Hi all i would like to create some transmission for the fostex FE103EN i would like to achieve something similar to these fostex in this you tube video
My Other Listening Room - YouTube
Cheers James
My Other Listening Room - YouTube
Cheers James
What I can tell you for sure is that you can go that low (48-58Hz in the video) with a 4 inch fullranger, because I have experimented enough to be convinced that it can be done, but you will probably need 2 things: a big enclosure, and a good/suitable driver... I don't know how can you know for sure if it will play that low, for example the Fostex in the video (Fe103En) has a Fs of 83 (in reality it's probably higher) which is discouraging but it has been done not just with the design in the video but with the Zigmahornet which is also tuned much lower than Fs.
I have made an estimation of the dimensions of the Hexibase Fostex Fe103En TL and here you are (in cm):
External Height: 90-100 cm
Internal width: 12.3 cm (+- a few mm)
Actual tube cross section: 10 x 12.3 cm (S=123 cm2)
Tube length: 180 - 200 cm
Tuning frequency: 41-47 Hz
Volume (internal): 22-24.5 liters
I've spend some time before arriving at those dimensions and I'm pretty sure they are correct within those limits.
I have made an estimation of the dimensions of the Hexibase Fostex Fe103En TL and here you are (in cm):
External Height: 90-100 cm
Internal width: 12.3 cm (+- a few mm)
Actual tube cross section: 10 x 12.3 cm (S=123 cm2)
Tube length: 180 - 200 cm
Tuning frequency: 41-47 Hz
Volume (internal): 22-24.5 liters
I've spend some time before arriving at those dimensions and I'm pretty sure they are correct within those limits.
You don't need to thank me for calculating them, you are not the only one around the globe seduced by those towers you see in the video.
By the way, if you have acces to the MJKing's spreadsheets you might want to see how it behaves, from my hornresponse simulation it's ok for the volume but it will lose 2-4 dB in relation to the nominal SPL, however it may not reflect reality, in the sense that the peaks and nulls might be much less severe and the depression in the the 50-90hz region (about 1-2.5 db) might not exist in reality. But that doesn't mean it won't sound ok in reality, BIB's have a very rugger frequency response but they sound good in reality (my ears don't know that for sure, I'm just reproducing other people's words).
Or even better - you can build the real thing from scrap wood to get an idea of how it sounds.
You might want to take a look at this build too - Ok, I lied. Here are a few pics of my “almost” most recent build | MiltonBilt - much larger in volume (don't forget the simple rule of transmission lines and wave guide based enclosures - bigger is better).
And this thread from the pwkdesigns forum - • View topic - My "Other" Listening Room
One last thing I wanted to say (for now) is that I read somewhere that the towers from the video didn't had any stuffing.
By the way, if you have acces to the MJKing's spreadsheets you might want to see how it behaves, from my hornresponse simulation it's ok for the volume but it will lose 2-4 dB in relation to the nominal SPL, however it may not reflect reality, in the sense that the peaks and nulls might be much less severe and the depression in the the 50-90hz region (about 1-2.5 db) might not exist in reality. But that doesn't mean it won't sound ok in reality, BIB's have a very rugger frequency response but they sound good in reality (my ears don't know that for sure, I'm just reproducing other people's words).
Or even better - you can build the real thing from scrap wood to get an idea of how it sounds.
You might want to take a look at this build too - Ok, I lied. Here are a few pics of my “almost” most recent build | MiltonBilt - much larger in volume (don't forget the simple rule of transmission lines and wave guide based enclosures - bigger is better).
And this thread from the pwkdesigns forum - • View topic - My "Other" Listening Room
One last thing I wanted to say (for now) is that I read somewhere that the towers from the video didn't had any stuffing.
