think it is unfair to say that people forced the choice of driver and have a vested interest. Mark, your measurements have been wonderful...Thank you. However, it is your choice to share your modifications. No one here expects anything. There is nothing stoping people from using your TB mods for commercial projects.
Cheers,
Gio.
Greetings everyone.
I am a little disapointed in where things have gone of late.
The choice of driver was made based on the available information, that being the Fostex published specifications. Drivers considered ranged between the FE103 to the FE206, with Fostex being the chosen brand as it had a good rep and is generally available worldwide. Trying to keep costs down, we focused on the FE126/127. While I liked the extra sensitivity of the FE126, the FE127 was better suited to the chosen enclosure, that being a TL. While the published specs showed a few less peaks for the 126, it showed rising response that the 127 did not.
Having said that, while too many people did not vote, the driver selection was done fairly. I personally voted for the 126, but have no regrets with having gone with the 127.
I think it is unfair to say that people forced the choice of driver and have a vested interest. Mark, your measurements have been wonderful...Thank you. However, it is your choice to share your modifications. No one here expects anything. There is nothing stoping people from using your TB mods for commercial projects.
Cheers,
Gio.
I understand your point but don't be disappointed, Mark's measurments have brought information, confirmations that wasn't available at the begining of the thread and that should be discussed IMHO, this is the reason of being of this forum and group working...
OTOH I fully agree with you and I also see a danger of dilution of the interest.
Perhaps it's time to imagine the crossover which will be able to tame the FE127's peaks and gaps.
Lionel said:
I understand your point but don't be disappointed, Mark's measurments have brought information, confirmations that wasn't available at the begining of the thread and that should be discussed IMHO, this is the reason of being of this forum and group working...
My disappointment is not with the frequency measurements, the more information we have, the better.
Yes, we need to discuss the remaining options. Those being,
1) Filter and/or modifications.
2) A possible new driver / project.
While I have already ordered four FE127E, my feelings would not be hurt if we selected a new driver. I will find other uses for them.
In the end, we all want the same thing...a very nice sounding full range speaker.
Regards,
Gio.
well, kids.
i have been reading this thread with interest...until lately. now it just feels sour.
it seems that commercial interests and DIY are suddenly at odds. well, i for one do NOT see it that way, never have.
the avant-garde informs the world of commerce, but that's nothing new. no one design serves very many purposes, there's always another good design around the corner to do something different for another situation, no end all and be all. commerce (i.e. fostex et al) provides us fun stuff to improve and mess with.
and there is nothing really new under the sun in this little fun world of high performance handmade audio. no zillion dollar ideas to protect, no giant financial rewards to gain, really. maybe for bose or some giant corp. hahaha all stafff engineers raise your hands? anyways if the idea is REALLY amazing some clever wag will backwards engineer it haha
we're really just playing with classic ideas here anyway...tqwp, transmission line etc.
really nobody on this thread has the resources (i.e. GIANT PROMOTIONAL DOLLARS) to mount a hugely successful commercial product.
sheesh. thinking about pennies while i'm having fun building stuff with my hands just bums me out.
lets build some stuff, listen to it, tweak it, and talk about it.
never mind the bollocks.
i have been reading this thread with interest...until lately. now it just feels sour.
it seems that commercial interests and DIY are suddenly at odds. well, i for one do NOT see it that way, never have.
the avant-garde informs the world of commerce, but that's nothing new. no one design serves very many purposes, there's always another good design around the corner to do something different for another situation, no end all and be all. commerce (i.e. fostex et al) provides us fun stuff to improve and mess with.
and there is nothing really new under the sun in this little fun world of high performance handmade audio. no zillion dollar ideas to protect, no giant financial rewards to gain, really. maybe for bose or some giant corp. hahaha all stafff engineers raise your hands? anyways if the idea is REALLY amazing some clever wag will backwards engineer it haha
we're really just playing with classic ideas here anyway...tqwp, transmission line etc.
really nobody on this thread has the resources (i.e. GIANT PROMOTIONAL DOLLARS) to mount a hugely successful commercial product.
sheesh. thinking about pennies while i'm having fun building stuff with my hands just bums me out.
lets build some stuff, listen to it, tweak it, and talk about it.
never mind the bollocks.
