Hello Everyone,
I just ordered a pair of the Fostex FE88ES-R you may have seen my post about earlier, and now I am starting the process of designing a system around it. I have decided that rather than torture the driver into some minimal low end response (it has an Fs of 107 Hz) somewhere near 70-90 Hz, I would look for a woofer driver that could contribute up to any point south of 1 kHz and handle things down low (at least 42 Hz with a good cabinet design). Obviously, given my 40-45 Hz goal I am not a listener that craves any serious bass response, I just want something tight and tunefull to let me know what the bass line is without exciting too many room response issues.
Given my interest in the single driver cult, I was hoping to stay as simple and near cross-over free as possible, maybe even building a small amp to driver the woofer that was designed to be bandwidth limited so as not to interfere with the critical range and imaging of the main driver. Am I dreaming or is this within the realm of the possible???
I just ordered a pair of the Fostex FE88ES-R you may have seen my post about earlier, and now I am starting the process of designing a system around it. I have decided that rather than torture the driver into some minimal low end response (it has an Fs of 107 Hz) somewhere near 70-90 Hz, I would look for a woofer driver that could contribute up to any point south of 1 kHz and handle things down low (at least 42 Hz with a good cabinet design). Obviously, given my 40-45 Hz goal I am not a listener that craves any serious bass response, I just want something tight and tunefull to let me know what the bass line is without exciting too many room response issues.
Given my interest in the single driver cult, I was hoping to stay as simple and near cross-over free as possible, maybe even building a small amp to driver the woofer that was designed to be bandwidth limited so as not to interfere with the critical range and imaging of the main driver. Am I dreaming or is this within the realm of the possible???
It Works
Greggo,
I've been running 2x 8" woofers in sealed boxes with no xover (too lazy to get around to building one - will bi-amp one day...)
for the last 6 months; it sounds fine.
Even more un-kosher - the two drivers aren't the same!!!! couldn't find another of the carbon-fibre cone drivers, so the newest one has a polyprop. cone - that's probably better for just adding lows, the mids are a bit more evident on the carbon fibre cone driver.
I've got to buy some inductors for another project, so I'll try them on this set-up, but I think you're right, if appropriate drivers are used, then no x-over is possible
Pete McK
Greggo,
I've been running 2x 8" woofers in sealed boxes with no xover (too lazy to get around to building one - will bi-amp one day...)
for the last 6 months; it sounds fine.
Even more un-kosher - the two drivers aren't the same!!!! couldn't find another of the carbon-fibre cone drivers, so the newest one has a polyprop. cone - that's probably better for just adding lows, the mids are a bit more evident on the carbon fibre cone driver.
I've got to buy some inductors for another project, so I'll try them on this set-up, but I think you're right, if appropriate drivers are used, then no x-over is possible
Pete McK
Well, right now I am at the blue sky point, not constrained by any notion of cabinet size and style, and I have a fairly complete shop and good wood working skills so nothing scares for the most part. Since the FE88ES-R is a small driver I did think it would be nice to keep the baffle narrow but this is not really a big deal for me because I think that even a wide baffle can be deisgned along with the rest of the system to image quite nicely.
I have been thinking about a floor stander with a small upper cabinet for the FE88, maybe 7 inches wide by 12 inches tall 14 inches deep. That could be designed as a bass reflex or small transmission line with a goal of helping the FE88 behave well from 90 Hz out to the limit of the driver which is almost 40 kHz. That cabinet could then sit on top of or on stands beside another matching cabinet (in style not necessarily in size) that contained a single or dual woofers, and they could be mounted high. low, on the side, or facing the rear. They could be mounted in a standard fashion or have some kind of physical absorption or tuning device mounted in front of them to help dampen any unwanted peaks or frequency extension. Ideally I suppose I would want the woofer driver to face the rear and have a natural roll off around 900 Hz so as to create a nice bipolar effect in tandem with the FE88 and not be too forcefull in its contribution so as to preserve the point source effect of the FE88 above that range as much as possible. Then its contribution below 90 Hz, though directed toward the rear I would expect that it would still provide a satisfying extension for the listener seated in front of the front firing FE88.
That is a rough starting point, but I have not begun any modeling or serious thought as to the cabinet design because I first want to consider potential woofer drivers and what challenge they would face in attempting to integrate them with the response of the FE88 in as natural a manner as possible, i.e. - no crossover if I can get away with it...
