Fostex Fe206en Fullrange Speaker Driver
Fostex FE206E 8' Full-range Driver Driver Choices I chose to use a Fostex FE206E 8″ driver mostly because it was relatively cheap and fit perfectly with what I planned to do; it was made for rear-horn applications and – unlike the higher-end FE208EΣ – didn’t require the use of a super-tweeter. Fostex FE206En Rear-Loaded Horn Speakers. Once again Mark tries on the Fostex FE206En high sensitivity fullrange driver, but this time in large rear-loaded horn loudspeaker cabinets. The horn speaker cabinet plans are from the FE206En driver datasheet.
Flea power valve ampsThose who know me know that I love my flea power single-ended (SE) valve amplifiers. The three valve amps that are in my current rotation are The Silver Dragon - 300B SET, Luciano - 807 SE UL and Paris - SE 6EM7 fully integrated amp. The power output from these amps ranges from 2.5W to 5.8W. With so little available power it is easy to understand why high-sensitivity loudspeakers are required. I have had a pair of Fostex single driver back-loaded horns for a few years now.
The horn speakers use the. The FE206En driver has a rated sensitivity of 96dB/1W/1m.
The back loaded horn speakers are large and (according to my wife) ugly speakers. But when it comes to flea power amps they can make 'boogie' real loud.A family friend had built me the and at the same time a pair double bass-reflex boxes also for the Fostex FE206En driver. The horn speakers I kept for myself but the double bass-reflex speakers went to my son's house along with a two-stage KT88 SE UL amp that I built. Kit, my son, had the FE206En double bass-reflex speakers in the corner of the room on a wood floor. The bass from these speakers was always very impressive. So much so that I had to have a pair for myself.Photograph 1: First pair Fostex FE206En Double Bass Reflex SpeakersDouble Bass-Reflex Type Speaker EnclosuresThe double bass-reflex (DBR) speaker system is a variation of the standard bass-reflex (BR) enclosure that is intended to achieve further extension of the bass response.
The augmentation to the bass output is achieved by the use an additional chamber in the bass-reflex process. Other advantages of the double bass-reflex speaker compared to a conventional bass-reflex system are a reduction of the cone excursion around F 3 and a corresponding reduction distortion.
The use of an additional chamber in the speaker enclosure also reduces the likelihood of resonances.The interior chambers of the double bass-reflex speaker box is typically lined with a thick damping material and/or stuffed with loose synthetic or wool fill. The fill material is used to dampen the rear wave from the driver and minimize standing waves and reflections within the speaker enclosure.Fostex FE206En Double Bass-Reflex Speaker Box PlanThe double bass-reflex speaker enclosure plan is from the datasheet that was included with the Fostex FE206En driver. Figure 1 below shows the speaker box plan from the datasheet.Figure 1: Fostex FE206En Double Bass-Reflex Enclosure PlanFostex FE206En Fullrange Speaker DriversThe photos below show the. I have added bituminous aluminium foil to dampen the driver frame. The extremely large magnet of the driver is also covered with bitumanized heavy aluminium foil to reduce sound reflections from the back of the box.
There are many tweaks and modifications that can be done to improve the drivers. For more ideas, see the page.Photograph 2: Fostex FE206En Fullrange Speaker DriversPhotograph 3: Damping the Frame of Fostex FE206En Fullrange DriversMore than one skillAnyone who has tried a DIY audio project knows that you generally need to know more than how to just read a schematic and use a soldering iron. The skills required can vary from simple drilling holes to complex carpentry. When it comes to carpentry I leave that to those who are better skilled than I. But I don't shy from timber or metal enclosure preparation and finishing.Photograph 4: Unfinished Fostex FE206En Double Bass-Reflex Speakers CabinetsLuckily when the double bass-reflex speaker boxes arrived they had already been sanded down and that meant I only had to finish the surface preparation with a pass of fine sand paper before applying a coat of primer. I wanted a dull stipple finish so reflections from the big screen TV from the sides of the speaker boxes would be minimized.
