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Let’s do a more honest evaluation of the pros and cons of the FE108 vs a tweeter such as the Seas TW29DN.
It seems that a tweeter will have to XO at say 2kHz (due to limited excursion) but generally has a better behaved FR and lower distortion whereas the Fostex can XO lower but there are more than one set of measurements showing a clear anomaly in the FR at around 1kHz.
The tweeter will give extension out past 15kHz but the Fostex will struggle
The tweeter doesn’t require extensive cabinet changes.
I’m struggling to understand if the benefit of the lower XO of the Fostex outweighs the benefits of dropping in a new tweeter in terms of FR, distortion, extension and construction ?
It seems that a tweeter will have to XO at say 2kHz (due to limited excursion) but generally has a better behaved FR and lower distortion whereas the Fostex can XO lower but there are more than one set of measurements showing a clear anomaly in the FR at around 1kHz.
The tweeter will give extension out past 15kHz but the Fostex will struggle
The tweeter doesn’t require extensive cabinet changes.
I’m struggling to understand if the benefit of the lower XO of the Fostex outweighs the benefits of dropping in a new tweeter in terms of FR, distortion, extension and construction ?
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Butcher? The rebate for the midTweeter will be larger than the tweeter cutout, and the enclsore can be fitted throu the woofer hole.
It can be done to look like it was factory.
Put a grill over it and compare it to a stock pair and people will be asking, “what’s wrong with mine?"
dave
That's a good point, but won't the enclosure partially block the transmission line? This is the PMC GB1i? Doesn't look like a very big speaker.
jeff
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A bit.but not enuff to cause a serious issue.Right where one would often see. deflector. But don’t make it too big.
dave
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One has been ‘poked’ with a finger, who knows when but I would acknowledge it as cosmetic. What I don’t like is that they sound too hot when pushed. Currently they’re doing fine as my main fronts in HT set up. There’s no rush to ‘upgrade’ but I like to do some research on ideas, such as this thread. If I return these speakers to hi fi use they will compete with my main mono set up, so they need to do something special that stereo does and mono does not i.e. image. I’ve never had holographic imaging from them before and wonder if shifting XO would address that.
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yes, that's what I meant. BUT it isn't an approach I've heard or tried so I'm talking out of my backpack and relying on the forum knowledge here.
FYI - I've only once experienced superb imaging that I remember, that was from a pair of A10.3 Pencil's that I built for a friend. I had them set up in my basement to tweak the stuffing. There was a tradeoff between the quality of the mid-bass and the imaging performance that was very intriguing but boy they imaged well. That was many years ago and since then I've been a mono guy because my main living space is prioritized for family use and doesn't allow the uncluttered stereo-triangle type of set up that would be the usual go-to scenario for stereo. I've been so happy with the mono set up that there's be no need to change it and I would thoroughly recommend the mono route as being a better solution for many people who may not realize it would suit them better. You get to spend twice as much on one channel too. My interest in stereo is more a case of exploring a bit more about what this hobby has to offer and I thought about my motivation for doing so is to focus on what stereo can offer me that mono can not and the one thing that pops up is imaging.
I do have a pair of A10.3's in 13 litre ported BR enclosures along with a pair of A10p drivers to try out in these enclosures but have been too lazy to get this set up. The A10.3's are my favorite MA driver (probably to the extent that it's the only driver from MA that I would purchase again).
The Fostex FE108ES has another appeal for me, not to be under-estimated, it reminds me of the time when I first entered this hobby and I remember those days fondly. It was quite a surprise for me to see this driver on the web recently, which back when I joined up here was something I considered too expensive, yet it is still available. Now that I'm older I can easily afford to buy a pair of these drivers but my gut tells me I should probably not butcher my FB1's without doing some experiments first - such as building some boxes for the Fostex drivers and strapping them to my FB1's in a kind of Frankenstein arrangement to see if they can deliver a sound that motivates me to get out my router on my PMCs. Such a project would also be my first foray into two-way speakers and passive XO's which is another opportunity to do something new. But as with any new project, it may have to wait for me to finish some ongoing projects.
I've not seen any chit chat around here about this Fostex driver. Maybe it's day has come and gone ?
FYI - I've only once experienced superb imaging that I remember, that was from a pair of A10.3 Pencil's that I built for a friend. I had them set up in my basement to tweak the stuffing. There was a tradeoff between the quality of the mid-bass and the imaging performance that was very intriguing but boy they imaged well. That was many years ago and since then I've been a mono guy because my main living space is prioritized for family use and doesn't allow the uncluttered stereo-triangle type of set up that would be the usual go-to scenario for stereo. I've been so happy with the mono set up that there's be no need to change it and I would thoroughly recommend the mono route as being a better solution for many people who may not realize it would suit them better. You get to spend twice as much on one channel too. My interest in stereo is more a case of exploring a bit more about what this hobby has to offer and I thought about my motivation for doing so is to focus on what stereo can offer me that mono can not and the one thing that pops up is imaging.
I do have a pair of A10.3's in 13 litre ported BR enclosures along with a pair of A10p drivers to try out in these enclosures but have been too lazy to get this set up. The A10.3's are my favorite MA driver (probably to the extent that it's the only driver from MA that I would purchase again).