Sorry for the long post, I hope my thinking is clear and I am explaining this correctly....
Thanks,
Greg Jensen
I have been thinking about a floor stander with a small upper cabinet for the FE88, maybe 7 inches wide by 12 inches tall 14 inches deep. That could be designed as a bass reflex or small transmission line with a goal of helping the FE88 behave well from 90 Hz out to the limit of the driver which is almost 40 kHz. That cabinet could then sit on top of or on stands beside another matching cabinet (in style not necessarily in size) that contained a single or dual woofers, and they could be mounted high. low, on the side, or facing the rear. They could be mounted in a standard fashion or have some kind of physical absorption or tuning device mounted in front of them to help dampen any unwanted peaks or frequency extension. Ideally I suppose I would want the woofer driver to face the rear and have a natural roll off around 900 Hz so as to create a nice bipolar effect in tandem with the FE88 and not be too forcefull in its contribution so as to preserve the point source effect of the FE88 above that range as much as possible. Then its contribution below 90 Hz, though directed toward the rear I would expect that it would still provide a satisfying extension for the listener seated in front of the front firing FE88.
That is a rough starting point, but I have not begun any modeling or serious thought as to the cabinet design because I first want to consider potential woofer drivers and what challenge they would face in attempting to integrate them with the response of the FE88 in as natural a manner as possible, i.e. - no crossover if I can get away with it...
Sorry for the long post, I hope my thinking is clear and I am explaining this correctly....
Thanks,
Greg Jensen
Oh yeah, here is another thought I had on this...
Ever notice how with many woofer drivers the on axis response has some peakiness/nastiness but when you look at the 30 degress and then the 60 degree off axis freq response lines things look great and sometimes look like you could just naturally roll in a mid or tweeter to take over from there???
Well I was wondering, what if you mounted such a woofer on a baffle, and then built another cabinet in front of it, an open back cabinet so the woofer could fire straight into it, and that cabinet was stuffed with foam/fiberglass to effectively dampen anything above 8 or 9 hundred Hertz. And then what if you space the gap between the woofer baffle and this open back so that everything coming off the cone at 60 degrees or more was going into free air and everything less was hitting the trap and getting re-directed to the floor through a web of filling that left the sound waves rather lifeless by the time they found their way out.
Any thoughts on this purely physical approach to limiting the woofers response at the listening seat?
Do these break up modes and nasty peaks have a significant effect on the lower range response, meaning am I still compromising the drivers ability to play cleanly from 40-400 Hz as an example by letting my amplifier send it a full bandwidth signal?
Just some more thoughts on this zero crossover quest, which I know is somewhat misguided but I just love the idea of clean and clear wire from an amp to the driver terminals with nothing else in between.
Any Thoughts???
Greg Jensen
Ever notice how with many woofer drivers the on axis response has some peakiness/nastiness but when you look at the 30 degress and then the 60 degree off axis freq response lines things look great and sometimes look like you could just naturally roll in a mid or tweeter to take over from there???
Well I was wondering, what if you mounted such a woofer on a baffle, and then built another cabinet in front of it, an open back cabinet so the woofer could fire straight into it, and that cabinet was stuffed with foam/fiberglass to effectively dampen anything above 8 or 9 hundred Hertz. And then what if you space the gap between the woofer baffle and this open back so that everything coming off the cone at 60 degrees or more was going into free air and everything less was hitting the trap and getting re-directed to the floor through a web of filling that left the sound waves rather lifeless by the time they found their way out.
Any thoughts on this purely physical approach to limiting the woofers response at the listening seat?
Do these break up modes and nasty peaks have a significant effect on the lower range response, meaning am I still compromising the drivers ability to play cleanly from 40-400 Hz as an example by letting my amplifier send it a full bandwidth signal?
Just some more thoughts on this zero crossover quest, which I know is somewhat misguided but I just love the idea of clean and clear wire from an amp to the driver terminals with nothing else in between.
Any Thoughts???
Greg Jensen
how come you chose the Fe88?
i too am looking at a fullrange project.
i am looking at 2 options.
option 1. wall mounted system operating frm 100Hz up.
option 2. small foot print floor stander operating from 45Hz up.