To achieve this I used a cheap paint-roller and after going once around the box with a white undercoating paint, I went around three more times with a semi-dry roller to really tease-up that stipple finish. This process worked out very well.After two hours of drying time I applied the top coat to the speaker boxes. This was a satin finish in black. Not quite black more of a dark charcoal. Once more I went back over each surface three or more times using a semi-dry roller.
The stipple finish, which had started with the undercoat, was now built on with the top coat. That was the finished I had envisaged, dull and heavily stippled.Photograph 5: Painted Fostex FE206En Double Bass Reflex Speakers CabinetsAssembly - Fostex FE206En Double Bass-Reflex SpeakersThe top chamber of the double bass-reflex speaker boxes is lined (but not stuffed) with Dacron poly fill. The bottom chamber of the speakers remains empty.Photograph 6: Speaker Damping Materials FE206En Double Bass-Reflex Speakers CabinetsGold plated binding posts are used to connect the speakers at the back. Two strands of wire wrap wire (fine 30 silver plated copper wire) is use for both positive and negative of the speakers. A special pair of single strand wire wrap wire speaker leads was made for the speakers knowing the amp of 2.5W would require no heavier wire.Photograph 7: Wire Wrap Wire and Speaker Binding PostsIn the final assembly steps, most of the slack from the connecting wire (double strains of lightly twisted wire wrap wire) was removed and the drive screwed securely onto the boxes with supplied gasket.
The fine metal grills are held on with four rare earth button magnets and are easy to pop on and off.Photograph 8: Fostex FE206En Double Bass Reflex SpeakersPhotograph 9: Fostex FE206En Double Bass Reflex SpeakersNo speaker crossover, baffling?The Fostex FE206En drivers are 'fullrange' types and their main appeals is that no crossover is required. The advantage is that there is no crossover distortion or suppression of the dynamics which occurs with almost all passive crossover circuits. Now some builders may opt to use a use a. You can use the to determine the value of choke and resistor required based on the width of the speaker baffle and impedance of the speaker. The circuit is simple, just one inductor and one resistor in parallel with each other and in series with the speaker.
Figure 2 shows typical values for use with this double bass-reflex speaker enclosure.Figure 2: Baffle Step Compensation Circuit - Fostex FE206En Double Bass-Reflex SpeakerWhat the BSC network does is to tame from the mid-range on up, without affect the lower bass response. Where these drivers can sound overly forward (too hot in the mid-range) this adjusts that forwardness leaving the bass and treble better balanced. I find that the mid-range richness is why these drivers can sound good with acoustic instruments and especially vocal. Now many may find that the BSC circuit can reduce or suppress the dynamics and for that reason I don't really like to use them. With the circuit you also lose a little of the speakers sensitivity, which could be an issue with low power amps. Another way to try and compensate for the natural rising response of the FE206En is to position the speakers off-axis (ie. Toe-in the speakers).
The amount of speaker toe-in will vary dependent on the listening room, amplifier and personal preference. Experiment by starting with a speaker toe-in of about 30-degrees and adjust for best results. You can also try to wall-load the speakers but pulling them closer to the rear wall to try lift the low-end. You will want to take time to find the best sepaker placement as proper placement will be rewarded with excellent acoustics.For those who will ask, the for the Fostex FE206En driver shown Figure 3 can be used.Figure 3: Zobel Circuit - Fostex FE206En Double Bass-Reflex SpeakerAnd the sound?The Fostex FE206En double bass reflex speakers sound excellent. I don't have a microphone setup but using the Stereophile test CD, bass starts to roll off very slowly from about 100hz until you reach about 50Hz where there is a definite rise and a there is an even bigger rise at 40Hz. That seems consistent with what is described on the enclosure plan, 'Internal volume of 45 liters tuned to approximately 50Hz (Fb).
Low frequency response from around 120Hz is gently damped with a controlled peak at 50-60Hz.' This was quite a surprise! Putting your ear to the port with a 40Hz tone you can hear air rushing in and out.