I'm quite mystified about this. For the record, I have no commercial interests, goals or investments in whatever results from this project. Yes, I have a very (and I mean VERY) small start up business and anyone can check out what I do anytime they want. Yes, I have a FE127E based design for sale outside the USA. I have provided FE127E drivers to a few of my friends at my cost because I like to help people when it's in my power to do so. The design suggestions I made are different than my commercial design for a reason. I was excited about the possibilities for a bipole full range design especially since one of my personal bipole projects turned out so well and I don't feel that bipole designs are commercially viable in the market I'm attempting to serve. I also enjoy participating and contributing to the members of this forum. For me, and I'm sure for many, this type of activity is just plain FUN! I think I'll just sit back and see what happens from here. Good luck gang!
Back on track
Hello all:
Boy I go away for the weekend and the kids start fighting.
It seems we are in a bit of a quandry right now. Some of us have a pile of drivers to play with. Some of us are just reading and dreaming. We even have a group that is considering starting all over again. Hmmmm, do we split the party up and go our separate ways. Do we reunite and try something with these Fostex drivers.
I figure there are at least a few good reasons to continue with the fe126/127, gmilitano points them out quite elequently. Heck there are compromises with all drivers. Maybe we do not end up with an official reference speaker, maybe we end up with something that is okay, but we are 27 pages allong this road, we should be able to get something. noisenyc made a good point regarding Marks concerns about commercialism, heck we are all small potatos with big ideas just playing around. If someone thinks they can make a buck from our group design, I really do not care that much. The big mass market guys have things sown up for the real money.
So can we now get back to designing and modifying?
Mark are you going to share your ideas with the rest of us.
Hello all:
Boy I go away for the weekend and the kids start fighting.
It seems we are in a bit of a quandry right now. Some of us have a pile of drivers to play with. Some of us are just reading and dreaming. We even have a group that is considering starting all over again. Hmmmm, do we split the party up and go our separate ways. Do we reunite and try something with these Fostex drivers.
I figure there are at least a few good reasons to continue with the fe126/127, gmilitano points them out quite elequently. Heck there are compromises with all drivers. Maybe we do not end up with an official reference speaker, maybe we end up with something that is okay, but we are 27 pages allong this road, we should be able to get something. noisenyc made a good point regarding Marks concerns about commercialism, heck we are all small potatos with big ideas just playing around. If someone thinks they can make a buck from our group design, I really do not care that much. The big mass market guys have things sown up for the real money.
So can we now get back to designing and modifying?
Mark are you going to share your ideas with the rest of us.
I believe its time to re-group and redefine what you are trying to do. I too have followed this thread and see that the intent and the ultimate goals are not compatible. This started out as a "reference" speaker which, although optimized, I doent feel is an accurate description of what will be produced. This is because there is a cap, and a low one I might add, on the expenditures used for the drivers.
So you really now have a " budget reference" FR speaker.
Next the move towards a bipole which doubled the cost. I own two FR bipoles and think they are an excellent way to optimize a 4" driver but they are not the last word in FR sound. They are really a cheat in that a single driver isnt up to the task at hand unless additional SD is used or they are backloaded to boost LF so as to avoid excess excursion and mucking up the mids/highs. Yes BLHs are harder to build - so no free lunch. So then the VOCAL majority voted on a driver, using the only data availabel at the time, and the design process started.
Now, new drivers are being looked at after many already purchased drivers and became enthused. Bad decision. Once this happened, the project lost its legs. Time to re-evaluate the original intent of the project.
I personally believe that this should be an "optimized, low cost reference FR" project and continue with stock drivers and use the ones that everyone bought. If you really want a real "reference speaker" a $35 dollar driver isnt going to do it. Tweaking is fine but if you spend two days modding it, you could work an extra two days instead and buy a far superior driver. Will a modded $35 4" sound as good as a $100+ 6.5" ? I doubt it. And you'll still have a $35 driver.