I would like to have the same drivers or similar drivers for both these.
drivers i have considered are the FE103, JX92 maybe with a tweeter on top this would mean only a single cap as a XO.
the other alternate would be to use a smaller fullrange like the JX53 or FE83 XOed to a larger wide range driver like the JX125 or FW108N. this would mean a XOs for the bass and hf units. However if one chooses the drivers propoerly one might be able to manage with a single inductor which has the bass driver in series with it and the hf unit in parallel with it.
i too am looking at a fullrange project.
i am looking at 2 options.
option 1. wall mounted system operating frm 100Hz up.
option 2. small foot print floor stander operating from 45Hz up.
I would like to have the same drivers or similar drivers for both these.
drivers i have considered are the FE103, JX92 maybe with a tweeter on top this would mean only a single cap as a XO.
the other alternate would be to use a smaller fullrange like the JX53 or FE83 XOed to a larger wide range driver like the JX125 or FW108N. this would mean a XOs for the bass and hf units. However if one chooses the drivers propoerly one might be able to manage with a single inductor which has the bass driver in series with it and the hf unit in parallel with it.
Navin,
I chose the FE88ES-R for a couple of reasons:
1) I am interested in wide range and/or full range drivers, believing that multiple drivers and crossovers make it extremely difficult to get the kind of sound I like most out of stereo system
2) Since most if not all drivers in the above category are challenged at either the lower end and/or higher end of the music frequency spectrum, I thought it best to deal with the lower end challenges for the following reasons:
a) electrical filtering and tone shaping seems to do more damage in the 300 Hz to 6 kHz range than anywhere else.
b) physical seperation of multiple drivers seems to be more challenging in the 900 Hz to 9 kHz range due to lobing, phase, and other issues that affect point source imaging (which is after pitch and timbre is one of my most valued qualities in a system).
c) I don't really care about low bass, and in fact I consider decent bass response below 40 Hz to be more of a liability than an asset due to room problems. I find that solid response into the 50s, with fair response dipping into the 40s, and then just a hint of sound pressure below that point works best for me and the way I like to listen to music and not bother the rest of my family or put up with less deliniated bass lines due to room modes getting excited and causing bloat and overhang of the bass notes
3) The FE88ES-R reminded me of other limited edition drivers from Fostex that have met with great success among audio types that seem to value many of the same things I do in a system. Also, the response curve looked very good to me and the physical design of the driver looked good to me as well. The response looks fantastic from 120 Hz to out past 20 kHz, with a little dip rather than a peak running between 1.4 - 2.8 kHz which I feel will be critical in helping to keep the sound tame rather than shrill as many full range drivers have a rising response in the worst possible place (between 2-5 kHz).
4) Given the fact that lower range sounds are much less directional than higher range sounds, I thought I would have more flexibility in designing a woofer solution to help out below 120Hz than anything else. Looking at potential baffle step issues as well I could mount a woofer above, below, behind, beside, etc... all to varrying degrees depending on how much I wanted the woofer to contribute above 120 Hz knowing that everything below would get to the listening seat regardless of which way the woofer driver was oriented. Also, phase and timing issues, though still important, are much less detrimental in the lower ranges than the mid and upper ranges, so I thought it would be the lesser of all evils.
5) And finally, to answer your second post as well, I like the idea of having something a bit different, somewhat exclusive if you will in so far as these drivers are very difficult to get outside of Japan. If you look at the Single Driver Forum the James Melhuish runs you will find a small group of us that worked on this issue for a while and finally found a solution, here is a cut/paste of the post from a guy namged "Quest" over there:
Hello folks!
Great news! Koji-San from EIFL corp has agreed to take our orders and ship them to us. Here's the detail information:
*******************************************************************************************
Hi! Quest,
Thank you for your inquiry.
Here is the quote.
FOSTEX FE88ES-R-----------US$ 252/pair +US$ 50 poatage&insurance
=US$ 302/pair
The expected delivery is about 2 weeks after payment.
I accept wire transfer and credit card with 6% card charge.
I look forward to serving you soon.
Regards
*********************************
Koji Wakabayashi
EIFL Co.