The whole box sounds like it is working real hard. Because of the big bass lift offered by the double bass-reflex type enclosure, test tones at 40Hz, 31Hz, 25Hz and even 20Hz are quite audible. 20Hz is finished in terms of volume but as stated, still quite audible and surprising from a bass-shy speaker driver. While the rise at 40Hz does not make itself present in general music listening, it does add drama when listening to movies which is the primary role these speakers are intended to fill. Because these speakers are so fast and dynamic it really is a challenge to find a subwoofer that can keep up.All-in-all, this has been a very pleasing project and to get the stippled finish I wanted with a $5 roller and tray is doubly pleasing. With only 2.5W or so on tap and the speakers at a full 96 dB / 1W /1m, there is plenty of volume. Not only do these speakers round-out the 2 channel TV end of the house but it also gives me an excellent third music listening area with quality DIY gear (don't tell the wife).
Fostex Fe206en Fullrange Speaker Driver For Windows 7
Now I'm triply happy. See the thread for more information or to ask any questions.Mark Houston, Classic Convenor, Melbourne Audio Club.UPDATE - 29 October 2012I made up the BSC circuit using a non-inductive 2.2 ohm 5W resistor and 0.82 mH air coil inductor (a little over 2 dB of attenuation).
To evaluate I listened to the speakers with and without the BSC circuit, with and without the grill covers and all possible combinations in between. The test music was a Steinway legends/digipack which contains heavy solo piano with massive dynamics and a thundering sound. The best combination turned out to be with the BSC circuit and no grills covering the drivers. The Ashkenazy/Steinway digipack sounds its very best when played through the Oppo BDP-93 and Paris (6EM7) amplifier.
On my main system which consists of a Oppo BDP-95, Silver Dragon (300B SET) and large 3-way Osborn loudspeakers the dynamics are no where near as 'startling' nor the sound as rich and natural (even raw).An interesting observation with the Fostex FE206En in Double Bass-Reflex Speakers is that there appears to be a volume related sweet-spot. Play the volume too softy and the speakers can sound quite plain and flat - play them too loudly and they start to sound compressed and the bass lacks detail while the mid-range sounds shouty.
But if you find just the right volume the speakers can really sing.Fostex FE206En Speaker Links. (Project).
A better place to discuss DIY audio, share plans and schematics, and link to interesting projects. Hello,I'm thinking of building a pair full range speakers to do mixing and mastering on. My room is quite small and I already have a few pairs of speakers.
My current setup are NS10's and Auratone's. I also have the Studiospares SN10's (NS10 nock-offs) and Realistic minimus 7's.I'm leaning towards the Fostex FE206En drivers but am uncertain about the enclosure.
I don't like ported designs that much but haven't found any info on these drivers in sealed box designs. I understand that the bass response will be not go as deep in a sealed box but I might supplement the system with a sub later down the line.
A pair of super tweeters could be added later as well.Any advice is highly appreciated!Cheers. The question is: why do you want a full-range sealed box for mixing/mastering? You have two pairs of speakers designed to emulate shit-speakers (NS10 and Auratones), some super cheap low-budget monitors and you want to add another pair of speakers with lots of compromises? My unsolicited advice would be to sell everything (some people value the NS10, I don't) and buy or build one pair of the best and flattest monitors you can afford.
You won't get good mixes with four pairs of shitty speakers. That's not true. Sealed and ported speakers act the same across the midrange, it's only the bass that is effected. Essentially, in a ported speaker, the speaker cabinet/port cross area create what's called a helmholtz resonator, ie it resonates at particular frequency. If the ported speaker is designed well, this frequency is just before the natural roll off of the drivers bass response, then the port kicks in, and supplements the bass frequencies, giving you a slightly deeper bass extension.