And another thing - hexibase uses he's own software and formulas which take into account everything, not just the parameters of the driver, also placement in the room and driver placement in box, probably the position of the mouth too ... so in order to reproduce the sound from the setup in the video ... I don't know, you need to be a little lucky, unless you have the means to take into account the room and speaker placement in your design. Just try a simple improvised build of the design (one enclosure) to see if you can get the same sort of sound, and if you can get the song from the video it's even better, I don't know what it is, I would use it my self for testing.
yeah ok i thought by the way he calculates it there is something to do with the placement in his room, But by the looks of the room he has got it in my bedroom is the same sort of size i have got more ceiling space but the plan was to build them and see what happen but after reading your post i might just build one of them and see how i go just in case it turns out nothing to what i have expected
cheers james
cheers james
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K's TL for FE103En
Hi there K: What is the area of the port? Do you recommend corner deflectors as shown in Supersteve's TL ( deflectors reduce box volume )? ...regards, Michael
Hi there K: What is the area of the port? Do you recommend corner deflectors as shown in Supersteve's TL ( deflectors reduce box volume )? ...regards, Michael
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I forgot to mention that the tube (TL) has a constant section, the "deflector" is probably a means to maintain the S of the tube constant as it corners in the box... so it is 123 cm2, but don't forget I'm just estimating, I don't know for sure.
I have never heard of anything like "deflectors reduce box volume"; the apparent box volume maybe can be enlarged by adding something fluffy on the walls but since it is not a common practice it probably doesn't do much good.
By the way, I don't know how much a deflectors would help but considering that the nearest wall behind the cone is the magnet itself, and it's very close and in this case very large.
To Jameslc: do you own a pair of Fe103en s ? If you already have them you might have tested them in free air, and any enclosure so you can get an idea how low below Fs they can play, in the sense that it is audible but not distorted, and compare it with a driver of similar size that has allot of bass.
well i have order the fostex but haven't received them yet, i have made a bit of a mock up of the transmission lines using your dims from up the page and put my corals 4a-70 in it to see how they go but not really the right driver for the TL, i'm going to wait and see what it sounds like with the fostex and go from there but somehow i think the bass in the video is too clean for the xmax of the speaker
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Even so, you might get an idea of the "personality" of the enclosure... actually it's a tone coloration that is unique to every enclosure, related to all sorts of things (size, material, height of speaker, shape etc.).
I'm very curious how it turns out, I my self have been on a trip for a few month to get that sound (from the video) in my room, but since my first attempt has failed, I'm much more reluctant to order drivers and see how they sound. The Fostex is a little expensive for me, but if I would know it sounds like that in my room, I would go for it, for now I'm experimenting with enclosures and any driver I can find to see what makes one sound like that. It might be the x max, but I'm also interested in the quality of the tonal balance... that's where I got it wrong in my fist try.
I'm very curious how it turns out, I my self have been on a trip for a few month to get that sound (from the video) in my room, but since my first attempt has failed, I'm much more reluctant to order drivers and see how they sound. The Fostex is a little expensive for me, but if I would know it sounds like that in my room, I would go for it, for now I'm experimenting with enclosures and any driver I can find to see what makes one sound like that. It might be the x max, but I'm also interested in the quality of the tonal balance... that's where I got it wrong in my fist try.
I would imagine that the distance from the cone to the magnet would only create reflections in the bandwidth eminating mostly from the dust cap so would not really have much of an effect that way.(correct me if I'm wrong) The reflections off the back of the cabinets are much more significant.
I don't know how important are the reflections from the back of the cabinet, if you want the best of the best when it comes to enclosures I assume you would want to avoid reflections from the wall in the back of the cabinet by one design feature or another.
If you have some experience with Fostex drivers you might want to take a look a the video in the original post from this thread and share your opinion in regards to the 4 incher going as low as 49 hz, from my incomplete analysis of the recording (in the sense that it might have gone even lower). The purpose of the thread is how can you get that kind of low response/deep sound from the Fostex Fe103En.