1-8 Fujimi 2 Chome Sayama City
Saitama Prf.350-1306 Japan
TEL +81(0)4-2956-1178
FAX +81(0)4-2950-1667
E-mail koji@eifl.co.jp
Website http://www.eifl.co.jp
**********************************
I chose the FE88ES-R for a couple of reasons:
1) I am interested in wide range and/or full range drivers, believing that multiple drivers and crossovers make it extremely difficult to get the kind of sound I like most out of stereo system
2) Since most if not all drivers in the above category are challenged at either the lower end and/or higher end of the music frequency spectrum, I thought it best to deal with the lower end challenges for the following reasons:
a) electrical filtering and tone shaping seems to do more damage in the 300 Hz to 6 kHz range than anywhere else.
b) physical seperation of multiple drivers seems to be more challenging in the 900 Hz to 9 kHz range due to lobing, phase, and other issues that affect point source imaging (which is after pitch and timbre is one of my most valued qualities in a system).
c) I don't really care about low bass, and in fact I consider decent bass response below 40 Hz to be more of a liability than an asset due to room problems. I find that solid response into the 50s, with fair response dipping into the 40s, and then just a hint of sound pressure below that point works best for me and the way I like to listen to music and not bother the rest of my family or put up with less deliniated bass lines due to room modes getting excited and causing bloat and overhang of the bass notes
3) The FE88ES-R reminded me of other limited edition drivers from Fostex that have met with great success among audio types that seem to value many of the same things I do in a system. Also, the response curve looked very good to me and the physical design of the driver looked good to me as well. The response looks fantastic from 120 Hz to out past 20 kHz, with a little dip rather than a peak running between 1.4 - 2.8 kHz which I feel will be critical in helping to keep the sound tame rather than shrill as many full range drivers have a rising response in the worst possible place (between 2-5 kHz).
4) Given the fact that lower range sounds are much less directional than higher range sounds, I thought I would have more flexibility in designing a woofer solution to help out below 120Hz than anything else. Looking at potential baffle step issues as well I could mount a woofer above, below, behind, beside, etc... all to varrying degrees depending on how much I wanted the woofer to contribute above 120 Hz knowing that everything below would get to the listening seat regardless of which way the woofer driver was oriented. Also, phase and timing issues, though still important, are much less detrimental in the lower ranges than the mid and upper ranges, so I thought it would be the lesser of all evils.
5) And finally, to answer your second post as well, I like the idea of having something a bit different, somewhat exclusive if you will in so far as these drivers are very difficult to get outside of Japan. If you look at the Single Driver Forum the James Melhuish runs you will find a small group of us that worked on this issue for a while and finally found a solution, here is a cut/paste of the post from a guy namged "Quest" over there:
Hello folks!
Great news! Koji-San from EIFL corp has agreed to take our orders and ship them to us. Here's the detail information:
*******************************************************************************************
Hi! Quest,
Thank you for your inquiry.
Here is the quote.
FOSTEX FE88ES-R-----------US$ 252/pair +US$ 50 poatage&insurance
=US$ 302/pair
The expected delivery is about 2 weeks after payment.
I accept wire transfer and credit card with 6% card charge.
I look forward to serving you soon.
Regards
*********************************
Koji Wakabayashi
EIFL Co.
1-8 Fujimi 2 Chome Sayama City
Saitama Prf.350-1306 Japan
TEL +81(0)4-2956-1178
FAX +81(0)4-2950-1667
E-mail koji@eifl.co.jp
Website http://www.eifl.co.jp
**********************************
Good question... from what I have seen from system graphs of a cabinet recommended by Fostex for this driver and for other similar drivers (similar as far as Q and Free Air Resonance anyways), a hybrid horn (I don't consider most of the Fostex designs to be true horns) can bring things down to the high 70s low 80s before level drops off, and simple bass reflex designs could easily bring things down to 80 or 90 Hz. I will be doing some experimenting to see how the character of the driver changes from open baffle to various sizes of sealed and ported enclosures before I begin to run simulations on box size and port (I don't have any software yet to do that but I intend to get some). I am prepared to keep the FE88 at 120 Hz and above if need be, but I am hoping that I can get great sound all the way down to 90 Hz and then hand off to a woofer from there. I think a cabinet could be designed to bring it down lower, but I am concerned that even at 90 Hz I am asking a lot of the driver and intermodulation distortion will rise tremendously as one journeys from 200 Hz on downward with a single cone driver attempting to cover everything (which is why I may end up just going with 120 Hz as a lower limit design goal). My primary concern will be to design in a manner that best protects the excursion of the FE88 and does not compromise its best musical attributes (assuming it has some because this is a gamble on my part to buy an unproven driver like this one). I am hoping to design a bandwidth limited amp that drives the FE88 and protects it somewhat from information below 90 Hz and then design a bandwidth limited amp that will limit the woofer to some degree above that range. This is all based on the assumption (still much research to do) that I can best manage tonal shaping or frequency limiting at the input to a gain stage and that perhaps with subltle approaches I will have a musical system that produces much less interference to the source signal than a full blown passive crossover would. I am really looking for something like a hybrid between an active crossover and a tube equalizer to go between the pre and power stages, with each gain stage of two amps per channel being directly connected to their intended drivers with nothing else in between, not even binding posts...