There isn't any effect up on the midrange transient response. You are correct regarding the roll off rate though, sealed speakers roll off at 12db/ocatve, and ported at 24db/octave.The one exception is if you get midrange 'leakage' from the port. This is when midrange frequencies are audible from the port. That is often found in very shitty designs, and rare.As for the 'quality' of bass, sealed and ported are quite equal. It entirely depends on how the speaker is designed. You can have either system have a booming bass, emphasis on certain regions, etc. If you want an example, look at JBLs M2 monitor.
Their top of the line mastering one, it uses a ported enclosure.If you want more info, you can read this article:. If I had to chose between the Fostex FE206En and the Visaton B200 I'd go for the Fostex for sure.The best enclosure for the Fostex will probably be a horn, have a look around, there are plenty of designs out there for this driver.Generally speaking, I don't think 8' fullrange drivers are what you want for mixing/mastering or near field listening. I'd recommend at least 1,5 - 2 meter distance. Another issue you will be facing is size.
As you said in your reply you are looking at enclosures around 100 liter, that's not even close to small and will be difficult to fit on a desk. But of course I don't know your environment. After doing some more research I found a good website with some info. Not all drivers work well in sealed enclosures. The FE206En appears to not be a good driver for sealed box design. I'm now leaning towards a Visaton B200 driver. This one should work fine in a big volume box (120liter).From the site:Recommended speakers for sealed enclosureIf you want to build a sealed enclosure, picking the right woofer will be very easy.
You are looking at low free air resonance (Fs), high cone mass and long voice coils. Don’t get too caught up by the actual values, because most of them will work fine in a sealed enclosure. If you really want to get more technical, you can calculate the Efficiency Bandwidth Product (EBP) EBP = Fs / QesIf EBP around 50 or less, then the woofer is suited for sealed.If EBP 100 then the woofer is suited for bass reflex.If EBP is between 50 and 100, then it is good for either closed or bass reflex.The length of the voice coil is something to consider also, because in a sealed enclosure, the woofer will have a longer excursion than the equivalent bass reflex. What are you looking for these Xmax values (please don’t stress too much on this):For small woofers (6″ – 8″) Xmax should be 2-4 mm.For larger woofers (10″ – 12″) Xmax should be 5-8 mm.The site:. You should always simulate the drivers with the specific enclosure.
If you want to go with the B200 you can use Boxsim for that. Boxsim already has most of the TSP datasets from all Visaton drivers included.You can try simulate different enclosure types and volumes for the B200. If you can't get the frequency response to be linear by any means (the human ear is really sensitive to drops in the frequency response) I would recommend you to go with a proven well engineered build. Speakers that are well engineered with a long tested and adapted correction network and well fitting enclosure sound much better than just a driver randomly mounted into a box.EDIT: After reading and thinking over it again I would recommend you to go with a proven sealed 2-way bookshelf kit. Others already mentioned that fullrange speakers are not the best for mixing and mastering and a vented enclosure might be too much in a small room if you cannot realize a fair distance to the walls. The B200 has a pretty high Qts (0,75) and fs is somewhere around 40 Hz.
May I ask how big your room is? In a small room you normally want to get the Qtc value (combined Q factor of speaker + enclosure) to be under 0.707 (butterworth tuning) otherwise the bass response will be to blown up.However you won't be able to get Qtc under this value with the B200 in a sealed enclosure (unless the volume is about 1000 liters).So in other words the B200 is good in a sealed box (for larger rooms) or good in open baffle (hard to implement, only for experts).Please take my advice and look up some good (sealed) 2-way bookshelf kits.
Sorry I only know kits that are available in germany. Thanks again for pointing me to Boxsim, it's a wonderful program that answers most of my questions by tweaking parameters.My room is tiny actually, about 12m2, but it's used solely as a mixing room so it's kitted out with two floor to ceiling bass traps in the front corners and about 10m2 of broadband absorbers all around. I use room eq wizard to measure and adjust when building.
There are some real low end standing waves that need some additional trapping that I'll do on my next build.Currently I'm thinking of splitting up the system in a 2-way monitor with added subwoofer. For the monitors I'm thinking of following eighter.For the subwoofer I'm not so sure.