I have a pair of F120A in Metronomes. I love their sound when driven with tubes. On direct coupled SS amps they sound kind of pitiful--the high freq just dies. I would not have discovered this if not for MJK bringing a tube amp over to try on the F120A Mets. This caused me to first buy a small single ended tube amp, then build a Dynakitparts ST-35. The F120A is definitely a keeper! (for me at least)
The FX120 probably has most of the goodness of the F120A, and might work OK with SS amps. (Although tubes would probably be better!)
Cheers, Jim
While it's been a few years now, I've heard both the FX and F120A, and yes the alnico does some things with a degree of delicacy / finesse that the ceramics don't - however, at a substantial price premium.
Also, take a look at the TSP for each, ( since I know a guy who does this, I pay little attention to those numbers) - IIRC the alnicos might require different enclosure volume/tuning - I wouldn't assume either as a direct drop in substitute for the other
As for long term availability of the two, the F120A has more than once been on "production hiatus" - i.e. awaiting demand to justify consumption of the ever more expensive rare magnetic materials? - and it's anyone's guess when Fostex might retire any given model for whatever reason, as the list of drivers discontinued during the period of over 30yrs will attest. (note this list is from 2003, so already quite short)
Compatibility - Speaker Components
Also, take a look at the TSP for each, ( since I know a guy who does this, I pay little attention to those numbers) - IIRC the alnicos might require different enclosure volume/tuning - I wouldn't assume either as a direct drop in substitute for the other
As for long term availability of the two, the F120A has more than once been on "production hiatus" - i.e. awaiting demand to justify consumption of the ever more expensive rare magnetic materials? - and it's anyone's guess when Fostex might retire any given model for whatever reason, as the list of drivers discontinued during the period of over 30yrs will attest. (note this list is from 2003, so already quite short)
Compatibility - Speaker Components
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Looking at the FX120 for now (I'm not unwilling to pay for the F120A but then I'd be looking at some better enclosures...)
The T-S parameters look as if they would work in the Moon Onken boxes without any changes to the ports. I don't expect them to be bass monsters, but they would give the kind of alignment that Dave recommends - somewhere between a closed box and a 'traditional' vented alignment. With the current boxes it looks like f3 around 70Hz, f6 around 60Hz and f10 around 50Hz. Very tempting...
The T-S parameters look as if they would work in the Moon Onken boxes without any changes to the ports. I don't expect them to be bass monsters, but they would give the kind of alignment that Dave recommends - somewhere between a closed box and a 'traditional' vented alignment. With the current boxes it looks like f3 around 70Hz, f6 around 60Hz and f10 around 50Hz. Very tempting...
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CHN-70
With the very recent launch of the Mark Audio CHN-70 I decided to dust off my Moon Onken enclosures. I sold all the Fostex drivers as I couldn’t live with their specific h.f. response.
The new CHN-70 is slightly smaller, the screw holes of the older Fostex drivers are just visible outside of the new driver but I’m slowly making them disappear with some wood filler. The new drivers have a blue tinged paper. The frame is stamped metal like the Fostex, but it's sturdier and finished in what I believe is called a powder coating.
The key thing is that the driver specs are a fair match to the Moon Onken enclosure, based on a bass-reflex type calculation.
The new driver is still breaking-in at the present time. I've re-lined the box with thicker material to better control any h.f. bouncing back out through the cone too.
With the very recent launch of the Mark Audio CHN-70 I decided to dust off my Moon Onken enclosures. I sold all the Fostex drivers as I couldn’t live with their specific h.f. response.
The new CHN-70 is slightly smaller, the screw holes of the older Fostex drivers are just visible outside of the new driver but I’m slowly making them disappear with some wood filler. The new drivers have a blue tinged paper. The frame is stamped metal like the Fostex, but it's sturdier and finished in what I believe is called a powder coating.
The key thing is that the driver specs are a fair match to the Moon Onken enclosure, based on a bass-reflex type calculation.
The new driver is still breaking-in at the present time. I've re-lined the box with thicker material to better control any h.f. bouncing back out through the cone too.
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Using the same calculator as at the start of this thread: Loudspeaker enclosure calculating with Thiele Small parameter
I've attached two plots. One of them is the as-built simulation (assuming bass reflex type behaviour) and shows a little peaking (< 0.5dB) in the bass (red trace).
In the past Dave Duglos has recommended pulling this curve down a little. I can readily do that if I reduce the area of the ports by around 20% - that's the 2nd plot.
I've attached two plots. One of them is the as-built simulation (assuming bass reflex type behaviour) and shows a little peaking (< 0.5dB) in the bass (red trace).
In the past Dave Duglos has recommended pulling this curve down a little. I can readily do that if I reduce the area of the ports by around 20% - that's the 2nd plot.
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Bigun, thanks for posting the link to the speaker calculator. I've been using it since WinISD doesn't work on my Mac. I've got three new projects cooking now! Sincerely appreciative!