Greg Jensen
Greg Jensen
Well, research is a very relative term. I have not done any extensive research though over the last few years I have read just about everything on the net regarding single driver systems and quite a bit on just drivers in general so I feel fairly confident that I have a good idea of what just about every manufacturer out there has to offer. Originally, I was planning on the FE103, but was hoping to find the FE103 Memorial for sale somewhere as I have heard that it is a bit smoother sounding than the regular FE103. But then I was tempted by all the good things I have heard about the FE108 so I was looking at the latest version being sold at the Madisound web site, the FE108EZ, and that was pretty much the way I was going to go until news of this FE88ES-R came along. It really is for the most part an impulse buy, but one that my instincts tell me is the right way to go for me. I have no doubts that I am overpaying a bit, somewhere between 30 and 50 percent by my estimates, but I feel that it is worth it to me for two reasons:
1) Given the tremendous upper range response of the FE88 and the slightly smaller cone size I am hoping that the extra cost of this driver is simply an insurance policy against feeling the need for a tweeter and or better upper range dispersion down the road. Reviews of the FE108 led me to believe that this may be a problem for me on some material depending driver/cabinet and listening position, though less so from what I have read about the FE103 (but then the 103 seems to not have the dynamic range of the 108, so that was my take on the trade-off between the two of them).
2) As I mentioned in my earlier post, I will admit that part of my decision to go with this driver was simply for the novelty of it, my feeling that it is a bit more exotic than the standard fair but not so wacky that it will be hard to make part of a decent system that anyone can appreciate.
3) I guess the final balance of the decision for me was feeling confident that I would not ever feel the need for a helper tweeter, and confident that the driver would do well down to just under 120 Hz making a woofer driver a very manageable integration effort. Other drivers like the FE103 also meet this criteria and I would probably be just as happy with the end results of a system based around that as well. I am just hoping that the FE88, due to its cone material, voice coil, magnet, and surround design will offer me just a little something extra that makes me feel good about the extra cost.
Regards,
Greg Jensen
1) Given the tremendous upper range response of the FE88 and the slightly smaller cone size I am hoping that the extra cost of this driver is simply an insurance policy against feeling the need for a tweeter and or better upper range dispersion down the road. Reviews of the FE108 led me to believe that this may be a problem for me on some material depending driver/cabinet and listening position, though less so from what I have read about the FE103 (but then the 103 seems to not have the dynamic range of the 108, so that was my take on the trade-off between the two of them).
2) As I mentioned in my earlier post, I will admit that part of my decision to go with this driver was simply for the novelty of it, my feeling that it is a bit more exotic than the standard fair but not so wacky that it will be hard to make part of a decent system that anyone can appreciate.
3) I guess the final balance of the decision for me was feeling confident that I would not ever feel the need for a helper tweeter, and confident that the driver would do well down to just under 120 Hz making a woofer driver a very manageable integration effort. Other drivers like the FE103 also meet this criteria and I would probably be just as happy with the end results of a system based around that as well. I am just hoping that the FE88, due to its cone material, voice coil, magnet, and surround design will offer me just a little something extra that makes me feel good about the extra cost.
Regards,
Greg Jensen
I think you should apply some sound practical acoustic engineering.
You are neglecting completely "baffle step compensation".
I suggest you research this and decide whether you want
to acoustically compensate for this or use line level EQ.
For acoustic compensation you need a bass driver 5dB to 6dB
more sensitive than the Fostex which I presume is around 90dB.
