The FE83En is a "softer" ilk of sonic signature in terms of its presentation and volume capabilities when its not being crossed over pretty steeply, and OB's tend to sound rather soft as well (I think they give a softness to any given driver, but its hard for me to explain exactly how that effect comes about).
So what I am saying is that I'd wonder pretty hard if an FE83En/OB is a good match up in terms of combined midrange presentation. I think in sound system design (in general) its a good idea to mix aesthetics in order to balance things out rather than to "chase the dragon" of ultimate purity along a singular "purists" approach. So I guess what I am saying is that you might want to try a brighter sounding 3" driver for an OB to give the "yin/yang" effect of a balanced out design in terms of sound aesthetics. Sorry I don't have a valid scientific explaination for this. You can move my post to the "woo-woo" thread if you like, I wouldn't be offended in the slightest.
Other 3"ers to try are the FF85Wk (should be on your short list for an OB). I've finally gotten my pair to sound darned good as a miniature shop stereo in small BR cabinets powered by a Fostex AP-05 amplifier. All is squeezed into a bookshelf in order to give maximum LF reinforcement.
Also, peerless, HiVi, and Tang Band, Mark Audio offerings are solid as well. The benefit of the 3" driver category in an open baffle is that you could buy several models (for cheap, because they are 3" prices!) and make interchangable baffles on top of your open baffle. all could probably work with the same woofer. A modular FAST system of sorts.
Some folks like to tube roll, but there is no other kind of adjustability as profound as simply switching out the transducer. Its always the single greatest coloring factor, no matter how expensive the things are!
Cheers,
Clark
The Madisound Speaker Store
This is a really well considered OB project, as a point of reference, IMO. Instead of an infinite baffle, it uses a nearly zero point of baffle which might sound nice with an FE83 driver (From experience with my old Naga enclosures, (which were modeled after the Nagaoka F-81)).
Another interesting concept of zero baffle with lowthers:
Lowther Madness
fun stuff!
cheers!
-Clark
This is a really well considered OB project, as a point of reference, IMO. Instead of an infinite baffle, it uses a nearly zero point of baffle which might sound nice with an FE83 driver (From experience with my old Naga enclosures, (which were modeled after the Nagaoka F-81)).
Another interesting concept of zero baffle with lowthers:
Lowther Madness
fun stuff!
cheers!
-Clark
For me, the nasal sound was from that 2.2khz resonance, which isn't correctable with baffle shape. With a very small baffle some FR shaping can be done, but hardly what it needs. I would normally say "in my opinion" but its not my opinion. Baffle shapes don't fix driver resonances. Despite this, I still really enjoyed the FAST I built with the driver. Not everything is perfect 🙂
The FE83s are great at low volume but ran out of steam for me.
See my Open Baffle Party!
http://www.diyaudio.com/forums/mult...-tool-real-time-dsp-crossover-adjustment.html
Do some off axis measurement to see how quickly the high freq drops--definitely beamy and thus produce a sweet spot.
See my Open Baffle Party!
http://www.diyaudio.com/forums/mult...-tool-real-time-dsp-crossover-adjustment.html
Do some off axis measurement to see how quickly the high freq drops--definitely beamy and thus produce a sweet spot.
I thought the Fe83 was a decent choose for OB because of the Qts and the Qms parameters. I understand the Fs of 165 and Xmax of 0.4mm doesn't lend itself to producing anything lower than the Fs. That being said, should it not be a mid to hi speaker not "full range"?
More measurements with some confusion.
My seconded OB, 35" high by 24" wide, ~1/4 thick foam core, with 35 by 12 "wings" at 15 degrees from parallel to main baffle. Blue at 6 inches, and Red at 24 inches.
NB. this baffle has the damaged dust cap.
Interesting enough, with off cuts I was able to make a sealed box with ~16L volume with the following measurements. Yellow at 6 inches, Green at 24 inches.
NB. undamaged driver.