The Fostex FE108ES has another appeal for me, not to be under-estimated, it reminds me of the time when I first entered this hobby and I remember those days fondly. It was quite a surprise for me to see this driver on the web recently, which back when I joined up here was something I considered too expensive, yet it is still available. Now that I'm older I can easily afford to buy a pair of these drivers but my gut tells me I should probably not butcher my FB1's without doing some experiments first - such as building some boxes for the Fostex drivers and strapping them to my FB1's in a kind of Frankenstein arrangement to see if they can deliver a sound that motivates me to get out my router on my PMCs. Such a project would also be my first foray into two-way speakers and passive XO's which is another opportunity to do something new. But as with any new project, it may have to wait for me to finish some ongoing projects.
I've not seen any chit chat around here about this Fostex driver. Maybe it's day has come and gone ?
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I still have a pair mounted on the wall in my garage.
I listened mono for a few years. I went through a stage where duplicating everything I did on a second speaker and going through a matching process was holding me back.
In any case, listening to a stereo pair in mono can be revealing in how imaging will be.
I listened mono for a few years. I went through a stage where duplicating everything I did on a second speaker and going through a matching process was holding me back.
In any case, listening to a stereo pair in mono can be revealing in how imaging will be.
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I consider the ability to do imaging/soundstage a very important characteristic. The best i have experienced — given appropriate source material — produce a clear 3D space, the speakers and the wall behind disappearing.
dave
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Dave, you are also mostly a single driver kind of guy (that's a compliment by the way!) but in the case of a FAST set-up, or two-way in general, what have you learned about the factors that are critical to achieve, or make sure to avoid, for good imaging ? - and which may be relevant for the FE108ES
Keeping the critical telephone band very “clean”.
Low XO and keeping the XO as coherent as possible, so that it does not intrude higher up. Turns out that is not necessarily required that it be first order, but that is my target. The example being the big A12pw MTM, where when going active it worked well with both a first order PLLXO and the digital forth order LR in Chris’ Onkyo HT receiver. The passive XO guy (thanx Aaron) ended up with a forth order acoustic XO (simplier electrically). He also derived a first order series. The latter did a few things better, but the quicker XO won overall. As always, everything is a compromise.
Get the box out of the picture. No audiabe box resonances. A low diffraction signature is required. It was a bit of a revelation when we compared the CGR vrs the trapezoidal miniOnkens for the A12eN. Same box alignment, just different shapes. The box that looks more like a tear-drop has the box dissapearing to a greater extent than the rectangular box and the image./soundstage is better. Note: i was never a big fan of this driver.
And EnABL (as well as treatents i discovered before EnABL) can do a surprising job at improving this. EnABL requires some serious practise, but, particualrily for the paper cones (and the Fostex drivers) there are some fairly simple mods that can improve things.
dave
Low XO and keeping the XO as coherent as possible, so that it does not intrude higher up. Turns out that is not necessarily required that it be first order, but that is my target. The example being the big A12pw MTM, where when going active it worked well with both a first order PLLXO and the digital forth order LR in Chris’ Onkyo HT receiver. The passive XO guy (thanx Aaron) ended up with a forth order acoustic XO (simplier electrically). He also derived a first order series. The latter did a few things better, but the quicker XO won overall. As always, everything is a compromise.
Get the box out of the picture. No audiabe box resonances. A low diffraction signature is required. It was a bit of a revelation when we compared the CGR vrs the trapezoidal miniOnkens for the A12eN. Same box alignment, just different shapes. The box that looks more like a tear-drop has the box dissapearing to a greater extent than the rectangular box and the image./soundstage is better. Note: i was never a big fan of this driver.
And EnABL (as well as treatents i discovered before EnABL) can do a surprising job at improving this. EnABL requires some serious practise, but, particualrily for the paper cones (and the Fostex drivers) there are some fairly simple mods that can improve things.
dave
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This may be a dumb question, certainly it is borne from some ignorance, but what if the Fostex were placed into the PMC TL cabinet without it’s own enclosure?
Would the h.f. from the back of the Fostex cone pollute the output from the transmission line or pollute the output from the mid-woofer by passing back out through the mid-woofer cone ? Or perhaps not, given the already liberal use of acoustic foam inside the PMC cabinet which could be augmented in strategic locations ?
Would the l.f. pressure waves from the mid woofer in the transmission line load the Fostex cone beneficially or at the least benignly ? Or, as I suspect, would they produce significant FM distortion of the h.f. and/or worse, damage the Fostex driver ?
Construction wise it avoids a box within a box and removes a possible constriction in the TL which was not part of the OEM design. I expect the XO would need to be designed differently than in the case of a box within a box.
Would the h.f. from the back of the Fostex cone pollute the output from the transmission line or pollute the output from the mid-woofer by passing back out through the mid-woofer cone ? Or perhaps not, given the already liberal use of acoustic foam inside the PMC cabinet which could be augmented in strategic locations ?
Would the l.f. pressure waves from the mid woofer in the transmission line load the Fostex cone beneficially or at the least benignly ? Or, as I suspect, would they produce significant FM distortion of the h.f. and/or worse, damage the Fostex driver ?
Construction wise it avoids a box within a box and removes a possible constriction in the TL which was not part of the OEM design. I expect the XO would need to be designed differently than in the case of a box within a box.
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