Not an easy task, but two 6.5" units around 88dB to 90dB
will combine to give 94dB to 96dB sensitivity with 4ohm loading.
I also assume the Fostex excursion capability is limited.
So some filtering will help maintain clean midrange / treble.
Obviously you want it as simple as possible.
The Fostex on its own in a 7" x 12" (14" sounds very deep)
(presumably the Fostex is offset to smooth the baffle step)
box will exhibit a 6dB rise in response centred at 650Hz,
over the range 200 Hz to 2Khz.
This is too high a range for acoustic compensation with
the bass units according to your wanted requirements,
as crossover would be 500hz to 850 Hz.
I'd suggest passive line level EQ is needed, see hear :
http://sound.westhost.com/bafflestep.htm
With a small baffle room gain is not going to help.
Assuming line level BS correction :
I don't know the parameters of the Fostex, but possibly
a sealed box alignment with a Q of ~ 0.6 is possible ?
I reckon Fb would be around 180 Hz ? whats the Fostex Qts ?
If so you you can crossover to the bass unit, this filtered
With a 2nd order Q of 0.6 filter also to give ~ a Linkwitz /
Riley 2nd order alignment.
The bass unit needs to be the same sensitivity as the Fostex.
Adding a series capacitor for the Fostex would be a good
idea, it would cut out low bass below resonance.
If you crossover a little higher, say 300Hz, then a 1st
order series crossover should do the job, and this would
be my choice, as the Fostex power handling is better.
The bass unit needs a clean midrange with no peaking.
sreten.
The above can also be done with seperate amplifiers,
here you have the advantage the units do not need
to be the same sensitivity.
You are neglecting completely "baffle step compensation".
I suggest you research this and decide whether you want
to acoustically compensate for this or use line level EQ.
For acoustic compensation you need a bass driver 5dB to 6dB
more sensitive than the Fostex which I presume is around 90dB.
Not an easy task, but two 6.5" units around 88dB to 90dB
will combine to give 94dB to 96dB sensitivity with 4ohm loading.
I also assume the Fostex excursion capability is limited.
So some filtering will help maintain clean midrange / treble.
Obviously you want it as simple as possible.
The Fostex on its own in a 7" x 12" (14" sounds very deep)
(presumably the Fostex is offset to smooth the baffle step)
box will exhibit a 6dB rise in response centred at 650Hz,
over the range 200 Hz to 2Khz.
This is too high a range for acoustic compensation with
the bass units according to your wanted requirements,
as crossover would be 500hz to 850 Hz.
I'd suggest passive line level EQ is needed, see hear :
http://sound.westhost.com/bafflestep.htm
With a small baffle room gain is not going to help.
Assuming line level BS correction :
I don't know the parameters of the Fostex, but possibly
a sealed box alignment with a Q of ~ 0.6 is possible ?
I reckon Fb would be around 180 Hz ? whats the Fostex Qts ?
If so you you can crossover to the bass unit, this filtered
With a 2nd order Q of 0.6 filter also to give ~ a Linkwitz /
Riley 2nd order alignment.
The bass unit needs to be the same sensitivity as the Fostex.
Adding a series capacitor for the Fostex would be a good
idea, it would cut out low bass below resonance.
If you crossover a little higher, say 300Hz, then a 1st
order series crossover should do the job, and this would
be my choice, as the Fostex power handling is better.
The bass unit needs a clean midrange with no peaking.
sreten.The above can also be done with seperate amplifiers,
here you have the advantage the units do not need
to be the same sensitivity.
Have you considered a 4th order bandpass design for the woofer? This encloses the driver entirely and only exposes a port. The curves I get when I use WINISD to model common 8" woofers in this alignment roll off at about exactly where I think you want to be.
(P.S - I'm a rookie at this speaker design thingie, so if this is a retarded idea - _someone_ should speak up!
(P.S - I'm a rookie at this speaker design thingie, so if this is a retarded idea - _someone_ should speak up!
Greggo said:
this must be ESP. Actually my starter design involved a Jordan JX 92 supported by a JX125 for baffle step. however i was told the JX92 might have limted HF response and to consider the JX53. The JX53 however could not be run fullrange. that meant making a 2way speaker with the 53 operating above 200Hz and the 125 or 150 operating below that.