If you could sum it up succinctly, how does the Fostex sound differ from the MA sound in this particular (and very compact) project?
If you could sum it up succinctly, how does the Fostex sound differ from the MA sound in this particular (and very compact) project?
I just re read the entire thread. I'm sorry you are disappointed with the upper registers of a few of these drivers. This could be why you and I enjoyed the Pioneer B20s so much. My son has my only pair of B20s and enjoys their mellow sound every day. I hope in the future someone comes out with a reasonably priced, smooth and mellow sounding full range driver without the bite on top. Even my (expensive) TB 1808 isn't perfect and sometimes sounds bright.
The bright sounding 127e sounds bad with solid state IMO. It needs tubes or digital to sound its best. The brightness of the 127e is similar to the Radio Shack 1197 (which is like the Fostex 103e). Dammaring the cone helped reduce the confused, garbled top octaves but I'm not willing to dammar the 127e.
The three inch TB 319 doesn't have any bite in the upper registers but I haven't listened to it in years.
Good luck with your search to find good sounding drivers for your Moon's!
The bright sounding 127e sounds bad with solid state IMO. It needs tubes or digital to sound its best. The brightness of the 127e is similar to the Radio Shack 1197 (which is like the Fostex 103e). Dammaring the cone helped reduce the confused, garbled top octaves but I'm not willing to dammar the 127e.
The three inch TB 319 doesn't have any bite in the upper registers but I haven't listened to it in years.
Good luck with your search to find good sounding drivers for your Moon's!
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The driver is made by Mark Audio. They are based out of Hong Kong and I don't know who would sell them in your area. There is a Mark Audio forum in the Manufacturers section of DIY Audio where you can ask about availability of this in Europe. I got mine from Creative Sound Solutions in Canada.
L.rivera, I already have a pair. They didn't sound as good as the Pioneer B20, unfortunately. The drivers look the same but the B20 was mellow and full while the GRS is thin and garbled. They are in nice looking sealed cabinets and were lost in the divorce. I wanted to try them on open baffles with bass support since they couldn't do bass like the B20 but I'll pass for now. I'd probably first try the Goldwood 8" on open baffle (which I understand makes a nice sounding speaker).
Thanks for the suggestion!
Thanks for the suggestion!
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Interim assessment:
This is a nice driver. It doesn't generate any 'wow' factors but it doesn't anything to complain about - typically I worry about nasty treble but not here. The response sounds neutral over the range I can hear. I don't have enough hours on it yet, but I believe enough that the main character of it's sound (or lack of - it's neutral !) is evident.
My amp is limiting me now, it's my Cellini SET, my first ever attempt at a tube amp and it has a number of limitations.
This is a nice driver. It doesn't generate any 'wow' factors but it doesn't anything to complain about - typically I worry about nasty treble but not here. The response sounds neutral over the range I can hear. I don't have enough hours on it yet, but I believe enough that the main character of it's sound (or lack of - it's neutral !) is evident.
My amp is limiting me now, it's my Cellini SET, my first ever attempt at a tube amp and it has a number of limitations.
Yeah, with dips at ~2, 4, 8 kHz and a slow roll off above it, it's my kind of wide BW response.
WRT to SET loading, its medium high Qts limits its output impedance to a couple of ohms at most and ideally needs to be PP coupled, so from your description it 'sounds' like its dynamics, etc., are somewhat compromised.
That, or your source are highly compressed as all wide BW drivers should have some 'wow' factor no matter how flat its response.
GM
WRT to SET loading, its medium high Qts limits its output impedance to a couple of ohms at most and ideally needs to be PP coupled, so from your description it 'sounds' like its dynamics, etc., are somewhat compromised.
That, or your source
GM
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I haven't tried my CD player on it yet, I'm using my FM tuner and on many stations it is highly compressed. But there is one channel I pick up a strong signal for that appears to be far less compromised than the others. The 'wow' factor is not there but it is still a very good sounding speaker. And I would still mention that my amplifier is suspect here and I do need to try it with another amp.
One thing I've realized though. After a few years in this hobby I've made a number of single driver full range speakers from small desktop units, A10.3 pencils and even a huge 15 inch unit in a large cab. I've realized that it's hard for a small cone to produce convincing 'punch' for my ears, for want of a better word. I don't see myself using the smaller single full range drivers for use beyond near-field listening - the EL-70 was the only small driver that came close to doing more. Medium sized speakers may simply need a 2-way design to deliver what I need. Or I'll be using large drivers.
One thing I've realized though. After a few years in this hobby I've made a number of single driver full range speakers from small desktop units, A10.3 pencils and even a huge 15 inch unit in a large cab. I've realized that it's hard for a small cone to produce convincing 'punch' for my ears, for want of a better word. I don't see myself using the smaller single full range drivers for use beyond near-field listening - the EL-70 was the only small driver that came close to doing more. Medium sized speakers may simply need a 2-way design to deliver what I need. Or I'll be using large drivers.
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