Start a new thread specifically for the speaker under developement. For those with other drivers,designs and ideas, start an alternative for a different design.
And as noisenyc stated, theres nothing groundbreaking going on here. And the likelyhood of a successfull (actual profit) commercial product coming out of this is close to nill. If it were possible, Bert D would have taken his version to market, but he didnt bother. And hes had years to refine it, with a credible company to back it.
Hope you all get back to it.
amt
So you really now have a " budget reference" FR speaker.
Next the move towards a bipole which doubled the cost. I own two FR bipoles and think they are an excellent way to optimize a 4" driver but they are not the last word in FR sound. They are really a cheat in that a single driver isnt up to the task at hand unless additional SD is used or they are backloaded to boost LF so as to avoid excess excursion and mucking up the mids/highs. Yes BLHs are harder to build - so no free lunch. So then the VOCAL majority voted on a driver, using the only data availabel at the time, and the design process started.
Now, new drivers are being looked at after many already purchased drivers and became enthused. Bad decision. Once this happened, the project lost its legs. Time to re-evaluate the original intent of the project.
I personally believe that this should be an "optimized, low cost reference FR" project and continue with stock drivers and use the ones that everyone bought. If you really want a real "reference speaker" a $35 dollar driver isnt going to do it. Tweaking is fine but if you spend two days modding it, you could work an extra two days instead and buy a far superior driver. Will a modded $35 4" sound as good as a $100+ 6.5" ? I doubt it. And you'll still have a $35 driver.
Start a new thread specifically for the speaker under developement. For those with other drivers,designs and ideas, start an alternative for a different design.
And as noisenyc stated, theres nothing groundbreaking going on here. And the likelyhood of a successfull (actual profit) commercial product coming out of this is close to nill. If it were possible, Bert D would have taken his version to market, but he didnt bother. And hes had years to refine it, with a credible company to back it.
Hope you all get back to it.
amt
Re: Back on track
It is time to regroup and get back on track. I want to restate most of the original goals.
Full range, a reptuable speaker that is commonly available, a simple enclosure, low cost, decent performance and a good time and learning experience.
I think we can meet those goals with the FE127E. Please do not get caught up on the word "reference". When I selected that name, I was thinking more along the lines that several people could build this speaker and then compare (reference) it with other speaker systems which may be better or worse. Kinda like a baseline for a study.
Ok, how about this, we can consider a new name. "diyAudio.com Full Range Baseline Project with FE127E"?
A design is in place, I know some others are building and I am expecting my drivers soon. If this works out well, perhaps we can even try something with the FE126E and compare the two.
Cheers,
Gio.
It is time to regroup and get back on track. I want to restate most of the original goals.
Full range, a reptuable speaker that is commonly available, a simple enclosure, low cost, decent performance and a good time and learning experience.
I think we can meet those goals with the FE127E. Please do not get caught up on the word "reference". When I selected that name, I was thinking more along the lines that several people could build this speaker and then compare (reference) it with other speaker systems which may be better or worse. Kinda like a baseline for a study.
Ok, how about this, we can consider a new name. "diyAudio.com Full Range Baseline Project with FE127E"?
A design is in place, I know some others are building and I am expecting my drivers soon. If this works out well, perhaps we can even try something with the FE126E and compare the two.
Cheers,
Gio.
SCD said:
amt said:
Original goals can be found here. 
Digression? Where are we going, and why are we in this handbasket? Commercial interests? If someone was selling something, no one told me.
Are there secrets to hide? Profits to protect? I've been gone a little while, what did I miss?
If you're a lurking newbie looking for a real good first project with a single full ranger, stop reading this thread and do a search on the CSS WR125S. If you're here because of a reference I made elsewhere comparing the FE127E to the Vifa P13 project, you'll have to wait a couple days to get a fair dollar/cost comparison. I was waiting for a group consensus on the actual bipole design.
If no one expresses any particular preference, I'll do something and report my impressions....."clock cleaning" or not.
Please excuse me for ranting, I know some will, as I'm regularly ignored anyway.....I thought we simply picked decent accessible drivers to implement as best we could to have a reference to develop and compare. I would think all information should be welcomed. Is someone suggesting "snuberizing" the group design, or is it the other way around?