I am confused though, for one thing there seems to be a roughly similar slope at the 10K+ and 20 - 200hz with a completely different enclosure. 400 hz is ugly in both cases. 2.2khz is just ugly in the OB.
I am right to be confused?
My seconded OB, 35" high by 24" wide, ~1/4 thick foam core, with 35 by 12 "wings" at 15 degrees from parallel to main baffle. Blue at 6 inches, and Red at 24 inches.
NB. this baffle has the damaged dust cap.
An externally hosted image should be here but it was not working when we last tested it.
Interesting enough, with off cuts I was able to make a sealed box with ~16L volume with the following measurements. Yellow at 6 inches, Green at 24 inches.
NB. undamaged driver.
An externally hosted image should be here but it was not working when we last tested it.
I am confused though, for one thing there seems to be a roughly similar slope at the 10K+ and 20 - 200hz with a completely different enclosure. 400 hz is ugly in both cases. 2.2khz is just ugly in the OB.
I am right to be confused?
Has anyone done this or other mods to this driver before? Do I follow the procedures from the larger fostex drivers and just scale them down for a phase plug?
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Can you overlay the plots?
That's a really big baffle. For that driver, which rolls off around 200hz in that big of sealed box, that baffle is pseudo infinite baffle.
That's a really big baffle. For that driver, which rolls off around 200hz in that big of sealed box, that baffle is pseudo infinite baffle.
A few helpful hints:
1. Looking at the last graph you posted, this speaker is going to sound shouty. A positive spin on this sound can be called detailed, revealing, ruthless. However, a quick comparison with a neutral (read flat response) speaker will show that it is quite harsh on most recordings.
I wouldn't worry too much about the 2.5 kHz dip. There's not much you can do about it unless you have DSP.
2. You want to see something like the attached.
Even then you are lacking bass. But you mentioned you plan to add helper woofers.
3. Try an inductor with a shunt resistor. That should help flatten the response above 100-200 Hz or so. You can look at Jeff Bagby's excellent PCD software to model the inductor/resistor filter and simulate the response. There's some newer simpler versions of the original excel spreadsheet on these forums. Check software pages.
If you hit the dark black line I drew, you should have some reasonable balance, but you will run out of steam pretty quickly. This can be perceived as sounding dead, flat, boring, lifeless, compared to the original sound. Don't blame the filter, it's because you can't turn it up. Your problem is the driver.
Finally, keep up the good work. You are already far ahead of the rest because you can measure. Next step is a good guide on measurements. D'Appollitto's book is excellent and a must have. It will save a lot of time and frustration. Before you do anything else, order the book.
Good luck!
1. Looking at the last graph you posted, this speaker is going to sound shouty. A positive spin on this sound can be called detailed, revealing, ruthless. However, a quick comparison with a neutral (read flat response) speaker will show that it is quite harsh on most recordings.
I wouldn't worry too much about the 2.5 kHz dip. There's not much you can do about it unless you have DSP.
2. You want to see something like the attached.
Even then you are lacking bass. But you mentioned you plan to add helper woofers.
3. Try an inductor with a shunt resistor. That should help flatten the response above 100-200 Hz or so. You can look at Jeff Bagby's excellent PCD software to model the inductor/resistor filter and simulate the response. There's some newer simpler versions of the original excel spreadsheet on these forums. Check software pages.
If you hit the dark black line I drew, you should have some reasonable balance, but you will run out of steam pretty quickly. This can be perceived as sounding dead, flat, boring, lifeless, compared to the original sound. Don't blame the filter, it's because you can't turn it up. Your problem is the driver.
Finally, keep up the good work. You are already far ahead of the rest because you can measure. Next step is a good guide on measurements. D'Appollitto's book is excellent and a must have. It will save a lot of time and frustration. Before you do anything else, order the book.
Good luck!
Attachments
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First I figure people might want to see the drivers and the enclosures.
Last pic is the damage to the driver in question.
WARNING! they are not ment to be pretty!!!!!
Last pic is the damage to the driver in question.