If you have some experience with Fostex drivers you might want to take a look a the video in the original post from this thread and share your opinion in regards to the 4 incher going as low as 49 hz, from my incomplete analysis of the recording (in the sense that it might have gone even lower). The purpose of the thread is how can you get that kind of low response/deep sound from the Fostex Fe103En.
not a T-line, but works like a charm with 2 drivers per side
BD-Pipes
and
Greg M's folded ML Voigt for single
http://www.diyaudio.com/forums/full...ll-range-reference-project-23.html#post535015
BD-Pipes
An externally hosted image should be here but it was not working when we last tested it.
and
Greg M's folded ML Voigt for single
http://www.diyaudio.com/forums/full...ll-range-reference-project-23.html#post535015
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I just watched the video. The drivers may play that low in the cabinet but not very loudly. It looks like he is in a small bedroom and it may work well for that purpose, but I would be very wary of blowing the drivers trying to play too loud, and in a normal sized living room you would lose that bass and tuning it that low would limit the voulme of the speaker over all. This design is good for a small room or near field monitors, but for a mid sized to large room these drivers work best tuned to 70hz or above and augmented with a subwoofer. At least that's what my experience and the specs of the drivers would indicate.
some thoughts
Here is the way I presume it was done by hexibase (he's name is Pete in reality): you take conventional alignment theory and add a few more variables such as driver placement in room, room size(s), windows, doors, and the same for the mouth of the TL and make some king of an impedance match between all sound sources and portions of the surrounding environment that are of interest, such as listening position, room in general. In other words he chose the lowest tuning possible for the given acoustic system (driver, enclosure, room), not arbitrarily but by mathematical means, something that you cannot reproduce just by copying the architecture of the enclosure and/or the dimensions; the real question that bothers you or I is how much tolerance you have before you have a faulty design (bad coupling). The truth is that you can probably replicate the effect without the secret formula, as long as you have the time/energy to experiment with what works and what doesn’t in your listening room.
I’m really curios why he chose to place the mouth so far from the floor and so close to the driver.
By the way, the lowest tuning generally used for a TL is 0.707 Fs, and in the case of Fostex Fe103En that would be 58.6 hz (Fs=83hz); tuning at about 45hz would mean to tune almost an octave lower that Fs.
I would not be surprised to find out that he placed the microphone near the wall where bass is stronger.
Here is the way I presume it was done by hexibase (he's name is Pete in reality): you take conventional alignment theory and add a few more variables such as driver placement in room, room size(s), windows, doors, and the same for the mouth of the TL and make some king of an impedance match between all sound sources and portions of the surrounding environment that are of interest, such as listening position, room in general. In other words he chose the lowest tuning possible for the given acoustic system (driver, enclosure, room), not arbitrarily but by mathematical means, something that you cannot reproduce just by copying the architecture of the enclosure and/or the dimensions; the real question that bothers you or I is how much tolerance you have before you have a faulty design (bad coupling). The truth is that you can probably replicate the effect without the secret formula, as long as you have the time/energy to experiment with what works and what doesn’t in your listening room.
I’m really curios why he chose to place the mouth so far from the floor and so close to the driver.
By the way, the lowest tuning generally used for a TL is 0.707 Fs, and in the case of Fostex Fe103En that would be 58.6 hz (Fs=83hz); tuning at about 45hz would mean to tune almost an octave lower that Fs.
I would not be surprised to find out that he placed the microphone near the wall where bass is stronger.
Maximum power is almost irrelivant. It's probably something like 5-10 watts, but that doesn't mean it won't kick you in the chest and pop your ears. 1 watt of actual acoustic energy is enough to blow your ear drums. I think what you really want to know is how loud will it play. It's tough to say. The above comment makes it sound a bit worse than it really is. I've gotten excellent bass from Fostex FE206Es which aren't much bigger than the103s. A few things to consider; how big is your bedroom? Would you be better served with large towers or smaller ones and a sub? How complex of a cabinet are you willing to make?
I imagine the high mounted mouth was for two reasons. One being that's where the end of the line ended up being, and two to minimize imaging problem associated with mid frequencies coming out of the mouth. Damping materials (not "dampening") greatly reduce midrange through the mouth but also reduce bass.
I imagine the high mounted mouth was for two reasons. One being that's where the end of the line ended up being, and two to minimize imaging problem associated with mid frequencies coming out of the mouth. Damping materials (not "dampening") greatly reduce midrange through the mouth but also reduce bass.
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