Mark, I'd also be interested in any further posts concerning mods.
Digression? Where are we going, and why are we in this handbasket? Commercial interests? If someone was selling something, no one told me.
Are there secrets to hide? Profits to protect? I've been gone a little while, what did I miss?
If you're a lurking newbie looking for a real good first project with a single full ranger, stop reading this thread and do a search on the CSS WR125S. If you're here because of a reference I made elsewhere comparing the FE127E to the Vifa P13 project, you'll have to wait a couple days to get a fair dollar/cost comparison. I was waiting for a group consensus on the actual bipole design.
If no one expresses any particular preference, I'll do something and report my impressions....."clock cleaning" or not.
Please excuse me for ranting, I know some will, as I'm regularly ignored anyway.....I thought we simply picked decent accessible drivers to implement as best we could to have a reference to develop and compare. I would think all information should be welcomed. Is someone suggesting "snuberizing" the group design, or is it the other way around?
Mark, I'd also be interested in any further posts concerning mods.
So much for sitting back and watching. 
I still support the decision to use the FE127E driver. A little story first.
I had a friend in the Philippines build a TQWT for the FE127E following an invitation to put something in the DIY room at a hi-fi show in Manila. The reception was completely unexpected (although I liked the way it sounded). Suddenly I was being asked to produce retail versions to team up with a vendor's new tube amp that just happened to make a great combo. I contacted Martin King since I used his worksheet to come up with the cabinet dimensions and we have a standing agreement in place. (As a side note there have been several auditions but I have not sold a single unit yet. Things move very slow in the Philippines and I've only had a business registration for a couple of months.)
My design is single driver and uses a BSC and Zobel circuit. I have not now nor ever had any intention of adding modifications to the drivers. I happen to believe that many irksome qualities of raw Fostex drivers decrease over time. Besides, my Pinoy customers are very concerned about the appearance of their audio equipment. Modding the driver could detract from that. Hence, I'm happy to leave my design as is. End of that story.
One major reason for selecting Fostex (brand not model) was global availability. Reasons for selecting the FE127E included ease of application, a wide FR, low cost and shielding. I can't think of another driver that meets this criteria as well as the FE127E. No, it's not perfect but that should be a given. I'm planning on building the bipole design posted earlier in this thread. I'm pretty busy but I'll attempt to get it done soon.
I still support the decision to use the FE127E driver. A little story first.
I had a friend in the Philippines build a TQWT for the FE127E following an invitation to put something in the DIY room at a hi-fi show in Manila. The reception was completely unexpected (although I liked the way it sounded). Suddenly I was being asked to produce retail versions to team up with a vendor's new tube amp that just happened to make a great combo. I contacted Martin King since I used his worksheet to come up with the cabinet dimensions and we have a standing agreement in place. (As a side note there have been several auditions but I have not sold a single unit yet. Things move very slow in the Philippines and I've only had a business registration for a couple of months.)
My design is single driver and uses a BSC and Zobel circuit. I have not now nor ever had any intention of adding modifications to the drivers. I happen to believe that many irksome qualities of raw Fostex drivers decrease over time. Besides, my Pinoy customers are very concerned about the appearance of their audio equipment. Modding the driver could detract from that. Hence, I'm happy to leave my design as is. End of that story.
One major reason for selecting Fostex (brand not model) was global availability. Reasons for selecting the FE127E included ease of application, a wide FR, low cost and shielding. I can't think of another driver that meets this criteria as well as the FE127E. No, it's not perfect but that should be a given. I'm planning on building the bipole design posted earlier in this thread. I'm pretty busy but I'll attempt to get it done soon.
my observation, at least as far as the fe166 goes, is that it sounds COMPLETELY different from amp to amp.
in the last to days, i have hooked it up to:
PSE 6l6gc
SE 300b
SE 2a3
PP 2a3
SS carver
with major differences in each. my guess is that if you design with BSC in place (if necessary for your box) and a range of zobel choices, you will be lookin good.
if you mod these physically, it would be on a per case basis in a given system and room!