WARNING! they are not ment to be pretty!!!!!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
More measurements....
I tried something different and its obviously better because it is more precise. Forgive me please I am learn too!!! (that book will be ordered soon!).
So this time it is different: speakers are measured in the same location, same side of amp, all at 24 inches. So the graphs are different: yellow is the giant baffle wings in, green is as out as the baffle can be without falling over and the purple one is the sealed box.
I tried something different and its obviously better because it is more precise. Forgive me please I am learn too!!! (that book will be ordered soon!).
So this time it is different: speakers are measured in the same location, same side of amp, all at 24 inches. So the graphs are different: yellow is the giant baffle wings in, green is as out as the baffle can be without falling over and the purple one is the sealed box.
An externally hosted image should be here but it was not working when we last tested it.
Note that except for the glitch between 400 and 500, and again around 1600-1800?, there's not a whole helluva lot of difference between the 3 plots - which, if any, of those was the damaged unit?
Further to what ra7 noted, the 2.5K dip - which judicious application of DSP might mitigate - is inherent in the driver's raw response, as I think is much of what you're seeing above that. Now, if you had a series of off axis measurements, you might find artifacts / discrepancies between the enclosure / OB configurations that might relate more to what you're hearing - or be even more confusing ? 😕.
Any damping material on back / side walls or fill in cavity of sealed box?
Could you get another photo of the damaged dust cap - perhaps from more of a side angle? They can sometimes be repaired, but if the paper is creased significantly it can get very difficult.
As tuxedocivic noted, this driver will not do much of anything well below 200 in a large sealed or OB/IB, and Clark has had great success with it in a small ported enclosure with out any fill. Those I've heard - without any supporting woofers, IIRC, and they certainly sounded fine - of course I've never seen any measurements for them.
Further to what ra7 noted, the 2.5K dip - which judicious application of DSP might mitigate - is inherent in the driver's raw response, as I think is much of what you're seeing above that. Now, if you had a series of off axis measurements, you might find artifacts / discrepancies between the enclosure / OB configurations that might relate more to what you're hearing - or be even more confusing ? 😕.
Any damping material on back / side walls or fill in cavity of sealed box?
Could you get another photo of the damaged dust cap - perhaps from more of a side angle? They can sometimes be repaired, but if the paper is creased significantly it can get very difficult.
As tuxedocivic noted, this driver will not do much of anything well below 200 in a large sealed or OB/IB, and Clark has had great success with it in a small ported enclosure with out any fill. Those I've heard - without any supporting woofers, IIRC, and they certainly sounded fine - of course I've never seen any measurements for them.
The damaged driver is seen on green and yellow lines. Which is the open baffle.
The sealed box is stuffed with old comforter material.
Another picture is forthcoming.
I am looking to port the box, I just do not have the hole saw size yet. Using Bagby's response modeler for port design and baffle diffraction.
The best EQ to me is proper design 😛.
To be clear I am focusing on getting the most out of these drivers as possible than if needed supplement with woofers. I am not looking for thumping bass, just present.
Sealed box doesn't sound as "present" and more covered than the OB.
More measurements will be conducted tonight at 30 and 60 degrees at 24 inches. As well as a few at listening position.
I have a small magnet and will as well post measurements on the effects of bucking or "adding more" magnet. It is about the same size as the drivers existing magnet.
I think 16 liters is much larger than this driver wants for a ported enclosure.
While Fostex's own "factory recommended" designs are not always considered the best performer by folks who've heard them,, they do have a pretty good understanding of the general category in which each model would tend to flourish, Their simple BR for this little guy is 6 liters, their dual chamber reflex is a total of just under 16 (5.3 + 10), Clark's very good little Orca is by my calculations around 4 (assuming 3/4" material), and our own designs for the "sister" driver ( FF85WK) are between 2 -3 liters IIRC.
To me "proper design" is that which takes into full consideration the parameters / and real world performance / limitation of the drivers when considering their suitability for a given application.