Then i siwthced my focus to Tangband and Fostex. I envisoned a system using a FE103 for the fullrange and 2 x FW108N for the baffle step. However again i was told that the 103 migth have limited hf response.
seems like any driver that can be run full range (100Hz+) has limited hf response.
hi
i manufacture sub drivers which naturally roll off at about 150 and progressivly above 200 to 250 quite impressivly
they hardly require cross overs active or passive , improving phase and timing ets
but i dont know how i could get them across to you , as i have a small company and am only able to cater to local need here in calcutta ,
all i could advise is such drivers can be designd and sound great
try adire audio there will be such drivers available for the diy community surely
suranjan
transducer design engineer
i manufacture sub drivers which naturally roll off at about 150 and progressivly above 200 to 250 quite impressivly
they hardly require cross overs active or passive , improving phase and timing ets
but i dont know how i could get them across to you , as i have a small company and am only able to cater to local need here in calcutta ,
all i could advise is such drivers can be designd and sound great
try adire audio there will be such drivers available for the diy community surely
suranjan
transducer design engineer
Guys,
Thanks for your input on this. I have concluded that I am going to have to get more involved with filtering/modifying the woofer signal that I originally wanted to in order to really address the system as a whole. Natural roll is probably not going to cut it. I am considering baffle step and I am not afraid to have some acoustic overlap still come into play as high as 800 or 900 Hz though I realize this can be very tricky.
It looks like I would be best served to protect the FE88ES-R from as much information below 120 Hz as I can in order to manage excursion, I intend to build an amp that does this at the line level signal before sending any music to the driver. Then depending on baffle size and configuration of a second driver, I am going to attempt to design a line level filter for the woofer amp that will have this driver handle all the bass below 120 Hz and then possbily contribute a few dB from 120 up to around 6-700 and then start rolling off gradually with signal finally being 18 dB down around 1 kHz or something in that ballpark. I am not sure what the best way will be to accomplish this but once I have a design I will report back in another thread and invite some input as I certainly appreciate getting different perspectives on this project.
Navin,
Yes, is does seem like everything except a Lowther or a driver designed as a direct replacement/competitor to Lowther needs a tweeter. I would go with the FE108EZ, though I have not heard it, my general impression is that the high frequency roll off is a bit smoother than the Jordan, but that the Jordan has a smoother sounding mid-range quality (Oh the compromises we must make). The clincher for me was finding so many posts where people felt quite comfortable living with the FE108 for its overall very good musical qualities across the spectrum. This is why I jumped on the FE88, hoping that the woofer issues would be more fun to solve and the results would be better balanced and closer to the full-range single-driver ideal than anything else I could come up with. Good luck with your journey.
Thanks for your input on this. I have concluded that I am going to have to get more involved with filtering/modifying the woofer signal that I originally wanted to in order to really address the system as a whole. Natural roll is probably not going to cut it. I am considering baffle step and I am not afraid to have some acoustic overlap still come into play as high as 800 or 900 Hz though I realize this can be very tricky.
It looks like I would be best served to protect the FE88ES-R from as much information below 120 Hz as I can in order to manage excursion, I intend to build an amp that does this at the line level signal before sending any music to the driver. Then depending on baffle size and configuration of a second driver, I am going to attempt to design a line level filter for the woofer amp that will have this driver handle all the bass below 120 Hz and then possbily contribute a few dB from 120 up to around 6-700 and then start rolling off gradually with signal finally being 18 dB down around 1 kHz or something in that ballpark. I am not sure what the best way will be to accomplish this but once I have a design I will report back in another thread and invite some input as I certainly appreciate getting different perspectives on this project.
Navin,
Yes, is does seem like everything except a Lowther or a driver designed as a direct replacement/competitor to Lowther needs a tweeter. I would go with the FE108EZ, though I have not heard it, my general impression is that the high frequency roll off is a bit smoother than the Jordan, but that the Jordan has a smoother sounding mid-range quality (Oh the compromises we must make). The clincher for me was finding so many posts where people felt quite comfortable living with the FE108 for its overall very good musical qualities across the spectrum. This is why I jumped on the FE88, hoping that the woofer issues would be more fun to solve and the results would be better balanced and closer to the full-range single-driver ideal than anything else I could come up with. Good luck with your journey.
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