I'm fairly confident in my construction abilities, but fully aware of my lack of technical prowess, which is why on such matters I trust forum members possessing those skills, but ultimately make decisions, right or wrong, based on my own particular calculus.
While Fostex's own "factory recommended" designs are not always considered the best performer by folks who've heard them,, they do have a pretty good understanding of the general category in which each model would tend to flourish, Their simple BR for this little guy is 6 liters, their dual chamber reflex is a total of just under 16 (5.3 + 10), Clark's very good little Orca is by my calculations around 4 (assuming 3/4" material), and our own designs for the "sister" driver ( FF85WK) are between 2 -3 liters IIRC.
To me "proper design" is that which takes into full consideration the parameters / and real world performance / limitation of the drivers when considering their suitability for a given application.
I'm fairly confident in my construction abilities, but fully aware of my lack of technical prowess, which is why on such matters I trust forum members possessing those skills, but ultimately make decisions, right or wrong, based on my own particular calculus.
I am not saying or trying to portray your building or any one else's building technique as incorrect or wrong. I had some scrap wood and I was able to make a 16L box fairly quickly with it. That is the reasoning for a big box, it was convenient and that alone. I have not ported it and it is for experimental reasons only, I wouldn't want that ugly box in my living room!
Anyways more measurements.
First with OB wings at 30 degrees a difference between having a bucketing magnet, "add" magnet, and no extra magnet. Mic position 0 degrees at 24 inches. Blue is normal driver, light buck is bucking, and green is "add"
An externally hosted image should be here but it was not working when we last tested it.
There is "some" difference on the measurements at 30 and 60 degrees but similar to above. Will post if asked. DOES change tone while playing though, the driver without any added or bucking magnet sounds best.
Now a comparison of the OB at 0, 30, 60 degrees measured at 24 inches, wings at 30 degrees. Red is at 30 degrees, Purple is at 60 degrees, and Blue is 0 degrees (perpendicular). It seems interesting at 60 degrees the ~ 350 to 450 hz range is boasted and in particular at 400 hz by 15 dB!
An externally hosted image should be here but it was not working when we last tested it.
Feel free to chase your tail but in the end you'll come back to OB, I did and am set for life now. by far the best sounding system I have ever come up with. 4" fostexs (103En) and a 12" dayton sub.
Well, I'm glad that you like your OB's. My H-frames are cocooned awaiting a new owner and the OB's that were on top went to the landfill long ago. The drivers are happily mounted in in MLTL's and I am all smiles.
To each his own.
Bob
To each his own.
Bob
In MY room and for MY ears, I have to agree that the OB is the better sounding, cradeldorf.
I wanted to see if I could objectively show a difference between OB, sealed and ported enclosures, for this driver. I know I can use modelers, until the cows come home, but the actual testing is what I am really interested in.
Clark, I haven't answered your post on page 2, post #19. I could not recall if I had significant hours on the drivers or not. I have been playing them since Sunday afternoon switching between jazz and orchestral music.
I am willing to take suggestions on "an appropriate" size sealed and ported enclosures.
According, to the response modeler I am using, if I were to cut a 1.75" hole that is 3/4" deep (which is the material width) will produce a port that has a Fb of 75 hz with a 16.1L enclosure.
If there is any difference after measuring tonight, I will post as the drivers will have been playing about ~96 hours.
I wanted to see if I could objectively show a difference between OB, sealed and ported enclosures, for this driver. I know I can use modelers, until the cows come home, but the actual testing is what I am really interested in.
Clark, I haven't answered your post on page 2, post #19. I could not recall if I had significant hours on the drivers or not. I have been playing them since Sunday afternoon switching between jazz and orchestral music.
I am willing to take suggestions on "an appropriate" size sealed and ported enclosures.
According, to the response modeler I am using, if I were to cut a 1.75" hole that is 3/4" deep (which is the material width) will produce a port that has a Fb of 75 hz with a 16.1L enclosure.
If there is any difference after measuring tonight, I will post as the drivers will have been playing about ~96 hours.
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